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Merged
giordano merged 1 commit into from
Sep 11, 2024
Merged

codegen: some cleanup of layout computations #55730

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14 changes: 5 additions & 9 deletions src/ccall.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -446,15 +446,13 @@ static Value *llvm_type_rewrite(
const DataLayout &DL = ctx.builder.GetInsertBlock()->getModule()->getDataLayout();
Align align = std::max(DL.getPrefTypeAlign(target_type), DL.getPrefTypeAlign(from_type));
if (DL.getTypeAllocSize(target_type) >= DL.getTypeAllocSize(from_type)) {
to = emit_static_alloca(ctx, target_type);
to = emit_static_alloca(ctx, target_type, align);
setName(ctx.emission_context, to, "type_rewrite_buffer");
cast<AllocaInst>(to)->setAlignment(align);
from = to;
}
else {
from = emit_static_alloca(ctx, from_type);
from = emit_static_alloca(ctx, from_type, align);
setName(ctx.emission_context, from, "type_rewrite_buffer");
cast<AllocaInst>(from)->setAlignment(align);
to = from;
}
ctx.builder.CreateAlignedStore(v, from, align);
Expand Down Expand Up @@ -555,9 +553,8 @@ static Value *julia_to_native(

// pass the address of an alloca'd thing, not a box
// since those are immutable.
Value *slot = emit_static_alloca(ctx, to);
Align align(julia_alignment(jlto));
cast<AllocaInst>(slot)->setAlignment(align);
Value *slot = emit_static_alloca(ctx, to, align);
setName(ctx.emission_context, slot, "native_convert_buffer");
if (!jvinfo.ispointer()) {
jl_aliasinfo_t ai = jl_aliasinfo_t::fromTBAA(ctx, jvinfo.tbaa);
Expand Down Expand Up @@ -2090,7 +2087,7 @@ jl_cgval_t function_sig_t::emit_a_ccall(
if (sret) {
assert(!retboxed && jl_is_datatype(rt) && "sret return type invalid");
if (jl_is_pointerfree(rt)) {
result = emit_static_alloca(ctx, lrt);
result = emit_static_alloca(ctx, lrt, Align(julia_alignment(rt)));
setName(ctx.emission_context, result, "ccall_sret");
sretty = lrt;
argvals[0] = result;
Expand Down Expand Up @@ -2266,9 +2263,8 @@ jl_cgval_t function_sig_t::emit_a_ccall(
if (DL.getTypeStoreSize(resultTy) > rtsz) {
// ARM and AArch64 can use a LLVM type larger than the julia type.
// When this happens, cast through memory.
auto slot = emit_static_alloca(ctx, resultTy);
auto slot = emit_static_alloca(ctx, resultTy, boxalign);
setName(ctx.emission_context, slot, "type_pun_slot");
slot->setAlignment(boxalign);
ctx.builder.CreateAlignedStore(result, slot, boxalign);
jl_aliasinfo_t ai = jl_aliasinfo_t::fromTBAA(ctx, tbaa);
emit_memcpy(ctx, strct, ai, slot, ai, rtsz, boxalign, boxalign);
Expand Down
36 changes: 16 additions & 20 deletions src/cgutils.cpp
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Expand Up @@ -1937,18 +1937,22 @@ static jl_cgval_t typed_load(jl_codectx_t &ctx, Value *ptr, Value *idx_0based, j
ctx.builder.CreateFence(Order);
return ghostValue(ctx, jltype);
}
if (isboxed)
alignment = sizeof(void*);
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@gbaraldi gbaraldi Sep 10, 2024

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I was under the impression that GC objects where 16 byte aligned?

