Revert [InstCombine] Use SimplifyFMulInst to simplify multiply in fma.
This introduces additional rounding error in some cases. See D67434.
This reverts r371518 (git commit 18a1f0818b659cee13865b4fad2648d85984a4ed)
llvm-svn: 371634
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
index 1cef8d9..e96e45e 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -2258,11 +2258,9 @@
return II;
}
- // Try to simplify the underlying FMul.
- if (Value *V = SimplifyFMulInst(II->getArgOperand(0), II->getArgOperand(1),
- II->getFastMathFlags(),
- SQ.getWithInstruction(II))) {
- auto *FAdd = BinaryOperator::CreateFAdd(V, II->getArgOperand(2));
+ // fma x, 1, z -> fadd x, z
+ if (match(Src1, m_FPOne())) {
+ auto *FAdd = BinaryOperator::CreateFAdd(Src0, II->getArgOperand(2));
FAdd->copyFastMathFlags(II);
return FAdd;
}
diff --git a/llvm/test/Transforms/InstCombine/fma.ll b/llvm/test/Transforms/InstCombine/fma.ll
index 42ed587..89fdc6b 100644
--- a/llvm/test/Transforms/InstCombine/fma.ll
+++ b/llvm/test/Transforms/InstCombine/fma.ll
@@ -372,7 +372,8 @@
define <2 x double> @fmuladd_a_0_b(<2 x double> %a, <2 x double> %b) {
; CHECK-LABEL: @fmuladd_a_0_b(
; CHECK-NEXT: entry:
-; CHECK-NEXT: ret <2 x double> [[B:%.*]]
+; CHECK-NEXT: [[RES:%.*]] = call nnan nsz <2 x double> @llvm.fmuladd.v2f64(<2 x double> [[A:%.*]], <2 x double> zeroinitializer, <2 x double> [[B:%.*]])
+; CHECK-NEXT: ret <2 x double> [[RES]]
;
entry:
%res = call nnan nsz <2 x double> @llvm.fmuladd.v2f64(<2 x double> %a, <2 x double> zeroinitializer, <2 x double> %b)
@@ -382,7 +383,8 @@
define <2 x double> @fmuladd_0_a_b(<2 x double> %a, <2 x double> %b) {
; CHECK-LABEL: @fmuladd_0_a_b(
; CHECK-NEXT: entry:
-; CHECK-NEXT: ret <2 x double> [[B:%.*]]
+; CHECK-NEXT: [[RES:%.*]] = call nnan nsz <2 x double> @llvm.fmuladd.v2f64(<2 x double> [[A:%.*]], <2 x double> zeroinitializer, <2 x double> [[B:%.*]])
+; CHECK-NEXT: ret <2 x double> [[RES]]
;
entry:
%res = call nnan nsz <2 x double> @llvm.fmuladd.v2f64(<2 x double> zeroinitializer, <2 x double> %a, <2 x double> %b)
@@ -405,7 +407,8 @@
define <2 x double> @fma_a_0_b(<2 x double> %a, <2 x double> %b) {
; CHECK-LABEL: @fma_a_0_b(
; CHECK-NEXT: entry:
-; CHECK-NEXT: ret <2 x double> [[B:%.*]]
+; CHECK-NEXT: [[RES:%.*]] = call nnan nsz <2 x double> @llvm.fma.v2f64(<2 x double> [[A:%.*]], <2 x double> zeroinitializer, <2 x double> [[B:%.*]])
+; CHECK-NEXT: ret <2 x double> [[RES]]
;
entry:
%res = call nnan nsz <2 x double> @llvm.fma.v2f64(<2 x double> %a, <2 x double> zeroinitializer, <2 x double> %b)
@@ -415,7 +418,8 @@
define <2 x double> @fma_0_a_b(<2 x double> %a, <2 x double> %b) {
; CHECK-LABEL: @fma_0_a_b(
; CHECK-NEXT: entry:
-; CHECK-NEXT: ret <2 x double> [[B:%.*]]
+; CHECK-NEXT: [[RES:%.*]] = call nnan nsz <2 x double> @llvm.fma.v2f64(<2 x double> [[A:%.*]], <2 x double> zeroinitializer, <2 x double> [[B:%.*]])
+; CHECK-NEXT: ret <2 x double> [[RES]]
;
entry:
%res = call nnan nsz <2 x double> @llvm.fma.v2f64(<2 x double> zeroinitializer, <2 x double> %a, <2 x double> %b)
@@ -436,7 +440,8 @@
define <2 x double> @fma_sqrt(<2 x double> %a, <2 x double> %b) {
; CHECK-LABEL: @fma_sqrt(
; CHECK-NEXT: entry:
-; CHECK-NEXT: [[RES:%.*]] = fadd fast <2 x double> [[A:%.*]], [[B:%.*]]
+; CHECK-NEXT: [[SQRT:%.*]] = call fast <2 x double> @llvm.sqrt.v2f64(<2 x double> [[A:%.*]])
+; CHECK-NEXT: [[RES:%.*]] = call fast <2 x double> @llvm.fma.v2f64(<2 x double> [[SQRT]], <2 x double> [[SQRT]], <2 x double> [[B:%.*]])
; CHECK-NEXT: ret <2 x double> [[RES]]
;
entry: