Allow constant folding of fma and fmuladd
llvm-svn: 202914
diff --git a/llvm/lib/Analysis/ConstantFolding.cpp b/llvm/lib/Analysis/ConstantFolding.cpp
index 10f8e4e..254f2d9 100644
--- a/llvm/lib/Analysis/ConstantFolding.cpp
+++ b/llvm/lib/Analysis/ConstantFolding.cpp
@@ -1193,6 +1193,8 @@
case Intrinsic::ctpop:
case Intrinsic::ctlz:
case Intrinsic::cttz:
+ case Intrinsic::fma:
+ case Intrinsic::fmuladd:
case Intrinsic::sadd_with_overflow:
case Intrinsic::uadd_with_overflow:
case Intrinsic::ssub_with_overflow:
@@ -1615,5 +1617,30 @@
}
return 0;
}
+
+ if (Operands.size() != 3)
+ return 0;
+
+ if (const ConstantFP *Op1 = dyn_cast<ConstantFP>(Operands[0])) {
+ if (const ConstantFP *Op2 = dyn_cast<ConstantFP>(Operands[1])) {
+ if (const ConstantFP *Op3 = dyn_cast<ConstantFP>(Operands[2])) {
+ switch (F->getIntrinsicID()) {
+ default: break;
+ case Intrinsic::fma:
+ case Intrinsic::fmuladd: {
+ APFloat V = Op1->getValueAPF();
+ APFloat::opStatus s = V.fusedMultiplyAdd(Op2->getValueAPF(),
+ Op3->getValueAPF(),
+ APFloat::rmNearestTiesToEven);
+ if (s != APFloat::opInvalidOp)
+ return ConstantFP::get(Ty->getContext(), V);
+
+ return 0;
+ }
+ }
+ }
+ }
+ }
+
return 0;
}
diff --git a/llvm/test/Transforms/InstCombine/constant-fold-math.ll b/llvm/test/Transforms/InstCombine/constant-fold-math.ll
new file mode 100644
index 0000000..00fceb19
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/constant-fold-math.ll
@@ -0,0 +1,39 @@
+; RUN: opt -S -instcombine < %s | FileCheck %s
+
+declare float @llvm.fma.f32(float, float, float) #0
+declare float @llvm.fmuladd.f32(float, float, float) #0
+
+declare double @llvm.fma.f64(double, double, double) #0
+declare double @llvm.fmuladd.f64(double, double, double) #0
+
+
+
+; CHECK-LABEL: @constant_fold_fma_f32
+; CHECK-NEXT: ret float 6.000000e+00
+define float @constant_fold_fma_f32() #0 {
+ %x = call float @llvm.fma.f32(float 1.0, float 2.0, float 4.0) #0
+ ret float %x
+}
+
+; CHECK-LABEL: @constant_fold_fmuladd_f32
+; CHECK-NEXT: ret float 6.000000e+00
+define float @constant_fold_fmuladd_f32() #0 {
+ %x = call float @llvm.fmuladd.f32(float 1.0, float 2.0, float 4.0) #0
+ ret float %x
+}
+
+; CHECK-LABEL: @constant_fold_fma_f64
+; CHECK-NEXT: ret double 6.000000e+00
+define double @constant_fold_fma_f64() #0 {
+ %x = call double @llvm.fma.f64(double 1.0, double 2.0, double 4.0) #0
+ ret double %x
+}
+
+; CHECK-LABEL: @constant_fold_fmuladd_f64
+; CHECK-NEXT: ret double 6.000000e+00
+define double @constant_fold_fmuladd_f64() #0 {
+ %x = call double @llvm.fmuladd.f64(double 1.0, double 2.0, double 4.0) #0
+ ret double %x
+}
+
+attributes #0 = { nounwind readnone }