[InstCombine] Remove foldSelectICmpEq() fold #122098
Merged
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This fold matches complex patterns, for which we have no proof of real-world relevance, and which does not actually handle the originally motivating cases from llvm#71792. In llvm#121708 and llvm#121753 we have handled some simpler variants by extending existing folds. I propose to remove this code until we have evidence that it is useful for something.
llvmbot
added
llvm:instcombine
|
@llvm/pr-subscribers-llvm-transforms Author: Nikita Popov (nikic) ChangesThis fold matches complex patterns, for which we have no proof of real-world relevance, and which does not actually handle the originally motivating cases from #71792 either. In #121708 and #121753 we have handled some simpler variants by extending existing folds. I propose to remove this code until we have evidence that it is useful for something. Full diff: https://github.com/llvm/llvm-project/pull/122098.diff 2 Files Affected:
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
index c58a63483a717e..4ba9d52213aaf6 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
@@ -1843,92 +1843,6 @@ static Instruction *foldSelectICmpEq(SelectInst &SI, ICmpInst *ICI,
foldSelectWithExtremeEqCond(CmpLHS, CmpRHS, TrueVal, FalseVal))
return Res;
- // Transform (X == C) ? X : Y -> (X == C) ? C : Y
- // specific handling for Bitwise operation.
- // x&y -> (x|y) ^ (x^y) or (x|y) & ~(x^y)
- // x|y -> (x&y) | (x^y) or (x&y) ^ (x^y)
- // x^y -> (x|y) ^ (x&y) or (x|y) & ~(x&y)
- Value *X, *Y;
- if (!match(CmpLHS, m_BitwiseLogic(m_Value(X), m_Value(Y))) ||
- !match(TrueVal, m_c_BitwiseLogic(m_Specific(X), m_Specific(Y))))
- return nullptr;
-
- const unsigned AndOps = Instruction::And, OrOps = Instruction::Or,
- XorOps = Instruction::Xor, NoOps = 0;
- enum NotMask { None = 0, NotInner, NotRHS };
-
- auto matchFalseVal = [&](unsigned OuterOpc, unsigned InnerOpc,
- unsigned NotMask) {
- auto matchInner = m_c_BinOp(InnerOpc, m_Specific(X), m_Specific(Y));
- if (OuterOpc == NoOps)
- return match(CmpRHS, m_Zero()) && match(FalseVal, matchInner);
-
- if (NotMask == NotInner) {
- return match(FalseVal, m_c_BinOp(OuterOpc, m_NotForbidPoison(matchInner),
- m_Specific(CmpRHS)));
- } else if (NotMask == NotRHS) {
- return match(FalseVal, m_c_BinOp(OuterOpc, matchInner,
