[PPC] Properly update register save area offsets

The variables MinGPR/MinG8R were not updated properly when resetting the
offsets, which in the included testcase lead to saving the CR register
in the same location as R30.

This fixes another issue reported in PR26519.

Differential Revision: https://reviews.llvm.org/D33017

llvm-svn: 303257
This commit is contained in:
Krzysztof Parzyszek 2017-05-17 13:25:09 +00:00
parent 63144359c5
commit 2b0533126e
4 changed files with 171 additions and 9 deletions

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@ -1765,31 +1765,36 @@ void PPCFrameLowering::processFunctionBeforeFrameFinalized(MachineFunction &MF,
// Check whether the frame pointer register is allocated. If so, make sure it
// is spilled to the correct offset.
if (needsFP(MF)) {
HasGPSaveArea = true;
int FI = PFI->getFramePointerSaveIndex();
assert(FI && "No Frame Pointer Save Slot!");
MFI.setObjectOffset(FI, LowerBound + MFI.getObjectOffset(FI));
// FP is R31/X31, so no need to update MinGPR/MinG8R.
HasGPSaveArea = true;
}
if (PFI->usesPICBase()) {
HasGPSaveArea = true;
int FI = PFI->getPICBasePointerSaveIndex();
assert(FI && "No PIC Base Pointer Save Slot!");
MFI.setObjectOffset(FI, LowerBound + MFI.getObjectOffset(FI));
MinGPR = std::min<unsigned>(MinGPR, PPC::R30);
HasGPSaveArea = true;
}
const PPCRegisterInfo *RegInfo = Subtarget.getRegisterInfo();
if (RegInfo->hasBasePointer(MF)) {
HasGPSaveArea = true;
int FI = PFI->getBasePointerSaveIndex();
assert(FI && "No Base Pointer Save Slot!");
MFI.setObjectOffset(FI, LowerBound + MFI.getObjectOffset(FI));
unsigned BP = RegInfo->getBaseRegister(MF);
if (PPC::G8RCRegClass.contains(BP)) {
MinG8R = std::min<unsigned>(MinG8R, BP);
HasG8SaveArea = true;
} else if (PPC::GPRCRegClass.contains(BP)) {
MinGPR = std::min<unsigned>(MinGPR, BP);
HasGPSaveArea = true;
}
}
// General register save area starts right below the Floating-point

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@ -0,0 +1,54 @@
; RUN: llc -march=ppc64 -ppc-always-use-base-pointer < %s | FileCheck %s --check-prefix CHECK --check-prefix PPC64
; RUN: llc -march=ppc32 -ppc-always-use-base-pointer < %s | FileCheck %s --check-prefix CHECK --check-prefix PPC32
; RUN: llc -march=ppc32 -ppc-always-use-base-pointer -relocation-model pic < %s | FileCheck %s --check-prefix CHECK --check-prefix PPC32PIC
; CHECK-LABEL: fred:
; Check for saving/restoring frame pointer (X31) and base pointer (X30)
; on ppc64:
; PPC64: std 31, -8(1)
; PPC64: std 30, -16(1)
; PPC64: ld 31, -8(1)
; PPC64: ld 30, -16(1)
; Check for saving/restoring frame pointer (R31) and base pointer (R30)
; on ppc32:
; PPC32: stwux 1, 1, 0
; PPC32; addic 0, 0, -4
; PPC32: stwx 31, 0, 0
; PPC32: addic 0, 0, -4
; PPC32: stwx 30, 0, 0
; The restore sequence:
; PPC32: lwz 31, 0(1)
; PPC32: addic 30, 0, 8
; PPC32: lwz 0, -4(31)
; PPC32: lwz 30, -8(31)
; PPC32: mr 1, 31
; PPC32: mr 31, 0
; Check for saving/restoring frame pointer (R31) and base pointer (R29)
; on ppc32/pic. This is mostly the same as without pic, except that base
; pointer is in R29.
; PPC32PIC: stwux 1, 1, 0
; PPC32PIC; addic 0, 0, -4
; PPC32PIC: stwx 31, 0, 0
; PPC32PIC: addic 0, 0, -8
; PPC32PIC: stwx 29, 0, 0
; The restore sequence:
; PPC32PIC: lwz 31, 0(1)
; PPC32PIC: addic 29, 0, 12
; PPC32PIC: lwz 0, -4(31)
; PPC32PIC: lwz 29, -12(31)
; PPC32PIC: mr 1, 31
; PPC32PIC: mr 31, 0
target datalayout = "E-m:e-p:32:32-i64:64-n32"
target triple = "powerpc-unknown-freebsd"
define i64 @fred() local_unnamed_addr #0 {
entry:
ret i64 0
}
attributes #0 = { norecurse readnone nounwind sspstrong "no-frame-pointer-elim"="true" "target-cpu"="ppc" }

