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[InstCombine] reduce or-xor-or patterns

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(A | ?) | (A ^ B) --> (A | ?) | B
https://alive2.llvm.org/ce/z/dbNQw4

This extends the existing transform to peek through
another 'or' instruction for the common operand.

This is the underlying missing fold that should allow
issue #56711 and issue #57120 to reduce even more.
This commit is contained in:
Sanjay Patel
2022-08-13 09:47:28 -04:00
parent c771d0fd4b
commit 9d218b61cc
2 changed files with 17 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files

7
llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
View File

@@ -2914,6 +2914,13 @@ Instruction *InstCombinerImpl::visitOr(BinaryOperator &I) {
if (Op0 == A || Op0 == B)
return BinaryOperator::CreateOr(A, B);
// (A | ?) | (A ^ B) --> (A | ?) | B
// (B | ?) | (A ^ B) --> (B | ?) | A
if (match(Op0, m_c_Or(m_Specific(A), m_Value())))
return BinaryOperator::CreateOr(Op0, B);
if (match(Op0, m_c_Or(m_Specific(B), m_Value())))
return BinaryOperator::CreateOr(Op0, A);
// (A & B) | (A ^ B) --> A | B
// (B & A) | (A ^ B) --> A | B
if (match(Op0, m_And(m_Specific(A), m_Specific(B))) ||