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@vtjnash vtjnash Sep 10, 2024

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A pointer to a gc object only occupies a pointer sized space

else if (!alignment)
alignment = julia_alignment(jltype);
unsigned nb = isboxed ? sizeof(void*) : jl_datatype_size(jltype);
// note that nb == jl_Module->getDataLayout().getTypeAllocSize(elty) or getTypeStoreSize, depending on whether it is a struct or primitive type
AllocaInst *intcast = NULL;
if (Order == AtomicOrdering::NotAtomic) {
if (!isboxed && !aliasscope && elty->isAggregateType() && !CountTrackedPointers(elty).count) {
intcast = emit_static_alloca(ctx, elty);
intcast = emit_static_alloca(ctx, elty, Align(alignment));
setName(ctx.emission_context, intcast, "aggregate_load_box");
}
}
else {
if (!isboxed && !elty->isIntOrPtrTy()) {
intcast = emit_static_alloca(ctx, elty);
intcast = emit_static_alloca(ctx, elty, Align(alignment));
setName(ctx.emission_context, intcast, "atomic_load_box");
elty = Type::getIntNTy(ctx.builder.getContext(), 8 * nb);
}
Expand All @@ -1963,10 +1967,6 @@ static jl_cgval_t typed_load(jl_codectx_t &ctx, Value *ptr, Value *idx_0based, j
if (idx_0based)
data = ctx.builder.CreateInBoundsGEP(elty, data, idx_0based);
Value *instr = nullptr;
if (isboxed)
alignment = sizeof(void*);
else if (!alignment)
alignment = julia_alignment(jltype);
if (intcast && Order == AtomicOrdering::NotAtomic) {
emit_memcpy(ctx, intcast, jl_aliasinfo_t::fromTBAA(ctx, ctx.tbaa().tbaa_stack), data, jl_aliasinfo_t::fromTBAA(ctx, tbaa), nb, Align(alignment), intcast->getAlign());
}
Expand Down Expand Up @@ -2053,6 +2053,10 @@ static jl_cgval_t typed_store(jl_codectx_t &ctx,
ret = update_julia_type(ctx, ret, jltype);
return ret;
};
if (isboxed)
alignment = sizeof(void*);
else if (!alignment)
alignment = julia_alignment(jltype);
Type *elty = isboxed ? ctx.types().T_prjlvalue : julia_type_to_llvm(ctx, jltype);
if (type_is_ghost(elty) ||
(issetfieldonce && !maybe_null_if_boxed) ||
Expand Down Expand Up @@ -2095,7 +2099,7 @@ static jl_cgval_t typed_store(jl_codectx_t &ctx,
intcast_eltyp = elty;
elty = Type::getIntNTy(ctx.builder.getContext(), 8 * nb);
if (!issetfield) {
intcast = emit_static_alloca(ctx, elty);
intcast = emit_static_alloca(ctx, elty, Align(alignment));
setName(ctx.emission_context, intcast, "atomic_store_box");
}
}
Expand All @@ -2121,10 +2125,6 @@ static jl_cgval_t typed_store(jl_codectx_t &ctx,
if (realelty != elty)
r = ctx.builder.CreateZExt(r, elty);
}
if (isboxed)
alignment = sizeof(void*);
else if (!alignment)
alignment = julia_alignment(jltype);
Value *instr = nullptr;
Value *Compare = nullptr;
Value *Success = nullptr;
Expand Down Expand Up @@ -2657,10 +2657,8 @@ static jl_cgval_t emit_unionload(jl_codectx_t &ctx, Value *addr, Value *ptindex,
if (fsz > 0 && mutabl) {
// move value to an immutable stack slot (excluding tindex)
Type *AT = ArrayType::get(IntegerType::get(ctx.builder.getContext(), 8 * al), (fsz + al - 1) / al);
AllocaInst *lv = emit_static_alloca(ctx, AT);
AllocaInst *lv = emit_static_alloca(ctx, AT, Align(al));
setName(ctx.emission_context, lv, "immutable_union");
if (al > 1)
lv->setAlignment(Align(al));
jl_aliasinfo_t ai = jl_aliasinfo_t::fromTBAA(ctx, tbaa);
emit_memcpy(ctx, lv, ai, addr, ai, fsz, Align(al), Align(al));
addr = lv;
Expand Down Expand Up @@ -2903,7 +2901,7 @@ static jl_cgval_t emit_getfield_knownidx(jl_codectx_t &ctx, const jl_cgval_t &st
unsigned st_idx = convert_struct_offset(ctx, T, byte_offset);
IntegerType *ET = cast<IntegerType>(T->getStructElementType(st_idx));
unsigned align = (ET->getBitWidth() + 7) / 8;
lv = emit_static_alloca(ctx, ET);
lv = emit_static_alloca(ctx, ET, Align(align));
lv->setOperand(0, ConstantInt::get(getInt32Ty(ctx.builder.getContext()), (fsz + align - 1) / align));
// emit all of the align-sized words
unsigned i = 0;
Expand Down Expand Up @@ -3324,10 +3322,8 @@ static AllocaInst *try_emit_union_alloca(jl_codectx_t &ctx, jl_uniontype_t *ut,
// at least some of the values can live on the stack
// try to pick an Integer type size such that SROA will emit reasonable code
Type *AT = ArrayType::get(IntegerType::get(ctx.builder.getContext(), 8 * min_align), (nbytes + min_align - 1) / min_align);
AllocaInst *lv = emit_static_alloca(ctx, AT);
AllocaInst *lv = emit_static_alloca(ctx, AT, Align(align));
setName(ctx.emission_context, lv, "unionalloca");
if (align > 1)
lv->setAlignment(Align(align));
return lv;
}
return NULL;
Expand Down Expand Up @@ -3886,7 +3882,7 @@ static jl_cgval_t emit_new_struct(jl_codectx_t &ctx, jl_value_t *ty, size_t narg
}
}
else {
strct = emit_static_alloca(ctx, lt);
strct = emit_static_alloca(ctx, lt, Align(julia_alignment(ty)));
setName(ctx.emission_context, strct, arg_typename);
if (tracked.count)
undef_derived_strct(ctx, strct, sty, ctx.tbaa().tbaa_stack);
Expand Down Expand Up @@ -3966,7 +3962,7 @@ static jl_cgval_t emit_new_struct(jl_codectx_t &ctx, jl_value_t *ty, size_t narg
if (fsz1 > 0 && !fval_info.isghost) {
Type *ET = IntegerType::get(ctx.builder.getContext(), 8 * al);
assert(lt->getStructElementType(llvm_idx) == ET);
AllocaInst *lv = emit_static_alloca(ctx, ET);
AllocaInst *lv = emit_static_alloca(ctx, ET, Align(al));
setName(ctx.emission_context, lv, "unioninit");
lv->setOperand(0, ConstantInt::get(getInt32Ty(ctx.builder.getContext()), (fsz1 + al - 1) / al));
emit_unionmove(ctx, lv, ctx.tbaa().tbaa_stack, fval_info, nullptr);
Expand Down
34 changes: 15 additions & 19 deletions src/codegen.cpp
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Expand Up @@ -2208,10 +2208,10 @@ static GlobalVariable *get_pointer_to_constant(jl_codegen_params_t &emission_con
return gv;
}

