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llvm / llvm-archive / 48649d2c83b557841c9e5c978d9ab5af13cb52e5 / . / clang-tests-external / gdb / 7.5 / gdb / s390-tdep.c
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/* Target-dependent code for GDB, the GNU debugger.
Copyright (C) 2001-2012 Free Software Foundation, Inc.
Contributed by D.J. Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
for IBM Deutschland Entwicklung GmbH, IBM Corporation.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
#include "arch-utils.h"
#include "frame.h"
#include "inferior.h"
#include "symtab.h"
#include "target.h"
#include "gdbcore.h"
#include "gdbcmd.h"
#include "objfiles.h"
#include "floatformat.h"
#include "regcache.h"
#include "trad-frame.h"
#include "frame-base.h"
#include "frame-unwind.h"
#include "dwarf2-frame.h"
#include "reggroups.h"
#include "regset.h"
#include "value.h"
#include "gdb_assert.h"
#include "dis-asm.h"
#include "solib-svr4.h"
#include "prologue-value.h"
#include "linux-tdep.h"
#include "s390-tdep.h"
#include "stap-probe.h"
#include "ax.h"
#include "ax-gdb.h"
#include "user-regs.h"
#include "cli/cli-utils.h"
#include <ctype.h>
#include "features/s390-linux32.c"
#include "features/s390-linux32v1.c"
#include "features/s390-linux32v2.c"
#include "features/s390-linux64.c"
#include "features/s390-linux64v1.c"
#include "features/s390-linux64v2.c"
#include "features/s390x-linux64.c"
#include "features/s390x-linux64v1.c"
#include "features/s390x-linux64v2.c"
/* The tdep structure. */
struct gdbarch_tdep
{
/* ABI version. */
enum { ABI_LINUX_S390, ABI_LINUX_ZSERIES } abi;
/* Pseudo register numbers. */
int gpr_full_regnum;
int pc_regnum;
int cc_regnum;
/* Core file register sets. */
const struct regset *gregset;
int sizeof_gregset;
const struct regset *fpregset;
int sizeof_fpregset;
};
/* ABI call-saved register information. */
static int
s390_register_call_saved (struct gdbarch *gdbarch, int regnum)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
switch (tdep->abi)
{
case ABI_LINUX_S390:
if ((regnum >= S390_R6_REGNUM && regnum <= S390_R15_REGNUM)
|| regnum == S390_F4_REGNUM || regnum == S390_F6_REGNUM
|| regnum == S390_A0_REGNUM)
return 1;
break;
case ABI_LINUX_ZSERIES:
if ((regnum >= S390_R6_REGNUM && regnum <= S390_R15_REGNUM)
|| (regnum >= S390_F8_REGNUM && regnum <= S390_F15_REGNUM)
|| (regnum >= S390_A0_REGNUM && regnum <= S390_A1_REGNUM))
return 1;
break;
}
return 0;
}
static int
s390_cannot_store_register (struct gdbarch *gdbarch, int regnum)
{
/* The last-break address is read-only. */
return regnum == S390_LAST_BREAK_REGNUM;
}
static void
s390_write_pc (struct regcache *regcache, CORE_ADDR pc)
{
struct gdbarch *gdbarch = get_regcache_arch (regcache);
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
regcache_cooked_write_unsigned (regcache, tdep->pc_regnum, pc);
/* Set special SYSTEM_CALL register to 0 to prevent the kernel from
messing with the PC we just installed, if we happen to be within
an interrupted system call that the kernel wants to restart.
Note that after we return from the dummy call, the SYSTEM_CALL and
ORIG_R2 registers will be automatically restored, and the kernel
continues to restart the system call at this point. */
if (register_size (gdbarch, S390_SYSTEM_CALL_REGNUM) > 0)
regcache_cooked_write_unsigned (regcache, S390_SYSTEM_CALL_REGNUM, 0);
}
/* DWARF Register Mapping. */
static int s390_dwarf_regmap[] =
{
/* General Purpose Registers. */
S390_R0_REGNUM, S390_R1_REGNUM, S390_R2_REGNUM, S390_R3_REGNUM,
S390_R4_REGNUM, S390_R5_REGNUM, S390_R6_REGNUM, S390_R7_REGNUM,
S390_R8_REGNUM, S390_R9_REGNUM, S390_R10_REGNUM, S390_R11_REGNUM,
S390_R12_REGNUM, S390_R13_REGNUM, S390_R14_REGNUM, S390_R15_REGNUM,
/* Floating Point Registers. */
S390_F0_REGNUM, S390_F2_REGNUM, S390_F4_REGNUM, S390_F6_REGNUM,
S390_F1_REGNUM, S390_F3_REGNUM, S390_F5_REGNUM, S390_F7_REGNUM,
S390_F8_REGNUM, S390_F10_REGNUM, S390_F12_REGNUM, S390_F14_REGNUM,
S390_F9_REGNUM, S390_F11_REGNUM, S390_F13_REGNUM, S390_F15_REGNUM,
/* Control Registers (not mapped). */
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1,
/* Access Registers. */
S390_A0_REGNUM, S390_A1_REGNUM, S390_A2_REGNUM, S390_A3_REGNUM,
S390_A4_REGNUM, S390_A5_REGNUM, S390_A6_REGNUM, S390_A7_REGNUM,
S390_A8_REGNUM, S390_A9_REGNUM, S390_A10_REGNUM, S390_A11_REGNUM,
S390_A12_REGNUM, S390_A13_REGNUM, S390_A14_REGNUM, S390_A15_REGNUM,
/* Program Status Word. */
S390_PSWM_REGNUM,
S390_PSWA_REGNUM,
/* GPR Lower Half Access. */
S390_R0_REGNUM, S390_R1_REGNUM, S390_R2_REGNUM, S390_R3_REGNUM,
S390_R4_REGNUM, S390_R5_REGNUM, S390_R6_REGNUM, S390_R7_REGNUM,
S390_R8_REGNUM, S390_R9_REGNUM, S390_R10_REGNUM, S390_R11_REGNUM,
S390_R12_REGNUM, S390_R13_REGNUM, S390_R14_REGNUM, S390_R15_REGNUM,
/* GNU/Linux-specific registers (not mapped). */
-1, -1, -1,
};
/* Convert DWARF register number REG to the appropriate register
number used by GDB. */
static int
s390_dwarf_reg_to_regnum (struct gdbarch *gdbarch, int reg)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
/* In a 32-on-64 debug scenario, debug info refers to the full 64-bit
GPRs. Note that call frame information still refers to the 32-bit
lower halves, because s390_adjust_frame_regnum uses register numbers
66 .. 81 to access GPRs. */
if (tdep->gpr_full_regnum != -1 && reg >= 0 && reg < 16)
return tdep->gpr_full_regnum + reg;
if (reg >= 0 && reg < ARRAY_SIZE (s390_dwarf_regmap))
return s390_dwarf_regmap[reg];
warning (_("Unmapped DWARF Register #%d encountered."), reg);
return -1;
}
/* Translate a .eh_frame register to DWARF register, or adjust a
.debug_frame register. */
static int
s390_adjust_frame_regnum (struct gdbarch *gdbarch, int num, int eh_frame_p)
{
/* See s390_dwarf_reg_to_regnum for comments. */
return (num >= 0 && num < 16)? num + 66 : num;
}
/* Pseudo registers. */
static const char *
s390_pseudo_register_name (struct gdbarch *gdbarch, int regnum)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
if (regnum == tdep->pc_regnum)
return "pc";
if (regnum == tdep->cc_regnum)
return "cc";
if (tdep->gpr_full_regnum != -1
&& regnum >= tdep->gpr_full_regnum
&& regnum < tdep->gpr_full_regnum + 16)
{
static const char *full_name[] = {
"r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
"r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15"
};
return full_name[regnum - tdep->gpr_full_regnum];
}
internal_error (__FILE__, __LINE__, _("invalid regnum"));
}
static struct type *
s390_pseudo_register_type (struct gdbarch *gdbarch, int regnum)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
if (regnum == tdep->pc_regnum)
return builtin_type (gdbarch)->builtin_func_ptr;
if (regnum == tdep->cc_regnum)
return builtin_type (gdbarch)->builtin_int;
if (tdep->gpr_full_regnum != -1
&& regnum >= tdep->gpr_full_regnum
&& regnum < tdep->gpr_full_regnum + 16)
return builtin_type (gdbarch)->builtin_uint64;
internal_error (__FILE__, __LINE__, _("invalid regnum"));
}
static enum register_status
s390_pseudo_register_read (struct gdbarch *gdbarch, struct regcache *regcache,
int regnum, gdb_byte *buf)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
int regsize = register_size (gdbarch, regnum);
ULONGEST val;
if (regnum == tdep->pc_regnum)
{
enum register_status status;
status = regcache_raw_read_unsigned (regcache, S390_PSWA_REGNUM, &val);
if (status == REG_VALID)
{
if (register_size (gdbarch, S390_PSWA_REGNUM) == 4)
val &= 0x7fffffff;
store_unsigned_integer (buf, regsize, byte_order, val);
}
return status;
}
if (regnum == tdep->cc_regnum)
{
enum register_status status;
status = regcache_raw_read_unsigned (regcache, S390_PSWM_REGNUM, &val);
if (status == REG_VALID)
{
if (register_size (gdbarch, S390_PSWA_REGNUM) == 4)
val = (val >> 12) & 3;
else
val = (val >> 44) & 3;
store_unsigned_integer (buf, regsize, byte_order, val);
}
return status;
}
if (tdep->gpr_full_regnum != -1
&& regnum >= tdep->gpr_full_regnum
&& regnum < tdep->gpr_full_regnum + 16)
{
enum register_status status;
ULONGEST val_upper;
regnum -= tdep->gpr_full_regnum;
status = regcache_raw_read_unsigned (regcache, S390_R0_REGNUM + regnum, &val);
if (status == REG_VALID)
status = regcache_raw_read_unsigned (regcache, S390_R0_UPPER_REGNUM + regnum,
&val_upper);
if (status == REG_VALID)
{
val |= val_upper << 32;
store_unsigned_integer (buf, regsize, byte_order, val);
}
return status;
}
internal_error (__FILE__, __LINE__, _("invalid regnum"));
}
static void
s390_pseudo_register_write (struct gdbarch *gdbarch, struct regcache *regcache,
int regnum, const gdb_byte *buf)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
int regsize = register_size (gdbarch, regnum);
ULONGEST val, psw;
if (regnum == tdep->pc_regnum)
{
val = extract_unsigned_integer (buf, regsize, byte_order);
if (register_size (gdbarch, S390_PSWA_REGNUM) == 4)
{
regcache_raw_read_unsigned (regcache, S390_PSWA_REGNUM, &psw);
val = (psw & 0x80000000) | (val & 0x7fffffff);
}
regcache_raw_write_unsigned (regcache, S390_PSWA_REGNUM, val);
return;
}
if (regnum == tdep->cc_regnum)
{
val = extract_unsigned_integer (buf, regsize, byte_order);
regcache_raw_read_unsigned (regcache, S390_PSWM_REGNUM, &psw);
if (register_size (gdbarch, S390_PSWA_REGNUM) == 4)
val = (psw & ~((ULONGEST)3 << 12)) | ((val & 3) << 12);
else
val = (psw & ~((ULONGEST)3 << 44)) | ((val & 3) << 44);
regcache_raw_write_unsigned (regcache, S390_PSWM_REGNUM, val);
return;
}
if (tdep->gpr_full_regnum != -1
&& regnum >= tdep->gpr_full_regnum
&& regnum < tdep->gpr_full_regnum + 16)
{
regnum -= tdep->gpr_full_regnum;
val = extract_unsigned_integer (buf, regsize, byte_order);
regcache_raw_write_unsigned (regcache, S390_R0_REGNUM + regnum,
val & 0xffffffff);
regcache_raw_write_unsigned (regcache, S390_R0_UPPER_REGNUM + regnum,
val >> 32);
return;
}
internal_error (__FILE__, __LINE__, _("invalid regnum"));
}
/* 'float' values are stored in the upper half of floating-point
registers, even though we are otherwise a big-endian platform. */
static struct value *
s390_value_from_register (struct type *type, int regnum,
struct frame_info *frame)
{
struct value *value = default_value_from_register (type, regnum, frame);
int len = TYPE_LENGTH (check_typedef (type));
if (regnum >= S390_F0_REGNUM && regnum <= S390_F15_REGNUM && len < 8)
set_value_offset (value, 0);
return value;
}
/* Register groups. */
static int
s390_pseudo_register_reggroup_p (struct gdbarch *gdbarch, int regnum,
struct reggroup *group)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
/* We usually save/restore the whole PSW, which includes PC and CC.
