[PATCH] D28364: SimplifyLibCalls: Remove incorrect optimization of fabs

Matt Arsenault via Phabricator via llvm-commits llvm-commits at lists.llvm.org
Fri Jan 6 11:45:38 PST 2017


arsenm added inline comments.


================
Comment at: lib/Transforms/Utils/SimplifyLibCalls.cpp:1200
-    // Fold fabs(x * x) -> x * x; any squared FP value must already be positive.
-    if (I->getOpcode() == Instruction::FMul)
-      if (I->getOperand(0) == I->getOperand(1))
----------------
majnemer wrote:
> Couldn't this stay if the `fmul` is marked as `nnan`?
Yes, but I want to move this to an optimization on the intrinsic


https://reviews.llvm.org/D28364





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