static AllocaInst *emit_static_alloca(jl_codectx_t &ctx, Type *lty)
static AllocaInst *emit_static_alloca(jl_codectx_t &ctx, Type *lty, Align align)
{
++EmittedAllocas;
return new AllocaInst(lty, ctx.topalloca->getModule()->getDataLayout().getAllocaAddrSpace(), "", /*InsertBefore=*/ctx.topalloca);
return new AllocaInst(lty, ctx.topalloca->getModule()->getDataLayout().getAllocaAddrSpace(), nullptr, align, "", /*InsertBefore=*/ctx.topalloca);
}

static void undef_derived_strct(jl_codectx_t &ctx, Value *ptr, jl_datatype_t *sty, MDNode *tbaa)
Expand Down Expand Up @@ -2323,7 +2323,7 @@ static inline jl_cgval_t value_to_pointer(jl_codectx_t &ctx, Value *v, jl_value_
loc = get_pointer_to_constant(ctx.emission_context, cast<Constant>(v), Align(julia_alignment(typ)), "_j_const", *jl_Module);
}
else {
loc = emit_static_alloca(ctx, v->getType());
loc = emit_static_alloca(ctx, v->getType(), Align(julia_alignment(typ)));
ctx.builder.CreateStore(v, loc);
}
return mark_julia_slot(loc, typ, tindex, ctx.tbaa().tbaa_stack);
Expand Down Expand Up @@ -2435,7 +2435,7 @@ static void alloc_def_flag(jl_codectx_t &ctx, jl_varinfo_t& vi)
{
assert((!vi.boxroot || vi.pTIndex) && "undef check is null pointer for boxed things");
if (vi.usedUndef) {
vi.defFlag = emit_static_alloca(ctx, getInt1Ty(ctx.builder.getContext()));
vi.defFlag = emit_static_alloca(ctx, getInt1Ty(ctx.builder.getContext()), Align(1));
setName(ctx.emission_context, vi.defFlag, "isdefined");
store_def_flag(ctx, vi, false);
}
Expand Down Expand Up @@ -5025,25 +5025,20 @@ static jl_cgval_t emit_call_specfun_other(jl_codectx_t &ctx, bool is_opaque_clos
case jl_returninfo_t::Ghosts:
break;
case jl_returninfo_t::SRet:
result = emit_static_alloca(ctx, getAttributeAtIndex(returninfo.attrs, 1, Attribute::StructRet).getValueAsType());
#if JL_LLVM_VERSION < 170000
assert(cast<PointerType>(result->getType())->hasSameElementTypeAs(cast<PointerType>(cft->getParamType(0))));
#endif
result = emit_static_alloca(ctx, getAttributeAtIndex(returninfo.attrs, 1, Attribute::StructRet).getValueAsType(), Align(julia_alignment(jlretty)));
argvals[idx] = result;
idx++;
break;
case jl_returninfo_t::Union:
result = emit_static_alloca(ctx, ArrayType::get(getInt8Ty(ctx.builder.getContext()), returninfo.union_bytes));
result = emit_static_alloca(ctx, ArrayType::get(getInt8Ty(ctx.builder.getContext()), returninfo.union_bytes), Align(returninfo.union_align));
setName(ctx.emission_context, result, "sret_box");
if (returninfo.union_align > 1)
result->setAlignment(Align(returninfo.union_align));
argvals[idx] = result;
idx++;
break;
}

