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| author | Alina Sbirlea <asbirlea@google.com> | 2023-08-09 11:32:08 -0700 |
|---|---|---|
| committer | Alina Sbirlea <asbirlea@google.com> | 2023-08-10 09:57:32 -0700 |
| commit | 89fa0dd1fb25698270e9382a94929d2f5747e802 (patch) | |
| tree | dd198d9df85e188378a536a96aa89da3c9a1c2be | |
| parent | 0d459b71dc280eede85f443921240df4f7a5c6ff (diff) | |
| download | llvm-89fa0dd1fb25698270e9382a94929d2f5747e802.zip llvm-89fa0dd1fb25698270e9382a94929d2f5747e802.tar.gz llvm-89fa0dd1fb25698270e9382a94929d2f5747e802.tar.bz2 | |
[MemorySSA] Handle queries with empty memory location.
| -rw-r--r-- | llvm/lib/Analysis/MemorySSA.cpp | 4 | ||||
| -rw-r--r-- | llvm/test/Transforms/NewGVN/nomemlocation.ll | 26 |
2 files changed, 30 insertions, 0 deletions
diff --git a/llvm/lib/Analysis/MemorySSA.cpp b/llvm/lib/Analysis/MemorySSA.cpp index d166580..2cf92ce 100644 --- a/llvm/lib/Analysis/MemorySSA.cpp +++ b/llvm/lib/Analysis/MemorySSA.cpp @@ -2390,6 +2390,10 @@ MemoryAccess *MemorySSA::ClobberWalkerBase::getClobberingMemoryAccessBase( BatchAAResults &BAA, unsigned &UpwardWalkLimit) { assert(!isa<MemoryUse>(StartingAccess) && "Use cannot be defining access"); + // If location is undefined, conservatively return starting access. + if (Loc.Ptr == nullptr) + return StartingAccess; + Instruction *I = nullptr; if (auto *StartingUseOrDef = dyn_cast<MemoryUseOrDef>(StartingAccess)) { if (MSSA->isLiveOnEntryDef(StartingUseOrDef)) diff --git a/llvm/test/Transforms/NewGVN/nomemlocation.ll b/llvm/test/Transforms/NewGVN/nomemlocation.ll new file mode 100644 index 0000000..0f716b3 --- /dev/null +++ b/llvm/test/Transforms/NewGVN/nomemlocation.ll @@ -0,0 +1,26 @@ +; RUN: opt < %s -S -p='newgvn' | FileCheck %s +; MemorySSA should be able to handle a clobber query with an empty MemoryLocation. + +; CHECK: @userread +define ptr @userread(ptr %p) { +entry: + br label %loop + +loop: ; preds = %loop, %entry +; 2 = MemoryPhi({entry,liveOnEntry},{loop,1}) + %pos = phi i64 [ 1, %entry ], [ %diff, %loop ] + %gep = getelementptr inbounds i8, ptr %p, i64 %pos +; MemoryUse(2) + %ld = load ptr, ptr %gep, align 8 +; 1 = MemoryDef(2)->2 + %readval = call i64 @fread(ptr noundef nonnull %gep, i64 noundef 1, i64 noundef %pos, ptr noundef %ld) + %readvalispos = icmp eq i64 %readval, %pos + call void @llvm.assume(i1 %readvalispos) + %diff = sub i64 0, %pos + br label %loop +} + +declare noundef i64 @fread(ptr nocapture noundef %0, i64 noundef %1, i64 noundef %2, ptr nocapture noundef %3) local_unnamed_addr #0 +declare void @llvm.assume(i1 %cond) + +attributes #0 = { nofree nounwind "frame-pointer"="non-leaf" "no-trapping-math"="true" "prefer-vector-width"="128" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+aes,+cmov,+crc32,+cx16,+cx8,+fxsr,+mmx,+pclmul,+popcnt,+sse,+sse2,+sse3,+sse4.1,+sse4.2,+ssse3,+x87" "tune-cpu"="generic" } |