However, some older gdbservers may not support saving/restoring
the whole PSW yet, and will return an XML register description
excluding those from the save/restore register groups. In those
cases, we still need to explicitly save/restore PC and CC in order
to push or pop frames. Since this doesn't hurt anything if we
already save/restore the whole PSW (it's just redundant), we add
PC and CC at this point unconditionally. */
if (group == save_reggroup || group == restore_reggroup)
return regnum == tdep->pc_regnum || regnum == tdep->cc_regnum;
return default_register_reggroup_p (gdbarch, regnum, group);
}
/* Core file register sets. */
int s390_regmap_gregset[S390_NUM_REGS] =
{
/* Program Status Word. */
0x00, 0x04,
/* General Purpose Registers. */
0x08, 0x0c, 0x10, 0x14,
0x18, 0x1c, 0x20, 0x24,
0x28, 0x2c, 0x30, 0x34,
0x38, 0x3c, 0x40, 0x44,
/* Access Registers. */
0x48, 0x4c, 0x50, 0x54,
0x58, 0x5c, 0x60, 0x64,
0x68, 0x6c, 0x70, 0x74,
0x78, 0x7c, 0x80, 0x84,
/* Floating Point Control Word. */
-1,
/* Floating Point Registers. */
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1,
/* GPR Uppper Halves. */
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1,
/* GNU/Linux-specific optional "registers". */
0x88, -1, -1,
};
int s390x_regmap_gregset[S390_NUM_REGS] =
{
/* Program Status Word. */
0x00, 0x08,
/* General Purpose Registers. */
0x10, 0x18, 0x20, 0x28,
0x30, 0x38, 0x40, 0x48,
0x50, 0x58, 0x60, 0x68,
0x70, 0x78, 0x80, 0x88,
/* Access Registers. */
0x90, 0x94, 0x98, 0x9c,
0xa0, 0xa4, 0xa8, 0xac,
0xb0, 0xb4, 0xb8, 0xbc,
0xc0, 0xc4, 0xc8, 0xcc,
/* Floating Point Control Word. */
-1,
/* Floating Point Registers. */
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1,
/* GPR Uppper Halves. */
0x10, 0x18, 0x20, 0x28,
0x30, 0x38, 0x40, 0x48,
0x50, 0x58, 0x60, 0x68,
0x70, 0x78, 0x80, 0x88,
/* GNU/Linux-specific optional "registers". */
0xd0, -1, -1,
};
int s390_regmap_fpregset[S390_NUM_REGS] =
{
/* Program Status Word. */
-1, -1,
/* General Purpose Registers. */
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1,
/* Access Registers. */
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1,
/* Floating Point Control Word. */
0x00,
/* Floating Point Registers. */
0x08, 0x10, 0x18, 0x20,
0x28, 0x30, 0x38, 0x40,
0x48, 0x50, 0x58, 0x60,
0x68, 0x70, 0x78, 0x80,
/* GPR Uppper Halves. */
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1,
/* GNU/Linux-specific optional "registers". */
-1, -1, -1,
};
int s390_regmap_upper[S390_NUM_REGS] =
{
/* Program Status Word. */
-1, -1,
/* General Purpose Registers. */
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1,
/* Access Registers. */
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1,
/* Floating Point Control Word. */
-1,
/* Floating Point Registers. */
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1,
/* GPR Uppper Halves. */
0x00, 0x04, 0x08, 0x0c,
0x10, 0x14, 0x18, 0x1c,
0x20, 0x24, 0x28, 0x2c,
0x30, 0x34, 0x38, 0x3c,
/* GNU/Linux-specific optional "registers". */
-1, -1, -1,
};
int s390_regmap_last_break[S390_NUM_REGS] =
{
/* Program Status Word. */
-1, -1,
/* General Purpose Registers. */
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1,
/* Access Registers. */
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1,
/* Floating Point Control Word. */
-1,
/* Floating Point Registers. */
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1,
/* GPR Uppper Halves. */
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1,
/* GNU/Linux-specific optional "registers". */
-1, 4, -1,
};
int s390x_regmap_last_break[S390_NUM_REGS] =
{
/* Program Status Word. */
-1, -1,
/* General Purpose Registers. */
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1,
/* Access Registers. */
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1,
/* Floating Point Control Word. */
-1,
/* Floating Point Registers. */
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1,
/* GPR Uppper Halves. */
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1,
/* GNU/Linux-specific optional "registers". */
-1, 0, -1,
};
int s390_regmap_system_call[S390_NUM_REGS] =
{
/* Program Status Word. */
-1, -1,
/* General Purpose Registers. */
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1,
/* Access Registers. */
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1,
/* Floating Point Control Word. */
-1,
/* Floating Point Registers. */
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1,
/* GPR Uppper Halves. */
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1,
/* GNU/Linux-specific optional "registers". */
-1, -1, 0,
};
/* Supply register REGNUM from the register set REGSET to register cache
REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */
static void
s390_supply_regset (const struct regset *regset, struct regcache *regcache,
int regnum, const void *regs, size_t len)
{
const int *offset = regset->descr;
int i;
for (i = 0; i < S390_NUM_REGS; i++)
{
if ((regnum == i || regnum == -1) && offset[i] != -1)
regcache_raw_supply (regcache, i, (const char *)regs + offset[i]);
}
}
/* Collect register REGNUM from the register cache REGCACHE and store
it in the buffer specified by REGS and LEN as described by the
general-purpose register set REGSET. If REGNUM is -1, do this for
all registers in REGSET. */
static void
s390_collect_regset (const struct regset *regset,
const struct regcache *regcache,
int regnum, void *regs, size_t len)
{
const int *offset = regset->descr;
int i;
for (i = 0; i < S390_NUM_REGS; i++)
{
if ((regnum == i || regnum == -1) && offset[i] != -1)
regcache_raw_collect (regcache, i, (char *)regs + offset[i]);
}
}
static const struct regset s390_gregset = {
s390_regmap_gregset,
s390_supply_regset,
s390_collect_regset
};
static const struct regset s390x_gregset = {
s390x_regmap_gregset,
s390_supply_regset,
s390_collect_regset
};
static const struct regset s390_fpregset = {
s390_regmap_fpregset,
s390_supply_regset,
s390_collect_regset
};
static const struct regset s390_upper_regset = {
s390_regmap_upper,
s390_supply_regset,
s390_collect_regset
};
static const struct regset s390_last_break_regset = {
s390_regmap_last_break,
s390_supply_regset,
s390_collect_regset
};
static const struct regset s390x_last_break_regset = {
s390x_regmap_last_break,
s390_supply_regset,
s390_collect_regset
};
static const struct regset s390_system_call_regset = {
s390_regmap_system_call,
s390_supply_regset,
s390_collect_regset
};
static struct core_regset_section s390_linux32_regset_sections[] =
{
{ ".reg", s390_sizeof_gregset, "general-purpose" },
{ ".reg2", s390_sizeof_fpregset, "floating-point" },
{ NULL, 0}
};
static struct core_regset_section s390_linux32v1_regset_sections[] =
{
{ ".reg", s390_sizeof_gregset, "general-purpose" },
{ ".reg2", s390_sizeof_fpregset, "floating-point" },
{ ".reg-s390-last-break", 8, "s390 last-break address" },
{ NULL, 0}
};
static struct core_regset_section s390_linux32v2_regset_sections[] =
{
{ ".reg", s390_sizeof_gregset, "general-purpose" },
{ ".reg2", s390_sizeof_fpregset, "floating-point" },
{ ".reg-s390-last-break", 8, "s390 last-break address" },
{ ".reg-s390-system-call", 4, "s390 system-call" },
{ NULL, 0}
};
static struct core_regset_section s390_linux64_regset_sections[] =
{
{ ".reg", s390_sizeof_gregset, "general-purpose" },
{ ".reg2", s390_sizeof_fpregset, "floating-point" },
{ ".reg-s390-high-gprs", 16*4, "s390 GPR upper halves" },
{ NULL, 0}
};
static struct core_regset_section s390_linux64v1_regset_sections[] =
{
{ ".reg", s390_sizeof_gregset, "general-purpose" },
{ ".reg2", s390_sizeof_fpregset, "floating-point" },
{ ".reg-s390-high-gprs", 16*4, "s390 GPR upper halves" },
{ ".reg-s390-last-break", 8, "s930 last-break address" },
{ NULL, 0}
};
static struct core_regset_section s390_linux64v2_regset_sections[] =
{
{ ".reg", s390_sizeof_gregset, "general-purpose" },
{ ".reg2", s390_sizeof_fpregset, "floating-point" },
{ ".reg-s390-high-gprs", 16*4, "s390 GPR upper halves" },
{ ".reg-s390-last-break", 8, "s930 last-break address" },
{ ".reg-s390-system-call", 4, "s390 system-call" },
{ NULL, 0}
};
static struct core_regset_section s390x_linux64_regset_sections[] =
{
{ ".reg", s390x_sizeof_gregset, "general-purpose" },
{ ".reg2", s390_sizeof_fpregset, "floating-point" },
{ NULL, 0}
};
static struct core_regset_section s390x_linux64v1_regset_sections[] =
{
{ ".reg", s390x_sizeof_gregset, "general-purpose" },
{ ".reg2", s390_sizeof_fpregset, "floating-point" },
{ ".reg-s390-last-break", 8, "s930 last-break address" },
{ NULL, 0}
};
static struct core_regset_section s390x_linux64v2_regset_sections[] =
{
{ ".reg", s390x_sizeof_gregset, "general-purpose" },
{ ".reg2", s390_sizeof_fpregset, "floating-point" },
{ ".reg-s390-last-break", 8, "s930 last-break address" },
{ ".reg-s390-system-call", 4, "s390 system-call" },
{ NULL, 0}
};
/* Return the appropriate register set for the core section identified
by SECT_NAME and SECT_SIZE. */
static const struct regset *
s390_regset_from_core_section (struct gdbarch *gdbarch,
const char *sect_name, size_t sect_size)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
if (strcmp (sect_name, ".reg") == 0 && sect_size >= tdep->sizeof_gregset)
return tdep->gregset;
if (strcmp (sect_name, ".reg2") == 0 && sect_size >= tdep->sizeof_fpregset)
return tdep->fpregset;
if (strcmp (sect_name, ".reg-s390-high-gprs") == 0 && sect_size >= 16*4)
return &s390_upper_regset;
if (strcmp (sect_name, ".reg-s390-last-break") == 0 && sect_size >= 8)
return (gdbarch_ptr_bit (gdbarch) == 32
? &s390_last_break_regset : &s390x_last_break_regset);
if (strcmp (sect_name, ".reg-s390-system-call") == 0 && sect_size >= 4)
return &s390_system_call_regset;
return NULL;
}
static const struct target_desc *
s390_core_read_description (struct gdbarch *gdbarch,
struct target_ops *target, bfd *abfd)
{
asection *high_gprs = bfd_get_section_by_name (abfd, ".reg-s390-high-gprs");
asection *v1 = bfd_get_section_by_name (abfd, ".reg-s390-last-break");
asection *v2 = bfd_get_section_by_name (abfd, ".reg-s390-system-call");
asection *section = bfd_get_section_by_name (abfd, ".reg");
if (!section)
return NULL;
switch (bfd_section_size (abfd, section))
{
case s390_sizeof_gregset:
if (high_gprs)
return (v2? tdesc_s390_linux64v2 :
v1? tdesc_s390_linux64v1 : tdesc_s390_linux64);
else
return (v2? tdesc_s390_linux32v2 :
v1? tdesc_s390_linux32v1 : tdesc_s390_linux32);
case s390x_sizeof_gregset:
return (v2? tdesc_s390x_linux64v2 :
v1? tdesc_s390x_linux64v1 : tdesc_s390x_linux64);
default:
return NULL;
}
}
/* Decoding S/390 instructions. */
/* Named opcode values for the S/390 instructions we recognize. Some
instructions have their opcode split across two fields; those are the
op1_* and op2_* enums. */
enum
{
op1_lhi = 0xa7, op2_lhi = 0x08,
op1_lghi = 0xa7, op2_lghi = 0x09,
op1_lgfi = 0xc0, op2_lgfi = 0x01,
op_lr = 0x18,
op_lgr = 0xb904,
op_l = 0x58,
op1_ly = 0xe3, op2_ly = 0x58,
op1_lg = 0xe3, op2_lg = 0x04,
op_lm = 0x98,
op1_lmy = 0xeb, op2_lmy = 0x98,
op1_lmg = 0xeb, op2_lmg = 0x04,
op_st = 0x50,
op1_sty = 0xe3, op2_sty = 0x50,
op1_stg = 0xe3, op2_stg = 0x24,
op_std = 0x60,
op_stm = 0x90,
op1_stmy = 0xeb, op2_stmy = 0x90,
op1_stmg = 0xeb, op2_stmg = 0x24,
op1_aghi = 0xa7, op2_aghi = 0x0b,
op1_ahi = 0xa7, op2_ahi = 0x0a,
op1_agfi = 0xc2, op2_agfi = 0x08,
op1_afi = 0xc2, op2_afi = 0x09,
op1_algfi= 0xc2, op2_algfi= 0x0a,
op1_alfi = 0xc2, op2_alfi = 0x0b,
op_ar = 0x1a,
op_agr = 0xb908,
op_a = 0x5a,
op1_ay = 0xe3, op2_ay = 0x5a,
op1_ag = 0xe3, op2_ag = 0x08,
op1_slgfi= 0xc2, op2_slgfi= 0x04,
op1_slfi = 0xc2, op2_slfi = 0x05,
op_sr = 0x1b,
op_sgr = 0xb909,
op_s = 0x5b,
op1_sy = 0xe3, op2_sy = 0x5b,
op1_sg = 0xe3, op2_sg = 0x09,
op_nr = 0x14,
op_ngr = 0xb980,
op_la = 0x41,
op1_lay = 0xe3, op2_lay = 0x71,
op1_larl = 0xc0, op2_larl = 0x00,
op_basr = 0x0d,
op_bas = 0x4d,
op_bcr = 0x07,
op_bc = 0x0d,
op_bctr = 0x06,
op_bctgr = 0xb946,
op_bct = 0x46,
op1_bctg = 0xe3, op2_bctg = 0x46,
op_bxh = 0x86,
op1_bxhg = 0xeb, op2_bxhg = 0x44,
op_bxle = 0x87,
op1_bxleg= 0xeb, op2_bxleg= 0x45,
op1_bras = 0xa7, op2_bras = 0x05,
op1_brasl= 0xc0, op2_brasl= 0x05,
op1_brc = 0xa7, op2_brc = 0x04,
op1_brcl = 0xc0, op2_brcl = 0x04,
op1_brct = 0xa7, op2_brct = 0x06,
op1_brctg= 0xa7, op2_brctg= 0x07,
op_brxh = 0x84,
op1_brxhg= 0xec, op2_brxhg= 0x44,
op_brxle = 0x85,
op1_brxlg= 0xec, op2_brxlg= 0x45,
};
/* Read a single instruction from address AT. */
#define S390_MAX_INSTR_SIZE 6
static int
s390_readinstruction (bfd_byte instr[], CORE_ADDR at)
{
static int s390_instrlen[] = { 2, 4, 4, 6 };
int instrlen;
if (target_read_memory (at, &instr[0], 2))
return -1;
instrlen = s390_instrlen[instr[0] >> 6];
if (instrlen > 2)
{
if (target_read_memory (at + 2, &instr[2], instrlen - 2))
return -1;
}
return instrlen;
}
/* The functions below are for recognizing and decoding S/390
instructions of various formats. Each of them checks whether INSN
is an instruction of the given format, with the specified opcodes.
If it is, it sets the remaining arguments to the values of the
instruction's fields, and returns a non-zero value; otherwise, it
returns zero.
These functions' arguments appear in the order they appear in the
instruction, not in the machine-language form. So, opcodes always
come first, even though they're sometimes scattered around the
instructions. And displacements appear before base and extension
registers, as they do in the assembly syntax, not at the end, as
they do in the machine language. */
static int
is_ri (bfd_byte *insn, int op1, int op2, unsigned int *r1, int *i2)
{
if (insn[0] == op1 && (insn[1] & 0xf) == op2)
{
*r1 = (insn[1] >> 4) & 0xf;
/* i2 is a 16-bit signed quantity. */
*i2 = (((insn[2] << 8) | insn[3]) ^ 0x8000) - 0x8000;
return 1;
}
else
return 0;
}
static int
is_ril (bfd_byte *insn, int op1, int op2,
unsigned int *r1, int *i2)
{
if (insn[0] == op1 && (insn[1] & 0xf) == op2)
{
*r1 = (insn[1] >> 4) & 0xf;
/* i2 is a signed quantity. If the host 'int' is 32 bits long,
no sign extension is necessary, but we don't want to assume
that. */
*i2 = (((insn[2] << 24)
| (insn[3] << 16)
| (insn[4] << 8)
| (insn[5])) ^ 0x80000000) - 0x80000000;
return 1;
}
else
return 0;
}
static int
is_rr (bfd_byte *insn, int op, unsigned int *r1, unsigned int *r2)
{
if (insn[0] == op)
{
*r1 = (insn[1] >> 4) & 0xf;
*r2 = insn[1] & 0xf;
return 1;
}
else
return 0;
}
static int
is_rre (bfd_byte *insn, int op, unsigned int *r1, unsigned int *r2)
{
if (((insn[0] << 8) | insn[1]) == op)
{
/* Yes, insn[3]. insn[2] is unused in RRE format. */
*r1 = (insn[3] >> 4) & 0xf;
*r2 = insn[3] & 0xf;
return 1;
}
else
return 0;
}
static int
is_rs (bfd_byte *insn, int op,
unsigned int *r1, unsigned int *r3, unsigned int *d2, unsigned int *b2)
{
if (insn[0] == op)
{
*r1 = (insn[1] >> 4) & 0xf;
*r3 = insn[1] & 0xf;
*b2 = (insn[2] >> 4) & 0xf;
*d2 = ((insn[2] & 0xf) << 8) | insn[3];
return 1;
}
else
return 0;
}
static int
is_rsy (bfd_byte *insn, int op1, int op2,
unsigned int *r1, unsigned int *r3, unsigned int *d2, unsigned int *b2)
{
if (insn[0] == op1
&& insn[5] == op2)
{
*r1 = (insn[1] >> 4) & 0xf;
*r3 = insn[1] & 0xf;
*b2 = (insn[2] >> 4) & 0xf;
/* The 'long displacement' is a 20-bit signed integer. */
*d2 = ((((insn[2] & 0xf) << 8) | insn[3] | (insn[4] << 12))
^ 0x80000) - 0x80000;
return 1;
}
else
return 0;
}
static int
is_rsi (bfd_byte *insn, int op,
unsigned int *r1, unsigned int *r3, int *i2)
{
if (insn[0] == op)
{
*r1 = (insn[1] >> 4) & 0xf;
*r3 = insn[1] & 0xf;
/* i2 is a 16-bit signed quantity. */
*i2 = (((insn[2] << 8) | insn[3]) ^ 0x8000) - 0x8000;
return 1;
}
else
return 0;
}
static int
is_rie (bfd_byte *insn, int op1, int op2,
unsigned int *r1, unsigned int *r3, int *i2)
{
if (insn[0] == op1
&& insn[5] == op2)
{
*r1 = (insn[1] >> 4) & 0xf;
*r3 = insn[1] & 0xf;
/* i2 is a 16-bit signed quantity. */
*i2 = (((insn[2] << 8) | insn[3]) ^ 0x8000) - 0x8000;
return 1;
}
else
return 0;
}
static int
is_rx (bfd_byte *insn, int op,
unsigned int *r1, unsigned int *d2, unsigned int *x2, unsigned int *b2)
{
if (insn[0] == op)
{
*r1 = (insn[1] >> 4) & 0xf;
*x2 = insn[1] & 0xf;
*b2 = (insn[2] >> 4) & 0xf;
*d2 = ((insn[2] & 0xf) << 8) | insn[3];
return 1;
}
else
return 0;
}
static int
is_rxy (bfd_byte *insn, int op1, int op2,
unsigned int *r1, unsigned int *d2, unsigned int *x2, unsigned int *b2)
{
if (insn[0] == op1
&& insn[5] == op2)
{
*r1 = (insn[1] >> 4) & 0xf;
*x2 = insn[1] & 0xf;
*b2 = (insn[2] >> 4) & 0xf;
/* The 'long displacement' is a 20-bit signed integer. */
*d2 = ((((insn[2] & 0xf) << 8) | insn[3] | (insn[4] << 12))
^ 0x80000) - 0x80000;
return 1;
}
else
return 0;
}
/* Prologue analysis. */
#define S390_NUM_GPRS 16
#define S390_NUM_FPRS 16
struct s390_prologue_data {
/* The stack. */
struct pv_area *stack;
/* The size and byte-order of a GPR or FPR. */
int gpr_size;
int fpr_size;
enum bfd_endian byte_order;
/* The general-purpose registers. */
pv_t gpr[S390_NUM_GPRS];
/* The floating-point registers. */
pv_t fpr[S390_NUM_FPRS];
/* The offset relative to the CFA where the incoming GPR N was saved
by the function prologue. 0 if not saved or unknown. */
int gpr_slot[S390_NUM_GPRS];
/* Likewise for FPRs. */
int fpr_slot[S390_NUM_FPRS];
/* Nonzero if the backchain was saved. This is assumed to be the
case when the incoming SP is saved at the current SP location. */
int back_chain_saved_p;
};
/* Return the effective address for an X-style instruction, like:
L R1, D2(X2, B2)
Here, X2 and B2 are registers, and D2 is a signed 20-bit
constant; the effective address is the sum of all three. If either
X2 or B2 are zero, then it doesn't contribute to the sum --- this
means that r0 can't be used as either X2 or B2. */
static pv_t
s390_addr (struct s390_prologue_data *data,
int d2, unsigned int x2, unsigned int b2)
{
pv_t result;
result = pv_constant (d2);
if (x2)
result = pv_add (result, data->gpr[x2]);
if (b2)
result = pv_add (result, data->gpr[b2]);
return result;
}
/* Do a SIZE-byte store of VALUE to D2(X2,B2). */
static void
s390_store (struct s390_prologue_data *data,
int d2, unsigned int x2, unsigned int b2, CORE_ADDR size,
pv_t value)
{
pv_t addr = s390_addr (data, d2, x2, b2);
pv_t offset;
/* Check whether we are storing the backchain. */
offset = pv_subtract (data->gpr[S390_SP_REGNUM - S390_R0_REGNUM], addr);
if (pv_is_constant (offset) && offset.k == 0)
if (size == data->gpr_size
&& pv_is_register_k (value, S390_SP_REGNUM, 0))
{
data->back_chain_saved_p = 1;
return;
}
/* Check whether we are storing a register into the stack. */
if (!pv_area_store_would_trash (data->stack, addr))
pv_area_store (data->stack, addr, size, value);
/* Note: If this is some store we cannot identify, you might think we
should forget our cached values, as any of those might have been hit.
However, we make the assumption that the register save areas are only
ever stored to once in any given function, and we do recognize these
stores. Thus every store we cannot recognize does not hit our data. */
}
/* Do a SIZE-byte load from D2(X2,B2). */
static pv_t
s390_load (struct s390_prologue_data *data,
int d2, unsigned int x2, unsigned int b2, CORE_ADDR size)
{
pv_t addr = s390_addr (data, d2, x2, b2);
/* If it's a load from an in-line constant pool, then we can
simulate that, under the assumption that the code isn't
going to change between the time the processor actually
executed it creating the current frame, and the time when
we're analyzing the code to unwind past that frame. */
if (pv_is_constant (addr))
{
struct target_section *secp;
secp = target_section_by_addr (&current_target, addr.k);
if (secp != NULL
&& (bfd_get_section_flags (secp->bfd, secp->the_bfd_section)
& SEC_READONLY))
return pv_constant (read_memory_integer (addr.k, size,
data->byte_order));
}
/* Check whether we are accessing one of our save slots. */
return pv_area_fetch (data->stack, addr, size);
}
/* Function for finding saved registers in a 'struct pv_area'; we pass
this to pv_area_scan.
If VALUE is a saved register, ADDR says it was saved at a constant
offset from the frame base, and SIZE indicates that the whole
register was saved, record its offset in the reg_offset table in
PROLOGUE_UNTYPED. */
static void
s390_check_for_saved (void *data_untyped, pv_t addr,
CORE_ADDR size, pv_t value)
{
struct s390_prologue_data *data = data_untyped;
int i, offset;
if (!pv_is_register (addr, S390_SP_REGNUM))
return;
offset = 16 * data->gpr_size + 32 - addr.k;
/* If we are storing the original value of a register, we want to
record the CFA offset. If the same register is stored multiple
times, the stack slot with the highest address counts. */
for (i = 0; i < S390_NUM_GPRS; i++)
if (size == data->gpr_size
&& pv_is_register_k (value, S390_R0_REGNUM + i, 0))
if (data->gpr_slot[i] == 0
|| data->gpr_slot[i] > offset)
{
data->gpr_slot[i] = offset;
return;
}
for (i = 0; i < S390_NUM_FPRS; i++)
if (size == data->fpr_size
&& pv_is_register_k (value, S390_F0_REGNUM + i, 0))
if (data->fpr_slot[i] == 0
|| data->fpr_slot[i] > offset)
{
data->fpr_slot[i] = offset;
return;
}
}
/* Analyze the prologue of the function starting at START_PC,
continuing at most until CURRENT_PC. Initialize DATA to
hold all information we find out about the state of the registers
and stack slots. Return the address of the instruction after
the last one that changed the SP, FP, or back chain; or zero
on error. */
static CORE_ADDR
s390_analyze_prologue (struct gdbarch *gdbarch,
CORE_ADDR start_pc,
CORE_ADDR current_pc,
struct s390_prologue_data *data)
{
int word_size = gdbarch_ptr_bit (gdbarch) / 8;
/* Our return value:
The address of the instruction after the last one that changed
the SP, FP, or back chain; zero if we got an error trying to
read memory. */
CORE_ADDR result = start_pc;
/* The current PC for our abstract interpretation. */
CORE_ADDR pc;
/* The address of the next instruction after that. */
CORE_ADDR next_pc;
/* Set up everything's initial value. */
{
int i;
data->stack = make_pv_area (S390_SP_REGNUM, gdbarch_addr_bit (gdbarch));
/* For the purpose of prologue tracking, we consider the GPR size to
be equal to the ABI word size, even if it is actually larger
(i.e. when running a 32-bit binary under a 64-bit kernel). */
data->gpr_size = word_size;
data->fpr_size = 8;
data->byte_order = gdbarch_byte_order (gdbarch);
for (i = 0; i < S390_NUM_GPRS; i++)
data->gpr[i] = pv_register (S390_R0_REGNUM + i, 0);
for (i = 0; i < S390_NUM_FPRS; i++)
data->fpr[i] = pv_register (S390_F0_REGNUM + i, 0);
for (i = 0; i < S390_NUM_GPRS; i++)
data->gpr_slot[i] = 0;
for (i = 0; i < S390_NUM_FPRS; i++)
data->fpr_slot[i] = 0;
data->back_chain_saved_p = 0;
}
/* Start interpreting instructions, until we hit the frame's
current PC or the first branch instruction. */
for (pc = start_pc; pc > 0 && pc < current_pc; pc = next_pc)
{
bfd_byte insn[S390_MAX_INSTR_SIZE];
int insn_len = s390_readinstruction (insn, pc);
bfd_byte dummy[S390_MAX_INSTR_SIZE] = { 0 };
bfd_byte *insn32 = word_size == 4 ? insn : dummy;
bfd_byte *insn64 = word_size == 8 ? insn : dummy;
/* Fields for various kinds of instructions. */
unsigned int b2, r1, r2, x2, r3;
int i2, d2;
/* The values of SP and FP before this instruction,
for detecting instructions that change them. */
pv_t pre_insn_sp, pre_insn_fp;
/* Likewise for the flag whether the back chain was saved. */
int pre_insn_back_chain_saved_p;
/* If we got an error trying to read the instruction, report it. */
if (insn_len < 0)
{
result = 0;
break;
}
next_pc = pc + insn_len;
pre_insn_sp = data->gpr[S390_SP_REGNUM - S390_R0_REGNUM];
pre_insn_fp = data->gpr[S390_FRAME_REGNUM - S390_R0_REGNUM];
pre_insn_back_chain_saved_p = data->back_chain_saved_p;
/* LHI r1, i2 --- load halfword immediate. */
/* LGHI r1, i2 --- load halfword immediate (64-bit version). */
/* LGFI r1, i2 --- load fullword immediate. */
if (is_ri (insn32, op1_lhi, op2_lhi, &r1, &i2)
|| is_ri (insn64, op1_lghi, op2_lghi, &r1, &i2)
|| is_ril (insn, op1_lgfi, op2_lgfi, &r1, &i2))
data->gpr[r1] = pv_constant (i2);
/* LR r1, r2 --- load from register. */
/* LGR r1, r2 --- load from register (64-bit version). */
else if (is_rr (insn32, op_lr, &r1, &r2)
|| is_rre (insn64, op_lgr, &r1, &r2))
data->gpr[r1] = data->gpr[r2];
/* L r1, d2(x2, b2) --- load. */
/* LY r1, d2(x2, b2) --- load (long-displacement version). */
/* LG r1, d2(x2, b2) --- load (64-bit version). */
else if (is_rx (insn32, op_l, &r1, &d2, &x2, &b2)
|| is_rxy (insn32, op1_ly, op2_ly, &r1, &d2, &x2, &b2)
|| is_rxy (insn64, op1_lg, op2_lg, &r1, &d2, &x2, &b2))
data->gpr[r1] = s390_load (data, d2, x2, b2, data->gpr_size);
/* ST r1, d2(x2, b2) --- store. */
/* STY r1, d2(x2, b2) --- store (long-displacement version). */
/* STG r1, d2(x2, b2) --- store (64-bit version). */
else if (is_rx (insn32, op_st, &r1, &d2, &x2, &b2)
|| is_rxy (insn32, op1_sty, op2_sty, &r1, &d2, &x2, &b2)
|| is_rxy (insn64, op1_stg, op2_stg, &r1, &d2, &x2, &b2))
s390_store (data, d2, x2, b2, data->gpr_size, data->gpr[r1]);
/* STD r1, d2(x2,b2) --- store floating-point register. */
else if (is_rx (insn, op_std, &r1, &d2, &x2, &b2))
s390_store (data, d2, x2, b2, data->fpr_size, data->fpr[r1]);
/* STM r1, r3, d2(b2) --- store multiple. */
/* STMY r1, r3, d2(b2) --- store multiple (long-displacement
version). */
/* STMG r1, r3, d2(b2) --- store multiple (64-bit version). */
else if (is_rs (insn32, op_stm, &r1, &r3, &d2, &b2)
|| is_rsy (insn32, op1_stmy, op2_stmy, &r1, &r3, &d2, &b2)
|| is_rsy (insn64, op1_stmg, op2_stmg, &r1, &r3, &d2, &b2))
{
for (; r1 <= r3; r1++, d2 += data->gpr_size)
s390_store (data, d2, 0, b2, data->gpr_size, data->gpr[r1]);
}
/* AHI r1, i2 --- add halfword immediate. */
/* AGHI r1, i2 --- add halfword immediate (64-bit version). */
/* AFI r1, i2 --- add fullword immediate. */
/* AGFI r1, i2 --- add fullword immediate (64-bit version). */
else if (is_ri (insn32, op1_ahi, op2_ahi, &r1, &i2)
|| is_ri (insn64, op1_aghi, op2_aghi, &r1, &i2)
|| is_ril (insn32, op1_afi, op2_afi, &r1, &i2)
|| is_ril (insn64, op1_agfi, op2_agfi, &r1, &i2))
data->gpr[r1] = pv_add_constant (data->gpr[r1], i2);
/* ALFI r1, i2 --- add logical immediate. */
/* ALGFI r1, i2 --- add logical immediate (64-bit version). */
else if (is_ril (insn32, op1_alfi, op2_alfi, &r1, &i2)
|| is_ril (insn64, op1_algfi, op2_algfi, &r1, &i2))
data->gpr[r1] = pv_add_constant (data->gpr[r1],
(CORE_ADDR)i2 & 0xffffffff);
/* AR r1, r2 -- add register. */
/* AGR r1, r2 -- add register (64-bit version). */
else if (is_rr (insn32, op_ar, &r1, &r2)
|| is_rre (insn64, op_agr, &r1, &r2))
data->gpr[r1] = pv_add (data->gpr[r1], data->gpr[r2]);
/* A r1, d2(x2, b2) -- add. */
/* AY r1, d2(x2, b2) -- add (long-displacement version). */
/* AG r1, d2(x2, b2) -- add (64-bit version). */
else if (is_rx (insn32, op_a, &r1, &d2, &x2, &b2)
|| is_rxy (insn32, op1_ay, op2_ay, &r1, &d2, &x2, &b2)
|| is_rxy (insn64, op1_ag, op2_ag, &r1, &d2, &x2, &b2))
data->gpr[r1] = pv_add (data->gpr[r1],
s390_load (data, d2, x2, b2, data->gpr_size));
/* SLFI r1, i2 --- subtract logical immediate. */
/* SLGFI r1, i2 --- subtract logical immediate (64-bit version). */
else if (is_ril (insn32, op1_slfi, op2_slfi, &r1, &i2)
|| is_ril (insn64, op1_slgfi, op2_slgfi, &r1, &i2))
data->gpr[r1] = pv_add_constant (data->gpr[r1],
-((CORE_ADDR)i2 & 0xffffffff));
/* SR r1, r2 -- subtract register. */
/* SGR r1, r2 -- subtract register (64-bit version). */
else if (is_rr (insn32, op_sr, &r1, &r2)
|| is_rre (insn64, op_sgr, &r1, &r2))
data->gpr[r1] = pv_subtract (data->gpr[r1], data->gpr[r2]);
/* S r1, d2(x2, b2) -- subtract. */
/* SY r1, d2(x2, b2) -- subtract (long-displacement version). */
/* SG r1, d2(x2, b2) -- subtract (64-bit version). */
else if (is_rx (insn32, op_s, &r1, &d2, &x2, &b2)
|| is_rxy (insn32, op1_sy, op2_sy, &r1, &d2, &x2, &b2)
|| is_rxy (insn64, op1_sg, op2_sg, &r1, &d2, &x2, &b2))
data->gpr[r1] = pv_subtract (data->gpr[r1],
s390_load (data, d2, x2, b2, data->gpr_size));
/* LA r1, d2(x2, b2) --- load address. */
/* LAY r1, d2(x2, b2) --- load address (long-displacement version). */
else if (is_rx (insn, op_la, &r1, &d2, &x2, &b2)
|| is_rxy (insn, op1_lay, op2_lay, &r1, &d2, &x2, &b2))
data->gpr[r1] = s390_addr (data, d2, x2, b2);
/* LARL r1, i2 --- load address relative long. */
else if (is_ril (insn, op1_larl, op2_larl, &r1, &i2))
data->gpr[r1] = pv_constant (pc + i2 * 2);
/* BASR r1, 0 --- branch and save.
