[PATCH] D143279: InstCombine: Handle folding fcmp of 0 into llvm.is.fpclass

[Jay Foad via Phabricator via llvm-commits]

foad added inline comments.


================
Comment at: llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp:1272
     switch (Pred) {
-#if 0
     // TODO: Compares with 0 depends on the denormal handling mode.
     case FCmpInst::FCMP_OEQ: // Match x == 0.0
----------------
This is done?


================
Comment at: llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp:1278
     case FCmpInst::FCMP_UNE: // Match (x != 0.0)
       return {LHS, (~fcZero & fcAllFlags) | fcNan};
     case FCmpInst::FCMP_ONE: // Match !isnan(x) && x != 0.0
----------------
Simplify this to `~fcZero & fcAllFlags`


================
Comment at: llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp:1499
+    auto [ClassValRHS, ClassMaskRHS] =
+        fcmpToClassTest(PredR, *RHS->getParent()->getParent(), RHS0, RHS1);
     if (ClassValRHS) {
----------------
You can use getFunction, here and below


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D143279/new/

https://reviews.llvm.org/D143279