InstCombine: call FoldOpIntoSelect for all floating binops, not just fmul

llvm-svn: 186759

3 files changed, 94 insertions, 3 deletions

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
index fecbd5c3010..0aa301bc7a8 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
@@ -1186,9 +1186,15 @@ Instruction *InstCombiner::visitFAdd(BinaryOperator &I) {
   if (Value *V = SimplifyFAddInst(LHS, RHS, I.getFastMathFlags(), TD))
     return ReplaceInstUsesWith(I, V);
 
-  if (isa<Constant>(RHS) && isa<PHINode>(LHS))
-    if (Instruction *NV = FoldOpIntoPhi(I))
-      return NV;
+  if (isa<Constant>(RHS)) {
+    if (isa<PHINode>(LHS))
+      if (Instruction *NV = FoldOpIntoPhi(I))
+        return NV;
+
+    if (SelectInst *SI = dyn_cast<SelectInst>(LHS))
+      if (Instruction *NV = FoldOpIntoSelect(I, SI))
+        return NV;
+  }
 
   // -A + B  -->  B - A
   // -A + -B  -->  -(A + B)
@@ -1517,6 +1523,11 @@ Instruction *InstCombiner::visitFSub(BinaryOperator &I) {
   if (Value *V = SimplifyFSubInst(Op0, Op1, I.getFastMathFlags(), TD))
     return ReplaceInstUsesWith(I, V);
 
+  if (isa<Constant>(Op0))
+    if (SelectInst *SI = dyn_cast<SelectInst>(Op1))
+      if (Instruction *NV = FoldOpIntoSelect(I, SI))
+        return NV;
+
   // If this is a 'B = x-(-A)', change to B = x+A...
   if (Value *V = dyn_castFNegVal(Op1))
     return BinaryOperator::CreateFAdd(Op0, V);
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp b/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
index c3621af638b..780e0eb0dcb 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
@@ -990,10 +990,19 @@ Instruction *InstCombiner::visitFDiv(BinaryOperator &I) {
   if (Value *V = SimplifyFDivInst(Op0, Op1, TD))
     return ReplaceInstUsesWith(I, V);
 
+  if (isa<Constant>(Op0))
+    if (SelectInst *SI = dyn_cast<SelectInst>(Op1))
+      if (Instruction *R = FoldOpIntoSelect(I, SI))
+        return R;
+
   bool AllowReassociate = I.hasUnsafeAlgebra();
   bool AllowReciprocal = I.hasAllowReciprocal();
 
   if (ConstantFP *Op1C = dyn_cast<ConstantFP>(Op1)) {
+    if (SelectInst *SI = dyn_cast<SelectInst>(Op0))
+      if (Instruction *R = FoldOpIntoSelect(I, SI))
+        return R;
+
     if (AllowReassociate) {
       ConstantFP *C1 = 0;
       ConstantFP *C2 = Op1C;
diff --git a/llvm/test/Transforms/InstCombine/fold-fops-into-selects.ll b/llvm/test/Transforms/InstCombine/fold-fops-into-selects.ll
new file mode 100644
index 00000000000..07aebb13eff
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/fold-fops-into-selects.ll
@@ -0,0 +1,71 @@
+; RUN: opt < %s -instcombine -S | FileCheck %s
+
+define float @test1(i1 %A) {
+EntryBlock:
+  %cf = select i1 %A, float 1.000000e+00, float 0.000000e+00
+  %op = fsub float 1.000000e+00, %cf
+  ret float %op
+; CHECK-LABEL: @test1(
+; CHECK: select i1 %A, float 0.000000e+00, float 1.000000e+00
+}
+
+define float @test2(i1 %A, float %B) {
+EntryBlock:
+  %cf = select i1 %A, float 1.000000e+00, float %B
+  %op = fadd float 2.000000e+00, %cf
+  ret float %op
+; CHECK-LABEL: @test2(
+; CHECK: [[OP:%.*]] = fadd float %B, 2.000000e+00
+; CHECK: select i1 %A, float 3.000000e+00, float [[OP]]
+}
+
+define float @test3(i1 %A, float %B) {
+EntryBlock:
+  %cf = select i1 %A, float 1.000000e+00, float %B
+  %op = fsub float 2.000000e+00, %cf
+  ret float %op
+; CHECK-LABEL: @test3(
+; CHECK: [[OP:%.*]] = fsub float 2.000000e+00, %B
+; CHECK: select i1 %A, float 1.000000e+00, float [[OP]]
+}
+
+define float @test4(i1 %A, float %B) {
+EntryBlock:
+  %cf = select i1 %A, float 1.000000e+00, float %B
+  %op = fmul float 2.000000e+00, %cf
+  ret float %op
+; CHECK-LABEL: @test4(
+; CHECK: [[OP:%.*]] = fmul float %B, 2.000000e+00
+; CHECK: select i1 %A, float 2.000000e+00, float [[OP]]
+}
+
+define float @test5(i1 %A, float %B) {
+EntryBlock:
+  %cf = select i1 %A, float 1.000000e+00, float %B
+  %op = fdiv float 2.000000e+00, %cf
+  ret float %op
+; CHECK-LABEL: @test5(
+; CHECK: [[OP:%.*]] = fdiv float 2.000000e+00, %B
+; CHECK: select i1 %A, float 2.000000e+00, float [[OP]]
+}
+
+define float @test6(i1 %A, float %B) {
+EntryBlock:
+  %cf = select i1 %A, float 1.000000e+00, float %B
+  %op = fdiv float %cf, 2.000000e+00
+  ret float %op
+; CHECK-LABEL: @test6(
+; CHECK: [[OP:%.*]] = fmul float %B, 5.000000e-01
+; CHECK: select i1 %A, float 5.000000e-01, float [[OP]]
+}
+
+define float @test7(i1 %A, float %B) {
+EntryBlock:
+  %cf = select i1 %A, float 1.000000e+00, float %B
+  %op = fdiv float %cf, 3.000000e+00
+  ret float %op
+; CHECK-LABEL: @test7(
+; CHECK: [[OP:%.*]] = fdiv float %B, 3.000000e+00
+; CHECK: select i1 %A, float 0x3FD5555560000000, float [[OP]]
+}
+