[InstCombine] Follow-up to "When -A + B both have nsw flag, set nsw f…

[Z572]

…lag."

In 3c037b7, I've miss suggested about cast.

[llvmbot]

@llvm/pr-subscribers-llvm-transforms

Author: None (Z572)

Changes

…lag."

In 3c037b7, I've miss suggested about cast.

---

Full diff: https://github.com/llvm/llvm-project/pull/72282.diff

1 Files Affected:

• (modified) llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp (+1-1)

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
index d390d3a581fcaa2..2bd738c95ecaa7f 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
@@ -1488,7 +1488,7 @@ Instruction *InstCombinerImpl::visitAdd(BinaryOperator &I) {
 
     // -A + B --> B - A
     auto *Sub = BinaryOperator::CreateSub(RHS, A);
-    auto *OB0 = dyn_cast<OverflowingBinaryOperator>(LHS);
+    auto *OB0 = cast<OverflowingBinaryOperator>(LHS);
     Sub->setHasNoSignedWrap(I.hasNoSignedWrap() && OB0->hasNoSignedWrap());
 
     return Sub;

[arichardson]

Second part of commit message should probably be something like "Use cast instead of dyn_cast for cast that cannot fail.`