diff --git a/llvm/lib/CodeGen/GlobalISel/Utils.cpp b/llvm/lib/CodeGen/GlobalISel/Utils.cpp --- a/llvm/lib/CodeGen/GlobalISel/Utils.cpp +++ b/llvm/lib/CodeGen/GlobalISel/Utils.cpp @@ -1051,6 +1051,25 @@ llvm::shouldOptimizeForSize(MBB.getBasicBlock(), PSI, BFI); } +/// These artifacts generally don't have any debug users because they don't +/// directly originate from IR instructions, but instead usually from +/// legalization. Avoiding checking for debug users improves compile time. +/// Note that truncates or extends aren't included because they have IR +/// counterparts which can have debug users after translation. +static bool shouldSkipDbgValueFor(MachineInstr &MI) { + switch (MI.getOpcode()) { + case TargetOpcode::G_UNMERGE_VALUES: + case TargetOpcode::G_MERGE_VALUES: + case TargetOpcode::G_CONCAT_VECTORS: + case TargetOpcode::G_BUILD_VECTOR: + case TargetOpcode::G_EXTRACT: + case TargetOpcode::G_INSERT: + return true; + default: + return false; + } +} + void llvm::saveUsesAndErase(MachineInstr &MI, MachineRegisterInfo &MRI, LostDebugLocObserver *LocObserver, SmallInstListTy &DeadInstChain) { @@ -1060,7 +1079,10 @@ } LLVM_DEBUG(dbgs() << MI << "Is dead; erasing.\n"); DeadInstChain.remove(&MI); - MI.eraseFromParentAndMarkDBGValuesForRemoval(); + if (shouldSkipDbgValueFor(MI)) + MI.eraseFromParent(); + else + MI.eraseFromParentAndMarkDBGValuesForRemoval(); if (LocObserver) LocObserver->checkpoint(false); } diff --git a/llvm/test/CodeGen/AMDGPU/GlobalISel/bug-legalization-artifact-combiner-dead-def.mir b/llvm/test/CodeGen/AMDGPU/GlobalISel/bug-legalization-artifact-combiner-dead-def.mir --- a/llvm/test/CodeGen/AMDGPU/GlobalISel/bug-legalization-artifact-combiner-dead-def.mir +++ b/llvm/test/CodeGen/AMDGPU/GlobalISel/bug-legalization-artifact-combiner-dead-def.mir @@ -5,7 +5,6 @@ define void @value_finder_bug() { ret void } define void @value_finder_bug_before_artifact_combine() { ret void } - define void @value_finder_bug_before_artifact_combine_dbg_use() { ret void } !0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "llvm", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2) !1 = !DIFile(filename: "bug-legalization-artifact-combiner-dead-def", directory: "/tmp") @@ -86,40 +85,3 @@ G_STORE %11(s32), %13(p5) :: (store (s32) into unknown-address + 4, addrspace 5) ... - ---- -name: value_finder_bug_before_artifact_combine_dbg_use -body: | - bb.0: - liveins: $vgpr0, $vgpr1, $vgpr2 - - ; GFX10-LABEL: name: value_finder_bug_before_artifact_combine_dbg_use - ; GFX10: [[COPY:%[0-9]+]]:_(p5) = COPY $vgpr0 - ; GFX10: [[COPY1:%[0-9]+]]:_(s32) = COPY $vgpr1 - ; GFX10: [[COPY2:%[0-9]+]]:_(s32) = COPY $vgpr2 - ; GFX10: [[MV:%[0-9]+]]:_(p4) = G_MERGE_VALUES [[COPY1]](s32), [[COPY2]](s32) - ; GFX10: [[LOAD:%[0-9]+]]:_(<4 x s32>) = G_LOAD [[MV]](p4) :: (load (<4 x s32>), align 4, addrspace 4) - ; GFX10: [[EXTRACT:%[0-9]+]]:_(s32) = G_EXTRACT [[LOAD]](<4 x s32>), 96 - ; GFX10: [[EXTRACT1:%[0-9]+]]:_(s32) = G_EXTRACT [[LOAD]](<4 x s32>), 64 - ; GFX10: DBG_VALUE $noreg, $noreg, {{.*}}, !DIExpression(), debug-location !DILocation(line: 1, column: 1 - ; GFX10: G_STORE [[EXTRACT1]](s32), [[COPY]](p5) :: (store (s32), align 8, addrspace 5) - ; GFX10: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 4 - ; GFX10: [[PTR_ADD:%[0-9]+]]:_(p5) = G_PTR_ADD [[COPY]], [[C]](s32) - ; GFX10: G_STORE [[EXTRACT]](s32), [[PTR_ADD]](p5) :: (store (s32) into unknown-address + 4, addrspace 5) - %0:_(p5) = COPY $vgpr0 - %1:_(s32) = COPY $vgpr1 - %2:_(s32) = COPY $vgpr2 - %3:_(p4) = G_MERGE_VALUES %1(s32), %2(s32) - %4:_(<4 x s32>) = G_LOAD %3(p4) :: (load (<4 x s32>), align 4, addrspace 4) - %5:_(s32) = G_EXTRACT %4(<4 x s32>), 96 - %6:_(s32) = G_EXTRACT %4(<4 x s32>), 64 - %7:_(s32) = G_IMPLICIT_DEF - %8:_(<2 x s32>) = G_BUILD_VECTOR %6(s32), %7(s32) - %9:_(<2 x s32>) = G_INSERT %8, %5(s32), 32 - %dbg_use:_(s32), %11:_(s32) = G_UNMERGE_VALUES %9(<2 x s32>) - DBG_VALUE %dbg_use(s32), $noreg, !7, !DIExpression(), debug-location !9 - G_STORE %6(s32), %0(p5) :: (store (s32), align 8, addrspace 5) - %12:_(s32) = G_CONSTANT i32 4 - %13:_(p5) = G_PTR_ADD %0, %12(s32) - G_STORE %11(s32), %13(p5) :: (store (s32) into unknown-address + 4, addrspace 5) -...