https://github.com/arsenm created https://github.com/llvm/llvm-project/pull/119682
This reverts commit f7443905af1e06eaacda1e437fff8d54dc89c487. This is to avoid an assertion if an undef operand appears in a stackmap. This is important to avoid hitting verifier errors when register allocation starts adding undefs in error scenarios. Rather than trying to treat undef operands as special, leave them alone and avoid producing an invalid spill. It would a bit more precise to produce a spill of an undef register here, but that's not exposed through the storeRegToStackSlot API. https://reviews.llvm.org/D122605 This was an alternative to https://reviews.llvm.org/D122582 >From 03cca4cf3b65cb6988db7a983f3c3349fa0b390a Mon Sep 17 00:00:00 2001 From: Matt Arsenault <matthew.arsena...@amd.com> Date: Mon, 28 Mar 2022 14:11:28 -0400 Subject: [PATCH] [Statepoint] Treat undef operands less specially This reverts commit f7443905af1e06eaacda1e437fff8d54dc89c487. This is to avoid an assertion if an undef operand appears in a stackmap. This is important to avoid hitting verifier errors when register allocation starts adding undefs in error scenarios. Rather than trying to treat undef operands as special, leave them alone and avoid producing an invalid spill. It would a bit more precise to produce a spill of an undef register here, but that's not exposed through the storeRegToStackSlot API. https://reviews.llvm.org/D122605 This was an alternative to https://reviews.llvm.org/D122582 --- .../CodeGen/FixupStatepointCallerSaved.cpp | 2 - llvm/lib/CodeGen/StackMaps.cpp | 6 -- .../X86/stackmap-undef-operand-anyregcc.mir | 61 +++++++++++++++++++ .../CodeGen/X86/statepoint-fixup-undef.mir | 8 +-- 4 files changed, 65 insertions(+), 12 deletions(-) create mode 100644 llvm/test/CodeGen/X86/stackmap-undef-operand-anyregcc.mir diff --git a/llvm/lib/CodeGen/FixupStatepointCallerSaved.cpp b/llvm/lib/CodeGen/FixupStatepointCallerSaved.cpp index 3bb9da5f1a37bb..0ebe845e473fd6 100644 --- a/llvm/lib/CodeGen/FixupStatepointCallerSaved.cpp +++ b/llvm/lib/CodeGen/FixupStatepointCallerSaved.cpp @@ -381,8 +381,6 @@ class StatepointState { EndIdx = MI.getNumOperands(); Idx < EndIdx; ++Idx) { MachineOperand &MO = MI.getOperand(Idx); - // Leave `undef` operands as is, StackMaps will rewrite them - // into a constant. if (!MO.isReg() || MO.isImplicit() || MO.isUndef()) continue; Register Reg = MO.getReg(); diff --git a/llvm/lib/CodeGen/StackMaps.cpp b/llvm/lib/CodeGen/StackMaps.cpp index 81b288df3b07e0..7480963c1f5217 100644 --- a/llvm/lib/CodeGen/StackMaps.cpp +++ b/llvm/lib/CodeGen/StackMaps.cpp @@ -268,12 +268,6 @@ StackMaps::parseOperand(MachineInstr::const_mop_iterator MOI, if (MOI->isImplicit()) return ++MOI; - if (MOI->isUndef()) { - // Record `undef` register as constant. Use same value as ISel uses. - Locs.emplace_back(Location::Constant, sizeof(int64_t), 0, 0xFEFEFEFE); - return ++MOI; - } - assert(MOI->getReg().isPhysical() && "Virtreg operands should have been rewritten before now."); const TargetRegisterClass *RC = TRI->getMinimalPhysRegClass(MOI->getReg()); diff --git a/llvm/test/CodeGen/X86/stackmap-undef-operand-anyregcc.mir