Since r2 is zero, this saves the PC in r1, but doesn't branch. */
else if (is_rr (insn, op_basr, &r1, &r2)
&& r2 == 0)
data->gpr[r1] = pv_constant (next_pc);
/* BRAS r1, i2 --- branch relative and save. */
else if (is_ri (insn, op1_bras, op2_bras, &r1, &i2))
{
data->gpr[r1] = pv_constant (next_pc);
next_pc = pc + i2 * 2;
/* We'd better not interpret any backward branches. We'll
never terminate. */
if (next_pc <= pc)
break;
}
/* Terminate search when hitting any other branch instruction. */
else if (is_rr (insn, op_basr, &r1, &r2)
|| is_rx (insn, op_bas, &r1, &d2, &x2, &b2)
|| is_rr (insn, op_bcr, &r1, &r2)
|| is_rx (insn, op_bc, &r1, &d2, &x2, &b2)
|| is_ri (insn, op1_brc, op2_brc, &r1, &i2)
|| is_ril (insn, op1_brcl, op2_brcl, &r1, &i2)
|| is_ril (insn, op1_brasl, op2_brasl, &r2, &i2))
break;
else
/* An instruction we don't know how to simulate. The only
safe thing to do would be to set every value we're tracking
to 'unknown'. Instead, we'll be optimistic: we assume that
we *can* interpret every instruction that the compiler uses
to manipulate any of the data we're interested in here --
then we can just ignore anything else. */
;
/* Record the address after the last instruction that changed
the FP, SP, or backlink. Ignore instructions that changed
them back to their original values --- those are probably
restore instructions. (The back chain is never restored,
just popped.) */
{
pv_t sp = data->gpr[S390_SP_REGNUM - S390_R0_REGNUM];
pv_t fp = data->gpr[S390_FRAME_REGNUM - S390_R0_REGNUM];
if ((! pv_is_identical (pre_insn_sp, sp)
&& ! pv_is_register_k (sp, S390_SP_REGNUM, 0)
&& sp.kind != pvk_unknown)
|| (! pv_is_identical (pre_insn_fp, fp)
&& ! pv_is_register_k (fp, S390_FRAME_REGNUM, 0)
&& fp.kind != pvk_unknown)
|| pre_insn_back_chain_saved_p != data->back_chain_saved_p)
result = next_pc;
}
}
/* Record where all the registers were saved. */
pv_area_scan (data->stack, s390_check_for_saved, data);
free_pv_area (data->stack);
data->stack = NULL;
return result;
}
/* Advance PC across any function entry prologue instructions to reach
some "real" code. */
static CORE_ADDR
s390_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR pc)
{
struct s390_prologue_data data;
CORE_ADDR skip_pc;
skip_pc = s390_analyze_prologue (gdbarch, pc, (CORE_ADDR)-1, &data);
return skip_pc ? skip_pc : pc;
}
/* Return true if we are in the functin's epilogue, i.e. after the
instruction that destroyed the function's stack frame. */
static int
s390_in_function_epilogue_p (struct gdbarch *gdbarch, CORE_ADDR pc)
{
int word_size = gdbarch_ptr_bit (gdbarch) / 8;
/* In frameless functions, there's not frame to destroy and thus
we don't care about the epilogue.
In functions with frame, the epilogue sequence is a pair of
a LM-type instruction that restores (amongst others) the
return register %r14 and the stack pointer %r15, followed
by a branch 'br %r14' --or equivalent-- that effects the
actual return.
In that situation, this function needs to return 'true' in
exactly one case: when pc points to that branch instruction.
Thus we try to disassemble the one instructions immediately
preceding pc and check whether it is an LM-type instruction
modifying the stack pointer.
Note that disassembling backwards is not reliable, so there
is a slight chance of false positives here ... */
bfd_byte insn[6];
unsigned int r1, r3, b2;
int d2;
if (word_size == 4
&& !target_read_memory (pc - 4, insn, 4)
&& is_rs (insn, op_lm, &r1, &r3, &d2, &b2)
&& r3 == S390_SP_REGNUM - S390_R0_REGNUM)
return 1;
if (word_size == 4
&& !target_read_memory (pc - 6, insn, 6)
&& is_rsy (insn, op1_lmy, op2_lmy, &r1, &r3, &d2, &b2)
&& r3 == S390_SP_REGNUM - S390_R0_REGNUM)
return 1;
if (word_size == 8
&& !target_read_memory (pc - 6, insn, 6)
&& is_rsy (insn, op1_lmg, op2_lmg, &r1, &r3, &d2, &b2)
&& r3 == S390_SP_REGNUM - S390_R0_REGNUM)
return 1;
return 0;
}
/* Displaced stepping. */
/* Fix up the state of registers and memory after having single-stepped
a displaced instruction. */
static void
s390_displaced_step_fixup (struct gdbarch *gdbarch,
struct displaced_step_closure *closure,
CORE_ADDR from, CORE_ADDR to,
struct regcache *regs)
{
/* Since we use simple_displaced_step_copy_insn, our closure is a
copy of the instruction. */
gdb_byte *insn = (gdb_byte *) closure;
static int s390_instrlen[] = { 2, 4, 4, 6 };
int insnlen = s390_instrlen[insn[0] >> 6];
/* Fields for various kinds of instructions. */
unsigned int b2, r1, r2, x2, r3;
int i2, d2;
/* Get current PC and addressing mode bit. */
CORE_ADDR pc = regcache_read_pc (regs);
ULONGEST amode = 0;
if (register_size (gdbarch, S390_PSWA_REGNUM) == 4)
{
regcache_cooked_read_unsigned (regs, S390_PSWA_REGNUM, &amode);
amode &= 0x80000000;
}
if (debug_displaced)
fprintf_unfiltered (gdb_stdlog,
"displaced: (s390) fixup (%s, %s) pc %s len %d amode 0x%x\n",
paddress (gdbarch, from), paddress (gdbarch, to),
paddress (gdbarch, pc), insnlen, (int) amode);
/* Handle absolute branch and save instructions. */
if (is_rr (insn, op_basr, &r1, &r2)
|| is_rx (insn, op_bas, &r1, &d2, &x2, &b2))
{
/* Recompute saved return address in R1. */
regcache_cooked_write_unsigned (regs, S390_R0_REGNUM + r1,
amode | (from + insnlen));
}
/* Handle absolute branch instructions. */
else if (is_rr (insn, op_bcr, &r1, &r2)
|| is_rx (insn, op_bc, &r1, &d2, &x2, &b2)
|| is_rr (insn, op_bctr, &r1, &r2)
|| is_rre (insn, op_bctgr, &r1, &r2)
|| is_rx (insn, op_bct, &r1, &d2, &x2, &b2)
|| is_rxy (insn, op1_bctg, op2_brctg, &r1, &d2, &x2, &b2)
|| is_rs (insn, op_bxh, &r1, &r3, &d2, &b2)
|| is_rsy (insn, op1_bxhg, op2_bxhg, &r1, &r3, &d2, &b2)
|| is_rs (insn, op_bxle, &r1, &r3, &d2, &b2)
|| is_rsy (insn, op1_bxleg, op2_bxleg, &r1, &r3, &d2, &b2))
{
/* Update PC iff branch was *not* taken. */
if (pc == to + insnlen)
regcache_write_pc (regs, from + insnlen);
}
/* Handle PC-relative branch and save instructions. */
else if (is_ri (insn, op1_bras, op2_bras, &r1, &i2)
|| is_ril (insn, op1_brasl, op2_brasl, &r1, &i2))
{
/* Update PC. */
regcache_write_pc (regs, pc - to + from);
/* Recompute saved return address in R1. */
regcache_cooked_write_unsigned (regs, S390_R0_REGNUM + r1,
amode | (from + insnlen));
}
/* Handle PC-relative branch instructions. */
else if (is_ri (insn, op1_brc, op2_brc, &r1, &i2)
|| is_ril (insn, op1_brcl, op2_brcl, &r1, &i2)
|| is_ri (insn, op1_brct, op2_brct, &r1, &i2)
|| is_ri (insn, op1_brctg, op2_brctg, &r1, &i2)
|| is_rsi (insn, op_brxh, &r1, &r3, &i2)
|| is_rie (insn, op1_brxhg, op2_brxhg, &r1, &r3, &i2)
|| is_rsi (insn, op_brxle, &r1, &r3, &i2)
|| is_rie (insn, op1_brxlg, op2_brxlg, &r1, &r3, &i2))
{
/* Update PC. */
regcache_write_pc (regs, pc - to + from);
}
/* Handle LOAD ADDRESS RELATIVE LONG. */
else if (is_ril (insn, op1_larl, op2_larl, &r1, &i2))
{
/* Update PC. */
regcache_write_pc (regs, from + insnlen);
/* Recompute output address in R1. */
regcache_cooked_write_unsigned (regs, S390_R0_REGNUM + r1,
amode | (from + i2 * 2));
}
/* If we executed a breakpoint instruction, point PC right back at it. */
else if (insn[0] == 0x0 && insn[1] == 0x1)
regcache_write_pc (regs, from);
/* For any other insn, PC points right after the original instruction. */
else
regcache_write_pc (regs, from + insnlen);
if (debug_displaced)
fprintf_unfiltered (gdb_stdlog,
"displaced: (s390) pc is now %s\n",
paddress (gdbarch, regcache_read_pc (regs)));
}
/* Helper routine to unwind pseudo registers. */
static struct value *
s390_unwind_pseudo_register (struct frame_info *this_frame, int regnum)
{
struct gdbarch *gdbarch = get_frame_arch (this_frame);
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
struct type *type = register_type (gdbarch, regnum);
/* Unwind PC via PSW address. */
if (regnum == tdep->pc_regnum)
{
struct value *val;
val = frame_unwind_register_value (this_frame, S390_PSWA_REGNUM);
if (!value_optimized_out (val))
{
LONGEST pswa = value_as_long (val);
if (TYPE_LENGTH (type) == 4)
return value_from_pointer (type, pswa & 0x7fffffff);
else
return value_from_pointer (type, pswa);
}
}
/* Unwind CC via PSW mask. */
if (regnum == tdep->cc_regnum)
{
struct value *val;
val = frame_unwind_register_value (this_frame, S390_PSWM_REGNUM);
if (!value_optimized_out (val))
{
LONGEST pswm = value_as_long (val);
if (TYPE_LENGTH (type) == 4)
return value_from_longest (type, (pswm >> 12) & 3);
else
return value_from_longest (type, (pswm >> 44) & 3);
}
}
/* Unwind full GPRs to show at least the lower halves (as the
upper halves are undefined). */
if (tdep->gpr_full_regnum != -1
&& regnum >= tdep->gpr_full_regnum
&& regnum < tdep->gpr_full_regnum + 16)
{
int reg = regnum - tdep->gpr_full_regnum;
struct value *val;
val = frame_unwind_register_value (this_frame, S390_R0_REGNUM + reg);
if (!value_optimized_out (val))
return value_cast (type, val);
}
return allocate_optimized_out_value (type);
}
static struct value *
s390_trad_frame_prev_register (struct frame_info *this_frame,
struct trad_frame_saved_reg saved_regs[],
int regnum)
{
if (regnum < S390_NUM_REGS)
return trad_frame_get_prev_register (this_frame, saved_regs, regnum);
else
return s390_unwind_pseudo_register (this_frame, regnum);
}
/* Normal stack frames. */
struct s390_unwind_cache {
CORE_ADDR func;
CORE_ADDR frame_base;
CORE_ADDR local_base;
struct trad_frame_saved_reg *saved_regs;
};
static int
s390_prologue_frame_unwind_cache (struct frame_info *this_frame,
struct s390_unwind_cache *info)
{
struct gdbarch *gdbarch = get_frame_arch (this_frame);
int word_size = gdbarch_ptr_bit (gdbarch) / 8;
struct s390_prologue_data data;
pv_t *fp = &data.gpr[S390_FRAME_REGNUM - S390_R0_REGNUM];
pv_t *sp = &data.gpr[S390_SP_REGNUM - S390_R0_REGNUM];
int i;
CORE_ADDR cfa;
CORE_ADDR func;
CORE_ADDR result;
ULONGEST reg;
CORE_ADDR prev_sp;
int frame_pointer;
int size;
struct frame_info *next_frame;
/* Try to find the function start address. If we can't find it, we don't
bother searching for it -- with modern compilers this would be mostly
pointless anyway. Trust that we'll either have valid DWARF-2 CFI data
or else a valid backchain ... */
func = get_frame_func (this_frame);
if (!func)
return 0;
/* Try to analyze the prologue. */
result = s390_analyze_prologue (gdbarch, func,
get_frame_pc (this_frame), &data);
if (!result)
return 0;
/* If this was successful, we should have found the instruction that
sets the stack pointer register to the previous value of the stack
pointer minus the frame size. */
if (!pv_is_register (*sp, S390_SP_REGNUM))
return 0;
/* A frame size of zero at this point can mean either a real
frameless function, or else a failure to find the prologue.
