diff options
| -rw-r--r-- | llvm/lib/Analysis/ValueTracking.cpp | 4 | ||||
| -rw-r--r-- | llvm/test/Transforms/InstCombine/pr21891.ll | 18 |
2 files changed, 22 insertions, 0 deletions
diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp index fa428fa108d..4317bcde91e 100644 --- a/llvm/lib/Analysis/ValueTracking.cpp +++ b/llvm/lib/Analysis/ValueTracking.cpp @@ -511,6 +511,10 @@ static void computeKnownBitsFromAssume(Value *V, APInt &KnownZero, return; } + // The remaining tests are all recursive, so bail out if we hit the limit. + if (Depth == MaxDepth) + continue; + Value *A, *B; auto m_V = m_CombineOr(m_Specific(V), m_CombineOr(m_PtrToInt(m_Specific(V)), diff --git a/llvm/test/Transforms/InstCombine/pr21891.ll b/llvm/test/Transforms/InstCombine/pr21891.ll new file mode 100644 index 00000000000..8194976b623 --- /dev/null +++ b/llvm/test/Transforms/InstCombine/pr21891.ll @@ -0,0 +1,18 @@ +; RUN: opt %s -instcombine + +define i32 @f(i32 %theNumber) { +entry: + %cmp = icmp sgt i32 %theNumber, -1 + call void @llvm.assume(i1 %cmp) + br i1 true, label %if.then, label %if.end + +if.then: ; preds = %entry + %shl = shl nuw i32 %theNumber, 1 + br label %if.end + +if.end: ; preds = %if.then, %entry + %phi = phi i32 [ %shl, %if.then ], [ undef, %entry ] + ret i32 %phi +} + +declare void @llvm.assume(i1) |
