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author | Geoff Berry <gberry@codeaurora.org> | 2018-05-24 20:49:30 +0000 |
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committer | Geoff Berry <gberry@codeaurora.org> | 2018-05-24 20:49:30 +0000 |
commit | e8deffb827921bde4e149a386cbcfc654ddd3213 (patch) | |
tree | 1810a4d510ea6a0e3e1713fc0cce30a5a6b3d26d | |
parent | ffa16d6080670616d94eca9eecced73458c45ff2 (diff) | |
download | llvm-e8deffb827921bde4e149a386cbcfc654ddd3213.zip llvm-e8deffb827921bde4e149a386cbcfc654ddd3213.tar.gz llvm-e8deffb827921bde4e149a386cbcfc654ddd3213.tar.bz2 |
Merging r330976:
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r330976 | gberry | 2018-04-26 14:50:45 -0400 (Thu, 26 Apr 2018) | 15 lines
[AArch64] Fix scavenged spill slot base when stack realignment required.
Summary:
Use the FP for scavenged spill slot accesses to prevent corruption of
the callee-save region when the SP is re-aligned.
Based on problem and patch reported by @paulwalker-arm
This is an alternative to solution proposed in D45770
Reviewers: t.p.northover, paulwalker-arm, thegameg, javed.absar
Subscribers: qcolombet, mcrosier, paulwalker-arm, kristof.beyls, rengolin, javed.absar, llvm-commits
Differential Revision: https://reviews.llvm.org/D46063
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llvm-svn: 333223
-rw-r--r-- | llvm/lib/Target/AArch64/AArch64FrameLowering.cpp | 12 | ||||
-rw-r--r-- | llvm/test/CodeGen/AArch64/spill-stack-realignment.mir | 35 |
2 files changed, 45 insertions, 2 deletions
diff --git a/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp b/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp index d66f7b5..789200b 100644 --- a/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp +++ b/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp @@ -917,6 +917,8 @@ int AArch64FrameLowering::resolveFrameIndexReference(const MachineFunction &MF, int FPOffset = MFI.getObjectOffset(FI) + FixedObject + 16; int Offset = MFI.getObjectOffset(FI) + MFI.getStackSize(); bool isFixed = MFI.isFixedObjectIndex(FI); + bool isCSR = !isFixed && MFI.getObjectOffset(FI) >= + -((int)AFI->getCalleeSavedStackSize()); // Use frame pointer to reference fixed objects. Use it for locals if // there are VLAs or a dynamically realigned SP (and thus the SP isn't @@ -930,6 +932,12 @@ int AArch64FrameLowering::resolveFrameIndexReference(const MachineFunction &MF, // Argument access should always use the FP. if (isFixed) { UseFP = hasFP(MF); + } else if (isCSR && RegInfo->needsStackRealignment(MF)) { + // References to the CSR area must use FP if we're re-aligning the stack + // since the dynamically-sized alignment padding is between the SP/BP and + // the CSR area. + assert(hasFP(MF) && "Re-aligned stack must have frame pointer"); + UseFP = true; } else if (hasFP(MF) && !RegInfo->hasBasePointer(MF) && !RegInfo->needsStackRealignment(MF)) { // Use SP or FP, whichever gives us the best chance of the offset @@ -947,9 +955,9 @@ int AArch64FrameLowering::resolveFrameIndexReference(const MachineFunction &MF, } } - assert((isFixed || !RegInfo->needsStackRealignment(MF) || !UseFP) && + assert(((isFixed || isCSR) || !RegInfo->needsStackRealignment(MF) || !UseFP) && "In the presence of dynamic stack pointer realignment, " - "non-argument objects cannot be accessed through the frame pointer"); + "non-argument/CSR objects cannot be accessed through the frame pointer"); if (UseFP) { FrameReg = RegInfo->getFrameRegister(MF); diff --git a/llvm/test/CodeGen/AArch64/spill-stack-realignment.mir b/llvm/test/CodeGen/AArch64/spill-stack-realignment.mir new file mode 100644 index 0000000..fe85f4b --- /dev/null +++ b/llvm/test/CodeGen/AArch64/spill-stack-realignment.mir @@ -0,0 +1,35 @@ +# RUN: llc -mtriple=aarch64-none-linux-gnu -run-pass=prologepilog %s -o - | FileCheck %s + +# Ensure references to scavenged stack slots in the CSR area use the +# FP as a base when the stack pointer must be aligned to something +# larger than required by the target. This is necessary because the +# alignment padding area is between the CSR area and the SP, so the SP +# cannot be used to reference the CSR area. +name: test +tracksRegLiveness: true +frameInfo: + maxAlignment: 64 +# CHECK: stack: +# CHECK: id: 0, name: '', type: default, offset: -64, size: 4, alignment: 64 +# CHECK-NEXT: stack-id: 0 +# CHECK-NEXT: local-offset: -64 +# CHECK: id: 1, name: '', type: default, offset: -20, size: 4, alignment: 4 +# CHECK-NEXT: stack-id: 0 +# CHECK-NEXT: local-offset: -68 +stack: + - { id: 0, size: 4, alignment: 64, local-offset: -64 } + - { id: 1, size: 4, alignment: 4, local-offset: -68 } + +# CHECK: body: +# CHECK: %sp = ANDXri killed %{{x[0-9]+}}, 7865 +# CHECK: STRSui %s0, %sp, 0 +# CHECK: STURSi %s0, %fp, -4 +body: | + bb.0.entry: + liveins: %s0 + + STRSui %s0, %stack.0, 0 + STRSui %s0, %stack.1, 0 + ; Force preserve a CSR to create a hole in the CSR stack region. + %x28 = IMPLICIT_DEF + RET_ReallyLR |