Skip to content

[SCCP] Add support for trunc nuw range. #152990

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

Merged
andjo403 merged 2 commits into from
Aug 12, 2025
Merged

[SCCP] Add support for trunc nuw range. #152990

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
b8a512b
[SCCP] Add test for trunc nuw range (NFC).
andjo403 Aug 11, 2025
d5cd785
[SCCP] Add support for trunc nuw range.
andjo403 Aug 11, 2025
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
8 changes: 6 additions & 2 deletions llvm/lib/Transforms/Utils/SCCPSolver.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1442,8 +1442,12 @@ void SCCPInstVisitor::visitCastInst(CastInst &I) {
OpSt.asConstantRange(I.getSrcTy(), /*UndefAllowed=*/false);

Type *DestTy = I.getDestTy();
ConstantRange Res =
OpRange.castOp(I.getOpcode(), DestTy->getScalarSizeInBits());
ConstantRange Res = ConstantRange::getEmpty(DestTy->getScalarSizeInBits());
if (auto *Trunc = dyn_cast<TruncInst>(&I))
Res = OpRange.truncate(DestTy->getScalarSizeInBits(),
Trunc->getNoWrapKind());
else
Res = OpRange.castOp(I.getOpcode(), DestTy->getScalarSizeInBits());
mergeInValue(LV, &I, ValueLatticeElement::getRange(Res));
} else
markOverdefined(&I);
Expand Down
41 changes: 41 additions & 0 deletions llvm/test/Transforms/SCCP/conditions-ranges.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1436,6 +1436,47 @@ if.end:
ret i32 0
}

define void @trunc_nuw_i1_dominating_icmp_ne_0(i8 %x) {
; CHECK-LABEL: @trunc_nuw_i1_dominating_icmp_ne_0(
; CHECK-NEXT: [[ICMP:%.*]] = icmp ne i8 [[X:%.*]], 0
; CHECK-NEXT: br i1 [[ICMP]], label [[BB1:%.*]], label [[BB2:%.*]]
; CHECK: bb1:
; CHECK-NEXT: call void @use(i1 true)
; CHECK-NEXT: ret void
; CHECK: bb2:
; CHECK-NEXT: ret void
;
%icmp = icmp ne i8 %x, 0
br i1 %icmp, label %bb1, label %bb2
bb1:
%c1 = trunc nuw i8 %x to i1
call void @use(i1 %c1)
ret void
bb2:
ret void
}

define void @neg_trunc_i1_dominating_icmp_ne_0(i8 %x) {
; CHECK-LABEL: @neg_trunc_i1_dominating_icmp_ne_0(
; CHECK-NEXT: [[ICMP:%.*]] = icmp ne i8 [[X:%.*]], 0
; CHECK-NEXT: br i1 [[ICMP]], label [[BB1:%.*]], label [[BB2:%.*]]
; CHECK: bb1:
; CHECK-NEXT: [[C1:%.*]] = trunc i8 [[X]] to i1
; CHECK-NEXT: call void @use(i1 [[C1]])
; CHECK-NEXT: ret void
; CHECK: bb2:
; CHECK-NEXT: ret void
;
%icmp = icmp ne i8 %x, 0
br i1 %icmp, label %bb1, label %bb2
bb1:
%c1 = trunc i8 %x to i1
call void @use(i1 %c1)
ret void
bb2:
ret void
}

define i1 @ptr_icmp_data_layout() {
; CHECK-LABEL: @ptr_icmp_data_layout(
; CHECK-NEXT: ret i1 false
Expand Down