Author: gberry Date: Thu May 24 13:49:30 2018 New Revision: 333223 URL: http://llvm.org/viewvc/llvm-project?rev=333223&view=rev Log: Merging r330976: ------------------------------------------------------------------------ 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 ------------------------------------------------------------------------ Added: llvm/branches/release_60/test/CodeGen/AArch64/spill-stack-realignment.mir Modified: llvm/branches/release_60/lib/Target/AArch64/AArch64FrameLowering.cpp Modified: llvm/branches/release_60/lib/Target/AArch64/AArch64FrameLowering.cpp URL: http://llvm.org/viewvc/llvm-project/llvm/branches/release_60/lib/Target/AArch64/AArch64FrameLowering.cpp?rev=333223&r1=333222&r2=333223&view=diff ============================================================================== --- llvm/branches/release_60/lib/Target/AArch64/AArch64FrameLowering.cpp (original) +++ llvm/branches/release_60/lib/Target/AArch64/AArch64FrameLowering.cpp Thu May 24 13:49:30 2018 @@ -917,6 +917,8 @@ int AArch64FrameLowering::resolveFrameIn 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::resolveFrameIn // 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::resolveFrameIn } } - 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); Added: llvm/branches/release_60/test/CodeGen/AArch64/spill-stack-realignment.mir URL: http://llvm.org/viewvc/llvm-project/llvm/branches/release_60/test/CodeGen/AArch64/spill-stack-realignment.mir?rev=333223&view=auto ============================================================================== --- llvm/branches/release_60/test/CodeGen/AArch64/spill-stack-realignment.mir (added) +++ llvm/branches/release_60/test/CodeGen/AArch64/spill-stack-realignment.mir Thu May 24 13:49:30 2018 @@ -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 _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits