// -A + B --> B - A
// -A + -B --> -(A + B)
if (Value *LHSV = dyn_castNegVal(LHS)) {
- if (Value *RHSV = dyn_castNegVal(RHS)) {
- Value *NewAdd = Builder->CreateAdd(LHSV, RHSV, "sum");
- return BinaryOperator::CreateNeg(NewAdd);
- }
+ if (!isa<Constant>(RHS))
+ if (Value *RHSV = dyn_castNegVal(RHS)) {
+ Value *NewAdd = Builder->CreateAdd(LHSV, RHSV, "sum");
+ return BinaryOperator::CreateNeg(NewAdd);
+ }
return BinaryOperator::CreateSub(RHS, LHSV);
}
--- /dev/null
+; RUN: opt < %s -instcombine -S | FileCheck %s
+
+define void @entry() nounwind {\r
+entry:\r
+ br label %for.cond\r
+\r
+for.cond:\r
+ %local = phi <1 x i32> [ <i32 0>, %entry ], [ %phi2, %cond.end47 ]
+; CHECK: sub <1 x i32> <i32 92>, %local\r
+ %phi3 = sub <1 x i32> zeroinitializer, %local\r
+ br label %cond.end\r
+\r
+cond.false:\r
+ br label %cond.end\r
+\r
+cond.end:\r
+ %cond = phi <1 x i32> [ %phi3, %for.cond ], [ undef, %cond.false ]\r
+ br label %cond.end47\r
+\r
+cond.end47:\r
+ %sum = add <1 x i32> %cond, <i32 92>\r
+ %phi2 = sub <1 x i32> zeroinitializer, %sum\r
+ br label %for.cond\r
+}\r