diff --git a/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp --- a/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp +++ b/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp @@ -1142,7 +1142,8 @@ if (MI.getParent() == UseMI.getParent() && ((IsDiv && UseMI.getOpcode() == RemOpcode) || (!IsDiv && UseMI.getOpcode() == DivOpcode)) && - matchEqualDefs(MI.getOperand(2), UseMI.getOperand(2))) { + matchEqualDefs(MI.getOperand(2), UseMI.getOperand(2)) && + matchEqualDefs(MI.getOperand(1), UseMI.getOperand(1))) { OtherMI = &UseMI; return true; } diff --git a/llvm/test/CodeGen/AArch64/GlobalISel/combine-udivrem-use-bug.mir b/llvm/test/CodeGen/AArch64/GlobalISel/combine-udivrem-use-bug.mir new file mode 100644 --- /dev/null +++ b/llvm/test/CodeGen/AArch64/GlobalISel/combine-udivrem-use-bug.mir @@ -0,0 +1,25 @@ +# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py +# RUN: llc -o - -mtriple=aarch64-unknown-unknown -run-pass=aarch64-prelegalizer-combiner -verify-machineinstrs %s | FileCheck %s +# Check that we don't miscompile this into G_UDIVREM because of the different +# first operands. +--- +name: no_combine_divrem_different_src1 +body: | + bb.1: + liveins: $w0 + + ; CHECK-LABEL: name: no_combine_divrem_different_src1 + ; CHECK: liveins: $w0 + ; CHECK-NEXT: {{ $}} + ; CHECK-NEXT: [[COPY:%[0-9]+]]:_(s32) = COPY $w0 + ; CHECK-NEXT: [[UREM:%[0-9]+]]:_(s32) = G_UREM [[COPY]], [[COPY]] + ; CHECK-NEXT: [[UDIV:%[0-9]+]]:_(s32) = G_UDIV [[UREM]], [[COPY]] + ; CHECK-NEXT: $w0 = COPY [[UDIV]](s32) + ; CHECK-NEXT: RET_ReallyLR implicit $w0 + %0:_(s32) = COPY $w0 + %1:_(s32) = G_UREM %0, %0 + %2:_(s32) = G_UDIV %1, %0 + $w0 = COPY %2(s32) + RET_ReallyLR implicit $w0 + +...