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//=- SystemZCallingConv.td - Calling conventions for SystemZ -*- tablegen -*-=//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// This describes the calling conventions for the SystemZ ABI.
//===----------------------------------------------------------------------===//
class CCIfExtend<CCAction A>
: CCIf<"ArgFlags.isSExt() || ArgFlags.isZExt()", A>;
class CCIfSubtarget<string F, CCAction A>
: CCIf<!strconcat("static_cast<const SystemZSubtarget&>"
"(State.getMachineFunction().getSubtarget()).", F),
A>;
// Match if this specific argument is a fixed (i.e. named) argument.
class CCIfFixed<CCAction A>
: CCIf<"static_cast<SystemZCCState *>(&State)->IsFixed(ValNo)", A>;
// Match if this specific argument was widened from a short vector type.
class CCIfShortVector<CCAction A>
: CCIf<"static_cast<SystemZCCState *>(&State)->IsShortVector(ValNo)", A>;
//===----------------------------------------------------------------------===//
// z/Linux return value calling convention
//===----------------------------------------------------------------------===//
def RetCC_SystemZ : CallingConv<[
// Promote i32 to i64 if it has an explicit extension type.
CCIfType<[i32], CCIfExtend<CCPromoteToType<i64>>>,
// A SwiftError is returned in R9.
CCIfSwiftError<CCIfType<[i64], CCAssignToReg<[R9D]>>>,
// ABI-compliant code returns 64-bit integers in R2. Make the other
// call-clobbered argument registers available for code that doesn't
// care about the ABI. (R6 is an argument register too, but is
// call-saved and therefore not suitable for return values.)
CCIfType<[i32], CCAssignToReg<[R2L, R3L, R4L, R5L]>>,
CCIfType<[i64], CCAssignToReg<[R2D, R3D, R4D, R5D]>>,
// ABI-complaint code returns float and double in F0. Make the
// other floating-point argument registers available for code that
// doesn't care about the ABI. All floating-point argument registers
// are call-clobbered, so we can use all of them here.
CCIfType<[f32], CCAssignToReg<[F0S, F2S, F4S, F6S]>>,
CCIfType<[f64], CCAssignToReg<[F0D, F2D, F4D, F6D]>>,
// Similarly for vectors, with V24 being the ABI-compliant choice.
// Sub-128 vectors are returned in the same way, but they're widened
// to one of these types during type legalization.
CCIfSubtarget<"hasVector()",
CCIfType<[v16i8, v8i16, v4i32, v2i64, v4f32, v2f64],
CCAssignToReg<[V24, V26, V28, V30, V25, V27, V29, V31]>>>
]>;
//===----------------------------------------------------------------------===//
// z/Linux argument calling conventions
//===----------------------------------------------------------------------===//
def CC_SystemZ : CallingConv<[
// Promote i32 to i64 if it has an explicit extension type.
// The convention is that true integer arguments that are smaller
// than 64 bits should be marked as extended, but structures that
// are smaller than 64 bits shouldn't.
CCIfType<[i32], CCIfExtend<CCPromoteToType<i64>>>,
// A SwiftSelf is passed in callee-saved R10.
CCIfSwiftSelf<CCIfType<[i64], CCAssignToReg<[R10D]>>>,
// A SwiftError is passed in callee-saved R9.
CCIfSwiftError<CCIfType<[i64], CCAssignToReg<[R9D]>>>,
// Force long double values to the stack and pass i64 pointers to them.
CCIfType<[f128], CCPassIndirect<i64>>,
// Same for i128 values. These are already split into two i64 here,
// so we have to use a custom handler.
CCIfType<[i64], CCCustom<"CC_SystemZ_I128Indirect">>,
// The first 5 integer arguments are passed in R2-R6. Note that R6
// is call-saved.
CCIfType<[i32], CCAssignToReg<[R2L, R3L, R4L, R5L, R6L]>>,
CCIfType<[i64], CCAssignToReg<[R2D, R3D, R4D, R5D, R6D]>>,
// The first 4 float and double arguments are passed in even registers F0-F6.
CCIfType<[f32], CCAssignToReg<[F0S, F2S, F4S, F6S]>>,
CCIfType<[f64], CCAssignToReg<[F0D, F2D, F4D, F6D]>>,
// The first 8 named vector arguments are passed in V24-V31. Sub-128 vectors
// are passed in the same way, but they're widened to one of these types
// during type legalization.
CCIfSubtarget<"hasVector()",
CCIfType<[v16i8, v8i16, v4i32, v2i64, v4f32, v2f64],
CCIfFixed<CCAssignToReg<[V24, V26, V28, V30,
V25, V27, V29, V31]>>>>,
// However, sub-128 vectors which need to go on the stack occupy just a
// single 8-byte-aligned 8-byte stack slot. Pass as i64.
CCIfSubtarget<"hasVector()",
CCIfType<[v16i8, v8i16, v4i32, v2i64, v4f32, v2f64],
CCIfShortVector<CCBitConvertToType<i64>>>>,
// Other vector arguments are passed in 8-byte-aligned 16-byte stack slots.
CCIfSubtarget<"hasVector()",
CCIfType<[v16i8, v8i16, v4i32, v2i64, v4f32, v2f64],
CCAssignToStack<16, 8>>>,
// Other arguments are passed in 8-byte-aligned 8-byte stack slots.
CCIfType<[i32, i64, f32, f64], CCAssignToStack<8, 8>>
]>;
//===----------------------------------------------------------------------===//
// z/Linux callee-saved registers
//===----------------------------------------------------------------------===//
def CSR_SystemZ : CalleeSavedRegs<(add (sequence "R%dD", 6, 15),
(sequence "F%dD", 8, 15))>;
// R9 is used to return SwiftError; remove it from CSR.
def CSR_SystemZ_SwiftError : CalleeSavedRegs<(sub CSR_SystemZ, R9D)>;
// "All registers" as used by the AnyReg calling convention.
// Note that registers 0 and 1 are still defined as intra-call scratch
// registers that may be clobbered e.g. by PLT stubs.
def CSR_SystemZ_AllRegs : CalleeSavedRegs<(add (sequence "R%dD", 2, 15),
(sequence "F%dD", 0, 15))>;
def CSR_SystemZ_AllRegs_Vector : CalleeSavedRegs<(add (sequence "R%dD", 2, 15),
(sequence "V%d", 0, 31))>;