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Remove references to non opaque pointers in codegen and LLVM passes (#…
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…54853)

This is in preparation for the bump to LLVM18 where some of these APIs
are removed. This also removes uses of bitcasts between pointers since
those were already noops and just complicated the code.

This also changes a couple of the GEPs in the code to be int8 GEPs in
preparation for whatever version of
https://discourse.llvm.org/t/rfc-replacing-getelementptr-with-ptradd/68699
that eventually gets made. In any case LLVM already canonicalizes GEPs
to i8 GEPs so this doesn't hurt.
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@gbaraldi
gbaraldi authored Jun 21, 2024
1 parent 69269ab commit 5e1bcdf
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Showing 14 changed files with 201 additions and 365 deletions.
64 changes: 29 additions & 35 deletions src/ccall.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -85,9 +85,9 @@ static bool runtime_sym_gvs(jl_codectx_t &ctx, const char *f_lib, const char *f_
runtime_lib = true;
auto &libgv = ctx.emission_context.libMapGV[f_lib];
if (libgv.first == NULL) {
libptrgv = new GlobalVariable(*M, getInt8PtrTy(M->getContext()), false,
libptrgv = new GlobalVariable(*M, getPointerTy(M->getContext()), false,
GlobalVariable::ExternalLinkage,
Constant::getNullValue(getInt8PtrTy(M->getContext())), name);
Constant::getNullValue(getPointerTy(M->getContext())), name);
libgv.first = libptrgv;
}
else {
Expand Down Expand Up @@ -169,7 +169,7 @@ static Value *runtime_sym_lookup(
}
else {
// f_lib is actually one of the special sentinel values
libname = ConstantExpr::getIntToPtr(ConstantInt::get(emission_context.DL.getIntPtrType(irbuilder.getContext()), (uintptr_t)f_lib), getInt8PtrTy(irbuilder.getContext()));
libname = ConstantExpr::getIntToPtr(ConstantInt::get(emission_context.DL.getIntPtrType(irbuilder.getContext()), (uintptr_t)f_lib), getPointerTy(irbuilder.getContext()));
}
auto lookup = irbuilder.CreateCall(prepare_call_in(jl_builderModule(irbuilder), jldlsym_func),
{ libname, nameval, libptrgv });
Expand All @@ -186,7 +186,7 @@ static Value *runtime_sym_lookup(
p->addIncoming(llvmf_orig, enter_bb);
p->addIncoming(llvmf, llvmf->getParent());
setName(emission_context, p, f_name);
return irbuilder.CreateBitCast(p, funcptype);
return p;
}

static Value *runtime_sym_lookup(
Expand Down Expand Up @@ -244,7 +244,7 @@ static GlobalVariable *emit_plt_thunk(
auto T_pvoidfunc = JuliaType::get_pvoidfunc_ty(M->getContext());
GlobalVariable *got = new GlobalVariable(*M, T_pvoidfunc, false,
GlobalVariable::ExternalLinkage,
ConstantExpr::getBitCast(plt, T_pvoidfunc),
plt,
fname + "_got");
if (runtime_lib) {
got->addAttribute("julia.libname", f_lib);
Expand All @@ -256,7 +256,7 @@ static GlobalVariable *emit_plt_thunk(
IRBuilder<> irbuilder(b0);
Value *ptr = runtime_sym_lookup(ctx.emission_context, irbuilder, NULL, funcptype, f_lib, NULL, f_name, plt, libptrgv,
llvmgv, runtime_lib);
StoreInst *store = irbuilder.CreateAlignedStore(irbuilder.CreateBitCast(ptr, T_pvoidfunc), got, Align(sizeof(void*)));
StoreInst *store = irbuilder.CreateAlignedStore(ptr, got, Align(sizeof(void*)));
store->setAtomic(AtomicOrdering::Release);
SmallVector<Value*, 16> args;
for (auto &arg : plt->args())
Expand Down Expand Up @@ -311,7 +311,6 @@ static Value *emit_plt(
GlobalVariable *libptrgv;
GlobalVariable *llvmgv;
bool runtime_lib = runtime_sym_gvs(ctx, f_lib, f_name, libptrgv, llvmgv);
PointerType *funcptype = PointerType::get(functype, 0);

auto &pltMap = ctx.emission_context.allPltMap[attrs];
auto key = std::make_tuple(llvmgv, functype, cc);
Expand All @@ -328,7 +327,7 @@ static Value *emit_plt(
// since the only thing we do to this loaded pointer is to call it
// immediately.
got_val->setAtomic(AtomicOrdering::Unordered);
return ctx.builder.CreateBitCast(got_val, funcptype);
return got_val;
}

// --- ABI Implementations ---
Expand Down Expand Up @@ -411,7 +410,7 @@ static Value *llvm_type_rewrite(

assert(from_type->isPointerTy() == target_type->isPointerTy()); // expect that all ABIs consider all pointers to be equivalent
if (target_type->isPointerTy())
return emit_bitcast(ctx, v, target_type);
return v;

// simple integer and float widening & conversion cases
if (from_type->getPrimitiveSizeInBits() > 0 &&
Expand Down Expand Up @@ -447,13 +446,13 @@ static Value *llvm_type_rewrite(
to = emit_static_alloca(ctx, target_type);
setName(ctx.emission_context, to, "type_rewrite_buffer");
cast<AllocaInst>(to)->setAlignment(align);
from = emit_bitcast(ctx, to, from_type->getPointerTo());
from = to;
}
else {
from = emit_static_alloca(ctx, from_type);
setName(ctx.emission_context, from, "type_rewrite_buffer");
cast<AllocaInst>(from)->setAlignment(align);
to = emit_bitcast(ctx, from, target_type->getPointerTo());
to = from;
}
ctx.builder.CreateAlignedStore(v, from, align);
auto pun = ctx.builder.CreateAlignedLoad(target_type, to, align);
Expand Down Expand Up @@ -713,7 +712,7 @@ static jl_cgval_t emit_cglobal(jl_codectx_t &ctx, jl_value_t **args, size_t narg
}

if (sym.jl_ptr != NULL) {
res = ctx.builder.CreateBitCast(sym.jl_ptr, lrt);
res = sym.jl_ptr;
}
else if (sym.fptr != NULL) {
res = ConstantInt::get(lrt, (uint64_t)sym.fptr);
Expand All @@ -722,10 +721,10 @@ static jl_cgval_t emit_cglobal(jl_codectx_t &ctx, jl_value_t **args, size_t narg
}
else {
if (sym.lib_expr) {
res = runtime_sym_lookup(ctx, cast<PointerType>(getInt8PtrTy(ctx.builder.getContext())), NULL, sym.lib_expr, sym.f_name, ctx.f);
res = runtime_sym_lookup(ctx, getPointerTy(ctx.builder.getContext()), NULL, sym.lib_expr, sym.f_name, ctx.f);
}
else /*if (ctx.emission_context.imaging) */{
res = runtime_sym_lookup(ctx, cast<PointerType>(getInt8PtrTy(ctx.builder.getContext())), sym.f_lib, NULL, sym.f_name, ctx.f);
res = runtime_sym_lookup(ctx, getPointerTy(ctx.builder.getContext()), sym.f_lib, NULL, sym.f_name, ctx.f);
}
}