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@ -0,0 +1,46 @@
; RUN: llc -march=ppc32 -relocation-model pic < %s | FileCheck %s
;
; Make sure that the CR register is saved correctly on PPC32/SVR4.
; CHECK-LABEL: fred:
; CHECK: stwu 1, -32(1)
; CHECK: stw 31, 28(1)
; CHECK: mr 31, 1
; CHECK: stw 30, 24(1)
; CHECK: mfcr [[CR:[0-9]+]]
; CHECK: stw [[CR]], 20(31)
target datalayout = "E-m:e-p:32:32-i64:64-n32"
target triple = "powerpc-unknown-freebsd"
; Function Attrs: norecurse nounwind readnone sspstrong
define i64 @fred(double %a0) local_unnamed_addr #0 {
b1:
%v2 = fcmp olt double %a0, 0x43E0000000000000
br i1 %v2, label %b3, label %b7
b3: ; preds = %b1
%v4 = fcmp olt double %a0, 0xC3E0000000000000
%v5 = fptosi double %a0 to i64
%v6 = select i1 %v4, i64 -9223372036854775808, i64 %v5
br label %b14
b7: ; preds = %b1
%v8 = fcmp olt double %a0, 0x43F0000000000000
br i1 %v8, label %b9, label %b11
b9: ; preds = %b7
%v10 = fptoui double %a0 to i64
br label %b14
b11: ; preds = %b7
%v12 = fcmp ogt double %a0, 0.000000e+00
%v13 = sext i1 %v12 to i64
br label %b14
b14: ; preds = %b11, %b9, %b3
%v15 = phi i64 [ %v6, %b3 ], [ %v10, %b9 ], [ %v13, %b11 ]
ret i64 %v15
}
attributes #0 = { norecurse nounwind readnone sspstrong "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "stack-protector-buffer-size"="8" "target-cpu"="ppc" }

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@ -0,0 +1,57 @@
; RUN: llc -march=ppc32 -relocation-model pic < %s | FileCheck %s
; CHECK-LABEL: fred
; CHECK: stwux 1, 1, 0
; Save R31..R29 via R0:
; CHECK: addic 0, 0, -4
; CHECK: stwx 31, 0, 0
; CHECK: addic 0, 0, -4
; CHECK: stwx 30, 0, 0
; CHECK: addic 0, 0, -4
; CHECK: stwx 29, 0, 0
; Set R29 back to the value of R0 from before the updates:
; CHECK: addic 29, 0, 12
; Save CR through R12 using R29 as the stack pointer (aligned base pointer).
; CHECK: mfcr 12
; CHECK: stw 28, -16(29)
; CHECK: stw 12, -20(29)
target datalayout = "E-m:e-p:32:32-i64:64-n32"
target triple = "powerpc-unknown-freebsd"
; Function Attrs: norecurse readnone sspstrong
define i64 @fred(double %a0) local_unnamed_addr #0 {
b1:
%v2 = alloca i64, align 128
store i64 0, i64* %v2
%v3 = fcmp olt double %a0, 0x43E0000000000000
br i1 %v3, label %b4, label %b8
b4: ; preds = %b1
%v5 = fcmp olt double %a0, 0xC3E0000000000000
%v6 = fptosi double %a0 to i64
store i64 %v6, i64* %v2
%v7 = select i1 %v5, i64 -9223372036854775808, i64 %v6
br label %b15
b8: ; preds = %b1
%v9 = fcmp olt double %a0, 0x43F0000000000000
br i1 %v9, label %b10, label %b12
b10: ; preds = %b8
%v11 = fptoui double %a0 to i64
br label %b15
b12: ; preds = %b8
%v13 = fcmp ogt double %a0, 0.000000e+00
%v14 = sext i1 %v13 to i64
br label %b15
b15: ; preds = %b12, %b10, %b4
%v16 = phi i64 [ %v7, %b4 ], [ %v11, %b10 ], [ %v14, %b12 ]
%v17 = load i64, i64* %v2
%v18 = add i64 %v17, %v16
ret i64 %v18
}
attributes #0 = { norecurse readnone sspstrong "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "stack-protector-buffer-size"="8" "target-cpu"="ppc" }