[llvm] r177820 - Remove the type legality check from the SelectionDAGBuilder when it lowers @llvm.fmuladd to ISD::FMA nodes.

[Owen Anderson]

Author: resistor
Date: Sat Mar 23 03:26:53 2013
New Revision: 177820

URL: http://llvm.org/viewvc/llvm-project?rev=177820&view=rev
Log:
Remove the type legality check from the SelectionDAGBuilder when it lowers @llvm.fmuladd to ISD::FMA nodes.
Performing this check unilaterally prevented us from generating FMAs when the incoming IR contained illegal vector types which would eventually be legalized to underlying types that *did* support FMA.
For example, an @llvm.fmuladd on an OpenCL float16 should become a sequence of float4 FMAs, not float4 fmul+fadd's.

NOTE: Because we still call the target-specific profitability hook, individual targets can reinstate the old behavior, if desired, by simply performing the legality check inside their callback hook.  They can also perform more sophisticated legality checks, if, for example, some illegal vector types can be productively implemented as FMAs, but not others.

Added:
    llvm/trunk/test/CodeGen/X86/wide-fma-contraction.ll
Modified:
    llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp?rev=177820&r1=177819&r2=177820&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp Sat Mar 23 03:26:53 2013
@@ -4914,7 +4914,6 @@ SelectionDAGBuilder::visitIntrinsicCall(
   case Intrinsic::fmuladd: {
     EVT VT = TLI.getValueType(I.getType());
     if (TM.Options.AllowFPOpFusion != FPOpFusion::Strict &&
-        TLI.isOperationLegalOrCustom(ISD::FMA, VT) &&
         TLI.isFMAFasterThanMulAndAdd(VT)){
       setValue(&I, DAG.getNode(ISD::FMA, dl,
                                getValue(I.getArgOperand(0)).getValueType(),

Added: llvm/trunk/test/CodeGen/X86/wide-fma-contraction.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/wide-fma-contraction.ll?rev=177820&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/X86/wide-fma-contraction.ll (added)
+++ llvm/trunk/test/CodeGen/X86/wide-fma-contraction.ll Sat Mar 23 03:26:53 2013
@@ -0,0 +1,20 @@
+; RUN: llc -march=x86 -mattr=+fma4 -mtriple=x86_64-apple-darwin < %s | FileCheck %s
+
+; CHECK: fmafunc
+define <16 x float> @fmafunc(<16 x float> %a, <16 x float> %b, <16 x float> %c) {
+; CHECK-NOT: vmulps
+; CHECK-NOT: vaddps
+; CHECK: vfmaddps
+; CHECK-NOT: vmulps
+; CHECK-NOT: vaddps
+; CHECK: vfmaddps
+; CHECK-NOT: vmulps
+; CHECK-NOT: vaddps
+  %ret = tail call <16 x float> @llvm.fmuladd.v16f32(<16 x float> %a, <16 x float> %b, <16 x float> %c)
+  ret <16 x float> %ret
+}
+
+declare <16 x float> @llvm.fmuladd.v16f32(<16 x float>, <16 x float>, <16 x float>) nounwind readnone
+
+
+