[llvm-branch-commits] [llvm] 619fa4c - PowerPC: Don't hoist float multiply + add to fused operation on SPE

[Justin Hibbits via llvm-branch-commits]

Author: Justin Hibbits
Date: 2020-05-12T16:53:28-05:00
New Revision: 619fa4c9c852d438ec58bd7d4bedc9d1b8691a8f

URL: https://github.com/llvm/llvm-project/commit/619fa4c9c852d438ec58bd7d4bedc9d1b8691a8f
DIFF: https://github.com/llvm/llvm-project/commit/619fa4c9c852d438ec58bd7d4bedc9d1b8691a8f.diff

LOG: PowerPC: Don't hoist float multiply + add to fused operation on SPE

SPE doesn't have a fmadd instruction, so don't bother hoisting a
multiply and add sequence to this, as it'd become just a library call.
Hoisting happens too late for the CTR usability test to veto using the
CTR in a loop, and results in an assert "Invalid PPC CTR loop!".

Added: 
    

Modified: 
    llvm/lib/Target/PowerPC/PPCISelLowering.cpp

Removed: 
    


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diff  --git a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
index 83a119fec86b..2da0665d5123 100644
--- a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -15718,6 +15718,8 @@ bool PPCTargetLowering::isFMAFasterThanFMulAndFAdd(const MachineFunction &MF,
 
 bool PPCTargetLowering::isFMAFasterThanFMulAndFAdd(const Function &F,
                                                    Type *Ty) const {
+  if (Subtarget.hasSPE())
+    return false;
   switch (Ty->getScalarType()->getTypeID()) {
   case Type::FloatTyID:
   case Type::DoubleTyID: