[PATCH] D27879: [AVX-512][InstCombine] Teach InstCombine to turn scalar add/sub/mul/div with rounding intrinsics into normal IR operations if the rounding mode is CUR_DIRECTION.

[Zvi Rackover via Phabricator via llvm-commits]

zvi added a comment.

Other than a minor comment, LGTM.



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Comment at: lib/Transforms/InstCombine/InstCombineCalls.cpp:1783
+    // IR operations.
+    if (auto *R = dyn_cast<ConstantInt>(II->getArgOperand(4))) {
+      if (R->getValue() == 4) {
----------------
is if(dync_cast<>) really needed here? Can the cast ever fail?


https://reviews.llvm.org/D27879