[AArch64] Support for FP FMA when -ffp-contract=fast

Currently, the machine combiner can proceed matching when -ffast-math is on.
It should also match when only -ffp-contract=fast is specified as was the
case before when DAGCombiner was doing the job.

Patch by: Abderrazek Zaafrani <a.zaafrani@samsung.com>.

Differential Revision: https://reviews.llvm.org/D24366

llvm-svn: 281649

1 files changed, 5 insertions, 3 deletions

diff --git a/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp b/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp
index 6907e061332..859f7828901 100644
--- a/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp
+++ b/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp
@@ -2901,6 +2901,8 @@ static bool isCombineInstrCandidate64(unsigned Opc) {
 // FP Opcodes that can be combined with a FMUL
 static bool isCombineInstrCandidateFP(const MachineInstr &Inst) {
   switch (Inst.getOpcode()) {
+  default:
+    break;
   case AArch64::FADDSrr:
   case AArch64::FADDDrr:
   case AArch64::FADDv2f32:
@@ -2911,9 +2913,9 @@ static bool isCombineInstrCandidateFP(const MachineInstr &Inst) {
   case AArch64::FSUBv2f32:
   case AArch64::FSUBv2f64:
   case AArch64::FSUBv4f32:
-    return Inst.getParent()->getParent()->getTarget().Options.UnsafeFPMath;
-  default:
-    break;
+		TargetOptions Options = Inst.getParent()->getParent()->getTarget().Options; 
+    return (Options.UnsafeFPMath || 
+				    Options.AllowFPOpFusion == FPOpFusion::Fast);
   }
   return false;
 }