From ae3738f4a797263eab7bac04d5e65ef7c23b0ca6 Mon Sep 17 00:00:00 2001
From: Chad Rosier <mcrosier@codeaurora.org>
Date: Mon, 17 Nov 2014 15:52:51 +0000
Subject: [PATCH] [Reassociate] Canonicalize constants to RHS operand.

Fix a thinko where the RHS was already a constant.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222139 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Transforms/Scalar/Reassociate.cpp                 | 5 ++++-
 test/Transforms/Reassociate/canonicalize-neg-const.ll | 6 +++---
 test/Transforms/Reassociate/fast-AgressiveSubMove.ll  | 4 ++--
 test/Transforms/Reassociate/fast-fp-commute.ll        | 2 +-
 4 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/lib/Transforms/Scalar/Reassociate.cpp b/lib/Transforms/Scalar/Reassociate.cpp
index 30e9b88226b..abe7f28cece 100644
--- a/lib/Transforms/Scalar/Reassociate.cpp
+++ b/lib/Transforms/Scalar/Reassociate.cpp
@@ -332,6 +332,7 @@ unsigned Reassociate::getRank(Value *V) {
   return ValueRankMap[I] = Rank;
 }
 
+// Canonicalize constants to RHS.  Otherwise, sort the operands by rank.
 void Reassociate::canonicalizeOperands(Instruction *I) {
   assert(isa<BinaryOperator>(I) && "Expected binary operator.");
   assert(I->isCommutative() && "Expected commutative operator.");
@@ -341,7 +342,9 @@ void Reassociate::canonicalizeOperands(Instruction *I) {
   unsigned LHSRank = getRank(LHS);
   unsigned RHSRank = getRank(RHS);
 
-  // Canonicalize constants to RHS.  Otherwise, sort the operands by rank.
+  if (isa<Constant>(RHS))
+    return;
+
   if (isa<Constant>(LHS) || RHSRank < LHSRank)
     cast<BinaryOperator>(I)->swapOperands();
 }
diff --git a/test/Transforms/Reassociate/canonicalize-neg-const.ll b/test/Transforms/Reassociate/canonicalize-neg-const.ll
index 8952675a8cf..e85a963f6dd 100644
--- a/test/Transforms/Reassociate/canonicalize-neg-const.ll
+++ b/test/Transforms/Reassociate/canonicalize-neg-const.ll
@@ -20,7 +20,7 @@ define double @test1(double %x, double %y) {
 ; (x + -0.1234 * y) * (x + -0.1234 * y) -> (x - 0.1234 * y) * (x - 0.1234 * y)
 define double @test2(double %x, double %y) {
 ; CHECK-LABEL: @test2
-; CHECK-NEXT: fmul double 1.234000e-01, %y
+; CHECK-NEXT: fmul double %y, 1.234000e-01
 ; CHECK-NEXT: fsub double %x, %mul
 ; CHECK-NEXT: fmul double %add{{.*}}, %add{{.*}}
 ; CHECK-NEXT: ret double %mul
@@ -36,7 +36,7 @@ define double @test2(double %x, double %y) {
 ; (x + 0.1234 * y) * (x - -0.1234 * y) -> (x + 0.1234 * y) * (x + 0.1234 * y)
 define double @test3(double %x, double %y) {
 ; CHECK-LABEL: @test3
-; CHECK-NEXT: fmul double 1.234000e-01, %y
+; CHECK-NEXT: fmul double %y, 1.234000e-01
 ; CHECK-NEXT: fadd double %x, %mul
 ; CHECK-NEXT: fmul double %add{{.*}}, %add{{.*}}
 ; CHECK-NEXT: ret double
@@ -100,7 +100,7 @@ define double @test7(double %x, double %y) {
 ; Canonicalize (y * -0.1234 + x) -> (x - 0.1234 * y)
 define double @test8(double %x, double %y) {
 ; CHECK-LABEL: @test8
-; CHECK-NEXT: fmul double 1.234000e-01, %y
+; CHECK-NEXT: fmul double %y, 1.234000e-01
 ; CHECK-NEXT: fsub double %x, %mul
 ; CHECK-NEXT: ret double %add
 
diff --git a/test/Transforms/Reassociate/fast-AgressiveSubMove.ll b/test/Transforms/Reassociate/fast-AgressiveSubMove.ll
index 3b74fb6a30c..0c28ed16491 100644
--- a/test/Transforms/Reassociate/fast-AgressiveSubMove.ll
+++ b/test/Transforms/Reassociate/fast-AgressiveSubMove.ll
@@ -2,8 +2,8 @@
 
 define float @test1(float %A) {
 ; CHECK-LABEL: test1
-; CHECK-NEXT: %X = fadd float 1.000000e+00, %A
-; CHECK-NEXT: %Y = fadd float 1.000000e+00, %A
+; CHECK-NEXT: %X = fadd float %A, 1.000000e+00
+; CHECK-NEXT: %Y = fadd float %A, 1.000000e+00
 ; CHECK-NEXT: %r = fsub float %X, %Y
 ; CHECK-NEXT: ret float %r
 
diff --git a/test/Transforms/Reassociate/fast-fp-commute.ll b/test/Transforms/Reassociate/fast-fp-commute.ll
index 71fe7bb48a0..ad89607a21e 100644
--- a/test/Transforms/Reassociate/fast-fp-commute.ll
+++ b/test/Transforms/Reassociate/fast-fp-commute.ll
@@ -33,7 +33,7 @@ define float @test2(float %x, float %y) {
 
 define float @test3(float %x, float %y) {
 ; CHECK-LABEL: test3
-; CHECK-NEXT: %factor = fmul fast float 2.000000e+00, %y
+; CHECK-NEXT: %factor = fmul fast float %y, 2.000000e+00
 ; CHECK-NEXT: %tmp1 = fmul fast float %factor, %x
 ; CHECK-NEXT: ret float %tmp1
 
-- 
2.34.1