Perform some sanity checks to verify we really have a
frameless function. */
if (sp->k == 0)
{
/* If the next frame is a NORMAL_FRAME, this frame *cannot* have frame
size zero. This is only possible if the next frame is a sentinel
frame, a dummy frame, or a signal trampoline frame. */
/* FIXME: cagney/2004-05-01: This sanity check shouldn't be
needed, instead the code should simpliy rely on its
analysis. */
next_frame = get_next_frame (this_frame);
while (next_frame && get_frame_type (next_frame) == INLINE_FRAME)
next_frame = get_next_frame (next_frame);
if (next_frame
&& get_frame_type (get_next_frame (this_frame)) == NORMAL_FRAME)
return 0;
/* If we really have a frameless function, %r14 must be valid
-- in particular, it must point to a different function. */
reg = get_frame_register_unsigned (this_frame, S390_RETADDR_REGNUM);
reg = gdbarch_addr_bits_remove (gdbarch, reg) - 1;
if (get_pc_function_start (reg) == func)
{
/* However, there is one case where it *is* valid for %r14
to point to the same function -- if this is a recursive
call, and we have stopped in the prologue *before* the
stack frame was allocated.
Recognize this case by looking ahead a bit ... */
struct s390_prologue_data data2;
pv_t *sp = &data2.gpr[S390_SP_REGNUM - S390_R0_REGNUM];
if (!(s390_analyze_prologue (gdbarch, func, (CORE_ADDR)-1, &data2)
&& pv_is_register (*sp, S390_SP_REGNUM)
&& sp->k != 0))
return 0;
}
}
/* OK, we've found valid prologue data. */
size = -sp->k;
/* If the frame pointer originally also holds the same value
as the stack pointer, we're probably using it. If it holds
some other value -- even a constant offset -- it is most
likely used as temp register. */
if (pv_is_identical (*sp, *fp))
frame_pointer = S390_FRAME_REGNUM;
else
frame_pointer = S390_SP_REGNUM;
/* If we've detected a function with stack frame, we'll still have to
treat it as frameless if we're currently within the function epilog
code at a point where the frame pointer has already been restored.
This can only happen in an innermost frame. */
/* FIXME: cagney/2004-05-01: This sanity check shouldn't be needed,
instead the code should simpliy rely on its analysis. */
next_frame = get_next_frame (this_frame);
while (next_frame && get_frame_type (next_frame) == INLINE_FRAME)
next_frame = get_next_frame (next_frame);
if (size > 0
&& (next_frame == NULL
|| get_frame_type (get_next_frame (this_frame)) != NORMAL_FRAME))
{
/* See the comment in s390_in_function_epilogue_p on why this is
not completely reliable ... */
if (s390_in_function_epilogue_p (gdbarch, get_frame_pc (this_frame)))
{
memset (&data, 0, sizeof (data));
size = 0;
frame_pointer = S390_SP_REGNUM;
}
}
/* Once we know the frame register and the frame size, we can unwind
the current value of the frame register from the next frame, and
add back the frame size to arrive that the previous frame's
stack pointer value. */
prev_sp = get_frame_register_unsigned (this_frame, frame_pointer) + size;
cfa = prev_sp + 16*word_size + 32;
/* Set up ABI call-saved/call-clobbered registers. */
for (i = 0; i < S390_NUM_REGS; i++)
if (!s390_register_call_saved (gdbarch, i))
trad_frame_set_unknown (info->saved_regs, i);
/* CC is always call-clobbered. */
trad_frame_set_unknown (info->saved_regs, S390_PSWM_REGNUM);
/* Record the addresses of all register spill slots the prologue parser
has recognized. Consider only registers defined as call-saved by the
ABI; for call-clobbered registers the parser may have recognized
spurious stores. */
for (i = 0; i < 16; i++)
if (s390_register_call_saved (gdbarch, S390_R0_REGNUM + i)
&& data.gpr_slot[i] != 0)
info->saved_regs[S390_R0_REGNUM + i].addr = cfa - data.gpr_slot[i];
for (i = 0; i < 16; i++)
if (s390_register_call_saved (gdbarch, S390_F0_REGNUM + i)
&& data.fpr_slot[i] != 0)
info->saved_regs[S390_F0_REGNUM + i].addr = cfa - data.fpr_slot[i];
/* Function return will set PC to %r14. */
info->saved_regs[S390_PSWA_REGNUM] = info->saved_regs[S390_RETADDR_REGNUM];
/* In frameless functions, we unwind simply by moving the return
address to the PC. However, if we actually stored to the
save area, use that -- we might only think the function frameless
because we're in the middle of the prologue ... */
if (size == 0
&& !trad_frame_addr_p (info->saved_regs, S390_PSWA_REGNUM))
{
info->saved_regs[S390_PSWA_REGNUM].realreg = S390_RETADDR_REGNUM;
}
/* Another sanity check: unless this is a frameless function,
we should have found spill slots for SP and PC.
If not, we cannot unwind further -- this happens e.g. in
libc's thread_start routine. */
if (size > 0)
{
if (!trad_frame_addr_p (info->saved_regs, S390_SP_REGNUM)
|| !trad_frame_addr_p (info->saved_regs, S390_PSWA_REGNUM))
prev_sp = -1;
}
/* We use the current value of the frame register as local_base,
and the top of the register save area as frame_base. */
if (prev_sp != -1)
{
info->frame_base = prev_sp + 16*word_size + 32;
info->local_base = prev_sp - size;
}
info->func = func;
return 1;
}
static void
s390_backchain_frame_unwind_cache (struct frame_info *this_frame,
struct s390_unwind_cache *info)
{
struct gdbarch *gdbarch = get_frame_arch (this_frame);
int word_size = gdbarch_ptr_bit (gdbarch) / 8;
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
CORE_ADDR backchain;
ULONGEST reg;
LONGEST sp;
int i;
/* Set up ABI call-saved/call-clobbered registers. */
for (i = 0; i < S390_NUM_REGS; i++)
if (!s390_register_call_saved (gdbarch, i))
trad_frame_set_unknown (info->saved_regs, i);
/* CC is always call-clobbered. */
trad_frame_set_unknown (info->saved_regs, S390_PSWM_REGNUM);
/* Get the backchain. */
reg = get_frame_register_unsigned (this_frame, S390_SP_REGNUM);
backchain = read_memory_unsigned_integer (reg, word_size, byte_order);
/* A zero backchain terminates the frame chain. As additional
sanity check, let's verify that the spill slot for SP in the
save area pointed to by the backchain in fact links back to
the save area. */
if (backchain != 0
&& safe_read_memory_integer (backchain + 15*word_size,
word_size, byte_order, &sp)
&& (CORE_ADDR)sp == backchain)
{
/* We don't know which registers were saved, but it will have
to be at least %r14 and %r15. This will allow us to continue
unwinding, but other prev-frame registers may be incorrect ... */
info->saved_regs[S390_SP_REGNUM].addr = backchain + 15*word_size;
info->saved_regs[S390_RETADDR_REGNUM].addr = backchain + 14*word_size;
/* Function return will set PC to %r14. */
info->saved_regs[S390_PSWA_REGNUM]
= info->saved_regs[S390_RETADDR_REGNUM];
/* We use the current value of the frame register as local_base,
and the top of the register save area as frame_base. */
info->frame_base = backchain + 16*word_size + 32;
info->local_base = reg;
}
info->func = get_frame_pc (this_frame);
}
static struct s390_unwind_cache *
s390_frame_unwind_cache (struct frame_info *this_frame,
void **this_prologue_cache)
{
struct s390_unwind_cache *info;
if (*this_prologue_cache)
return *this_prologue_cache;
info = FRAME_OBSTACK_ZALLOC (struct s390_unwind_cache);
*this_prologue_cache = info;
info->saved_regs = trad_frame_alloc_saved_regs (this_frame);
info->func = -1;
info->frame_base = -1;
info->local_base = -1;
/* Try to use prologue analysis to fill the unwind cache.
