llvm-6502/test/Transforms/Reassociate/inverses.ll
Benjamin Kramer 37bc2f3216 [Reassociate] Similar to "X + -X" -> "0", added code to handle "X + ~X" -> "-1".
Handle "X + ~X" -> "-1" in the function Value *Reassociate::OptimizeAdd(Instruction *I, SmallVectorImpl<ValueEntry> &Ops);
This patch implements:
TODO: We could handle "X + ~X" -> "-1" if we wanted, since "-X = ~X+1".

Patch by Rahul Jain!

Differential Revision: http://reviews.llvm.org/D3835

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209973 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-31 15:01:54 +00:00

47 lines
1.1 KiB
LLVM

; RUN: opt < %s -reassociate -die -S | FileCheck %s
define i32 @test1(i32 %a, i32 %b) {
%tmp.2 = and i32 %b, %a
%tmp.4 = xor i32 %a, -1
; (A&B)&~A == 0
%tmp.5 = and i32 %tmp.2, %tmp.4
ret i32 %tmp.5
; CHECK-LABEL: @test1(
; CHECK: ret i32 0
}
define i32 @test2(i32 %a, i32 %b) {
%tmp.1 = and i32 %a, 1234
%tmp.2 = and i32 %b, %tmp.1
%tmp.4 = xor i32 %a, -1
; A&~A == 0
%tmp.5 = and i32 %tmp.2, %tmp.4
ret i32 %tmp.5
; CHECK-LABEL: @test2(
; CHECK: ret i32 0
}
define i32 @test3(i32 %b, i32 %a) {
%tmp.1 = add i32 %a, 1234
%tmp.2 = add i32 %b, %tmp.1
%tmp.4 = sub i32 0, %a
; (b+(a+1234))+-a -> b+1234
%tmp.5 = add i32 %tmp.2, %tmp.4
ret i32 %tmp.5
; CHECK-LABEL: @test3(
; CHECK: %tmp.5 = add i32 %b, 1234
; CHECK: ret i32 %tmp.5
}
define i32 @test4(i32 %b, i32 %a) {
%tmp.1 = add i32 %a, 1234
%tmp.2 = add i32 %b, %tmp.1
%tmp.4 = xor i32 %a, -1
; (b+(a+1234))+~a -> b+1233
%tmp.5 = add i32 %tmp.2, %tmp.4
ret i32 %tmp.5
; CHECK-LABEL: @test4(
; CHECK: %tmp.5 = add i32 %b, 1233
; CHECK: ret i32 %tmp.5
}