- m_NotForbidPoison(m_Specific(CmpRHS))));
- } else {
- return match(FalseVal,
- m_c_BinOp(OuterOpc, matchInner, m_Specific(CmpRHS)));
- }
- };
-
- // (X&Y)==C ? X|Y : X^Y -> (X^Y)|C : X^Y or (X^Y)^ C : X^Y
- // (X&Y)==C ? X^Y : X|Y -> (X|Y)^C : X|Y or (X|Y)&~C : X|Y
- if (match(CmpLHS, m_And(m_Value(X), m_Value(Y)))) {
- if (match(TrueVal, m_c_Or(m_Specific(X), m_Specific(Y)))) {
- // (X&Y)==C ? X|Y : (X^Y)|C -> (X^Y)|C : (X^Y)|C -> (X^Y)|C
- // (X&Y)==C ? X|Y : (X^Y)^C -> (X^Y)^C : (X^Y)^C -> (X^Y)^C
- if (matchFalseVal(OrOps, XorOps, None) ||
- matchFalseVal(XorOps, XorOps, None))
- return IC.replaceInstUsesWith(SI, FalseVal);
- } else if (match(TrueVal, m_c_Xor(m_Specific(X), m_Specific(Y)))) {
- // (X&Y)==C ? X^Y : (X|Y)^ C -> (X|Y)^ C : (X|Y)^ C -> (X|Y)^ C
- // (X&Y)==C ? X^Y : (X|Y)&~C -> (X|Y)&~C : (X|Y)&~C -> (X|Y)&~C
- if (matchFalseVal(XorOps, OrOps, None) ||
- matchFalseVal(AndOps, OrOps, NotRHS))
- return IC.replaceInstUsesWith(SI, FalseVal);
- }
- }
-
- // (X|Y)==C ? X&Y : X^Y -> (X^Y)^C : X^Y or ~(X^Y)&C : X^Y
- // (X|Y)==C ? X^Y : X&Y -> (X&Y)^C : X&Y or ~(X&Y)&C : X&Y
- if (match(CmpLHS, m_Or(m_Value(X), m_Value(Y)))) {
- if (match(TrueVal, m_c_And(m_Specific(X), m_Specific(Y)))) {
- // (X|Y)==C ? X&Y: (X^Y)^C -> (X^Y)^C: (X^Y)^C -> (X^Y)^C
- // (X|Y)==C ? X&Y:~(X^Y)&C ->~(X^Y)&C:~(X^Y)&C -> ~(X^Y)&C
- if (matchFalseVal(XorOps, XorOps, None) ||
- matchFalseVal(AndOps, XorOps, NotInner))
- return IC.replaceInstUsesWith(SI, FalseVal);
- } else if (match(TrueVal, m_c_Xor(m_Specific(X), m_Specific(Y)))) {
- // (X|Y)==C ? X^Y : (X&Y)^C -> (X&Y)^C : (X&Y)^C -> (X&Y)^C
- // (X|Y)==C ? X^Y :~(X&Y)&C -> ~(X&Y)&C :~(X&Y)&C -> ~(X&Y)&C
- if (matchFalseVal(XorOps, AndOps, None) ||
- matchFalseVal(AndOps, AndOps, NotInner))
- return IC.replaceInstUsesWith(SI, FalseVal);
- }
- }
-
- // (X^Y)==C ? X&Y : X|Y -> (X|Y)^C : X|Y or (X|Y)&~C : X|Y
- // (X^Y)==C ? X|Y : X&Y -> (X&Y)|C : X&Y or (X&Y)^ C : X&Y
- if (match(CmpLHS, m_Xor(m_Value(X), m_Value(Y)))) {
- if ((match(TrueVal, m_c_And(m_Specific(X), m_Specific(Y))))) {
- // (X^Y)==C ? X&Y : (X|Y)^C -> (X|Y)^C
- // (X^Y)==C ? X&Y : (X|Y)&~C -> (X|Y)&~C
- if (matchFalseVal(XorOps, OrOps, None) ||
- matchFalseVal(AndOps, OrOps, NotRHS))
- return IC.replaceInstUsesWith(SI, FalseVal);
- } else if (match(TrueVal, m_c_Or(m_Specific(X), m_Specific(Y)))) {
