[RISCV] Fix a bug in RISCVFrameLowering.
When we have out-going arguments passing through stack and we do not
reserve the stack space in the prologue. Use BP to access stack objects
after adjusting the stack pointer before function calls.
callseq_start -> sp = sp - reserved_space
//
// Use FP to access fixed stack objects.
// Use BP to access non-fixed stack objects.
//
call @foo
callseq_end -> sp = sp + reserved_space
Differential Revision: https://reviews.llvm.org/D114246
diff --git a/llvm/lib/Target/RISCV/RISCVFrameLowering.cpp b/llvm/lib/Target/RISCV/RISCVFrameLowering.cpp
index 697f177..f5d4919 100644
--- a/llvm/lib/Target/RISCV/RISCVFrameLowering.cpp
+++ b/llvm/lib/Target/RISCV/RISCVFrameLowering.cpp
@@ -237,7 +237,13 @@
const MachineFrameInfo &MFI = MF.getFrameInfo();
const TargetRegisterInfo *TRI = STI.getRegisterInfo();
- return MFI.hasVarSizedObjects() && TRI->hasStackRealignment(MF);
+ // If we do not reserve stack space for outgoing arguments in prologue,
+ // we will adjust the stack pointer before call instruction. After the
+ // adjustment, we can not use SP to access the stack objects for the
+ // arguments. Instead, use BP to access these stack objects.
+ return (MFI.hasVarSizedObjects() ||
+ (!hasReservedCallFrame(MF) && MFI.getMaxCallFrameSize() != 0)) &&
+ TRI->hasStackRealignment(MF);
}
// Determines the size of the frame and maximum call frame size.
diff --git a/llvm/test/CodeGen/RISCV/rvv/no-reserved-frame.ll b/llvm/test/CodeGen/RISCV/rvv/no-reserved-frame.ll
index 5c88eba7..78dc390 100644
--- a/llvm/test/CodeGen/RISCV/rvv/no-reserved-frame.ll
+++ b/llvm/test/CodeGen/RISCV/rvv/no-reserved-frame.ll
@@ -5,44 +5,46 @@
define signext i32 @foo(i32 signext %aa) #0 {
; CHECK-LABEL: foo:
; CHECK: # %bb.0: # %entry
-; CHECK-NEXT: addi sp, sp, -64
-; CHECK-NEXT: .cfi_def_cfa_offset 64
-; CHECK-NEXT: sd ra, 56(sp) # 8-byte Folded Spill
-; CHECK-NEXT: sd s0, 48(sp) # 8-byte Folded Spill
+; CHECK-NEXT: addi sp, sp, -80
+; CHECK-NEXT: .cfi_def_cfa_offset 80
+; CHECK-NEXT: sd ra, 72(sp) # 8-byte Folded Spill
+; CHECK-NEXT: sd s0, 64(sp) # 8-byte Folded Spill
+; CHECK-NEXT: sd s1, 56(sp) # 8-byte Folded Spill
; CHECK-NEXT: .cfi_offset ra, -8
; CHECK-NEXT: .cfi_offset s0, -16
-; CHECK-NEXT: addi s0, sp, 64
+; CHECK-NEXT: .cfi_offset s1, -24
+; CHECK-NEXT: addi s0, sp, 80
; CHECK-NEXT: .cfi_def_cfa s0, 0
; CHECK-NEXT: csrr a1, vlenb
; CHECK-NEXT: sub sp, sp, a1
; CHECK-NEXT: andi sp, sp, -8
-; CHECK-NEXT: lw t0, 36(sp)
-; CHECK-NEXT: lw a2, 32(sp)
-; CHECK-NEXT: lw a3, 28(sp)
-; CHECK-NEXT: lw a4, 24(sp)
-; CHECK-NEXT: lw a5, 20(sp)
-; CHECK-NEXT: lw a6, 16(sp)
-; CHECK-NEXT: lw a7, 12(sp)
-; CHECK-NEXT: lw t1, 8(sp)
-; CHECK-NEXT: lw t2, 4(sp)
-; CHECK-NEXT: lw a1, 0(sp)
-; CHECK-NEXT: sw a0, 44(sp)
-; CHECK-NEXT: sw a0, 40(sp)
+; CHECK-NEXT: mv s1, sp
+; CHECK-NEXT: lw t0, 44(s1)
+; CHECK-NEXT: lw a2, 40(s1)
+; CHECK-NEXT: lw a3, 36(s1)
+; CHECK-NEXT: lw a4, 32(s1)
+; CHECK-NEXT: lw a5, 28(s1)
+; CHECK-NEXT: lw a6, 24(s1)
+; CHECK-NEXT: lw a7, 20(s1)
+; CHECK-NEXT: lw t1, 16(s1)
+; CHECK-NEXT: lw t2, 12(s1)
+; CHECK-NEXT: lw a1, 8(s1)
+; CHECK-NEXT: sw a0, 52(s1)
+; CHECK-NEXT: sw a0, 48(s1)
; CHECK-NEXT: addi sp, sp, -32
; CHECK-NEXT: sd a1, 16(sp)
; CHECK-NEXT: sd t2, 8(sp)
-; CHECK-NEXT: addi a1, sp, 40
-; This is the incorrect calculation. It's after the addi sp, sp, -32. The 40
-; doesn't consider the -32 adjustment that was made.
+; CHECK-NEXT: addi a1, s1, 48
; CHECK-NEXT: sd t1, 0(sp)
; CHECK-NEXT: mv a0, t0
; CHECK-NEXT: call gfunc@plt
; CHECK-NEXT: addi sp, sp, 32
; CHECK-NEXT: li a0, 0
-; CHECK-NEXT: addi sp, s0, -64
-; CHECK-NEXT: ld ra, 56(sp) # 8-byte Folded Reload
-; CHECK-NEXT: ld s0, 48(sp) # 8-byte Folded Reload
-; CHECK-NEXT: addi sp, sp, 64
+; CHECK-NEXT: addi sp, s0, -80
+; CHECK-NEXT: ld ra, 72(sp) # 8-byte Folded Reload
+; CHECK-NEXT: ld s0, 64(sp) # 8-byte Folded Reload
+; CHECK-NEXT: ld s1, 56(sp) # 8-byte Folded Reload
+; CHECK-NEXT: addi sp, sp, 80
; CHECK-NEXT: ret
entry:
%aa.addr = alloca i32, align 4
