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Delete impCheckForNullPointer #61576

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merged 1 commit into from
Nov 15, 2021
Merged

Delete impCheckForNullPointer #61576

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1 change: 0 additions & 1 deletion src/coreclr/jit/compiler.h
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Original file line number Diff line number Diff line change
Expand Up @@ -4587,7 +4587,6 @@ class Compiler

unsigned impInitBlockLineInfo();

GenTree* impCheckForNullPointer(GenTree* obj);
bool impIsThis(GenTree* obj);
bool impIsLDFTN_TOKEN(const BYTE* delegateCreateStart, const BYTE* newobjCodeAddr);
bool impIsDUP_LDVIRTFTN_TOKEN(const BYTE* delegateCreateStart, const BYTE* newobjCodeAddr);
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53 changes: 0 additions & 53 deletions src/coreclr/jit/compiler.hpp
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Expand Up @@ -3773,59 +3773,6 @@ inline bool Compiler::compIsProfilerHookNeeded()
#endif // !PROFILING_SUPPORTED
}

/*****************************************************************************
*
* Check for the special case where the object is the constant 0.
* As we can't even fold the tree (null+fldOffs), we are left with
* op1 and op2 both being a constant. This causes lots of problems.
* We simply grab a temp and assign 0 to it and use it in place of the NULL.
*/

inline GenTree* Compiler::impCheckForNullPointer(GenTree* obj)
{
/* If it is not a GC type, we will be able to fold it.
So don't need to do anything */

if (!varTypeIsGC(obj->TypeGet()))
{
return obj;
}

if (obj->gtOper == GT_CNS_INT)
{
assert(obj->gtType == TYP_REF || obj->gtType == TYP_BYREF);

// We can see non-zero byrefs for RVA statics or for frozen strings.
if (obj->AsIntCon()->gtIconVal != 0)
{
#ifdef DEBUG
if (!obj->TypeIs(TYP_BYREF))
{
assert(obj->TypeIs(TYP_REF));
assert(obj->IsIconHandle(GTF_ICON_STR_HDL));
if (!doesMethodHaveFrozenString())
{
assert(compIsForInlining());
assert(impInlineInfo->InlinerCompiler->doesMethodHaveFrozenString());
}
}
#endif // DEBUG
return obj;
}

unsigned tmp = lvaGrabTemp(true DEBUGARG("CheckForNullPointer"));

// We don't need to spill while appending as we are only assigning
// NULL to a freshly-grabbed temp.

impAssignTempGen(tmp, obj, (unsigned)CHECK_SPILL_NONE);

obj = gtNewLclvNode(tmp, obj->gtType);
}

return obj;
}

/*****************************************************************************
*
* Check for the special case where the object is the methods original 'this' pointer.
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8 changes: 0 additions & 8 deletions src/coreclr/jit/importer.cpp
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Expand Up @@ -12786,8 +12786,6 @@ void Compiler::impImportBlockCode(BasicBlock* block)
}
}

op1 = impCheckForNullPointer(op1);

/* Mark the block as containing an index expression */

if (op1->gtOper == GT_LCL_VAR)
Expand Down Expand Up @@ -13001,8 +12999,6 @@ void Compiler::impImportBlockCode(BasicBlock* block)
op2->gtType = TYP_I_IMPL;
}

op3 = impCheckForNullPointer(op3);

// Mark the block as containing an index expression

if (op3->gtOper == GT_LCL_VAR)
Expand Down Expand Up @@ -15212,8 +15208,6 @@ void Compiler::impImportBlockCode(BasicBlock* block)
case CORINFO_FIELD_INSTANCE_WITH_BASE:
#endif
{
obj = impCheckForNullPointer(obj);

// If the object is a struct, what we really want is
// for the field to operate on the address of the struct.
if (!varTypeGCtype(obj->TypeGet()) && impIsValueType(tiObj))
Expand Down Expand Up @@ -15542,8 +15536,6 @@ void Compiler::impImportBlockCode(BasicBlock* block)
case CORINFO_FIELD_INSTANCE_WITH_BASE:
#endif
{
obj = impCheckForNullPointer(obj);

/* Create the data member node */
op1 = gtNewFieldRef(lclTyp, resolvedToken.hField, obj, fieldInfo.offset);
DWORD typeFlags = info.compCompHnd->getClassAttribs(resolvedToken.hClass);
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6 changes: 2 additions & 4 deletions src/coreclr/jit/morph.cpp
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Expand Up @@ -9236,10 +9236,8 @@ GenTree* Compiler::fgMorphCall(GenTreeCall* call)
fgWalkTreePost(&value, resetMorphedFlag);
#endif // DEBUG

GenTree* const nullCheckedArr = impCheckForNullPointer(arr);
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This is the morph bug: it was creating an ASG in a statement that did not get properly prepended.

GenTree* const arrIndexNode = gtNewIndexRef(TYP_REF, nullCheckedArr, index);
GenTree* const arrStore = gtNewAssignNode(arrIndexNode, value);
arrStore->gtFlags |= GTF_ASG;
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gtNewAssignNode already marks the node with the flag.

GenTree* const arrIndexNode = gtNewIndexRef(TYP_REF, arr, index);
GenTree* const arrStore = gtNewAssignNode(arrIndexNode, value);

GenTree* result = fgMorphTree(arrStore);
if (argSetup != nullptr)
Expand Down