24
llvm/test/Transforms/InstCombine/or-xor.ll
View File

@@ -639,8 +639,7 @@ define i32 @PR45977_f2(i32 %a, i32 %b) {
define i8 @or_xor_common_op_commute0(i8 %x, i8 %y, i8 %z) {
; CHECK-LABEL: @or_xor_common_op_commute0(
; CHECK-NEXT: [[OR:%.*]] = or i8 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: [[XOR:%.*]] = xor i8 [[X]], [[Z:%.*]]
; CHECK-NEXT: [[R:%.*]] = or i8 [[OR]], [[XOR]]
; CHECK-NEXT: [[R:%.*]] = or i8 [[OR]], [[Z:%.*]]
; CHECK-NEXT: ret i8 [[R]]
;
%or = or i8 %x, %y
@@ -653,8 +652,7 @@ define i8 @or_xor_common_op_commute1(i8 %x, i8 %y, i8 %z) {
; CHECK-LABEL: @or_xor_common_op_commute1(
; CHECK-NEXT: [[OR:%.*]] = or i8 [[Y:%.*]], [[X:%.*]]
; CHECK-NEXT: call void @use(i8 [[OR]])
; CHECK-NEXT: [[XOR:%.*]] = xor i8 [[X]], [[Z:%.*]]
; CHECK-NEXT: [[R:%.*]] = or i8 [[OR]], [[XOR]]
; CHECK-NEXT: [[R:%.*]] = or i8 [[OR]], [[Z:%.*]]
; CHECK-NEXT: ret i8 [[R]]
;
%or = or i8 %y, %x
@@ -669,7 +667,7 @@ define i8 @or_xor_common_op_commute2(i8 %x, i8 %y, i8 %z) {
; CHECK-NEXT: [[OR:%.*]] = or i8 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: [[XOR:%.*]] = xor i8 [[Z:%.*]], [[X]]
; CHECK-NEXT: call void @use(i8 [[XOR]])
; CHECK-NEXT: [[R:%.*]] = or i8 [[OR]], [[XOR]]
; CHECK-NEXT: [[R:%.*]] = or i8 [[OR]], [[Z]]
; CHECK-NEXT: ret i8 [[R]]
;
%or = or i8 %x, %y
@@ -685,7 +683,7 @@ define i8 @or_xor_common_op_commute3(i8 %x, i8 %y, i8 %z) {
; CHECK-NEXT: call void @use(i8 [[OR]])
; CHECK-NEXT: [[XOR:%.*]] = xor i8 [[Z:%.*]], [[X]]
; CHECK-NEXT: call void @use(i8 [[XOR]])
; CHECK-NEXT: [[R:%.*]] = or i8 [[OR]], [[XOR]]
; CHECK-NEXT: [[R:%.*]] = or i8 [[OR]], [[Z]]
; CHECK-NEXT: ret i8 [[R]]
;
%or = or i8 %y, %x
@@ -699,8 +697,7 @@ define i8 @or_xor_common_op_commute3(i8 %x, i8 %y, i8 %z) {
define <2 x i8> @or_xor_common_op_commute4(<2 x i8> %x, <2 x i8> %y, <2 x i8> %z) {
; CHECK-LABEL: @or_xor_common_op_commute4(
; CHECK-NEXT: [[OR:%.*]] = or <2 x i8> [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: [[XOR:%.*]] = xor <2 x i8> [[X]], [[Z:%.*]]
; CHECK-NEXT: [[R:%.*]] = or <2 x i8> [[XOR]], [[OR]]
; CHECK-NEXT: [[R:%.*]] = or <2 x i8> [[OR]], [[Z:%.*]]
; CHECK-NEXT: ret <2 x i8> [[R]]
;
%or = or <2 x i8> %x, %y
@@ -712,8 +709,7 @@ define <2 x i8> @or_xor_common_op_commute4(<2 x i8> %x, <2 x i8> %y, <2 x i8> %z
define i8 @or_xor_common_op_commute5(i8 %x, i8 %y, i8 %z) {
; CHECK-LABEL: @or_xor_common_op_commute5(
; CHECK-NEXT: [[OR:%.*]] = or i8 [[Y:%.*]], [[X:%.*]]
; CHECK-NEXT: [[XOR:%.*]] = xor i8 [[X]], [[Z:%.*]]
; CHECK-NEXT: [[R:%.*]] = or i8 [[XOR]], [[OR]]
; CHECK-NEXT: [[R:%.*]] = or i8 [[OR]], [[Z:%.*]]
; CHECK-NEXT: ret i8 [[R]]
;
%or = or i8 %y, %x
@@ -725,8 +721,7 @@ define i8 @or_xor_common_op_commute5(i8 %x, i8 %y, i8 %z) {
define i8 @or_xor_common_op_commute6(i8 %x, i8 %y, i8 %z) {
; CHECK-LABEL: @or_xor_common_op_commute6(
; CHECK-NEXT: [[OR:%.*]] = or i8 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: [[XOR:%.*]] = xor i8 [[Z:%.*]], [[X]]
; CHECK-NEXT: [[R:%.*]] = or i8 [[XOR]], [[OR]]
; CHECK-NEXT: [[R:%.*]] = or i8 [[OR]], [[Z:%.*]]
; CHECK-NEXT: ret i8 [[R]]
;
%or = or i8 %x, %y
@@ -738,8 +733,7 @@ define i8 @or_xor_common_op_commute6(i8 %x, i8 %y, i8 %z) {
define i8 @or_xor_common_op_commute7(i8 %x, i8 %y, i8 %z) {
; CHECK-LABEL: @or_xor_common_op_commute7(
; CHECK-NEXT: [[OR:%.*]] = or i8 [[Y:%.*]], [[X:%.*]]
; CHECK-NEXT: [[XOR:%.*]] = xor i8 [[Z:%.*]], [[X]]
; CHECK-NEXT: [[R:%.*]] = or i8 [[XOR]], [[OR]]
; CHECK-NEXT: [[R:%.*]] = or i8 [[OR]], [[Z:%.*]]
; CHECK-NEXT: ret i8 [[R]]
;
%or = or i8 %y, %x
@@ -748,6 +742,8 @@ define i8 @or_xor_common_op_commute7(i8 %x, i8 %y, i8 %z) {
ret i8 %r
}
; negative test - need common operand
define i8 @or_xor_notcommon_op(i8 %x, i8 %y, i8 %z, i8 %q) {
; CHECK-LABEL: @or_xor_notcommon_op(
; CHECK-NEXT: [[OR:%.*]] = or i8 [[X:%.*]], [[Y:%.*]]