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[IPSCCP] Intersect attribute info for interprocedural args #106397

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Merged
merged 1 commit into from
Aug 29, 2024
Merged

[IPSCCP] Intersect attribute info for interprocedural args #106397

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26 changes: 15 additions & 11 deletions llvm/lib/Transforms/Utils/SCCPSolver.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -820,19 +820,21 @@ class SCCPInstVisitor : public InstVisitor<SCCPInstVisitor> {
markOverdefined(ValueState[V], V);
}

void trackValueOfArgument(Argument *A) {
ValueLatticeElement getArgAttributeVL(Argument *A) {
if (A->getType()->isIntOrIntVectorTy()) {
if (std::optional<ConstantRange> Range = A->getRange()) {
markConstantRange(ValueState[A], A, *Range);
return;
}
}
if (A->hasNonNullAttr()) {
markNotNull(ValueState[A], A);
return;
if (std::optional<ConstantRange> Range = A->getRange())
return ValueLatticeElement::getRange(*Range);
}
if (A->hasNonNullAttr())
return ValueLatticeElement::getNot(Constant::getNullValue(A->getType()));
// Assume nothing about the incoming arguments without attributes.
markOverdefined(A);
return ValueLatticeElement::getOverdefined();
}

void trackValueOfArgument(Argument *A) {
if (A->getType()->isStructTy())
return (void)markOverdefined(A);
mergeInValue(A, getArgAttributeVL(A));
}

bool isStructLatticeConstant(Function *F, StructType *STy);
Expand Down Expand Up @@ -1800,7 +1802,9 @@ void SCCPInstVisitor::handleCallArguments(CallBase &CB) {
getMaxWidenStepsOpts());
}
} else
mergeInValue(&*AI, getValueState(*CAI), getMaxWidenStepsOpts());
mergeInValue(&*AI,
getValueState(*CAI).intersect(getArgAttributeVL(&*AI)),
getMaxWidenStepsOpts());
}
}
}
Expand Down
16 changes: 10 additions & 6 deletions llvm/test/Transforms/SCCP/pointer-nonnull.ll
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Expand Up @@ -210,18 +210,22 @@ define internal i1 @ip_test_nonnull_callee(ptr nonnull %p) {
;
; IPSCCP-LABEL: define internal i1 @ip_test_nonnull_callee(
; IPSCCP-SAME: ptr nonnull [[P:%.*]]) {
; IPSCCP-NEXT: [[CMP:%.*]] = icmp ne ptr [[P]], null
; IPSCCP-NEXT: ret i1 [[CMP]]
; IPSCCP-NEXT: ret i1 poison
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Is it correct? Shouldn't it be true?

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This is because IPSCCP replaces the the use of the return value in the caller, so the return value in the callee becomes unused and is replaced with poison.

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For IPSCCP, returned value isn't used any longer (at call sites we replaced by true)

;
%cmp = icmp ne ptr %p, null
ret i1 %cmp
}

define i1 @ip_test_nonnull_caller(ptr %p) {
; CHECK-LABEL: define i1 @ip_test_nonnull_caller(
; CHECK-SAME: ptr [[P:%.*]]) {
; CHECK-NEXT: [[RES:%.*]] = call i1 @ip_test_nonnull_callee(ptr [[P]])
; CHECK-NEXT: ret i1 [[RES]]
; SCCP-LABEL: define i1 @ip_test_nonnull_caller(
; SCCP-SAME: ptr [[P:%.*]]) {
; SCCP-NEXT: [[RES:%.*]] = call i1 @ip_test_nonnull_callee(ptr [[P]])
; SCCP-NEXT: ret i1 [[RES]]
;
; IPSCCP-LABEL: define i1 @ip_test_nonnull_caller(
; IPSCCP-SAME: ptr [[P:%.*]]) {
; IPSCCP-NEXT: [[RES:%.*]] = call i1 @ip_test_nonnull_callee(ptr [[P]])
; IPSCCP-NEXT: ret i1 true
;
%res = call i1 @ip_test_nonnull_callee(ptr %p)
ret i1 %res
Expand Down
27 changes: 16 additions & 11 deletions llvm/test/Transforms/SCCP/range-attribute.ll
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Expand Up @@ -193,8 +193,7 @@ define i1 @ip_range_attribute_constant() {

define internal i1 @ip_cmp_attribute_overdefined_callee(i32 range(i32 0, 10) %x) {
; IPSCCP-LABEL: @ip_cmp_attribute_overdefined_callee(
; IPSCCP-NEXT: [[CMP:%.*]] = icmp ult i32 [[X:%.*]], 10
; IPSCCP-NEXT: ret i1 [[CMP]]
; IPSCCP-NEXT: ret i1 poison
;
; SCCP-LABEL: @ip_cmp_attribute_overdefined_callee(
; SCCP-NEXT: ret i1 true
Expand All @@ -204,19 +203,21 @@ define internal i1 @ip_cmp_attribute_overdefined_callee(i32 range(i32 0, 10) %x)
}

define i1 @ip_cmp_attribute_overdefined_caller(i32 %x) {
; CHECK-LABEL: @ip_cmp_attribute_overdefined_caller(
; CHECK-NEXT: [[RES:%.*]] = call i1 @ip_cmp_attribute_overdefined_callee(i32 [[X:%.*]])
; CHECK-NEXT: ret i1 [[RES]]
; IPSCCP-LABEL: @ip_cmp_attribute_overdefined_caller(
; IPSCCP-NEXT: [[RES:%.*]] = call i1 @ip_cmp_attribute_overdefined_callee(i32 [[X:%.*]])
; IPSCCP-NEXT: ret i1 true
;
; SCCP-LABEL: @ip_cmp_attribute_overdefined_caller(
; SCCP-NEXT: [[RES:%.*]] = call i1 @ip_cmp_attribute_overdefined_callee(i32 [[X:%.*]])
; SCCP-NEXT: ret i1 [[RES]]
;
%res = call i1 @ip_cmp_attribute_overdefined_callee(i32 %x)
ret i1 %res
}

define internal i1 @ip_cmp_attribute_intersect_callee(i32 range(i32 0, 10) %x) {
; IPSCCP-LABEL: @ip_cmp_attribute_intersect_callee(
; IPSCCP-NEXT: [[CMP1:%.*]] = icmp ult i32 [[X:%.*]], 10
; IPSCCP-NEXT: [[AND:%.*]] = and i1 [[CMP1]], true
; IPSCCP-NEXT: ret i1 [[AND]]
; IPSCCP-NEXT: ret i1 poison
;
; SCCP-LABEL: @ip_cmp_attribute_intersect_callee(
; SCCP-NEXT: [[CMP2:%.*]] = icmp uge i32 [[X:%.*]], 5
Expand All @@ -230,9 +231,13 @@ define internal i1 @ip_cmp_attribute_intersect_callee(i32 range(i32 0, 10) %x) {
}

define i1 @ip_cmp_attribute_intersect_caller(i32 range(i32 5, 15) %x) {
; CHECK-LABEL: @ip_cmp_attribute_intersect_caller(
; CHECK-NEXT: [[RES:%.*]] = call i1 @ip_cmp_attribute_intersect_callee(i32 [[X:%.*]])
; CHECK-NEXT: ret i1 [[RES]]
; IPSCCP-LABEL: @ip_cmp_attribute_intersect_caller(
; IPSCCP-NEXT: [[RES:%.*]] = call i1 @ip_cmp_attribute_intersect_callee(i32 [[X:%.*]])
; IPSCCP-NEXT: ret i1 true
;
; SCCP-LABEL: @ip_cmp_attribute_intersect_caller(
; SCCP-NEXT: [[RES:%.*]] = call i1 @ip_cmp_attribute_intersect_callee(i32 [[X:%.*]])
; SCCP-NEXT: ret i1 [[RES]]
;
%res = call i1 @ip_cmp_attribute_intersect_callee(i32 %x)
ret i1 %res
Expand Down
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