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Enable TYP_STRUCT LCL_VAR/LCL_FLD call args on Windows x64 #70777

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Merged
jakobbotsch merged 3 commits into from
Jun 19, 2022
Merged

Enable TYP_STRUCT LCL_VAR/LCL_FLD call args on Windows x64 #70777

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043722c
Fix forward sub
SingleAccretion Apr 27, 2022
160bc7b
Enable folding in local morph
SingleAccretion Jun 15, 2022
ecc0422
Morph: TYP_STRUCT LCL_FLD
SingleAccretion Jun 1, 2022
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9 changes: 9 additions & 0 deletions src/coreclr/jit/forwardsub.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -665,6 +665,15 @@ bool Compiler::fgForwardSubStatement(Statement* stmt)

// Quirks:
//
// Don't substitute nodes "AddFinalArgsAndDetermineABIInfo" doesn't handle into struct args.
//
if (fsv.IsCallArg() && fsv.GetNode()->TypeIs(TYP_STRUCT) &&
!fwdSubNode->OperIs(GT_OBJ, GT_LCL_VAR, GT_LCL_FLD, GT_MKREFANY))
{
JITDUMP(" use is a struct arg; fwd sub node is not OBJ/LCL_VAR/LCL_FLD/MKREFANY\n");
return false;
}

// We may sometimes lose or change a type handle. Avoid substituting if so.
//
if (gtGetStructHandleIfPresent(fwdSubNode) != gtGetStructHandleIfPresent(fsv.GetNode()))
Expand Down
3 changes: 3 additions & 0 deletions src/coreclr/jit/gentree.cpp
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Expand Up @@ -597,6 +597,9 @@ ClassLayout* GenTree::GetLayout(Compiler* compiler) const
case GT_BLK:
return AsBlk()->GetLayout();

case GT_MKREFANY:
return compiler->typGetObjLayout(compiler->impGetRefAnyClass());

default:
unreached();
}
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44 changes: 21 additions & 23 deletions src/coreclr/jit/lclmorph.cpp
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Expand Up @@ -1049,10 +1049,9 @@ class LocalAddressVisitor final : public GenTreeVisitor<LocalAddressVisitor>
return IndirTransform::None;
}

if ((user == nullptr) || !user->OperIs(GT_ASG, GT_RETURN))
if ((user == nullptr) || !user->OperIs(GT_ASG, GT_CALL, GT_RETURN))
{
// TODO-ADDR: call args require extra work because currently they must
// be wrapped in OBJ nodes so we can't replace those with local nodes.
// TODO-ADDR: remove unused indirections.
return IndirTransform::None;
}

Expand All @@ -1075,7 +1074,6 @@ class LocalAddressVisitor final : public GenTreeVisitor<LocalAddressVisitor>
//
enum class StructMatch
{
Exact,
Compatible,
Partial
};
Expand All @@ -1084,44 +1082,44 @@ class LocalAddressVisitor final : public GenTreeVisitor<LocalAddressVisitor>
assert(varDsc->GetLayout() != nullptr);

StructMatch match = StructMatch::Partial;
if (val.Offset() == 0)
if ((val.Offset() == 0) && ClassLayout::AreCompatible(indirLayout, varDsc->GetLayout()))
{
if (indirLayout->GetClassHandle() == varDsc->GetStructHnd())
{
match = StructMatch::Exact;
}
else if (ClassLayout::AreCompatible(indirLayout, varDsc->GetLayout()))
{
match = StructMatch::Compatible;
}
match = StructMatch::Compatible;
}

