llvm/test/Transforms/Reassociate/negation1.ll
Owen Anderson eb2be34094 Give the Reassociate pass a bit more flexibility and autonomy when optimizing expressions.
Particularly, it addresses cases where Reassociate breaks Subtracts but then fails to optimize combinations like I1 + -I2 where I1 and I2 have the same rank and are identical.

Patch by Dmitri Shtilman.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219092 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-05 23:41:26 +00:00

16 lines
310 B
LLVM

; RUN: opt < %s -reassociate -instcombine -S | FileCheck %s
; Test that we can turn things like A*B + X - A*B -> X.
define i32 @test1(i32 %a, i32 %b, i32 %x) {
; CHECK-LABEL: test1
; CHECK: ret i32 %x
%c = mul i32 %a, %b
%d = add i32 %c, %x
%c1 = mul i32 %a, %b
%f = sub i32 %d, %c1
ret i32 %f
}