if (returninfo.return_roots) {
AllocaInst *return_roots = emit_static_alloca(ctx, ArrayType::get(ctx.types().T_prjlvalue, returninfo.return_roots));
AllocaInst *return_roots = emit_static_alloca(ctx, ArrayType::get(ctx.types().T_prjlvalue, returninfo.return_roots), Align(alignof(jl_value_t*)));
argvals[idx] = return_roots;
idx++;
}
Expand Down Expand Up @@ -5922,11 +5917,10 @@ static void emit_phinode_assign(jl_codectx_t &ctx, ssize_t idx, jl_value_t *r)
if (vtype->isAggregateType() && CountTrackedPointers(vtype).count == 0) {
// the value will be moved into dest in the predecessor critical block.
// here it's moved into phi in the successor (from dest)
dest = emit_static_alloca(ctx, vtype);
Value *phi = emit_static_alloca(ctx, vtype);
ctx.builder.CreateMemCpy(phi, Align(julia_alignment(phiType)),
dest, dest->getAlign(),
jl_datatype_size(phiType), false);
Align align(julia_alignment(phiType));
dest = emit_static_alloca(ctx, vtype, align);
Value *phi = emit_static_alloca(ctx, vtype, align);
ctx.builder.CreateMemCpy(phi, align, dest, align, jl_datatype_size(phiType), false);
ctx.builder.CreateLifetimeEnd(dest);
slot = mark_julia_slot(phi, phiType, NULL, ctx.tbaa().tbaa_stack);
}
Expand Down Expand Up @@ -7737,6 +7731,8 @@ static jl_returninfo_t get_specsig_function(jl_codectx_t &ctx, Module *M, Value
if (tracked.count && !tracked.all)
props.return_roots = tracked.count;
props.cc = jl_returninfo_t::SRet;
props.union_bytes = jl_datatype_size(jlrettype);
props.union_align = props.union_minalign = jl_datatype_align(jlrettype);
// sret is always passed from alloca
assert(M);
fsig.push_back(rt->getPointerTo(M->getDataLayout().getAllocaAddrSpace()));
Expand Down Expand Up @@ -8365,13 +8361,13 @@ static jl_llvm_functions_t
if (lv) {
lv->setName(jl_symbol_name(s));
varinfo.value = mark_julia_slot(lv, jt, NULL, ctx.tbaa().tbaa_stack);
varinfo.pTIndex = emit_static_alloca(ctx, getInt8Ty(ctx.builder.getContext()));
varinfo.pTIndex = emit_static_alloca(ctx, getInt8Ty(ctx.builder.getContext()), Align(1));
setName(ctx.emission_context, varinfo.pTIndex, "tindex");
// TODO: attach debug metadata to this variable
}
else if (allunbox) {
// all ghost values just need a selector allocated
AllocaInst *lv = emit_static_alloca(ctx, getInt8Ty(ctx.builder.getContext()));
AllocaInst *lv = emit_static_alloca(ctx, getInt8Ty(ctx.builder.getContext()), Align(1));
lv->setName(jl_symbol_name(s));
varinfo.pTIndex = lv;
varinfo.value.tbaa = NULL;
Expand Down
14 changes: 8 additions & 6 deletions src/intrinsics.cpp
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Expand Up @@ -405,10 +405,11 @@ static Value *emit_unboxed_coercion(jl_codectx_t &ctx, Type *to, Value *unboxed)
}
else if (!ty->isIntOrPtrTy() && !ty->isFloatingPointTy()) {
assert(DL.getTypeSizeInBits(ty) == DL.getTypeSizeInBits(to));
AllocaInst *cast = emit_static_alloca(ctx, ty);
Align align = std::max(DL.getPrefTypeAlign(ty), DL.getPrefTypeAlign(to));
AllocaInst *cast = emit_static_alloca(ctx, ty, align);
setName(ctx.emission_context, cast, "coercion");
ctx.builder.CreateStore(unboxed, cast);
unboxed = ctx.builder.CreateLoad(to, cast);
ctx.builder.CreateAlignedStore(unboxed, cast, align);
unboxed = ctx.builder.CreateAlignedLoad(to, cast, align);
}
else if (frompointer) {
Type *INTT_to = INTT(to, DL);
Expand Down Expand Up @@ -692,10 +693,11 @@ static jl_cgval_t generic_cast(
// understood that everything is implicitly rounded to 23 bits,
// but if we start looking at more bits we need to actually do the
// rounding first instead of carrying around incorrect low bits.
Value *jlfloattemp_var = emit_static_alloca(ctx, from->getType());
Align align(julia_alignment((jl_value_t*)jlto));
Value *jlfloattemp_var = emit_static_alloca(ctx, from->getType(), align);
setName(ctx.emission_context, jlfloattemp_var, "rounding_slot");
ctx.builder.CreateStore(from, jlfloattemp_var);
from = ctx.builder.CreateLoad(from->getType(), jlfloattemp_var, /*force this to load from the stack*/true);
ctx.builder.CreateAlignedStore(from, jlfloattemp_var, align);
from = ctx.builder.CreateAlignedLoad(from->getType(), jlfloattemp_var, align, /*force this to load from the stack*/true);
setName(ctx.emission_context, from, "rounded");
}
}
Expand Down