- // (X^Y)==C ? (X|Y) : (X&Y)|C -> (X&Y)|C
- // (X^Y)==C ? (X|Y) : (X&Y)^C -> (X&Y)^C
- if (matchFalseVal(OrOps, AndOps, None) ||
- matchFalseVal(XorOps, AndOps, None))
- return IC.replaceInstUsesWith(SI, FalseVal);
- }
- }
-
return nullptr;
}
diff --git a/llvm/test/Transforms/InstCombine/select.ll b/llvm/test/Transforms/InstCombine/select.ll
index 0f15fa6c0cc50a..3c3111492fc681 100644
--- a/llvm/test/Transforms/InstCombine/select.ll
+++ b/llvm/test/Transforms/InstCombine/select.ll
@@ -3841,9 +3841,13 @@ entry:
define i32 @src_and_eq_C_or_xororC(i32 %x, i32 %y, i32 %c) {
; CHECK-LABEL: @src_and_eq_C_or_xororC(
; CHECK-NEXT: entry:
-; CHECK-NEXT: [[XOR:%.*]] = xor i32 [[Y:%.*]], [[X:%.*]]
-; CHECK-NEXT: [[OR1:%.*]] = or i32 [[XOR]], [[C:%.*]]
-; CHECK-NEXT: ret i32 [[OR1]]
+; CHECK-NEXT: [[AND:%.*]] = and i32 [[Y:%.*]], [[X:%.*]]
+; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[AND]], [[C:%.*]]
+; CHECK-NEXT: [[OR:%.*]] = or i32 [[Y]], [[X]]
+; CHECK-NEXT: [[XOR:%.*]] = xor i32 [[Y]], [[X]]
+; CHECK-NEXT: [[OR1:%.*]] = or i32 [[XOR]], [[C]]
+; CHECK-NEXT: [[COND:%.*]] = select i1 [[CMP]], i32 [[OR]], i32 [[OR1]]
+; CHECK-NEXT: ret i32 [[COND]]
;
entry:
%and = and i32 %y, %x
@@ -3858,9 +3862,13 @@ entry:
define i32 @src_and_eq_C_or_xorxorC(i32 %x, i32 %y, i32 %c) {
; CHECK-LABEL: @src_and_eq_C_or_xorxorC(
; CHECK-NEXT: entry:
-; CHECK-NEXT: [[XOR:%.*]] = xor i32 [[Y:%.*]], [[X:%.*]]
-; CHECK-NEXT: [[XOR1:%.*]] = xor i32 [[XOR]], [[C:%.*]]
-; CHECK-NEXT: ret i32 [[XOR1]]
+; CHECK-NEXT: [[AND:%.*]] = and i32 [[Y:%.*]], [[X:%.*]]
+; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[AND]], [[C:%.*]]
+; CHECK-NEXT: [[OR:%.*]] = or i32 [[Y]], [[X]]
+; CHECK-NEXT: [[XOR:%.*]] = xor i32 [[Y]], [[X]]
+; CHECK-NEXT: [[XOR1:%.*]] = xor i32 [[XOR]], [[C]]
+; CHECK-NEXT: [[COND:%.*]] = select i1 [[CMP]], i32 [[OR]], i32 [[XOR1]]
+; CHECK-NEXT: ret i32 [[COND]]
;
entry:
%and = and i32 %y, %x
@@ -3875,10 +3883,14 @@ entry:
define i32 @src_and_eq_C_xor_OrAndNotC(i32 %x, i32 %y, i32 %c) {
; CHECK-LABEL: @src_and_eq_C_xor_OrAndNotC(
; CHECK-NEXT: entry:
-; CHECK-NEXT: [[OR:%.*]] = or i32 [[Y:%.*]], [[X:%.*]]
-; CHECK-NEXT: [[NOT:%.*]] = xor i32 [[C:%.*]], -1
+; CHECK-NEXT: [[AND:%.*]] = and i32 [[Y:%.*]], [[X:%.*]]
+; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[AND]], [[C:%.*]]