// Current matrix of matches/users/types:
//
// |------------|------|-------------|---------|
// | STRUCT | CALL | ASG | RETURN |
// |------------|------|-------------|---------|
// | Exact | None | LCL_VAR | LCL_VAR |
// | Compatible | None | LCL_VAR | LCL_VAR |
// | Partial | None | OBJ/LCL_FLD | LCL_FLD |
// |------------|------|-------------|---------|
// |------------|---------|-------------|---------|
// | STRUCT | CALL(*) | ASG | RETURN |
// |------------|---------|-------------|---------|
// | Compatible | LCL_VAR | LCL_VAR | LCL_VAR |
// | Partial | LCL_FLD | OBJ/LCL_FLD | LCL_FLD |
// |------------|---------|-------------|---------|
//
// * - On Windows x64 only.
//
// |------------|------|------|--------|----------|
// | SIMD | CALL | ASG | RETURN | HWI/SIMD |
// |------------|------|------|--------|----------|
// | Exact | None | None | None | None |
// | Compatible | None | None | None | None |
// | Partial | None | None | None | None |
// |------------|------|------|--------|----------|
//
// TODO-ADDR: delete all the "None" entries and always
// transform local nodes into LCL_VAR or LCL_FLD.

assert(indir->TypeIs(TYP_STRUCT) && user->OperIs(GT_ASG, GT_RETURN));
assert(indir->TypeIs(TYP_STRUCT) && user->OperIs(GT_ASG, GT_CALL, GT_RETURN));

*pStructLayout = indirLayout;

if ((match == StructMatch::Exact) || (match == StructMatch::Compatible))
if (user->IsCall())
{
#ifndef WINDOWS_AMD64_ABI
return IndirTransform::None;
#endif // !WINDOWS_AMD64_ABI
}

if (match == StructMatch::Compatible)
{
return IndirTransform::LclVar;
}
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36 changes: 4 additions & 32 deletions src/coreclr/jit/morph.cpp
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Expand Up @@ -2347,30 +2347,9 @@ void CallArgs::AddFinalArgsAndDetermineABIInfo(Compiler* comp, GenTreeCall* call
GenTree* actualArg = argx->gtEffectiveVal(true /* Commas only */);

// Here we look at "actualArg" to avoid calling "getClassSize".
if (actualArg->TypeGet() == TYP_STRUCT)
{
switch (actualArg->OperGet())
{
case GT_OBJ:
structSize = actualArg->AsObj()->Size();
break;
case GT_LCL_VAR:
structSize = comp->lvaGetDesc(actualArg->AsLclVarCommon())->lvExactSize;
break;
case GT_MKREFANY:
structSize = comp->info.compCompHnd->getClassSize(argSigClass);
break;
default:
BADCODE("illegal argument tree: cannot determine size for ABI handling");
break;
}
}
else
{
structSize = genTypeSize(actualArg);
}
structSize = actualArg->TypeIs(TYP_STRUCT) ? actualArg->GetLayout(comp)->GetSize() : genTypeSize(actualArg);
Comment on lines 2349 to +2350
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@jakobbotsch jakobbotsch Jun 16, 2022

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Maybe this is proof that we should actually be storing ClassLayout* instead of the class handle in CallArg?

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@SingleAccretion SingleAccretion Jun 16, 2022

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Perhaps, I am not sure. Essentially, the question is if we view the fact layout carries a handle to be a coincidence/artifact or its intrinsic property.

I think it would be beneficial to at some point move away from using handles in IR at large, and would that involve removing handles from layouts I do not know (yet).


assert(structSize = comp->info.compCompHnd->getClassSize(argSigClass));
assert(structSize == comp->info.compCompHnd->getClassSize(argSigClass));
}
#if defined(TARGET_AMD64)
#ifdef UNIX_AMD64_ABI
Expand Down Expand Up @@ -3190,15 +3169,8 @@ GenTreeCall* Compiler::fgMorphArgs(GenTreeCall* call)
unsigned originalSize;
if (argObj->TypeGet() == TYP_STRUCT)
{
if (argObj->OperIs(GT_OBJ))
{
originalSize = argObj->AsObj()->Size();
}
else
{
// Must be LCL_VAR: we have a BADCODE assert for this in AddFinalArgsAndDetermineABIInfo.
originalSize = lvaGetDesc(argObj->AsLclVar())->lvExactSize;
}
assert(argObj->OperIs(GT_OBJ, GT_LCL_VAR, GT_LCL_FLD));
originalSize = argObj->GetLayout(this)->GetSize();
}
else
{
Expand Down