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[InstCombine] Handle commuted patterns in foldBinOpShiftWithShift #122126

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Merged
dtcxzyw merged 2 commits into from
Jan 9, 2025
Merged

[InstCombine] Handle commuted patterns in foldBinOpShiftWithShift #122126

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c54b778
[InstCombine] Add pre-commit tests. NFC.
dtcxzyw Jan 8, 2025
7da9c6f
[InstCombine] Handle commuted patterns in `foldBinOpShiftWithShift`
dtcxzyw Jan 8, 2025
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9 changes: 4 additions & 5 deletions llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -939,12 +939,11 @@ Instruction *InstCombinerImpl::foldBinOpShiftWithShift(BinaryOperator &I) {
m_OneUse(m_Shift(m_Value(Y), m_Value(Shift)))))
return nullptr;
if (!match(I.getOperand(1 - ShOpnum),
m_BinOp(m_Value(ShiftedX), m_Value(Mask))))
m_c_BinOp(m_CombineAnd(
m_OneUse(m_Shift(m_Value(X), m_Specific(Shift))),
m_Value(ShiftedX)),
m_Value(Mask))))
return nullptr;

if (!match(ShiftedX, m_OneUse(m_Shift(m_Value(X), m_Specific(Shift)))))
return nullptr;

// Make sure we are matching instruction shifts and not ConstantExpr
auto *IY = dyn_cast<Instruction>(I.getOperand(ShOpnum));
auto *IX = dyn_cast<Instruction>(ShiftedX);
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59 changes: 51 additions & 8 deletions llvm/test/Transforms/InstCombine/and-xor-or.ll
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Original file line number Diff line number Diff line change
Expand Up @@ -388,10 +388,9 @@ define i8 @xor_shl(i8 %x, i8 %y, i8 %zarg, i8 %shamt) {
; CHECK-LABEL: define {{[^@]+}}@xor_shl
; CHECK-SAME: (i8 [[X:%.*]], i8 [[Y:%.*]], i8 [[ZARG:%.*]], i8 [[SHAMT:%.*]]) {
; CHECK-NEXT: [[Z:%.*]] = sdiv i8 42, [[ZARG]]
; CHECK-NEXT: [[SX:%.*]] = shl i8 [[X]], [[SHAMT]]
; CHECK-NEXT: [[SY:%.*]] = shl i8 [[Y]], [[SHAMT]]
; CHECK-NEXT: [[A:%.*]] = xor i8 [[Z]], [[SX]]
; CHECK-NEXT: [[R:%.*]] = xor i8 [[A]], [[SY]]
; CHECK-NEXT: [[TMP1:%.*]] = xor i8 [[X]], [[Y]]
; CHECK-NEXT: [[TMP2:%.*]] = shl i8 [[TMP1]], [[SHAMT]]
; CHECK-NEXT: [[R:%.*]] = xor i8 [[TMP2]], [[Z]]
; CHECK-NEXT: ret i8 [[R]]
;
%z = sdiv i8 42, %zarg ; thwart complexity-based canonicalization
Expand All @@ -406,10 +405,9 @@ define i8 @and_lshr(i8 %x, i8 %y, i8 %zarg, i8 %shamt) {
; CHECK-LABEL: define {{[^@]+}}@and_lshr
; CHECK-SAME: (i8 [[X:%.*]], i8 [[Y:%.*]], i8 [[ZARG:%.*]], i8 [[SHAMT:%.*]]) {
; CHECK-NEXT: [[Z:%.*]] = sdiv i8 42, [[ZARG]]
; CHECK-NEXT: [[SX:%.*]] = lshr i8 [[X]], [[SHAMT]]
; CHECK-NEXT: [[SY:%.*]] = lshr i8 [[Y]], [[SHAMT]]
; CHECK-NEXT: [[A:%.*]] = and i8 [[Z]], [[SX]]
; CHECK-NEXT: [[R:%.*]] = and i8 [[SY]], [[A]]
; CHECK-NEXT: [[TMP1:%.*]] = and i8 [[X]], [[Y]]
; CHECK-NEXT: [[TMP2:%.*]] = lshr i8 [[TMP1]], [[SHAMT]]
; CHECK-NEXT: [[R:%.*]] = and i8 [[TMP2]], [[Z]]
; CHECK-NEXT: ret i8 [[R]]
;
%z = sdiv i8 42, %zarg ; thwart complexity-based canonicalization
Expand All @@ -435,6 +433,51 @@ define i8 @or_lshr(i8 %x, i8 %y, i8 %z, i8 %shamt) {
ret i8 %r
}

define i8 @or_lshr_commuted1(i8 %x, i8 %y, i8 %z, i8 %shamt) {
; CHECK-LABEL: define {{[^@]+}}@or_lshr_commuted1
; CHECK-SAME: (i8 [[X:%.*]], i8 [[Y:%.*]], i8 [[Z:%.*]], i8 [[SHAMT:%.*]]) {
; CHECK-NEXT: [[TMP1:%.*]] = or i8 [[X]], [[Y]]
; CHECK-NEXT: [[TMP2:%.*]] = lshr i8 [[TMP1]], [[SHAMT]]
; CHECK-NEXT: [[R:%.*]] = or i8 [[TMP2]], [[Z]]
; CHECK-NEXT: ret i8 [[R]]
;
%sx = lshr i8 %x, %shamt
%sy = lshr i8 %y, %shamt
%a = or i8 %z, %sx
%r = or i8 %sy, %a
ret i8 %r
}

define i8 @or_lshr_commuted2(i8 %x, i8 %y, i8 %z, i8 %shamt) {
; CHECK-LABEL: define {{[^@]+}}@or_lshr_commuted2
; CHECK-SAME: (i8 [[X:%.*]], i8 [[Y:%.*]], i8 [[Z:%.*]], i8 [[SHAMT:%.*]]) {
; CHECK-NEXT: [[TMP1:%.*]] = or i8 [[X]], [[Y]]
; CHECK-NEXT: [[TMP2:%.*]] = lshr i8 [[TMP1]], [[SHAMT]]
; CHECK-NEXT: [[R:%.*]] = or i8 [[TMP2]], [[Z]]
; CHECK-NEXT: ret i8 [[R]]
;
%sx = lshr i8 %x, %shamt
%sy = lshr i8 %y, %shamt
%a = or i8 %z, %sx
%r = or i8 %a, %sy
ret i8 %r
}

define i8 @or_lshr_commuted3(i8 %x, i8 %y, i8 %z, i8 %shamt) {
; CHECK-LABEL: define {{[^@]+}}@or_lshr_commuted3
; CHECK-SAME: (i8 [[X:%.*]], i8 [[Y:%.*]], i8 [[Z:%.*]], i8 [[SHAMT:%.*]]) {
; CHECK-NEXT: [[TMP1:%.*]] = or i8 [[X]], [[Y]]
; CHECK-NEXT: [[TMP2:%.*]] = lshr i8 [[TMP1]], [[SHAMT]]
; CHECK-NEXT: [[R:%.*]] = or i8 [[TMP2]], [[Z]]
; CHECK-NEXT: ret i8 [[R]]
;
%sx = lshr i8 %x, %shamt
%sy = lshr i8 %y, %shamt
%a = or i8 %sx, %z
%r = or i8 %a, %sy
ret i8 %r
}

define i8 @xor_lshr(i8 %x, i8 %y, i8 %z, i8 %shamt) {
; CHECK-LABEL: define {{[^@]+}}@xor_lshr
; CHECK-SAME: (i8 [[X:%.*]], i8 [[Y:%.*]], i8 [[Z:%.*]], i8 [[SHAMT:%.*]]) {
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