+; CHECK-NEXT: [[XOR:%.*]] = xor i32 [[Y]], [[X]]
+; CHECK-NEXT: [[OR:%.*]] = or i32 [[Y]], [[X]]
+; CHECK-NEXT: [[NOT:%.*]] = xor i32 [[C]], -1
; CHECK-NEXT: [[AND1:%.*]] = and i32 [[OR]], [[NOT]]
-; CHECK-NEXT: ret i32 [[AND1]]
+; CHECK-NEXT: [[COND:%.*]] = select i1 [[CMP]], i32 [[XOR]], i32 [[AND1]]
+; CHECK-NEXT: ret i32 [[COND]]
;
entry:
%and = and i32 %y, %x
@@ -3917,9 +3929,13 @@ entry:
define i32 @src_and_eq_C_xor_orxorC(i32 %x, i32 %y, i32 %c) {
; CHECK-LABEL: @src_and_eq_C_xor_orxorC(
; CHECK-NEXT: entry:
-; CHECK-NEXT: [[OR:%.*]] = or i32 [[Y:%.*]], [[X:%.*]]
-; CHECK-NEXT: [[XOR1:%.*]] = xor i32 [[OR]], [[C:%.*]]
-; CHECK-NEXT: ret i32 [[XOR1]]
+; CHECK-NEXT: [[AND:%.*]] = and i32 [[Y:%.*]], [[X:%.*]]
+; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[AND]], [[C:%.*]]
+; CHECK-NEXT: [[XOR:%.*]] = xor i32 [[Y]], [[X]]
+; CHECK-NEXT: [[OR:%.*]] = or i32 [[Y]], [[X]]
+; CHECK-NEXT: [[XOR1:%.*]] = xor i32 [[OR]], [[C]]
+; CHECK-NEXT: [[COND:%.*]] = select i1 [[CMP]], i32 [[XOR]], i32 [[XOR1]]
+; CHECK-NEXT: ret i32 [[COND]]
;
entry:
%and = and i32 %y, %x
@@ -3968,9 +3984,13 @@ entry:
define i32 @src_or_eq_neg1_and_xor(i32 %x, i32 %y) {
; CHECK-LABEL: @src_or_eq_neg1_and_xor(
; CHECK-NEXT: entry:
-; CHECK-NEXT: [[TMP0:%.*]] = xor i32 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT: [[OR:%.*]] = or i32 [[Y:%.*]], [[X:%.*]]
+; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[OR]], -1
+; CHECK-NEXT: [[AND:%.*]] = and i32 [[Y]], [[X]]
+; CHECK-NEXT: [[TMP0:%.*]] = xor i32 [[X]], [[Y]]
; CHECK-NEXT: [[NOT:%.*]] = xor i32 [[TMP0]], -1
-; CHECK-NEXT: ret i32 [[NOT]]
+; CHECK-NEXT: [[COND:%.*]] = select i1 [[CMP]], i32 [[AND]], i32 [[NOT]]
+; CHECK-NEXT: ret i32 [[COND]]
;
entry:
%or = or i32 %y, %x
@@ -3985,9 +4005,13 @@ entry:
define i32 @src_or_eq_neg1_xor_and(i32 %x, i32 %y) {
; CHECK-LABEL: @src_or_eq_neg1_xor_and(
; CHECK-NEXT: entry:
-; CHECK-NEXT: [[AND:%.*]] = and i32 [[Y:%.*]], [[X:%.*]]
+; CHECK-NEXT: [[OR:%.*]] = or i32 [[Y:%.*]], [[X:%.*]]
+; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[OR]], -1
+; CHECK-NEXT: [[XOR:%.*]] = xor i32 [[Y]], [[X]]
+; CHECK-NEXT: [[AND:%.*]] = and i32 [[Y]], [[X]]
; CHECK-NEXT: [[NOT:%.*]] = xor i32 [[AND]], -1
-; CHECK-NEXT: ret i32 [[NOT]]
+; CHECK-NEXT: [[COND:%.*]] = select i1 [[CMP]], i32 [[XOR]], i32 [[NOT]]
+; CHECK-NEXT: ret i32 [[COND]]
;
entry:
