R600/SI: FMA is faster than fmul and fadd for f64
llvm-svn: 188136
diff --git a/llvm/lib/Target/R600/SIISelLowering.cpp b/llvm/lib/Target/R600/SIISelLowering.cpp
index b714fc1..a76e6ee 100644
--- a/llvm/lib/Target/R600/SIISelLowering.cpp
+++ b/llvm/lib/Target/R600/SIISelLowering.cpp
@@ -338,6 +338,24 @@
return MVT::i32;
}
+bool SITargetLowering::isFMAFasterThanFMulAndFAdd(EVT VT) const {
+ VT = VT.getScalarType();
+
+ if (!VT.isSimple())
+ return false;
+
+ switch (VT.getSimpleVT().SimpleTy) {
+ case MVT::f32:
+ return false; /* There is V_MAD_F32 for f32 */
+ case MVT::f64:
+ return true;
+ default:
+ break;
+ }
+
+ return false;
+}
+
//===----------------------------------------------------------------------===//
// Custom DAG Lowering Operations
//===----------------------------------------------------------------------===//
diff --git a/llvm/lib/Target/R600/SIISelLowering.h b/llvm/lib/Target/R600/SIISelLowering.h
index b4202c4..effbf1f 100644
--- a/llvm/lib/Target/R600/SIISelLowering.h
+++ b/llvm/lib/Target/R600/SIISelLowering.h
@@ -55,6 +55,7 @@
MachineBasicBlock * BB) const;
virtual EVT getSetCCResultType(LLVMContext &Context, EVT VT) const;
virtual MVT getScalarShiftAmountTy(EVT VT) const;
+ virtual bool isFMAFasterThanFMulAndFAdd(EVT VT) const;
virtual SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const;
virtual SDValue PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const;
virtual SDNode *PostISelFolding(MachineSDNode *N, SelectionDAG &DAG) const;
diff --git a/llvm/test/CodeGen/R600/fmuladd.ll b/llvm/test/CodeGen/R600/fmuladd.ll
new file mode 100644
index 0000000..ac379f4
--- /dev/null
+++ b/llvm/test/CodeGen/R600/fmuladd.ll
@@ -0,0 +1,31 @@
+; RUN: llc < %s -march=r600 -mcpu=SI | FileCheck %s
+
+; CHECK: @fmuladd_f32
+; CHECK: V_MAD_F32 {{VGPR[0-9]+, VGPR[0-9]+, VGPR[0-9]+, VGPR[0-9]+}}
+
+define void @fmuladd_f32(float addrspace(1)* %out, float addrspace(1)* %in1,
+ float addrspace(1)* %in2, float addrspace(1)* %in3) {
+ %r0 = load float addrspace(1)* %in1
+ %r1 = load float addrspace(1)* %in2
+ %r2 = load float addrspace(1)* %in3
+ %r3 = tail call float @llvm.fmuladd.f32(float %r0, float %r1, float %r2)
+ store float %r3, float addrspace(1)* %out
+ ret void
+}
+
+declare float @llvm.fmuladd.f32(float, float, float)
+
+; CHECK: @fmuladd_f64
+; CHECK: V_FMA_F64 {{VGPR[0-9]+_VGPR[0-9]+, VGPR[0-9]+_VGPR[0-9]+, VGPR[0-9]+_VGPR[0-9]+, VGPR[0-9]+_VGPR[0-9]+}}
+
+define void @fmuladd_f64(double addrspace(1)* %out, double addrspace(1)* %in1,
+ double addrspace(1)* %in2, double addrspace(1)* %in3) {
+ %r0 = load double addrspace(1)* %in1
+ %r1 = load double addrspace(1)* %in2
+ %r2 = load double addrspace(1)* %in3
+ %r3 = tail call double @llvm.fmuladd.f64(double %r0, double %r1, double %r2)
+ store double %r3, double addrspace(1)* %out
+ ret void
+}
+
+declare double @llvm.fmuladd.f64(double, double, double)