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JIT: Reimport full spill clique for I_IMPL<->BYREF mismatches #92307

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Merged
merged 7 commits into from
Sep 24, 2023
Merged

JIT: Reimport full spill clique for I_IMPL<->BYREF mismatches #92307

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dba366d
JIT: Make a quirk in block morphing more explicit
jakobbotsch Sep 19, 2023
d3c831c
JIT: Reimport full spill clique for I_IMPL<->BYREF mismatches
jakobbotsch Sep 19, 2023
e4dd78a
Address feedback, refactor stylistically
jakobbotsch Sep 19, 2023
49f5d6b
A bit more
jakobbotsch Sep 19, 2023
f6a3668
Remove impReimportMarkSuccessors
jakobbotsch Sep 19, 2023
5d4c120
Fix build
jakobbotsch Sep 19, 2023
3121513
Merge branch 'main' of github.com:dotnet/runtime into lcl-type-mismat…
jakobbotsch Sep 22, 2023
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57 changes: 27 additions & 30 deletions src/coreclr/jit/importer.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -11379,38 +11379,35 @@ void Compiler::impImportBlock(BasicBlock* block)
baseTmp = impGetSpillTmpBase(block);
}

/* Spill all stack entries into temps */
unsigned level, tempNum;
// Spill all stack entries into temps

JITDUMP("\nSpilling stack entries into temps\n");
for (level = 0, tempNum = baseTmp; level < verCurrentState.esStackDepth; level++, tempNum++)
for (unsigned level = 0, tempNum = baseTmp; level < verCurrentState.esStackDepth; level++, tempNum++)
{
GenTree* tree = verCurrentState.esStack[level].val;

/* VC generates code where it pushes a byref from one branch, and an int (ldc.i4 0) from
the other. This should merge to a byref in unverifiable code.
However, if the branch which leaves the TYP_I_IMPL on the stack is imported first, the
successor would be imported assuming there was a TYP_I_IMPL on
the stack. Thus the value would not get GC-tracked. Hence,
change the temp to TYP_BYREF and reimport the successors.
Note: We should only allow this in unverifiable code.
*/
if (tree->gtType == TYP_BYREF && lvaTable[tempNum].lvType == TYP_I_IMPL)
// VC generates code where it pushes a byref from one branch, and an int (ldc.i4 0) from
// the other. This should merge to a byref in unverifiable code.
// However, if the branch which leaves the TYP_I_IMPL on the stack is imported first, the
// successor would be imported assuming there was a TYP_I_IMPL on
// the stack. Thus the value would not get GC-tracked. Hence,
// change the temp to TYP_BYREF and reimport the clique.
LclVarDsc* tempDsc = lvaGetDesc(tempNum);
if (tree->TypeIs(TYP_BYREF) && (tempDsc->TypeGet() == TYP_I_IMPL))
{
lvaTable[tempNum].lvType = TYP_BYREF;
impReimportMarkSuccessors(block);
markImport = true;
tempDsc->lvType = TYP_BYREF;
reimportSpillClique = true;
}

#ifdef TARGET_64BIT
if (genActualType(tree->gtType) == TYP_I_IMPL && lvaTable[tempNum].lvType == TYP_INT)
if ((genActualType(tree) == TYP_I_IMPL) && (tempDsc->TypeGet() == TYP_INT))
{
// Some other block in the spill clique set this to "int", but now we have "native int".
// Change the type and go back to re-import any blocks that used the wrong type.
lvaTable[tempNum].lvType = TYP_I_IMPL;
reimportSpillClique = true;
tempDsc->lvType = TYP_I_IMPL;
reimportSpillClique = true;
}
else if (genActualType(tree->gtType) == TYP_INT && lvaTable[tempNum].lvType == TYP_I_IMPL)
else if ((genActualType(tree) == TYP_INT) && (tempDsc->TypeGet() == TYP_I_IMPL))
{
// Spill clique has decided this should be "native int", but this block only pushes an "int".
// Insert a sign-extension to "native int" so we match the clique.
Expand All @@ -11425,14 +11422,14 @@ void Compiler::impImportBlock(BasicBlock* block)
// imported already, we need to change the type of the local and reimport the spill clique.
// If the 'byref' side has imported, we insert a cast from int to 'native int' to match
// the 'byref' size.
if (genActualType(tree->gtType) == TYP_BYREF && lvaTable[tempNum].lvType == TYP_INT)
if ((genActualType(tree) == TYP_BYREF) && (tempDsc->TypeGet() == TYP_INT))
{
// Some other block in the spill clique set this to "int", but now we have "byref".
// Change the type and go back to re-import any blocks that used the wrong type.
lvaTable[tempNum].lvType = TYP_BYREF;
reimportSpillClique = true;
tempDsc->lvType = TYP_BYREF;
reimportSpillClique = true;
}
else if (genActualType(tree->gtType) == TYP_INT && lvaTable[tempNum].lvType == TYP_BYREF)
else if ((genActualType(tree) == TYP_INT) && (tempDsc->TypeGet() == TYP_BYREF)
{
// Spill clique has decided this should be "byref", but this block only pushes an "int".
// Insert a sign-extension to "native int" so we match the clique size.
Expand All @@ -11441,14 +11438,14 @@ void Compiler::impImportBlock(BasicBlock* block)

