[PATCH] D126774: [InstCombine] Use +0.0 instead of -0.0 as the FP identity for some folds

[David Sherwood via Phabricator via llvm-commits]

david-arm marked 4 inline comments as done.
david-arm added inline comments.


================
Comment at: llvm/lib/IR/Constants.cpp:2854-2855
         // TODO: If the fadd has 'nsz', should we return +0.0?
-        return ConstantFP::getNegativeZero(Ty);
+        return NSZ ? Constant::getNullValue(Ty)
+                   : ConstantFP::getNegativeZero(Ty);
       case Instruction::FMul: // X * 1.0 = X
----------------
spatel wrote:
> This API is awkward. Should we change the constant's method to take a positive/negative param (to match the APFloat call within this call)?
>   ConstantFP::getZero(Type, bool Negative = false)
Good suggestion @spatel !


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  https://reviews.llvm.org/D126774/new/

https://reviews.llvm.org/D126774