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| author | Sanjay Patel <spatel@rotateright.com> | 2020-04-21 14:22:13 -0400 |
|---|---|---|
| committer | Sanjay Patel <spatel@rotateright.com> | 2020-04-21 14:23:06 -0400 |
| commit | cf30aafa2d1ed79daabe979fedf9c34affb8b2a0 (patch) | |
| tree | 189f2a8843bbd81d7e48380c5344ab9cdacee4e7 | |
| parent | b349098d2297f8637525ed162bf37506ed70d7c7 (diff) | |
| download | llvm-cf30aafa2d1ed79daabe979fedf9c34affb8b2a0.zip llvm-cf30aafa2d1ed79daabe979fedf9c34affb8b2a0.tar.gz llvm-cf30aafa2d1ed79daabe979fedf9c34affb8b2a0.tar.bz2 | |
[Analysis] recognize the 'null' pointer constant as not poison
Differential Revision: https://reviews.llvm.org/D78575
| -rw-r--r-- | llvm/lib/Analysis/ValueTracking.cpp | 5 | ||||
| -rw-r--r-- | llvm/test/Transforms/InstSimplify/freeze.ll | 8 |
2 files changed, 5 insertions, 8 deletions
diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp index f80ec73..e547447 100644 --- a/llvm/lib/Analysis/ValueTracking.cpp +++ b/llvm/lib/Analysis/ValueTracking.cpp @@ -4693,8 +4693,9 @@ bool llvm::isGuaranteedNotToBeUndefOrPoison(const Value *V, if (isa<UndefValue>(C) || isa<ConstantExpr>(C)) return false; - // TODO: Add ConstantFP and pointers. - if (isa<ConstantInt>(C) || isa<GlobalVariable>(C) ) + // TODO: Add ConstantFP. + if (isa<ConstantInt>(C) || isa<GlobalVariable>(C) || + isa<ConstantPointerNull>(C)) return true; if (C->getType()->isVectorTy()) diff --git a/llvm/test/Transforms/InstSimplify/freeze.ll b/llvm/test/Transforms/InstSimplify/freeze.ll index e8950a8..31fbdabf 100644 --- a/llvm/test/Transforms/InstSimplify/freeze.ll +++ b/llvm/test/Transforms/InstSimplify/freeze.ll @@ -51,12 +51,9 @@ define i32()* @make_const_fn() { ret i32()* %k } -; TODO: This is not poison. - define i32* @make_const_null() { ; CHECK-LABEL: @make_const_null( -; CHECK-NEXT: [[K:%.*]] = freeze i32* null -; CHECK-NEXT: ret i32* [[K]] +; CHECK-NEXT: ret i32* null ; %k = freeze i32* null ret i32* %k @@ -208,8 +205,7 @@ define i8* @gep_inbounds_noopt(i32 %arg) { define i32* @gep_inbounds_null() { ; CHECK-LABEL: @gep_inbounds_null( -; CHECK-NEXT: [[K:%.*]] = freeze i32* null -; CHECK-NEXT: ret i32* [[K]] +; CHECK-NEXT: ret i32* null ; %p = getelementptr inbounds i32, i32* null, i32 0 %k = freeze i32* %p |