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[InstCombine] allow vector splat matching for bitwise logic folds 

This fold was added long ago (part of fixing PR4216),
and it matched scalars only. Intermediate folds have
been added subsequently, so extra uses are required
to exercise this code.

General proof:
https://alive2.llvm.org/ce/z/G6BBhB

One of the specific tests:
https://alive2.llvm.org/ce/z/t0JhEB
This commit is contained in:
Sanjay Patel 2021-10-31 12:50:05 -04:00
parent 511ee8759f
commit 54e969cffd
2 changed files with 32 additions and 30 deletions
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58
llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
View File

@ -2706,43 +2706,45 @@ Instruction *InstCombinerImpl::visitOr(BinaryOperator &I) {
// (A & MaskC0) | (B & MaskC1)
const APInt *MaskC0, *MaskC1;
if (match(C, m_APInt(MaskC0)) && match(D, m_APInt(MaskC1)) &&
*MaskC0 == ~*MaskC1) {
if (match(C, m_APInt(MaskC0)) && match(D, m_APInt(MaskC1))) {
Value *X;
if (*MaskC0 == ~*MaskC1) {
// ((X | B) & MaskC) | (B & ~MaskC) -> (X & MaskC) | B
if (match(A, m_c_Or(m_Value(X), m_Specific(B))))
return BinaryOperator::CreateOr(Builder.CreateAnd(X, *MaskC0), B);
// (A & MaskC) | ((X | A) & ~MaskC) -> (X & ~MaskC) | A
if (match(B, m_c_Or(m_Specific(A), m_Value(X))))
return BinaryOperator::CreateOr(Builder.CreateAnd(X, *MaskC1), A);
// ((X | B) & MaskC) | (B & ~MaskC) -> (X & MaskC) | B
if (match(A, m_c_Or(m_Value(X), m_Specific(B))))
return BinaryOperator::CreateOr(Builder.CreateAnd(X, *MaskC0), B);
// (A & MaskC) | ((X | A) & ~MaskC) -> (X & ~MaskC) | A
if (match(B, m_c_Or(m_Specific(A), m_Value(X))))
return BinaryOperator::CreateOr(Builder.CreateAnd(X, *MaskC1), A);
// ((X ^ B) & MaskC) | (B & ~MaskC) -> (X & MaskC) ^ B
if (match(A, m_c_Xor(m_Value(X), m_Specific(B))))
return BinaryOperator::CreateXor(Builder.CreateAnd(X, *MaskC0), B);
// (A & MaskC) | ((X ^ A) & ~MaskC) -> (X & ~MaskC) ^ A
if (match(B, m_c_Xor(m_Specific(A), m_Value(X))))
return BinaryOperator::CreateXor(Builder.CreateAnd(X, *MaskC1), A);
}
// ((X ^ B) & MaskC) | (B & ~MaskC) -> (X & MaskC) ^ B
if (match(A, m_c_Xor(m_Value(X), m_Specific(B))))
return BinaryOperator::CreateXor(Builder.CreateAnd(X, *MaskC0), B);
// (A & MaskC) | ((X ^ A) & ~MaskC) -> (X & ~MaskC) ^ A
if (match(B, m_c_Xor(m_Specific(A), m_Value(X))))
return BinaryOperator::CreateXor(Builder.CreateAnd(X, *MaskC1), A);
if ((*MaskC0 & *MaskC1).isZero()) {
// ((X | B) & C1) | (B & C2) --> (X | B) & (C1 | C2)
// iff (C1 & C2) == 0 and (X & ~C1) == 0
if (match(A, m_c_Or(m_Value(X), m_Specific(B))) &&
MaskedValueIsZero(X, ~*MaskC0, 0, &I))
return BinaryOperator::CreateAnd(
A, ConstantInt::get(I.getType(), *MaskC0 | *MaskC1));
// (A & C1) | ((X | A) & C2) --> (X | A) & (C1 | C2)
// iff (C1 & C2) == 0 and (X & ~C1) == 0
if (match(B, m_c_Or(m_Value(X), m_Specific(A))) &&
MaskedValueIsZero(X, ~*MaskC1, 0, &I))
return BinaryOperator::CreateAnd(
B, ConstantInt::get(I.getType(), *MaskC0 | *MaskC1));
}
}
// (A & C1)|(B & C2)
ConstantInt *C1, *C2;
if (match(C, m_ConstantInt(C1)) && match(D, m_ConstantInt(C2))) {
Value *N;
if ((C1->getValue() & C2->getValue()).isZero()) {
// ((B | N) & C1) | (B & C2) --> (B | N) & (C1 | C2)
// iff (C1 & C2) == 0 and (N & ~C1) == 0
if (match(A, m_c_Or(m_Specific(B), m_Value(N))) &&
MaskedValueIsZero(N, ~C1->getValue(), 0, &I))
return BinaryOperator::CreateAnd(
A, Builder.getInt(C1->getValue() | C2->getValue()));
// (A & C1) | ((A | N) & C2) --> (A | N) & (C1 | C2)
// iff (C1 & C2) == 0 and (N & ~C1) == 0
if (match(B, m_c_Or(m_Specific(A), m_Value(N))) &&
MaskedValueIsZero(N, ~C2->getValue(), 0, &I))
return BinaryOperator::CreateAnd(
B, Builder.getInt(C1->getValue() | C2->getValue()));
// ((V|C3)&C1) | ((V|C4)&C2) --> (V|C3|C4)&(C1|C2)
// iff (C1&C2) == 0 and (C3&~C1) == 0 and (C4&~C2) == 0.
Value *V1 = nullptr, *V2 = nullptr;

4
llvm/test/Transforms/InstCombine/and-or.ll
View File

@ -124,7 +124,7 @@ define <2 x i8> @or_and_or_commute1_splat(<2 x i8> %x) {
; CHECK-NEXT: call void @use_vec(<2 x i8> [[X1]])
; CHECK-NEXT: [[X2:%.*]] = and <2 x i8> [[X]], <i8 64, i8 64>
; CHECK-NEXT: call void @use_vec(<2 x i8> [[X2]])
; CHECK-NEXT: [[R:%.*]] = or <2 x i8> [[X2]], [[X1]]
; CHECK-NEXT: [[R:%.*]] = and <2 x i8> [[XN]], <i8 123, i8 123>
; CHECK-NEXT: ret <2 x i8> [[R]]
;
%xn = or <2 x i8> %x, <i8 16, i8 16>
@ -169,7 +169,7 @@ define <2 x i8> @or_and_or_commute2_splat(<2 x i8> %x, <2 x i8> %y) {
; CHECK-NEXT: call void @use_vec(<2 x i8> [[X1]])
; CHECK-NEXT: [[X2:%.*]] = and <2 x i8> [[X]], <i8 64, i8 64>
; CHECK-NEXT: call void @use_vec(<2 x i8> [[X2]])
; CHECK-NEXT: [[R:%.*]] = or <2 x i8> [[X1]], [[X2]]
; CHECK-NEXT: [[R:%.*]] = and <2 x i8> [[XN]], <i8 -5, i8 -5>
; CHECK-NEXT: ret <2 x i8> [[R]]
;
%n = lshr <2 x i8> %y, <i8 6, i8 6>