From 5f47d4456d192eaea8c56a2b4648023c8743c927 Mon Sep 17 00:00:00 2001 From: Sander de Smalen Date: Wed, 19 Aug 2020 11:06:51 +0100 Subject: [PATCH] [AArch64][SVE] Fix calculation restore point for SVE callee saves. This fixes an issue where the restore point of callee-saves in the function epilogues was incorrectly calculated when the basic block consisted of only a RET instruction. This caused dealloc instructions to be inserted in between the block of callee-save restore instructions, rather than before it. Reviewed By: paulwalker-arm Differential Revision: https://reviews.llvm.org/D86099 --- llvm/lib/Target/AArch64/AArch64FrameLowering.cpp | 7 ++--- .../AArch64/framelayout-sve-calleesaves-fix.mir | 36 ++++++++++++++++++++++ 2 files changed, 39 insertions(+), 4 deletions(-) create mode 100644 llvm/test/CodeGen/AArch64/framelayout-sve-calleesaves-fix.mir diff --git a/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp b/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp index 83653dc..c6cc6e9 100644 --- a/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp +++ b/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp @@ -1694,11 +1694,10 @@ void AArch64FrameLowering::emitEpilogue(MachineFunction &MF, StackOffset DeallocateBefore = {}, DeallocateAfter = SVEStackSize; MachineBasicBlock::iterator RestoreBegin = LastPopI, RestoreEnd = LastPopI; if (int64_t CalleeSavedSize = AFI->getSVECalleeSavedStackSize()) { - RestoreBegin = std::prev(RestoreEnd);; - while (IsSVECalleeSave(RestoreBegin) && - RestoreBegin != MBB.begin()) + RestoreBegin = std::prev(RestoreEnd); + while (RestoreBegin != MBB.begin() && + IsSVECalleeSave(std::prev(RestoreBegin))) --RestoreBegin; - ++RestoreBegin; assert(IsSVECalleeSave(RestoreBegin) && IsSVECalleeSave(std::prev(RestoreEnd)) && "Unexpected instruction"); diff --git a/llvm/test/CodeGen/AArch64/framelayout-sve-calleesaves-fix.mir b/llvm/test/CodeGen/AArch64/framelayout-sve-calleesaves-fix.mir new file mode 100644 index 0000000..a3cbd39 --- /dev/null +++ b/llvm/test/CodeGen/AArch64/framelayout-sve-calleesaves-fix.mir @@ -0,0 +1,36 @@ +# NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py +# RUN: llc -mattr=+sve -mtriple=aarch64-none-linux-gnu -start-before=prologepilog %s -o - | FileCheck %s + +--- | + define aarch64_sve_vector_pcs void @fix_restorepoint_p4() { entry: unreachable } + ; CHECK-LABEL: fix_restorepoint_p4: + ; CHECK: // %bb.0: // %entry + ; CHECK-NEXT: str x29, [sp, #-16]! // 8-byte Folded Spill + ; CHECK-NEXT: addvl sp, sp, #-2 + ; CHECK-NEXT: str p4, [sp, #7, mul vl] // 2-byte Folded Spill + ; CHECK-NEXT: str z8, [sp, #1, mul vl] // 16-byte Folded Spill + ; CHECK-NEXT: addvl sp, sp, #-1 + ; CHECK-NEXT: .cfi_escape 0x0f, 0x0c, 0x8f, 0x00, 0x11, 0x10, 0x22, 0x11, 0x18, 0x92, 0x2e, 0x00, 0x1e, 0x22 // sp + 16 + 24 * VG + ; CHECK-NEXT: .cfi_escape 0x10, 0x48, 0x0a, 0x11, 0x70, 0x22, 0x11, 0x78, 0x92, 0x2e, 0x00, 0x1e, 0x22 // $d8 @ cfa - 16 - 8 * VG + ; CHECK-NEXT: .cfi_offset w29, -16 + ; CHECK-NEXT: // implicit-def: $z8 + ; CHECK-NEXT: // implicit-def: $p4 + ; CHECK-NEXT: addvl sp, sp, #1 + ; CHECK-NEXT: ldr p4, [sp, #7, mul vl] // 2-byte Folded Reload + ; CHECK-NEXT: ldr z8, [sp, #1, mul vl] // 16-byte Folded Reload + ; CHECK-NEXT: addvl sp, sp, #2 + ; CHECK-NEXT: ldr x29, [sp], #16 // 8-byte Folded Reload + ; CHECK-NEXT: ret +... +name: fix_restorepoint_p4 +stack: + - { id: 0, stack-id: sve-vec, size: 16, alignment: 16 } +body: | + bb.0.entry: + $z8 = IMPLICIT_DEF + $p4 = IMPLICIT_DEF + B %bb.1 + + bb.1.entry: + RET_ReallyLR +--- -- 2.7.4