%or = or i32 %y, %x
@@ -4002,9 +4026,13 @@ entry:
define i32 @src_or_eq_C_and_xorC(i32 %x, i32 %y, i32 %c) {
; CHECK-LABEL: @src_or_eq_C_and_xorC(
; CHECK-NEXT: entry:
-; CHECK-NEXT: [[XOR:%.*]] = xor i32 [[Y:%.*]], [[X:%.*]]
-; CHECK-NEXT: [[XOR1:%.*]] = xor i32 [[XOR]], [[C:%.*]]
-; CHECK-NEXT: ret i32 [[XOR1]]
+; CHECK-NEXT: [[OR:%.*]] = or i32 [[Y:%.*]], [[X:%.*]]
+; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[OR]], [[C:%.*]]
+; CHECK-NEXT: [[AND:%.*]] = and i32 [[Y]], [[X]]
+; CHECK-NEXT: [[XOR:%.*]] = xor i32 [[Y]], [[X]]
+; CHECK-NEXT: [[XOR1:%.*]] = xor i32 [[XOR]], [[C]]
+; CHECK-NEXT: [[COND:%.*]] = select i1 [[CMP]], i32 [[AND]], i32 [[XOR1]]
+; CHECK-NEXT: ret i32 [[COND]]
;
entry:
%or = or i32 %y, %x
@@ -4019,10 +4047,14 @@ entry:
define i32 @src_or_eq_C_and_andnotxorC(i32 %x, i32 %y, i32 %c) {
; CHECK-LABEL: @src_or_eq_C_and_andnotxorC(
; CHECK-NEXT: entry:
-; CHECK-NEXT: [[TMP0:%.*]] = xor i32 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT: [[OR:%.*]] = or i32 [[Y:%.*]], [[X:%.*]]
+; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[OR]], [[C:%.*]]
+; CHECK-NEXT: [[AND:%.*]] = and i32 [[Y]], [[X]]
+; CHECK-NEXT: [[TMP0:%.*]] = xor i32 [[X]], [[Y]]
; CHECK-NEXT: [[NOT:%.*]] = xor i32 [[TMP0]], -1
-; CHECK-NEXT: [[AND1:%.*]] = and i32 [[C:%.*]], [[NOT]]
-; CHECK-NEXT: ret i32 [[AND1]]
+; CHECK-NEXT: [[AND1:%.*]] = and i32 [[C]], [[NOT]]
+; CHECK-NEXT: [[COND:%.*]] = select i1 [[CMP]], i32 [[AND]], i32 [[AND1]]
+; CHECK-NEXT: ret i32 [[COND]]
;
entry:
%or = or i32 %y, %x
@@ -4038,9 +4070,13 @@ entry:
define i32 @src_or_eq_C_xor_xorandC(i32 %x, i32 %y, i32 %c) {
; CHECK-LABEL: @src_or_eq_C_xor_xorandC(
; CHECK-NEXT: entry:
-; CHECK-NEXT: [[AND:%.*]] = and i32 [[Y:%.*]], [[X:%.*]]
-; CHECK-NEXT: [[XOR1:%.*]] = xor i32 [[AND]], [[C:%.*]]
-; CHECK-NEXT: ret i32 [[XOR1]]
+; CHECK-NEXT: [[OR:%.*]] = or i32 [[Y:%.*]], [[X:%.*]]
+; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[OR]], [[C:%.*]]
+; CHECK-NEXT: [[XOR:%.*]] = xor i32 [[Y]], [[X]]
+; CHECK-NEXT: [[AND:%.*]] = and i32 [[Y]], [[X]]
+; CHECK-NEXT: [[XOR1:%.*]] = xor i32 [[AND]], [[C]]
+; CHECK-NEXT: [[COND:%.*]] = select i1 [[CMP]], i32 [[XOR]], i32 [[XOR1]]
+; CHECK-NEXT: ret i32 [[COND]]
;
entry:
%or = or i32 %y, %x
@@ -4055,10 +4091,14 @@ entry:
define i32 @src_or_eq_C_xor_andnotandC(i32 %x, i32 %y, i32 %c) {
