[X86] Accept hasAVX512() as well as hasFMA() when generating FMA.

We don't always have FMA, for example when using 'clang -mavx512f'
without an explicit CPU.

Also check for an explicit +avx512f instead of CPUs in a couple
related tests.

llvm-svn: 240616

1 files changed, 5 insertions, 3 deletions

diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index ccf75f3319d..105c2ddfd9e 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -1111,7 +1111,7 @@ X86TargetLowering::X86TargetLowering(const X86TargetMachine &TM,
     setOperationAction(ISD::CTPOP,             MVT::v8i32, Custom);
     setOperationAction(ISD::CTPOP,             MVT::v4i64, Custom);
 
-    if (Subtarget->hasFMA() || Subtarget->hasFMA4()) {
+    if (Subtarget->hasFMA() || Subtarget->hasFMA4() || Subtarget->hasAVX512()) {
       setOperationAction(ISD::FMA,             MVT::v8f32, Legal);
       setOperationAction(ISD::FMA,             MVT::v4f64, Legal);
       setOperationAction(ISD::FMA,             MVT::v4f32, Legal);
@@ -18636,7 +18636,7 @@ bool X86TargetLowering::isVectorLoadExtDesirable(SDValue) const { return true; }
 
 bool
 X86TargetLowering::isFMAFasterThanFMulAndFAdd(EVT VT) const {
-  if (!(Subtarget->hasFMA() || Subtarget->hasFMA4()))
+  if (!(Subtarget->hasFMA() || Subtarget->hasFMA4() || Subtarget->hasAVX512()))
     return false;
 
   VT = VT.getScalarType();
@@ -19821,6 +19821,7 @@ X86TargetLowering::emitEHSjLjLongJmp(MachineInstr *MI,
 // Replace 213-type (isel default) FMA3 instructions with 231-type for
 // accumulator loops. Writing back to the accumulator allows the coalescer
 // to remove extra copies in the loop.
+// FIXME: Do this on AVX512.  We don't support 231 variants yet (PR23937).
 MachineBasicBlock *
 X86TargetLowering::emitFMA3Instr(MachineInstr *MI,
                                  MachineBasicBlock *MBB) const {
@@ -24182,7 +24183,8 @@ static SDValue PerformFMACombine(SDNode *N, SelectionDAG &DAG,
 
   EVT ScalarVT = VT.getScalarType();
   if ((ScalarVT != MVT::f32 && ScalarVT != MVT::f64) ||
-      (!Subtarget->hasFMA() && !Subtarget->hasFMA4()))
+      (!Subtarget->hasFMA() && !Subtarget->hasFMA4() &&
+       !Subtarget->hasAVX512()))
     return SDValue();
 
   SDValue A = N->getOperand(0);