If this fails, fall back to reading the stack backchain. */
if (!s390_prologue_frame_unwind_cache (this_frame, info))
s390_backchain_frame_unwind_cache (this_frame, info);
return info;
}
static void
s390_frame_this_id (struct frame_info *this_frame,
void **this_prologue_cache,
struct frame_id *this_id)
{
struct s390_unwind_cache *info
= s390_frame_unwind_cache (this_frame, this_prologue_cache);
if (info->frame_base == -1)
return;
*this_id = frame_id_build (info->frame_base, info->func);
}
static struct value *
s390_frame_prev_register (struct frame_info *this_frame,
void **this_prologue_cache, int regnum)
{
struct gdbarch *gdbarch = get_frame_arch (this_frame);
struct s390_unwind_cache *info
= s390_frame_unwind_cache (this_frame, this_prologue_cache);
return s390_trad_frame_prev_register (this_frame, info->saved_regs, regnum);
}
static const struct frame_unwind s390_frame_unwind = {
NORMAL_FRAME,
default_frame_unwind_stop_reason,
s390_frame_this_id,
s390_frame_prev_register,
NULL,
default_frame_sniffer
};
/* Code stubs and their stack frames. For things like PLTs and NULL
function calls (where there is no true frame and the return address
is in the RETADDR register). */
struct s390_stub_unwind_cache
{
CORE_ADDR frame_base;
struct trad_frame_saved_reg *saved_regs;
};
static struct s390_stub_unwind_cache *
s390_stub_frame_unwind_cache (struct frame_info *this_frame,
void **this_prologue_cache)
{
struct gdbarch *gdbarch = get_frame_arch (this_frame);
int word_size = gdbarch_ptr_bit (gdbarch) / 8;
struct s390_stub_unwind_cache *info;
ULONGEST reg;
if (*this_prologue_cache)
return *this_prologue_cache;
info = FRAME_OBSTACK_ZALLOC (struct s390_stub_unwind_cache);
*this_prologue_cache = info;
info->saved_regs = trad_frame_alloc_saved_regs (this_frame);
/* The return address is in register %r14. */
info->saved_regs[S390_PSWA_REGNUM].realreg = S390_RETADDR_REGNUM;
/* Retrieve stack pointer and determine our frame base. */
reg = get_frame_register_unsigned (this_frame, S390_SP_REGNUM);
info->frame_base = reg + 16*word_size + 32;
return info;
}
static void
s390_stub_frame_this_id (struct frame_info *this_frame,
void **this_prologue_cache,
struct frame_id *this_id)
{
struct s390_stub_unwind_cache *info
= s390_stub_frame_unwind_cache (this_frame, this_prologue_cache);
*this_id = frame_id_build (info->frame_base, get_frame_pc (this_frame));
}
static struct value *
s390_stub_frame_prev_register (struct frame_info *this_frame,
void **this_prologue_cache, int regnum)
{
struct s390_stub_unwind_cache *info
= s390_stub_frame_unwind_cache (this_frame, this_prologue_cache);
return s390_trad_frame_prev_register (this_frame, info->saved_regs, regnum);
}
static int
s390_stub_frame_sniffer (const struct frame_unwind *self,
struct frame_info *this_frame,
void **this_prologue_cache)
{
CORE_ADDR addr_in_block;
bfd_byte insn[S390_MAX_INSTR_SIZE];
/* If the current PC points to non-readable memory, we assume we
have trapped due to an invalid function pointer call. We handle
the non-existing current function like a PLT stub. */
addr_in_block = get_frame_address_in_block (this_frame);
if (in_plt_section (addr_in_block, NULL)
|| s390_readinstruction (insn, get_frame_pc (this_frame)) < 0)
return 1;
return 0;
}
static const struct frame_unwind s390_stub_frame_unwind = {
NORMAL_FRAME,
default_frame_unwind_stop_reason,
s390_stub_frame_this_id,
s390_stub_frame_prev_register,
NULL,
s390_stub_frame_sniffer
};
/* Signal trampoline stack frames. */
struct s390_sigtramp_unwind_cache {
CORE_ADDR frame_base;
struct trad_frame_saved_reg *saved_regs;
};
static struct s390_sigtramp_unwind_cache *
s390_sigtramp_frame_unwind_cache (struct frame_info *this_frame,
void **this_prologue_cache)
{
struct gdbarch *gdbarch = get_frame_arch (this_frame);
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
int word_size = gdbarch_ptr_bit (gdbarch) / 8;
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
struct s390_sigtramp_unwind_cache *info;
ULONGEST this_sp, prev_sp;
CORE_ADDR next_ra, next_cfa, sigreg_ptr, sigreg_high_off;
int i;
if (*this_prologue_cache)
return *this_prologue_cache;
info = FRAME_OBSTACK_ZALLOC (struct s390_sigtramp_unwind_cache);
*this_prologue_cache = info;
info->saved_regs = trad_frame_alloc_saved_regs (this_frame);
this_sp = get_frame_register_unsigned (this_frame, S390_SP_REGNUM);
next_ra = get_frame_pc (this_frame);
next_cfa = this_sp + 16*word_size + 32;
/* New-style RT frame:
retcode + alignment (8 bytes)
siginfo (128 bytes)
ucontext (contains sigregs at offset 5 words). */
if (next_ra == next_cfa)
{
sigreg_ptr = next_cfa + 8 + 128 + align_up (5*word_size, 8);
/* sigregs are followed by uc_sigmask (8 bytes), then by the
upper GPR halves if present. */
sigreg_high_off = 8;
}
/* Old-style RT frame and all non-RT frames:
old signal mask (8 bytes)
pointer to sigregs. */
else
{
sigreg_ptr = read_memory_unsigned_integer (next_cfa + 8,
word_size, byte_order);
/* sigregs are followed by signo (4 bytes), then by the
upper GPR halves if present. */
sigreg_high_off = 4;
}
/* The sigregs structure looks like this:
long psw_mask;
long psw_addr;
long gprs[16];
int acrs[16];
int fpc;
int __pad;
double fprs[16]; */
/* PSW mask and address. */
info->saved_regs[S390_PSWM_REGNUM].addr = sigreg_ptr;
sigreg_ptr += word_size;
info->saved_regs[S390_PSWA_REGNUM].addr = sigreg_ptr;
sigreg_ptr += word_size;
/* Then the GPRs. */
for (i = 0; i < 16; i++)
{
info->saved_regs[S390_R0_REGNUM + i].addr = sigreg_ptr;
sigreg_ptr += word_size;
}
/* Then the ACRs. */
for (i = 0; i < 16; i++)
{
info->saved_regs[S390_A0_REGNUM + i].addr = sigreg_ptr;
sigreg_ptr += 4;
}
/* The floating-point control word. */
info->saved_regs[S390_FPC_REGNUM].addr = sigreg_ptr;
sigreg_ptr += 8;
/* And finally the FPRs. */
for (i = 0; i < 16; i++)
{
info->saved_regs[S390_F0_REGNUM + i].addr = sigreg_ptr;
sigreg_ptr += 8;
}
/* If we have them, the GPR upper halves are appended at the end. */
sigreg_ptr += sigreg_high_off;
if (tdep->gpr_full_regnum != -1)
for (i = 0; i < 16; i++)
{
info->saved_regs[S390_R0_UPPER_REGNUM + i].addr = sigreg_ptr;
sigreg_ptr += 4;
}
/* Restore the previous frame's SP. */
prev_sp = read_memory_unsigned_integer (
info->saved_regs[S390_SP_REGNUM].addr,
word_size, byte_order);
/* Determine our frame base. */
info->frame_base = prev_sp + 16*word_size + 32;
return info;
}
static void
s390_sigtramp_frame_this_id (struct frame_info *this_frame,
void **this_prologue_cache,
struct frame_id *this_id)
{
struct s390_sigtramp_unwind_cache *info
= s390_sigtramp_frame_unwind_cache (this_frame, this_prologue_cache);
*this_id = frame_id_build (info->frame_base, get_frame_pc (this_frame));
}
static struct value *
s390_sigtramp_frame_prev_register (struct frame_info *this_frame,
void **this_prologue_cache, int regnum)
{
struct s390_sigtramp_unwind_cache *info
= s390_sigtramp_frame_unwind_cache (this_frame, this_prologue_cache);
return s390_trad_frame_prev_register (this_frame, info->saved_regs, regnum);
}
static int
s390_sigtramp_frame_sniffer (const struct frame_unwind *self,
struct frame_info *this_frame,
void **this_prologue_cache)
{
CORE_ADDR pc = get_frame_pc (this_frame);
bfd_byte sigreturn[2];
if (target_read_memory (pc, sigreturn, 2))
return 0;
if (sigreturn[0] != 0x0a /* svc */)
return 0;
if (sigreturn[1] != 119 /* sigreturn */
&& sigreturn[1] != 173 /* rt_sigreturn */)
return 0;
return 1;
}
static const struct frame_unwind s390_sigtramp_frame_unwind = {
SIGTRAMP_FRAME,
default_frame_unwind_stop_reason,
s390_sigtramp_frame_this_id,
s390_sigtramp_frame_prev_register,
NULL,
s390_sigtramp_frame_sniffer
};
/* Frame base handling. */
static CORE_ADDR
s390_frame_base_address (struct frame_info *this_frame, void **this_cache)
{
struct s390_unwind_cache *info
= s390_frame_unwind_cache (this_frame, this_cache);
return info->frame_base;
}
static CORE_ADDR
s390_local_base_address (struct frame_info *this_frame, void **this_cache)
{
struct s390_unwind_cache *info
= s390_frame_unwind_cache (this_frame, this_cache);
return info->local_base;
}
static const struct frame_base s390_frame_base = {
&s390_frame_unwind,
s390_frame_base_address,
s390_local_base_address,
s390_local_base_address
};
static CORE_ADDR
s390_unwind_pc (struct gdbarch *gdbarch, struct frame_info *next_frame)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
ULONGEST pc;
pc = frame_unwind_register_unsigned (next_frame, tdep->pc_regnum);
return gdbarch_addr_bits_remove (gdbarch, pc);
}
static CORE_ADDR
s390_unwind_sp (struct gdbarch *gdbarch, struct frame_info *next_frame)
{
ULONGEST sp;
sp = frame_unwind_register_unsigned (next_frame, S390_SP_REGNUM);
return gdbarch_addr_bits_remove (gdbarch, sp);
}
/* DWARF-2 frame support. */
static struct value *
s390_dwarf2_prev_register (struct frame_info *this_frame, void **this_cache,
int regnum)
{
return s390_unwind_pseudo_register (this_frame, regnum);
}
static void
s390_dwarf2_frame_init_reg (struct gdbarch *gdbarch, int regnum,
struct dwarf2_frame_state_reg *reg,
struct frame_info *this_frame)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
/* The condition code (and thus PSW mask) is call-clobbered. */
if (regnum == S390_PSWM_REGNUM)
reg->how = DWARF2_FRAME_REG_UNDEFINED;
/* The PSW address unwinds to the return address. */
else if (regnum == S390_PSWA_REGNUM)
reg->how = DWARF2_FRAME_REG_RA;
/* Fixed registers are call-saved or call-clobbered
depending on the ABI in use. */
else if (regnum < S390_NUM_REGS)
{
if (s390_register_call_saved (gdbarch, regnum))
reg->how = DWARF2_FRAME_REG_SAME_VALUE;
else
reg->how = DWARF2_FRAME_REG_UNDEFINED;
}
/* We install a special function to unwind pseudos. */
else
{
reg->how = DWARF2_FRAME_REG_FN;
reg->loc.fn = s390_dwarf2_prev_register;
}
}
/* Dummy function calls. */
/* Return non-zero if TYPE is an integer-like type, zero otherwise.
"Integer-like" types are those that should be passed the way
integers are: integers, enums, ranges, characters, and booleans. */
static int
is_integer_like (struct type *type)
{
enum type_code code = TYPE_CODE (type);
return (code == TYPE_CODE_INT
|| code == TYPE_CODE_ENUM
|| code == TYPE_CODE_RANGE
|| code == TYPE_CODE_CHAR
|| code == TYPE_CODE_BOOL);
}
/* Return non-zero if TYPE is a pointer-like type, zero otherwise.
"Pointer-like" types are those that should be passed the way
pointers are: pointers and references. */
static int
is_pointer_like (struct type *type)
{
enum type_code code = TYPE_CODE (type);
return (code == TYPE_CODE_PTR
|| code == TYPE_CODE_REF);
}
/* Return non-zero if TYPE is a `float singleton' or `double
singleton', zero otherwise.
A `T singleton' is a struct type with one member, whose type is
either T or a `T singleton'. So, the following are all float
singletons:
struct { float x };
struct { struct { float x; } x; };
struct { struct { struct { float x; } x; } x; };
... and so on.
All such structures are passed as if they were floats or doubles,
as the (revised) ABI says. */
static int
is_float_singleton (struct type *type)
{
if (TYPE_CODE (type) == TYPE_CODE_STRUCT && TYPE_NFIELDS (type) == 1)
{
struct type *singleton_type = TYPE_FIELD_TYPE (type, 0);
CHECK_TYPEDEF (singleton_type);
return (TYPE_CODE (singleton_type) == TYPE_CODE_FLT
|| TYPE_CODE (singleton_type) == TYPE_CODE_DECFLOAT
|| is_float_singleton (singleton_type));
}
return 0;
}
/* Return non-zero if TYPE is a struct-like type, zero otherwise.
"Struct-like" types are those that should be passed as structs are:
structs and unions.
As an odd quirk, not mentioned in the ABI, GCC passes float and
double singletons as if they were a plain float, double, etc. (The
corresponding union types are handled normally.) So we exclude
those types here. *shrug* */
static int
is_struct_like (struct type *type)
{
enum type_code code = TYPE_CODE (type);
return (code == TYPE_CODE_UNION
|| (code == TYPE_CODE_STRUCT && ! is_float_singleton (type)));
}
/* Return non-zero if TYPE is a float-like type, zero otherwise.
"Float-like" types are those that should be passed as
floating-point values are.
You'd think this would just be floats, doubles, long doubles, etc.
