[PATCH] D34308: [InstCombine] Cleanup some duplicated one use checks
Craig Topper via Phabricator via llvm-commits
llvm-commits at lists.llvm.org
Fri Jun 16 17:38:19 PDT 2017
craig.topper created this revision.
These 4 patterns have the same one use check repeated twice for each. Once without a cast and one with. But the cast has no effect on what method is called.
For the OR case I believe it is always profitable regardless of the number of uses since we'll never increase the instruction count.
For the AND case I believe it is profitable if the pair of xors has one use such that we'll get rid of it completely. Or if the C value is something freely invertible, in which case the not doesn't cost anything.
https://reviews.llvm.org/D34308
Files:
lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
test/Transforms/InstCombine/or-xor.ll
test/Transforms/InstCombine/xor2.ll
Index: test/Transforms/InstCombine/xor2.ll
===================================================================
--- test/Transforms/InstCombine/xor2.ll
+++ test/Transforms/InstCombine/xor2.ll
@@ -330,7 +330,7 @@
; CHECK-NEXT: [[XOR1:%.*]] = xor i8 [[B:%.*]], [[A:%.*]]
; CHECK-NEXT: [[NOT:%.*]] = xor i8 [[A]], 33
; CHECK-NEXT: [[XOR2:%.*]] = xor i8 [[NOT]], [[B]]
-; CHECK-NEXT: [[AND:%.*]] = and i8 [[XOR1]], [[XOR2]]
+; CHECK-NEXT: [[AND:%.*]] = and i8 [[XOR1]], -34
; CHECK-NEXT: [[RES:%.*]] = mul i8 [[AND]], [[XOR2]]
; CHECK-NEXT: ret i8 [[RES]]
;
@@ -347,7 +347,7 @@
; CHECK-NEXT: [[XOR1:%.*]] = xor i8 [[B:%.*]], [[A:%.*]]
; CHECK-NEXT: [[NOT:%.*]] = xor i8 [[A]], 33
; CHECK-NEXT: [[XOR2:%.*]] = xor i8 [[NOT]], [[B]]
-; CHECK-NEXT: [[AND:%.*]] = and i8 [[XOR2]], [[XOR1]]
+; CHECK-NEXT: [[AND:%.*]] = and i8 [[XOR1]], -34
; CHECK-NEXT: [[RES:%.*]] = mul i8 [[AND]], [[XOR2]]
; CHECK-NEXT: ret i8 [[RES]]
;
Index: test/Transforms/InstCombine/or-xor.ll
===================================================================
--- test/Transforms/InstCombine/or-xor.ll
+++ test/Transforms/InstCombine/or-xor.ll
@@ -316,7 +316,7 @@
; CHECK-NEXT: [[XOR1:%.*]] = xor i8 [[B:%.*]], [[A:%.*]]
; CHECK-NEXT: [[NOT:%.*]] = xor i8 [[A]], 33
; CHECK-NEXT: [[XOR2:%.*]] = xor i8 [[NOT]], [[B]]
-; CHECK-NEXT: [[OR:%.*]] = or i8 [[XOR1]], [[XOR2]]
+; CHECK-NEXT: [[OR:%.*]] = or i8 [[XOR1]], 33
; CHECK-NEXT: [[RES:%.*]] = mul i8 [[OR]], [[XOR2]]
; CHECK-NEXT: ret i8 [[RES]]
;
@@ -333,7 +333,7 @@
; CHECK-NEXT: [[XOR1:%.*]] = xor i8 [[B:%.*]], [[A:%.*]]
; CHECK-NEXT: [[NOT:%.*]] = xor i8 [[A]], 33
; CHECK-NEXT: [[XOR2:%.*]] = xor i8 [[NOT]], [[B]]
-; CHECK-NEXT: [[OR:%.*]] = or i8 [[XOR2]], [[XOR1]]
+; CHECK-NEXT: [[OR:%.*]] = or i8 [[XOR1]], 33
; CHECK-NEXT: [[RES:%.*]] = mul i8 [[OR]], [[XOR2]]
; CHECK-NEXT: ret i8 [[RES]]
;
Index: lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
===================================================================
--- lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
+++ lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
@@ -1442,13 +1442,13 @@
// (A ^ B) & ((B ^ C) ^ A) -> (A ^ B) & ~C
if (match(Op0, m_Xor(m_Value(A), m_Value(B))))
if (match(Op1, m_Xor(m_Xor(m_Specific(B), m_Value(C)), m_Specific(A))))
- if (Op1->hasOneUse() || cast<BinaryOperator>(Op1)->hasOneUse())
+ if (Op1->hasOneUse() || IsFreeToInvert(C, C->hasOneUse()))
return BinaryOperator::CreateAnd(Op0, Builder->CreateNot(C));
// ((A ^ C) ^ B) & (B ^ A) -> (B ^ A) & ~C
if (match(Op0, m_Xor(m_Xor(m_Value(A), m_Value(C)), m_Value(B))))
if (match(Op1, m_Xor(m_Specific(B), m_Specific(A))))
- if (Op0->hasOneUse() || cast<BinaryOperator>(Op0)->hasOneUse())
+ if (Op0->hasOneUse() || IsFreeToInvert(C, C->hasOneUse()))
return BinaryOperator::CreateAnd(Op1, Builder->CreateNot(C));
// (A | B) & ((~A) ^ B) -> (A & B)
@@ -2138,20 +2138,14 @@
}
// (A ^ B) | ((B ^ C) ^ A) -> (A ^ B) | C
- // FIXME: The two hasOneUse calls here are the same call, maybe we were
- // supposed to check Op1->operand(0)?
if (match(Op0, m_Xor(m_Value(A), m_Value(B))))
if (match(Op1, m_Xor(m_Xor(m_Specific(B), m_Value(C)), m_Specific(A))))
- if (Op1->hasOneUse() || cast<BinaryOperator>(Op1)->hasOneUse())
- return BinaryOperator::CreateOr(Op0, C);
+ return BinaryOperator::CreateOr(Op0, C);
// ((A ^ C) ^ B) | (B ^ A) -> (B ^ A) | C
- // FIXME: The two hasOneUse calls here are the same call, maybe we were
- // supposed to check Op0->operand(0)?
if (match(Op0, m_Xor(m_Xor(m_Value(A), m_Value(C)), m_Value(B))))
if (match(Op1, m_Xor(m_Specific(B), m_Specific(A))))
- if (Op0->hasOneUse() || cast<BinaryOperator>(Op0)->hasOneUse())
- return BinaryOperator::CreateOr(Op1, C);
+ return BinaryOperator::CreateOr(Op1, C);
// ((B | C) & A) | B -> B | (A & C)
if (match(Op0, m_And(m_Or(m_Specific(Op1), m_Value(C)), m_Value(A))))
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