diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index 9281b4eb92b05c..db9c857f0fd9d0 100644 --- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -14275,7 +14275,9 @@ SDValue DAGCombiner::visitFADDForFMACombine(SDNode *N) { SDValue D = FMul.getOperand(1); SDValue CDE = DAG.getNode(PreferredFusedOpcode, SL, VT, C, D, E); DAG.ReplaceAllUsesOfValueWith(FMul, CDE); - return FMA; + // Replacing the inner FMul could cause the outer FMA to be simplified + // away. + return FMA.getOpcode() == ISD::DELETED_NODE ? SDValue() : FMA; } TmpFMA = TmpFMA->getOperand(2); diff --git a/llvm/test/CodeGen/AMDGPU/dagcombine-fma-crash.ll b/llvm/test/CodeGen/AMDGPU/dagcombine-fma-crash.ll new file mode 100644 index 00000000000000..cf80833981436d --- /dev/null +++ b/llvm/test/CodeGen/AMDGPU/dagcombine-fma-crash.ll @@ -0,0 +1,80 @@ +; NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py +; RUN: llc -march=amdgcn -mcpu=gfx1030 -start-before=amdgpu-isel -stop-after=amdgpu-isel < %s | FileCheck %s + +define void @main(float %arg) { + ; CHECK-LABEL: name: main + ; CHECK: bb.0.bb: + ; CHECK-NEXT: successors: %bb.1(0x50000000), %bb.2(0x30000000) + ; CHECK-NEXT: liveins: $vgpr0 + ; CHECK-NEXT: {{ $}} + ; CHECK-NEXT: [[COPY:%[0-9]+]]:vgpr_32 = COPY $vgpr0 + ; CHECK-NEXT: [[S_MOV_B32_:%[0-9]+]]:sgpr_32 = S_MOV_B32 0 + ; CHECK-NEXT: [[S_MOV_B32_1:%[0-9]+]]:sreg_32 = S_MOV_B32 -1 + ; CHECK-NEXT: [[DEF:%[0-9]+]]:sgpr_32 = IMPLICIT_DEF + ; CHECK-NEXT: [[S_AND_B32_:%[0-9]+]]:sreg_32 = S_AND_B32 $exec_lo, [[S_MOV_B32_1]], implicit-def dead $scc + ; CHECK-NEXT: $vcc_lo = COPY [[S_AND_B32_]] + ; CHECK-NEXT: S_CBRANCH_VCCNZ %bb.2, implicit $vcc + ; CHECK-NEXT: S_BRANCH %bb.1 + ; CHECK-NEXT: {{ $}} + ; CHECK-NEXT: bb.1.bb2: + ; CHECK-NEXT: successors: %bb.2(0x80000000) + ; CHECK-NEXT: {{ $}} + ; CHECK-NEXT: [[V_MOV_B32_e32_:%[0-9]+]]:vgpr_32 = V_MOV_B32_e32 1065353216, implicit $exec + ; CHECK-NEXT: %20:vgpr_32 = contract reassoc nofpexcept V_FMAC_F32_e64 0, [[S_MOV_B32_]], 0, [[S_MOV_B32_]], 0, [[V_MOV_B32_e32_]], 0, 0, implicit $mode, implicit $exec + ; CHECK-NEXT: %1:vgpr_32 = contract reassoc nofpexcept V_FMAC_F32_e64 0, [[COPY]], 0, [[COPY]], 0, %20, 0, 0, implicit $mode, implicit $exec + ; CHECK-NEXT: %2:vgpr_32 = contract reassoc nofpexcept V_ADD_F32_e64 0, %1, 0, [[V_MOV_B32_e32_]], 0, 0, implicit $mode, implicit $exec + ; CHECK-NEXT: [[S_MOV_B32_2:%[0-9]+]]:sreg_32 = S_MOV_B32 0 + ; CHECK-NEXT: {{ $}} + ; CHECK-NEXT: bb.2.bb11: + ; CHECK-NEXT: successors: %bb.3(0x40000000), %bb.4(0x40000000) + ; CHECK-NEXT: {{ $}} + ; CHECK-NEXT: [[PHI:%[0-9]+]]:vgpr_32 = PHI [[DEF]], %bb.0, %1, %bb.1 + ; CHECK-NEXT: [[PHI1:%[0-9]+]]:vgpr_32 = PHI [[DEF]], %bb.0, %2, %bb.1 + ; CHECK-NEXT: [[PHI2:%[0-9]+]]:sreg_32_xm0_xexec = PHI [[S_MOV_B32_1]], %bb.0, [[S_MOV_B32_2]], %bb.1 + ; CHECK-NEXT: [[V_CNDMASK_B32_e64_:%[0-9]+]]:vgpr_32 = V_CNDMASK_B32_e64 0, 0, 0, 1, [[PHI2]], implicit $exec + ; CHECK-NEXT: [[S_MOV_B32_3:%[0-9]+]]:sreg_32 = S_MOV_B32 1 + ; CHECK-NEXT: [[COPY1:%[0-9]+]]:sreg_32 = COPY [[V_CNDMASK_B32_e64_]] + ; CHECK-NEXT: S_CMP_LG_U32 killed [[COPY1]], killed [[S_MOV_B32_3]], implicit-def $scc + ; CHECK-NEXT: [[COPY2:%[0-9]+]]:sreg_32 = COPY $scc + ; CHECK-NEXT: [[S_AND_B32_1:%[0-9]+]]:sreg_32 = S_AND_B32 $exec_lo, killed [[COPY2]], implicit-def dead $scc + ; CHECK-NEXT: $vcc_lo = COPY [[S_AND_B32_1]] + ; CHECK-NEXT: S_CBRANCH_VCCNZ %bb.4, implicit $vcc + ; CHECK-NEXT: S_BRANCH %bb.3 + ; CHECK-NEXT: {{ $}} + ; CHECK-NEXT: bb.3.bb15: + ; CHECK-NEXT: successors: %bb.4(0x80000000) + ; CHECK-NEXT: {{ $}} + ; CHECK-NEXT: {{ $}} + ; CHECK-NEXT: bb.4.bb17: + ; CHECK-NEXT: SI_RETURN +bb: + %i = fadd reassoc contract float 0.000000e+00, 0.000000e+00 + %i1 = icmp ne i32 0, 0 + br i1 %i1, label %bb2, label %bb11 + +bb2: + %i3 = fmul reassoc contract float %i, %i + %i4 = fmul reassoc contract float %arg, %arg + %i5 = fadd reassoc contract float %i3, 1.000000e+00 + %i6 = fadd reassoc contract float %i5, %i4 + %i7 = fmul reassoc contract float %arg, %arg + %i8 = fmul reassoc contract float %i, %i + %i9 = fadd reassoc contract float %i7, %i8 + %i10 = fadd reassoc contract float %i9, 1.000000e+00 + br label %bb11 + +bb11: + %i12 = phi float [ %i6, %bb2 ], [ undef, %bb ] + %i13 = phi float [ %i10, %bb2 ], [ undef, %bb ] + %i14 = phi i1 [ false, %bb2 ], [ true, %bb ] + br i1 %i14, label %bb15, label %bb17 + +bb15: + %i16 = fmul reassoc contract float %i, 0.000000e+00 + br label %bb17 + +bb17: + %i18 = phi float [ %i13, %bb11 ], [ 0.000000e+00, %bb15 ] + %i19 = phi float [ %i12, %bb11 ], [ 0.000000e+00, %bb15 ] + ret void +}