But as an odd quirk, not mentioned in the ABI, GCC passes float and
double singletons as if they were a plain float, double, etc. (The
corresponding union types are handled normally.) So we include
those types here. *shrug* */
static int
is_float_like (struct type *type)
{
return (TYPE_CODE (type) == TYPE_CODE_FLT
|| TYPE_CODE (type) == TYPE_CODE_DECFLOAT
|| is_float_singleton (type));
}
static int
is_power_of_two (unsigned int n)
{
return ((n & (n - 1)) == 0);
}
/* Return non-zero if TYPE should be passed as a pointer to a copy,
zero otherwise. */
static int
s390_function_arg_pass_by_reference (struct type *type)
{
unsigned length = TYPE_LENGTH (type);
if (length > 8)
return 1;
return (is_struct_like (type) && !is_power_of_two (TYPE_LENGTH (type)))
|| TYPE_CODE (type) == TYPE_CODE_COMPLEX
|| (TYPE_CODE (type) == TYPE_CODE_ARRAY && TYPE_VECTOR (type));
}
/* Return non-zero if TYPE should be passed in a float register
if possible. */
static int
s390_function_arg_float (struct type *type)
{
unsigned length = TYPE_LENGTH (type);
if (length > 8)
return 0;
return is_float_like (type);
}
/* Return non-zero if TYPE should be passed in an integer register
(or a pair of integer registers) if possible. */
static int
s390_function_arg_integer (struct type *type)
{
unsigned length = TYPE_LENGTH (type);
if (length > 8)
return 0;
return is_integer_like (type)
|| is_pointer_like (type)
|| (is_struct_like (type) && is_power_of_two (length));
}
/* Return ARG, a `SIMPLE_ARG', sign-extended or zero-extended to a full
word as required for the ABI. */
static LONGEST
extend_simple_arg (struct gdbarch *gdbarch, struct value *arg)
{
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
struct type *type = check_typedef (value_type (arg));
/* Even structs get passed in the least significant bits of the
register / memory word. It's not really right to extract them as
an integer, but it does take care of the extension. */
if (TYPE_UNSIGNED (type))
return extract_unsigned_integer (value_contents (arg),
TYPE_LENGTH (type), byte_order);
else
return extract_signed_integer (value_contents (arg),
TYPE_LENGTH (type), byte_order);
}
/* Return the alignment required by TYPE. */
static int
alignment_of (struct type *type)
{
int alignment;
if (is_integer_like (type)
|| is_pointer_like (type)
|| TYPE_CODE (type) == TYPE_CODE_FLT
|| TYPE_CODE (type) == TYPE_CODE_DECFLOAT)
alignment = TYPE_LENGTH (type);
else if (TYPE_CODE (type) == TYPE_CODE_STRUCT
|| TYPE_CODE (type) == TYPE_CODE_UNION)
{
int i;
alignment = 1;
for (i = 0; i < TYPE_NFIELDS (type); i++)
{
int field_alignment
= alignment_of (check_typedef (TYPE_FIELD_TYPE (type, i)));
if (field_alignment > alignment)
alignment = field_alignment;
}
}
else
alignment = 1;
/* Check that everything we ever return is a power of two. Lots of
code doesn't want to deal with aligning things to arbitrary
boundaries. */
gdb_assert ((alignment & (alignment - 1)) == 0);
return alignment;
}
/* Put the actual parameter values pointed to by ARGS[0..NARGS-1] in
place to be passed to a function, as specified by the "GNU/Linux
for S/390 ELF Application Binary Interface Supplement".
SP is the current stack pointer. We must put arguments, links,
padding, etc. whereever they belong, and return the new stack
pointer value.
If STRUCT_RETURN is non-zero, then the function we're calling is
going to return a structure by value; STRUCT_ADDR is the address of
a block we've allocated for it on the stack.
Our caller has taken care of any type promotions needed to satisfy
prototypes or the old K&R argument-passing rules. */
static CORE_ADDR
s390_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
struct regcache *regcache, CORE_ADDR bp_addr,
int nargs, struct value **args, CORE_ADDR sp,
int struct_return, CORE_ADDR struct_addr)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
int word_size = gdbarch_ptr_bit (gdbarch) / 8;
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
int i;
/* If the i'th argument is passed as a reference to a copy, then
copy_addr[i] is the address of the copy we made. */
CORE_ADDR *copy_addr = alloca (nargs * sizeof (CORE_ADDR));
/* Reserve space for the reference-to-copy area. */
for (i = 0; i < nargs; i++)
{
struct value *arg = args[i];
struct type *type = check_typedef (value_type (arg));
unsigned length = TYPE_LENGTH (type);
if (s390_function_arg_pass_by_reference (type))
{
sp -= length;
sp = align_down (sp, alignment_of (type));
copy_addr[i] = sp;
}
}
/* Reserve space for the parameter area. As a conservative
simplification, we assume that everything will be passed on the
stack. Since every argument larger than 8 bytes will be
passed by reference, we use this simple upper bound. */
sp -= nargs * 8;
/* After all that, make sure it's still aligned on an eight-byte
boundary. */
sp = align_down (sp, 8);
/* Allocate the standard frame areas: the register save area, the
word reserved for the compiler (which seems kind of meaningless),
and the back chain pointer. */
sp -= 16*word_size + 32;
/* Now we have the final SP value. Make sure we didn't underflow;
on 31-bit, this would result in addresses with the high bit set,
which causes confusion elsewhere. Note that if we error out
here, stack and registers remain untouched. */
if (gdbarch_addr_bits_remove (gdbarch, sp) != sp)
error (_("Stack overflow"));
/* Finally, place the actual parameters, working from SP towards
higher addresses. The code above is supposed to reserve enough
space for this. */
{
int fr = 0;
int gr = 2;
CORE_ADDR starg = sp + 16*word_size + 32;
/* A struct is returned using general register 2. */
if (struct_return)
{
regcache_cooked_write_unsigned (regcache, S390_R0_REGNUM + gr,
struct_addr);
gr++;
}
for (i = 0; i < nargs; i++)
{
struct value *arg = args[i];
struct type *type = check_typedef (value_type (arg));
unsigned length = TYPE_LENGTH (type);
if (s390_function_arg_pass_by_reference (type))
{
/* Actually copy the argument contents to the stack slot
that was reserved above. */
write_memory (copy_addr[i], value_contents (arg), length);
if (gr <= 6)
{
regcache_cooked_write_unsigned (regcache, S390_R0_REGNUM + gr,
copy_addr[i]);
gr++;
}
else
{
write_memory_unsigned_integer (starg, word_size, byte_order,
copy_addr[i]);
starg += word_size;
}
}
else if (s390_function_arg_float (type))
{
/* The GNU/Linux for S/390 ABI uses FPRs 0 and 2 to pass arguments,
the GNU/Linux for zSeries ABI uses 0, 2, 4, and 6. */
if (fr <= (tdep->abi == ABI_LINUX_S390 ? 2 : 6))
{
/* When we store a single-precision value in an FP register,
it occupies the leftmost bits. */
regcache_cooked_write_part (regcache, S390_F0_REGNUM + fr,
0, length, value_contents (arg));
fr += 2;
}
else
{
/* When we store a single-precision value in a stack slot,
it occupies the rightmost bits. */
starg = align_up (starg + length, word_size);
write_memory (starg - length, value_contents (arg), length);
}
}
else if (s390_function_arg_integer (type) && length <= word_size)
{
if (gr <= 6)
{
/* Integer arguments are always extended to word size. */
regcache_cooked_write_signed (regcache, S390_R0_REGNUM + gr,
extend_simple_arg (gdbarch,
arg));
gr++;
}
else
{
/* Integer arguments are always extended to word size. */
write_memory_signed_integer (starg, word_size, byte_order,
extend_simple_arg (gdbarch, arg));
starg += word_size;
}
}
else if (s390_function_arg_integer (type) && length == 2*word_size)
{
if (gr <= 5)
{
regcache_cooked_write (regcache, S390_R0_REGNUM + gr,
value_contents (arg));
regcache_cooked_write (regcache, S390_R0_REGNUM + gr + 1,
value_contents (arg) + word_size);
gr += 2;
}
else
{
/* If we skipped r6 because we couldn't fit a DOUBLE_ARG
in it, then don't go back and use it again later. */
gr = 7;
write_memory (starg, value_contents (arg), length);
starg += length;
}
}
else
internal_error (__FILE__, __LINE__, _("unknown argument type"));
}
}
/* Store return PSWA. In 31-bit mode, keep addressing mode bit. */
if (word_size == 4)
{
ULONGEST pswa;
regcache_cooked_read_unsigned (regcache, S390_PSWA_REGNUM, &pswa);
bp_addr = (bp_addr & 0x7fffffff) | (pswa & 0x80000000);
}
regcache_cooked_write_unsigned (regcache, S390_RETADDR_REGNUM, bp_addr);
/* Store updated stack pointer. */
regcache_cooked_write_unsigned (regcache, S390_SP_REGNUM, sp);
/* We need to return the 'stack part' of the frame ID,
which is actually the top of the register save area. */
return sp + 16*word_size + 32;
}
/* Assuming THIS_FRAME is a dummy, return the frame ID of that
dummy frame. The frame ID's base needs to match the TOS value
returned by push_dummy_call, and the PC match the dummy frame's
breakpoint. */
static struct frame_id
s390_dummy_id (struct gdbarch *gdbarch, struct frame_info *this_frame)
{
int word_size = gdbarch_ptr_bit (gdbarch) / 8;
CORE_ADDR sp = get_frame_register_unsigned (this_frame, S390_SP_REGNUM);
sp = gdbarch_addr_bits_remove (gdbarch, sp);
return frame_id_build (sp + 16*word_size + 32,
get_frame_pc (this_frame));
}
static CORE_ADDR
s390_frame_align (struct gdbarch *gdbarch, CORE_ADDR addr)
{
/* Both the 32- and 64-bit ABI's say that the stack pointer should
always be aligned on an eight-byte boundary. */
return (addr & -8);
}
/* Function return value access. */
static enum return_value_convention
s390_return_value_convention (struct gdbarch *gdbarch, struct type *type)
{
int length = TYPE_LENGTH (type);
if (length > 8)
return RETURN_VALUE_STRUCT_CONVENTION;
switch (TYPE_CODE (type))
{
case TYPE_CODE_STRUCT:
case TYPE_CODE_UNION:
case TYPE_CODE_ARRAY:
case TYPE_CODE_COMPLEX:
return RETURN_VALUE_STRUCT_CONVENTION;
default:
return RETURN_VALUE_REGISTER_CONVENTION;
}
}
static enum return_value_convention
s390_return_value (struct gdbarch *gdbarch, struct value *function,
struct type *type, struct regcache *regcache,
gdb_byte *out, const gdb_byte *in)
{
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
int word_size = gdbarch_ptr_bit (gdbarch) / 8;
enum return_value_convention rvc;
int length;
type = check_typedef (type);
rvc = s390_return_value_convention (gdbarch, type);
length = TYPE_LENGTH (type);
if (in)
{
switch (rvc)
{
case RETURN_VALUE_REGISTER_CONVENTION:
if (TYPE_CODE (type) == TYPE_CODE_FLT
|| TYPE_CODE (type) == TYPE_CODE_DECFLOAT)
{
/* When we store a single-precision value in an FP register,
it occupies the leftmost bits. */
regcache_cooked_write_part (regcache, S390_F0_REGNUM,
0, length, in);
}
else if (length <= word_size)
{
/* Integer arguments are always extended to word size. */
if (TYPE_UNSIGNED (type))
regcache_cooked_write_unsigned (regcache, S390_R2_REGNUM,
extract_unsigned_integer (in, length, byte_order));
else
regcache_cooked_write_signed (regcache, S390_R2_REGNUM,
extract_signed_integer (in, length, byte_order));
}
else if (length == 2*word_size)
{
regcache_cooked_write (regcache, S390_R2_REGNUM, in);
regcache_cooked_write (regcache, S390_R3_REGNUM, in + word_size);
}
else
internal_error (__FILE__, __LINE__, _("invalid return type"));
break;
case RETURN_VALUE_STRUCT_CONVENTION:
error (_("Cannot set function return value."));
break;
}
}
else if (out)
{
switch (rvc)
{
case RETURN_VALUE_REGISTER_CONVENTION:
if (TYPE_CODE (type) == TYPE_CODE_FLT
|| TYPE_CODE (type) == TYPE_CODE_DECFLOAT)
{
/* When we store a single-precision value in an FP register,
it occupies the leftmost bits. */
regcache_cooked_read_part (regcache, S390_F0_REGNUM,
0, length, out);
}
else if (length <= word_size)
{
/* Integer arguments occupy the rightmost bits. */
regcache_cooked_read_part (regcache, S390_R2_REGNUM,
word_size - length, length, out);
}
else if (length == 2*word_size)
{
regcache_cooked_read (regcache, S390_R2_REGNUM, out);