Skip to content

[ValueTracking] Add support for insertelement in isKnownNonZero #87703

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
wants to merge 2 commits into from
Closed

[ValueTracking] Add support for insertelement in isKnownNonZero #87703

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
7073e55
[ValueTracking] Add tests for `insertelement` in `isKnownNonZero`; NFC
goldsteinn Apr 4, 2024
fca4917
[ValueTracking] Add support for `insertelement` in `isKnownNonZero`
goldsteinn Apr 3, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
23 changes: 23 additions & 0 deletions llvm/lib/Analysis/ValueTracking.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2751,6 +2751,29 @@ static bool isKnownNonZeroFromOperator(const Operator *I,
return isKnownNonZero(U.get(), DemandedElts, NewDepth, RecQ);
});
}
case Instruction::InsertElement: {
if (isa<ScalableVectorType>(I->getType()))
break;

const Value *Vec = I->getOperand(0);
const Value *Elt = I->getOperand(1);
auto *CIdx = dyn_cast<ConstantInt>(I->getOperand(2));

unsigned NumElts = DemandedElts.getBitWidth();
APInt DemandedVecElts = DemandedElts;
bool SkipElt = false;
// If we know the index we are inserting too, clear it from Vec check.
if (CIdx && CIdx->getValue().ult(NumElts)) {
DemandedVecElts.clearBit(CIdx->getZExtValue());
SkipElt = !DemandedElts[CIdx->getZExtValue()];
}

// Result is zero if Elt is non-zero and rest of the demanded elts in Vec
// are non-zero.
return (SkipElt || isKnownNonZero(Elt, Depth, Q)) &&
(DemandedVecElts.isZero() ||
isKnownNonZero(Vec, DemandedVecElts, Depth, Q));
}
case Instruction::ExtractElement:
if (const auto *EEI = dyn_cast<ExtractElementInst>(I)) {
const Value *Vec = EEI->getVectorOperand();
Expand Down
84 changes: 84 additions & 0 deletions llvm/test/Transforms/InstSimplify/known-non-zero.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -166,3 +166,87 @@ A:
B:
ret i1 0
}

define <2 x i1> @insert_nonzero0(<2 x i8> %xx, i8 %yy) {
; CHECK-LABEL: @insert_nonzero0(
; CHECK-NEXT: ret <2 x i1> zeroinitializer
;
%x = add nuw <2 x i8> %xx, <i8 1, i8 0>
%y = add nuw i8 %yy, 1

%ins = insertelement <2 x i8> %x, i8 %y, i32 1
%r = icmp eq <2 x i8> %ins, zeroinitializer
ret <2 x i1> %r
}

define <2 x i1> @insert_nonzero1(<2 x i8> %xx, i8 %yy) {
; CHECK-LABEL: @insert_nonzero1(
; CHECK-NEXT: ret <2 x i1> zeroinitializer
;
%x = add nuw <2 x i8> %xx, <i8 0, i8 1>
%y = add nuw i8 %yy, 1

%ins = insertelement <2 x i8> %x, i8 %y, i32 0
%r = icmp eq <2 x i8> %ins, zeroinitializer
ret <2 x i1> %r
}

define <2 x i1> @insert_nonzero_fail(<2 x i8> %xx, i8 %yy) {
; CHECK-LABEL: @insert_nonzero_fail(
; CHECK-NEXT: [[X:%.*]] = add nuw <2 x i8> [[XX:%.*]], <i8 1, i8 0>
; CHECK-NEXT: [[Y:%.*]] = add nuw i8 [[YY:%.*]], 1
; CHECK-NEXT: [[INS:%.*]] = insertelement <2 x i8> [[X]], i8 [[Y]], i32 0
; CHECK-NEXT: [[R:%.*]] = icmp eq <2 x i8> [[INS]], zeroinitializer
; CHECK-NEXT: ret <2 x i1> [[R]]
;
%x = add nuw <2 x i8> %xx, <i8 1, i8 0>
%y = add nuw i8 %yy, 1

%ins = insertelement <2 x i8> %x, i8 %y, i32 0
%r = icmp eq <2 x i8> %ins, zeroinitializer
ret <2 x i1> %r
}

define <2 x i1> @insert_nonzero_fail2(<2 x i8> %xx, i8 %yy) {
; CHECK-LABEL: @insert_nonzero_fail2(
; CHECK-NEXT: [[X:%.*]] = add nuw <2 x i8> [[XX:%.*]], <i8 0, i8 1>
; CHECK-NEXT: [[Y:%.*]] = add i8 [[YY:%.*]], 1
; CHECK-NEXT: [[INS:%.*]] = insertelement <2 x i8> [[X]], i8 [[Y]], i32 0
; CHECK-NEXT: [[R:%.*]] = icmp eq <2 x i8> [[INS]], zeroinitializer
; CHECK-NEXT: ret <2 x i1> [[R]]
;
%x = add nuw <2 x i8> %xx, <i8 0, i8 1>
%y = add i8 %yy, 1

%ins = insertelement <2 x i8> %x, i8 %y, i32 0
%r = icmp eq <2 x i8> %ins, zeroinitializer
ret <2 x i1> %r
}

define <2 x i1> @insert_nonzero_any_idx(<2 x i8> %xx, i8 %yy, i32 %idx) {
; CHECK-LABEL: @insert_nonzero_any_idx(
; CHECK-NEXT: ret <2 x i1> zeroinitializer
;
%x = add nuw <2 x i8> %xx, <i8 1, i8 1>
%y = add nuw i8 %yy, 1

%ins = insertelement <2 x i8> %x, i8 %y, i32 %idx
%r = icmp eq <2 x i8> %ins, zeroinitializer
ret <2 x i1> %r
}

define <2 x i1> @insert_nonzero_any_idx_fail(<2 x i8> %xx, i8 %yy, i32 %idx) {
; CHECK-LABEL: @insert_nonzero_any_idx_fail(
; CHECK-NEXT: [[X:%.*]] = add nuw <2 x i8> [[XX:%.*]], <i8 1, i8 0>
; CHECK-NEXT: [[Y:%.*]] = add nuw i8 [[YY:%.*]], 1
; CHECK-NEXT: [[INS:%.*]] = insertelement <2 x i8> [[X]], i8 [[Y]], i32 [[IDX:%.*]]
; CHECK-NEXT: [[R:%.*]] = icmp eq <2 x i8> [[INS]], zeroinitializer
; CHECK-NEXT: ret <2 x i1> [[R]]
;
%x = add nuw <2 x i8> %xx, <i8 1, i8 0>
%y = add nuw i8 %yy, 1

%ins = insertelement <2 x i8> %x, i8 %y, i32 %idx
%r = icmp eq <2 x i8> %ins, zeroinitializer
ret <2 x i1> %r
}