maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

[InstCombine] sub(xor(x, y), or(x, y)) -> neg(and(x, y)) 

Summary:
```
Name: sub(xor(x, y), or(x, y)) -> neg(and(x, y))
%or = or i32 %y, %x
%xor = xor i32 %x, %y
%sub = sub i32 %xor, %or
  =>
%sub1 = and i32 %x, %y
%sub = sub i32 0, %sub1

Optimization: sub(xor(x, y), or(x, y)) -> neg(and(x, y))
Done: 1
Optimization is correct!
```

https://rise4fun.com/Alive/8OI

Reviewers: lebedev.ri

Reviewed By: lebedev.ri

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67188

llvm-svn: 370945
This commit is contained in:
David Bolvansky 2019-09-04 18:03:21 +00:00
parent 673e5476a8
commit 420cbb6190
2 changed files with 24 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
View File

@ -1742,6 +1742,15 @@ Instruction *InstCombiner::visitSub(BinaryOperator &I) {
return BinaryOperator::CreateAnd(A, B);
}
// (sub (xor A, B) (or A, B)) --> neg (and A, B)
{
Value *A, *B;
if (match(Op0, m_Xor(m_Value(A), m_Value(B))) &&
match(Op1, m_c_Or(m_Specific(A), m_Specific(B))) &&
(Op0->hasOneUse() || Op1->hasOneUse()))
return BinaryOperator::CreateNeg(Builder.CreateAnd(A, B));
}
{
Value *Y;
// ((X | Y) - X) --> (~X & Y)

35
llvm/test/Transforms/InstCombine/sub-xor-or-neg-and.ll
View File

@ -5,9 +5,8 @@ declare void @use(i32)
define i32 @sub_to_and(i32 %x, i32 %y) {
; CHECK-LABEL: @sub_to_and(
; CHECK-NEXT: [[OR:%.*]] = or i32 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: [[XOR:%.*]] = xor i32 [[X]], [[Y]]
; CHECK-NEXT: [[SUB:%.*]] = sub i32 [[XOR]], [[OR]]
; CHECK-NEXT: [[TMP1:%.*]] = and i32 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: [[SUB:%.*]] = sub i32 0, [[TMP1]]
; CHECK-NEXT: ret i32 [[SUB]]
;
%or = or i32 %x, %y
@ -18,9 +17,8 @@ define i32 @sub_to_and(i32 %x, i32 %y) {
define i32 @sub_to_and_extra_use_sub(i32 %x, i32 %y) {
; CHECK-LABEL: @sub_to_and_extra_use_sub(
; CHECK-NEXT: [[OR:%.*]] = or i32 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: [[XOR:%.*]] = xor i32 [[X]], [[Y]]
; CHECK-NEXT: [[SUB:%.*]] = sub i32 [[XOR]], [[OR]]
; CHECK-NEXT: [[TMP1:%.*]] = and i32 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: [[SUB:%.*]] = sub i32 0, [[TMP1]]
; CHECK-NEXT: call void @use(i32 [[SUB]])
; CHECK-NEXT: ret i32 [[SUB]]
;
@ -33,10 +31,10 @@ define i32 @sub_to_and_extra_use_sub(i32 %x, i32 %y) {
define i32 @sub_to_and_extra_use_and(i32 %x, i32 %y) {
; CHECK-LABEL: @sub_to_and_extra_use_and(
; CHECK-NEXT: [[OR:%.*]] = or i32 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: [[XOR:%.*]] = xor i32 [[X]], [[Y]]
; CHECK-NEXT: [[XOR:%.*]] = xor i32 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: call void @use(i32 [[XOR]])
; CHECK-NEXT: [[SUB:%.*]] = sub i32 [[XOR]], [[OR]]
; CHECK-NEXT: [[TMP1:%.*]] = and i32 [[X]], [[Y]]
; CHECK-NEXT: [[SUB:%.*]] = sub i32 0, [[TMP1]]
; CHECK-NEXT: ret i32 [[SUB]]
;
%or = or i32 %x, %y
@ -50,8 +48,8 @@ define i32 @sub_to_and_extra_use_or(i32 %x, i32 %y) {
; CHECK-LABEL: @sub_to_and_extra_use_or(
; CHECK-NEXT: [[OR:%.*]] = or i32 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: call void @use(i32 [[OR]])
; CHECK-NEXT: [[XOR:%.*]] = xor i32 [[X]], [[Y]]
; CHECK-NEXT: [[SUB:%.*]] = sub i32 [[XOR]], [[OR]]
; CHECK-NEXT: [[TMP1:%.*]] = and i32 [[X]], [[Y]]
; CHECK-NEXT: [[SUB:%.*]] = sub i32 0, [[TMP1]]
; CHECK-NEXT: ret i32 [[SUB]]
;
%or = or i32 %x, %y
@ -63,9 +61,8 @@ define i32 @sub_to_and_extra_use_or(i32 %x, i32 %y) {
define i32 @sub_to_and_or_commuted(i32 %x, i32 %y) {
; CHECK-LABEL: @sub_to_and_or_commuted(
; CHECK-NEXT: [[OR:%.*]] = or i32 [[Y:%.*]], [[X:%.*]]
; CHECK-NEXT: [[XOR:%.*]] = xor i32 [[X]], [[Y]]
; CHECK-NEXT: [[SUB:%.*]] = sub i32 [[XOR]], [[OR]]
; CHECK-NEXT: [[TMP1:%.*]] = and i32 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: [[SUB:%.*]] = sub i32 0, [[TMP1]]
; CHECK-NEXT: ret i32 [[SUB]]
;
%or = or i32 %y, %x
@ -76,9 +73,8 @@ define i32 @sub_to_and_or_commuted(i32 %x, i32 %y) {
define i32 @sub_to_and_and_commuted(i32 %x, i32 %y) {
; CHECK-LABEL: @sub_to_and_and_commuted(
; CHECK-NEXT: [[OR:%.*]] = or i32 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: [[XOR:%.*]] = xor i32 [[Y]], [[X]]
; CHECK-NEXT: [[SUB:%.*]] = sub i32 [[XOR]], [[OR]]
; CHECK-NEXT: [[TMP1:%.*]] = and i32 [[Y:%.*]], [[X:%.*]]
; CHECK-NEXT: [[SUB:%.*]] = sub i32 0, [[TMP1]]
; CHECK-NEXT: ret i32 [[SUB]]
;
%or = or i32 %x, %y
@ -89,9 +85,8 @@ define i32 @sub_to_and_and_commuted(i32 %x, i32 %y) {
define <2 x i32> @sub_to_and_vec(<2 x i32> %x, <2 x i32> %y) {
; CHECK-LABEL: @sub_to_and_vec(
; CHECK-NEXT: [[OR:%.*]] = or <2 x i32> [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: [[XOR:%.*]] = xor <2 x i32> [[Y]], [[X]]
; CHECK-NEXT: [[SUB:%.*]] = sub <2 x i32> [[XOR]], [[OR]]
; CHECK-NEXT: [[TMP1:%.*]] = and <2 x i32> [[Y:%.*]], [[X:%.*]]
; CHECK-NEXT: [[SUB:%.*]] = sub <2 x i32> zeroinitializer, [[TMP1]]
; CHECK-NEXT: ret <2 x i32> [[SUB]]
;
%or = or <2 x i32> %x, %y