; CHECK-LABEL: @src_or_eq_C_xor_andnotandC(
; CHECK-NEXT: entry:
-; CHECK-NEXT: [[AND:%.*]] = and i32 [[Y:%.*]], [[X:%.*]]
+; CHECK-NEXT: [[OR:%.*]] = or i32 [[Y:%.*]], [[X:%.*]]
+; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[OR]], [[C:%.*]]
+; CHECK-NEXT: [[XOR:%.*]] = xor i32 [[Y]], [[X]]
+; CHECK-NEXT: [[AND:%.*]] = and i32 [[Y]], [[X]]
; CHECK-NEXT: [[NOT:%.*]] = xor i32 [[AND]], -1
-; CHECK-NEXT: [[AND1:%.*]] = and i32 [[C:%.*]], [[NOT]]
-; CHECK-NEXT: ret i32 [[AND1]]
+; CHECK-NEXT: [[AND1:%.*]] = and i32 [[C]], [[NOT]]
+; CHECK-NEXT: [[COND:%.*]] = select i1 [[CMP]], i32 [[XOR]], i32 [[AND1]]
+; CHECK-NEXT: ret i32 [[COND]]
;
entry:
%or = or i32 %y, %x
@@ -4076,9 +4116,13 @@ entry:
define i32 @src_xor_eq_neg1_and(i32 %x, i32 %y) {
; CHECK-LABEL: @src_xor_eq_neg1_and(
; CHECK-NEXT: entry:
-; CHECK-NEXT: [[OR:%.*]] = or i32 [[Y:%.*]], [[X:%.*]]
+; CHECK-NEXT: [[XOR:%.*]] = xor i32 [[Y:%.*]], [[X:%.*]]
+; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[XOR]], -1
+; CHECK-NEXT: [[AND:%.*]] = and i32 [[Y]], [[X]]
+; CHECK-NEXT: [[OR:%.*]] = or i32 [[Y]], [[X]]
; CHECK-NEXT: [[NOT:%.*]] = xor i32 [[OR]], -1
-; CHECK-NEXT: ret i32 [[NOT]]
+; CHECK-NEXT: [[COND:%.*]] = select i1 [[CMP]], i32 [[AND]], i32 [[NOT]]
+; CHECK-NEXT: ret i32 [[COND]]
;
entry:
%xor = xor i32 %y, %x
@@ -4111,9 +4155,13 @@ entry:
define i32 @src_xor_eq_C_and_xororC(i32 %x, i32 %y, i32 %c) {
; CHECK-LABEL: @src_xor_eq_C_and_xororC(
; CHECK-NEXT: entry:
-; CHECK-NEXT: [[OR:%.*]] = or i32 [[Y:%.*]], [[X:%.*]]
-; CHECK-NEXT: [[XOR1:%.*]] = xor i32 [[OR]], [[C:%.*]]
-; CHECK-NEXT: ret i32 [[XOR1]]
+; CHECK-NEXT: [[XOR:%.*]] = xor i32 [[Y:%.*]], [[X:%.*]]
+; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[XOR]], [[C:%.*]]
+; CHECK-NEXT: [[AND:%.*]] = and i32 [[Y]], [[X]]
+; CHECK-NEXT: [[OR:%.*]] = or i32 [[Y]], [[X]]
+; CHECK-NEXT: [[XOR1:%.*]] = xor i32 [[OR]], [[C]]
+; CHECK-NEXT: [[COND:%.*]] = select i1 [[CMP]], i32 [[AND]], i32 [[XOR1]]
+; CHECK-NEXT: ret i32 [[COND]]
;
entry:
%xor = xor i32 %y, %x
@@ -4128,10 +4176,14 @@ entry:
define i32 @src_xor_eq_C_and_andornotC(i32 %x, i32 %y, i32 %c) {
; CHECK-LABEL: @src_xor_eq_C_and_andornotC(
; CHECK-NEXT: entry:
-; CHECK-NEXT: [[OR:%.*]] = or i32 [[Y:%.*]], [[X:%.*]]
-; CHECK-NEXT: [[NOT:%.*]] = xor i32 [[C:%.*]], -1
+; CHECK-NEXT: [[XOR:%.*]] = xor i32 [[Y:%.*]], [[X:%.*]]
+; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[XOR]], [[C:%.*]]
+; CHECK-NEXT: [[AND:%.*]] = and i32 [[Y]], [[X]]
+; CHECK-NEXT: [[OR:%.*]] = or i32 [[Y]], [[X]]
+; CHECK-NEXT: [[NOT:%.*]] = xor i32 [[C]], -1
; CHECK-NEXT: [[AND1:%.*]] = and i32 [[OR]], [[NOT]]
-; CHECK-NEXT: ret i32 [[AND1]]
+; CHECK-NEXT: [[COND:%.*]] = select i1 [[CMP]], i32 [[AND]], i32 [[AND1]]
+; CHECK-NEXT: ret i32 [[COND]]
;
entry:
%xor = xor i32 %y, %x
@@ -4147,9 +4199,13 @@ entry:
define i32 @src_xor_eq_C_or_xorandC(i32 %x, i32 %y, i32 %c) {
; CHECK-LABEL: @src_xor_eq_C_or_xorandC(
; CHECK-NEXT: entry:
-; CHECK-NEXT: [[AND:%.*]] = and i32 [[Y:%.*]], [[X:%.*]]
-; CHECK-NEXT: [[XOR1:%.*]] = xor i32 [[AND]], [[C:%.*]]
-; CHECK-NEXT: ret i32 [[XOR1]]
+; CHECK-NEXT: [[XOR:%.*]] = xor i32 [[Y:%.*]], [[X:%.*]]
+; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[XOR]], [[C:%.*]]
+; CHECK-NEXT: [[OR:%.*]] = or i32 [[Y]], [[X]]
+; CHECK-NEXT: [[AND:%.*]] = and i32 [[Y]], [[X]]
+; CHECK-NEXT: [[XOR1:%.*]] = xor i32 [[AND]], [[C]]
+; CHECK-NEXT: [[COND:%.*]] = select i1 [[CMP]], i32 [[OR]], i32 [[XOR1]]
+; CHECK-NEXT: ret i32 [[COND]]
;
entry:
%xor = xor i32 %y, %x
@@ -4164,9 +4220,13 @@ entry:
define i32 @src_xor_eq_C_or_orandC(i32 %x, i32 %y, i32 %c) {
; CHECK-LABEL: @src_xor_eq_C_or_orandC(
; CHECK-NEXT: entry:
-; CHECK-NEXT: [[AND:%.*]] = and i32 [[Y:%.*]], [[X:%.*]]
-; CHECK-NEXT: [[OR1:%.*]] = or i32 [[AND]], [[C:%.*]]
-; CHECK-NEXT: ret i32 [[OR1]]
+; CHECK-NEXT: [[XOR:%.*]] = xor i32 [[Y:%.*]], [[X:%.*]]
+; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[XOR]], [[C:%.*]]
+; CHECK-NEXT: [[OR:%.*]] = or i32 [[Y]], [[X]]
+; CHECK-NEXT: [[AND:%.*]] = and i32 [[Y]], [[X]]
+; CHECK-NEXT: [[OR1:%.*]] = or i32 [[AND]], [[C]]
+; CHECK-NEXT: [[COND:%.*]] = select i1 [[CMP]], i32 [[OR]], i32 [[OR1]]
+; CHECK-NEXT: ret i32 [[COND]]
;
entry:
%xor = xor i32 %y, %x
|
|
+1 |
dtcxzyw
approved these changes
Jan 9, 2025
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This fold matches complex patterns, for which we have no proof of real-world relevance, and which does not actually handle the originally motivating cases from #71792 either.
In #121708 and #121753 we have handled some simpler variants by extending existing folds.
I propose to remove this code until we have evidence that it is useful for something.