#endif // TARGET_64BIT

if (tree->gtType == TYP_DOUBLE && lvaTable[tempNum].lvType == TYP_FLOAT)
if (tree->TypeIs(TYP_DOUBLE) && (tempDsc->lvType == TYP_FLOAT))
{
// Some other block in the spill clique set this to "float", but now we have "double".
// Change the type and go back to re-import any blocks that used the wrong type.
lvaTable[tempNum].lvType = TYP_DOUBLE;
reimportSpillClique = true;
tempDsc->lvType = TYP_DOUBLE;
reimportSpillClique = true;
}
else if (tree->gtType == TYP_FLOAT && lvaTable[tempNum].lvType == TYP_DOUBLE)
else if (tree->TypeIs(TYP_FLOAT) && (tempDsc->TypeGet() == TYP_DOUBLE))
{
// Spill clique has decided this should be "double", but this block only pushes a "float".
// Insert a cast to "double" so we match the clique.
Expand All @@ -11459,11 +11456,11 @@ void Compiler::impImportBlock(BasicBlock* block)
are spilling to the temps already used by a previous block),
we need to spill addStmt */

if (addStmt != nullptr && !newTemps && gtHasRef(addStmt->GetRootNode(), tempNum))
if ((addStmt != nullptr) && !newTemps && gtHasRef(addStmt->GetRootNode(), tempNum))
{
GenTree* addTree = addStmt->GetRootNode();

if (addTree->gtOper == GT_JTRUE)
if (addTree->OperIs(GT_JTRUE))
{
GenTree* relOp = addTree->AsOp()->gtOp1;
assert(relOp->OperIsCompare());
Expand All @@ -11488,7 +11485,7 @@ void Compiler::impImportBlock(BasicBlock* block)
}
else
{
assert(addTree->gtOper == GT_SWITCH && genActualTypeIsIntOrI(addTree->AsOp()->gtOp1->TypeGet()));
assert(addTree->OperIs(GT_SWITCH) && genActualTypeIsIntOrI(addTree->AsOp()->gtOp1->TypeGet()));

unsigned temp = lvaGrabTemp(true DEBUGARG("spill addStmt SWITCH"));
impStoreTemp(temp, addTree->AsOp()->gtOp1, level);
Expand Down
1 change: 0 additions & 1 deletion src/coreclr/jit/lclvars.cpp
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Expand Up @@ -4146,7 +4146,6 @@ void Compiler::lvaMarkLclRefs(GenTree* tree, BasicBlock* block, Statement* stmt,

// Check that the LCL_VAR node has the same type as the underlying variable, save a few mismatches we allow.
assert(tree->TypeIs(varDsc->TypeGet(), genActualType(varDsc)) ||
(tree->TypeIs(TYP_I_IMPL) && (varDsc->TypeGet() == TYP_BYREF)) || // Created for spill clique import.
(tree->TypeIs(TYP_BYREF) && (varDsc->TypeGet() == TYP_I_IMPL)) || // Created by inliner substitution.
(tree->TypeIs(TYP_INT) && (varDsc->TypeGet() == TYP_LONG))); // Created by "optNarrowTree".
}
Expand Down
10 changes: 7 additions & 3 deletions src/coreclr/jit/morphblock.cpp
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Expand Up @@ -1183,8 +1183,7 @@ GenTree* MorphCopyBlockHelper::CopyFieldByField()
addrSpillTemp = m_comp->lvaGrabTemp(true DEBUGARG("BlockOp address local"));

LclVarDsc* addrSpillDsc = m_comp->lvaGetDesc(addrSpillTemp);
addrSpillDsc->lvType = addrSpill->TypeIs(TYP_REF) ? TYP_REF : TYP_BYREF; // TODO-ASG: zero-diff quirk, delete.
addrSpillStore = m_comp->gtNewTempStore(addrSpillTemp, addrSpill);
addrSpillStore = m_comp->gtNewTempStore(addrSpillTemp, addrSpill);
}

auto grabAddr = [=, &result](unsigned offs) {
Expand Down Expand Up @@ -1227,7 +1226,12 @@ GenTree* MorphCopyBlockHelper::CopyFieldByField()
// handling.
GenTreeIntCon* fldOffsetNode = m_comp->gtNewIconNode(fullOffs, TYP_I_IMPL);
fldOffsetNode->gtFieldSeq = addrBaseOffsFldSeq;
addrClone = m_comp->gtNewOperNode(GT_ADD, TYP_BYREF, addrClone, fldOffsetNode);
addrClone = m_comp->gtNewOperNode(GT_ADD, varTypeIsGC(addrClone) ? TYP_BYREF : TYP_I_IMPL, addrClone,
fldOffsetNode);
// Avoid constant prop propagating each field access with a large
// constant address. TODO-Cleanup: We should tune constant prop to
// have better heuristics around this.
addrClone->gtFlags |= GTF_DONT_CSE;
}

return addrClone;
Expand Down