diff options
| -rw-r--r-- | llvm/lib/CodeGen/CodeGenPrepare.cpp | 8 | ||||
| -rw-r--r-- | llvm/test/CodeGen/X86/codegen-prepare-replacephi.mir | 45 |
2 files changed, 51 insertions, 2 deletions
diff --git a/llvm/lib/CodeGen/CodeGenPrepare.cpp b/llvm/lib/CodeGen/CodeGenPrepare.cpp index e8498eb375e..44f1709b6e9 100644 --- a/llvm/lib/CodeGen/CodeGenPrepare.cpp +++ b/llvm/lib/CodeGen/CodeGenPrepare.cpp @@ -3282,6 +3282,8 @@ private: PhiNodeSet &PhiNodesToMatch) { SmallVector<PHIPair, 8> WorkList; Matcher.insert({ PHI, Candidate }); + SmallSet<PHINode *, 8> MatchedPHIs; + MatchedPHIs.insert(PHI); WorkList.push_back({ PHI, Candidate }); SmallSet<PHIPair, 8> Visited; while (!WorkList.empty()) { @@ -3314,8 +3316,10 @@ private: if (Matcher.count({ FirstPhi, SecondPhi })) continue; // So the values are different and does not match. So we need them to - // match. - Matcher.insert({ FirstPhi, SecondPhi }); + // match. (But we register no more than one match per PHI node, so that + // we won't later try to replace them twice.) + if (!MatchedPHIs.insert(FirstPhi).second) + Matcher.insert({ FirstPhi, SecondPhi }); // But me must check it. WorkList.push_back({ FirstPhi, SecondPhi }); } diff --git a/llvm/test/CodeGen/X86/codegen-prepare-replacephi.mir b/llvm/test/CodeGen/X86/codegen-prepare-replacephi.mir new file mode 100644 index 00000000000..476f0473098 --- /dev/null +++ b/llvm/test/CodeGen/X86/codegen-prepare-replacephi.mir @@ -0,0 +1,45 @@ +# RUN: llc -run-pass=codegenprepare -o - %s | FileCheck %s + +# This testcase without the accompanying fix triggers the assert +# "Replacement PHI node is already replaced." + +--- | + define void @f1() { + entry: + %arrayidx = getelementptr inbounds [2 x i16], [2 x i16]* undef, i16 0, i16 2 + %0 = bitcast i16* %arrayidx to i32* + %1 = bitcast [2 x i16]* undef to i32* + br label %for.cond + + for.cond: + %2 = phi i32* [ %0, %entry ], [ %7, %cleanup ] + %3 = phi i32* [ %0, %entry ], [ %9, %cleanup ] + br label %for.body + + for.body: + %4 = phi i32* [ %3, %for.cond ], [ %9, %cleanup ] + %5 = phi i32* [ %2, %for.cond ], [ %9, %cleanup ] + %6 = phi i32* [ %2, %for.cond ], [ %9, %cleanup ] + br i1 false, label %for.cond2, label %if.then + + if.then: + store i32 undef, i32* %4, align 1 + unreachable + + for.cond2: + %7 = phi i32* [ %6, %for.body ], [ %7, %if.then5 ], [ %1, %for.cond2 ] + %8 = phi i32* [ %5, %for.body ], [ %8, %if.then5 ], [ %1, %for.cond2 ] + %9 = phi i32* [ %4, %for.body ], [ %8, %if.then5 ], [ %1, %for.cond2 ] + br i1 undef, label %for.cond2, label %if.then5 + + if.then5: + br i1 undef, label %cleanup, label %for.cond2 + + cleanup: + br i1 true, label %for.cond, label %for.body + } + +... + +# Sanity check to verify that something got through. +# CHECK-LABEL: entry: |
