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[LVI] Handle nonnull attributes at callsite #125377

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Merged
merged 5 commits into from
Feb 3, 2025
Merged

[LVI] Handle nonnull attributes at callsite #125377

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bcc2746
[CVP] Add pre-commit tests. NFC.
dtcxzyw Feb 2, 2025
c3bacf0
[LVI] Handle nonnull at callsite
dtcxzyw Feb 2, 2025
498ac15
[LVI] Address review comments.
dtcxzyw Feb 2, 2025
074099d
[CVP] Add more tests. NFC.
dtcxzyw Feb 2, 2025
54cb334
[LVI] Fix miscompilation
dtcxzyw Feb 2, 2025
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7 changes: 7 additions & 0 deletions llvm/lib/Analysis/LazyValueInfo.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -644,6 +644,13 @@ static void AddNonNullPointersByInstruction(
AddNonNullPointer(MI->getRawDest(), PtrSet);
if (MemTransferInst *MTI = dyn_cast<MemTransferInst>(MI))
AddNonNullPointer(MTI->getRawSource(), PtrSet);
} else if (auto *CB = dyn_cast<CallBase>(I)) {
for (auto &U : CB->args()) {
if (U->getType()->isPointerTy() &&
CB->paramHasNonNullAttr(CB->getArgOperandNo(&U),
/*AllowUndefOrPoison=*/false))
AddNonNullPointer(U.get(), PtrSet);
}
}
}

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71 changes: 71 additions & 0 deletions llvm/test/Transforms/CorrelatedValuePropagation/non-null.ll
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Original file line number Diff line number Diff line change
Expand Up @@ -344,4 +344,75 @@ define i1 @test_store_same_block(ptr %arg) {
ret i1 %cmp
}


define i1 @test_known_nonnull_at_callsite(ptr %src) {
; CHECK-LABEL: @test_known_nonnull_at_callsite(
; CHECK-NEXT: entry:
; CHECK-NEXT: call void @callee(ptr noundef nonnull [[SRC:%.*]])
; CHECK-NEXT: [[NONNULL:%.*]] = icmp eq ptr [[SRC]], null
; CHECK-NEXT: ret i1 false
;
entry:
call void @callee(ptr noundef nonnull %src)
%nonnull = icmp eq ptr %src, null
ret i1 %nonnull
}

define i1 @test_known_nonnull_mixed(ptr %src) {
; CHECK-LABEL: @test_known_nonnull_mixed(
; CHECK-NEXT: entry:
; CHECK-NEXT: call void @callee2(ptr nonnull [[SRC:%.*]])
; CHECK-NEXT: [[NONNULL:%.*]] = icmp eq ptr [[SRC]], null
; CHECK-NEXT: ret i1 false
;
entry:
call void @callee2(ptr nonnull %src)
%nonnull = icmp eq ptr %src, null
ret i1 %nonnull
}

define i1 @test_known_nonnull_at_callsite_dereferenceable(ptr %src) {
; CHECK-LABEL: @test_known_nonnull_at_callsite_dereferenceable(
; CHECK-NEXT: entry:
; CHECK-NEXT: call void @callee(ptr dereferenceable(1) [[SRC:%.*]])
; CHECK-NEXT: [[NONNULL:%.*]] = icmp eq ptr [[SRC]], null
; CHECK-NEXT: ret i1 false
;
entry:
call void @callee(ptr dereferenceable(1) %src)
%nonnull = icmp eq ptr %src, null
ret i1 %nonnull
}

; Negative tests

define i1 @test_known_nonnull_at_callsite_without_noundef(ptr %src) {
; CHECK-LABEL: @test_known_nonnull_at_callsite_without_noundef(
; CHECK-NEXT: entry:
; CHECK-NEXT: call void @callee(ptr nonnull [[SRC:%.*]])
; CHECK-NEXT: [[NONNULL:%.*]] = icmp eq ptr [[SRC]], null
; CHECK-NEXT: ret i1 [[NONNULL]]
;
entry:
call void @callee(ptr nonnull %src)
%nonnull = icmp eq ptr %src, null
ret i1 %nonnull
}

define i1 @test_known_nonnull_at_callsite_dereferenceable_null_is_defined(ptr %src) #0 {
; CHECK-LABEL: @test_known_nonnull_at_callsite_dereferenceable_null_is_defined(
; CHECK-NEXT: entry:
; CHECK-NEXT: call void @callee(ptr dereferenceable(1) [[SRC:%.*]])
; CHECK-NEXT: [[NONNULL:%.*]] = icmp eq ptr [[SRC]], null
; CHECK-NEXT: ret i1 [[NONNULL]]
;
entry:
call void @callee(ptr dereferenceable(1) %src)
%nonnull = icmp eq ptr %src, null
ret i1 %nonnull
}

declare void @callee(ptr)
declare void @callee2(ptr noundef)

attributes #0 = { null_pointer_is_valid }