b/llvm/test/CodeGen/X86/stackmap-undef-operand-anyregcc.mir new file mode 100644 index 00000000000000..6a322eb105e6f7 --- /dev/null +++ b/llvm/test/CodeGen/X86/stackmap-undef-operand-anyregcc.mir @@ -0,0 +1,61 @@ +# RUN: llc -mtriple=x86_64-apple-darwin -start-after=virtregrewriter -o - %s | FileCheck %s + +# Check there's no assertion for anyregcc with an undef operand to a stackmap. + +# CHECK: __LLVM_StackMaps: +# CHECK-NEXT: .byte 3 +# CHECK-NEXT: .byte 0 +# CHECK-NEXT: .short 0 +# CHECK-NEXT: .long 1 +# CHECK-NEXT: .long 0 +# CHECK-NEXT: .long 1 +# CHECK-NEXT: .quad _undef_anyregcc_patchpoint +# CHECK-NEXT: .quad 8 +# CHECK-NEXT: .quad 1 +# CHECK-NEXT: .quad 12 +# CHECK-NEXT: .long Ltmp0-_undef_anyregcc_patchpoint +# CHECK-NEXT: .short 0 +# CHECK-NEXT: .short 2 +# CHECK-NEXT: .byte 1 +# CHECK-NEXT: .byte 0 +# CHECK-NEXT: .short 8 +# CHECK-NEXT: .short 0 +# CHECK-NEXT: .short 0 +# CHECK-NEXT: .long 0 +# CHECK-NEXT: .byte 1 +# CHECK-NEXT: .byte 0 +# CHECK-NEXT: .short 8 +# CHECK-NEXT: .short 0 +# CHECK-NEXT: .short 0 +# CHECK-NEXT: .long 0 +# CHECK-NEXT: .p2align 3 +# CHECK-NEXT: .short 0 +# CHECK-NEXT: .short 2 +# CHECK-NEXT: .short 0 +# CHECK-NEXT: .byte 0 +# CHECK-NEXT: .byte 8 +# CHECK-NEXT: .short 7 +# CHECK-NEXT: .byte 0 +# CHECK-NEXT: .byte 8 +# CHECK-NEXT: .p2align 3 +--- +name: undef_anyregcc_patchpoint +tracksRegLiveness: true +frameInfo: + hasPatchPoint: true + hasCalls: true +fixedStack: + - { id: 0, type: default, offset: 72, size: 8, alignment: 8, stack-id: default, + isImmutable: true, isAliased: false, callee-saved-register: '', callee-saved-restored: true, + debug-info-variable: '', debug-info-expression: '', debug-info-location: '' } +body: | + bb.0: + liveins: $rcx, $rdi, $rdx, $rsi, $r8, $r9 + + ADJCALLSTACKDOWN64 0, 0, 0, implicit-def dead $rsp, implicit-def dead $eflags, implicit-def dead $ssp, implicit $rsp, implicit $ssp + dead renamable $rax = MOV64rm %fixed-stack.0, 1, $noreg, 0, $noreg :: (load (s64) from %fixed-stack.0) + renamable $rax = PATCHPOINT 12, 15, 0, 1, 13, undef renamable $rax, csr_64_allregs, implicit-def dead early-clobber $r11, implicit-def $rsp, implicit-def $ssp + ADJCALLSTACKUP64 0, 0, implicit-def dead $rsp, implicit-def dead $eflags, implicit-def dead $ssp, implicit $rsp, implicit $ssp + RET 0, $rax + +... diff --git a/llvm/test/CodeGen/X86/statepoint-fixup-undef.mir b/llvm/test/CodeGen/X86/statepoint-fixup-undef.mir index 4a18351bde493d..edb0d517d5d52f 100644 --- a/llvm/test/CodeGen/X86/statepoint-fixup-undef.mir +++ b/llvm/test/CodeGen/X86/statepoint-fixup-undef.mir @@ -181,13 +181,13 @@ body: | ; STACKMAP-NEXT: .short 3 ; STACKMAP-NEXT: .short 0 ; STACKMAP-NEXT: .long 0 - ; This is a constant 0xFEFEFEFE we are looking for - ; STACKMAP-NEXT: .byte 4 + ; This is entry we're looking for + ; STACKMAP-NEXT: .byte 1 ; STACKMAP-NEXT: .byte 0 - ; STACKMAP-NEXT: .short 8 + ; STACKMAP-NEXT: .short 4 ; STACKMAP-NEXT: .short 0 ; STACKMAP-NEXT: .short 0 - ; STACKMAP-NEXT: .long -16843010 + ; STACKMAP-NEXT: .long 0 ; STACKMAP-NEXT: .byte 4 ; STACKMAP-NEXT: .byte 0 ; STACKMAP-NEXT: .short 8 _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
