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JIT: Don't use checked bounds in assertprop #113638

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Merged
EgorBo merged 1 commit into from
Mar 18, 2025
Merged

JIT: Don't use checked bounds in assertprop #113638

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27 changes: 16 additions & 11 deletions src/coreclr/jit/rangecheck.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -637,22 +637,27 @@ void RangeCheck::MergeEdgeAssertions(GenTreeLclVarCommon* lcl, ASSERT_VALARG_TP
//
bool RangeCheck::TryGetRangeFromAssertions(Compiler* comp, ValueNum num, ASSERT_VALARG_TP assertions, Range* pRange)
{
MergeEdgeAssertions(comp, num, num, assertions, pRange);
MergeEdgeAssertions(comp, num, ValueNumStore::NoVN, assertions, pRange, false);
return !pRange->LowerLimit().IsUnknown() || !pRange->UpperLimit().IsUnknown();
}

//------------------------------------------------------------------------
// MergeEdgeAssertions: Merge assertions on the edge flowing into the block about a variable
//
// Arguments:
// comp - the compiler instance
// normalLclVN - the value number to look for assertions for
// preferredBoundVN - when this VN is set, it will be given preference over constant limits
// assertions - the assertions to use
// pRange - the range to tighten with assertions
// comp - the compiler instance
// normalLclVN - the value number to look for assertions for
// preferredBoundVN - when this VN is set, it will be given preference over constant limits
// assertions - the assertions to use
// pRange - the range to tighten with assertions
// canUseCheckedBounds - true if we can use checked bounds assertions (cache)
//
void RangeCheck::MergeEdgeAssertions(
Compiler* comp, ValueNum normalLclVN, ValueNum preferredBoundVN, ASSERT_VALARG_TP assertions, Range* pRange)
void RangeCheck::MergeEdgeAssertions(Compiler* comp,
ValueNum normalLclVN,
ValueNum preferredBoundVN,
ASSERT_VALARG_TP assertions,
Range* pRange,
bool canUseCheckedBounds)
{
Range assertedRange = Range(Limit(Limit::keUnknown));
if (BitVecOps::IsEmpty(comp->apTraits, assertions))
Expand Down Expand Up @@ -680,7 +685,7 @@ void RangeCheck::MergeEdgeAssertions(
bool isUnsigned = false;

// Current assertion is of the form (i < len - cns) != 0
if (curAssertion->IsCheckedBoundArithBound())
if (canUseCheckedBounds && curAssertion->IsCheckedBoundArithBound())
{
ValueNumStore::CompareCheckedBoundArithInfo info;

Expand Down Expand Up @@ -709,7 +714,7 @@ void RangeCheck::MergeEdgeAssertions(
cmpOper = (genTreeOps)info.cmpOper;
}
// Current assertion is of the form (i < len) != 0
else if (curAssertion->IsCheckedBoundBound())
else if (canUseCheckedBounds && curAssertion->IsCheckedBoundBound())
{
ValueNumStore::CompareCheckedBoundArithInfo info;

Expand Down Expand Up @@ -767,7 +772,7 @@ void RangeCheck::MergeEdgeAssertions(
int cnstLimit = (int)curAssertion->op2.u1.iconVal;
assert(cnstLimit == comp->vnStore->CoercedConstantValue<int>(curAssertion->op2.vn));

if ((cnstLimit == 0) && (curAssertion->assertionKind == Compiler::OAK_NOT_EQUAL) &&
if ((cnstLimit == 0) && (curAssertion->assertionKind == Compiler::OAK_NOT_EQUAL) && canUseCheckedBounds &&
comp->vnStore->IsVNCheckedBound(curAssertion->op1.vn))
{
// we have arr.Len != 0, so the length must be atleast one
Expand Down
8 changes: 6 additions & 2 deletions src/coreclr/jit/rangecheck.h
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Original file line number Diff line number Diff line change
Expand Up @@ -728,8 +728,12 @@ class RangeCheck
void MergeEdgeAssertions(GenTreeLclVarCommon* lcl, ASSERT_VALARG_TP assertions, Range* pRange);

// Inspect the assertions about the current ValueNum to refine pRange
static void MergeEdgeAssertions(
Compiler* comp, ValueNum num, ValueNum preferredBoundVN, ASSERT_VALARG_TP assertions, Range* pRange);
static void MergeEdgeAssertions(Compiler* comp,
ValueNum num,
ValueNum preferredBoundVN,
ASSERT_VALARG_TP assertions,
Range* pRange,
bool canUseCheckedBounds = true);

// The maximum possible value of the given "limit". If such a value could not be determined
// return "false". For example: CORINFO_Array_MaxLength for array length.
Expand Down