Expand Down Expand Up @@ -1230,7 +1229,7 @@ std::string generate_func_sig(const char *fname)
bool isboxed;
if (jl_is_abstract_ref_type(tti)) {
tti = (jl_value_t*)jl_voidpointer_type;
t = getInt8PtrTy(LLVMCtx);
t = getPointerTy(LLVMCtx);
isboxed = false;
}
else if (llvmcall && jl_is_llvmpointer_type(tti)) {
Expand Down Expand Up @@ -1592,7 +1591,7 @@ static jl_cgval_t emit_ccall(jl_codectx_t &ctx, jl_value_t **args, size_t nargs)
Value *retval;
if (isboxed) {
retval = boxed(ctx, argv[0]);
retval = emit_pointer_from_objref(ctx, emit_bitcast(ctx, retval, ctx.types().T_prjlvalue));
retval = emit_pointer_from_objref(ctx, retval /*T_prjlvalue*/);
}
else {
retval = emit_unbox(ctx, largty, argv[0], tti);
Expand Down Expand Up @@ -1681,9 +1680,9 @@ static jl_cgval_t emit_ccall(jl_codectx_t &ctx, jl_value_t **args, size_t nargs)
assert(lrt == getInt16Ty(ctx.builder.getContext()));
assert(!isVa && !llvmcall && nccallargs == 0);
JL_GC_POP();
Value *ptask_i16 = emit_bitcast(ctx, get_current_task(ctx), getInt16PtrTy(ctx.builder.getContext()));
Value *ptask = get_current_task(ctx);
const int tid_offset = offsetof(jl_task_t, tid);
Value *ptid = ctx.builder.CreateInBoundsGEP(getInt16Ty(ctx.builder.getContext()), ptask_i16, ConstantInt::get(ctx.types().T_size, tid_offset / sizeof(int16_t)));
Value *ptid = ctx.builder.CreateInBoundsGEP(getInt8Ty(ctx.builder.getContext()), ptask, ConstantInt::get(ctx.types().T_size, tid_offset / sizeof(int8_t)));
setName(ctx.emission_context, ptid, "thread_id_ptr");
LoadInst *tid = ctx.builder.CreateAlignedLoad(getInt16Ty(ctx.builder.getContext()), ptid, Align(sizeof(int16_t)));
setName(ctx.emission_context, tid, "thread_id");
Expand Down Expand Up @@ -1711,9 +1710,9 @@ static jl_cgval_t emit_ccall(jl_codectx_t &ctx, jl_value_t **args, size_t nargs)
#endif
) {
JL_GC_POP();
Value *ptls_i32 = emit_bitcast(ctx, get_current_ptls(ctx), getInt32PtrTy(ctx.builder.getContext()));
Value *ptls_p = get_current_ptls(ctx);
const int finh_offset = offsetof(jl_tls_states_t, finalizers_inhibited);
Value *pfinh = ctx.builder.CreateInBoundsGEP(getInt32Ty(ctx.builder.getContext()), ptls_i32, ConstantInt::get(ctx.types().T_size, finh_offset / 4));
Value *pfinh = ctx.builder.CreateInBoundsGEP(getInt8Ty(ctx.builder.getContext()), ptls_p, ConstantInt::get(ctx.types().T_size, finh_offset / sizeof(int8_t)));
setName(ctx.emission_context, pfinh, "finalizers_inhibited_ptr");
LoadInst *finh = ctx.builder.CreateAlignedLoad(getInt32Ty(ctx.builder.getContext()), pfinh, Align(sizeof(int32_t)));
setName(ctx.emission_context, finh, "finalizers_inhibited");
Expand Down Expand Up @@ -1744,7 +1743,7 @@ static jl_cgval_t emit_ccall(jl_codectx_t &ctx, jl_value_t **args, size_t nargs)
assert(lrt == getVoidTy(ctx.builder.getContext()));
assert(!isVa && !llvmcall && nccallargs == 1);
JL_GC_POP();
Value *ptls_pv = emit_bitcast(ctx, get_current_ptls(ctx), ctx.types().T_ppjlvalue);
Value *ptls_pv = get_current_ptls(ctx);
const int nt_offset = offsetof(jl_tls_states_t, next_task);
Value *pnt = ctx.builder.CreateInBoundsGEP(ctx.types().T_pjlvalue, ptls_pv, ConstantInt::get(ctx.types().T_size, nt_offset / sizeof(void*)));
setName(ctx.emission_context, pnt, "next_task_ptr");
Expand Down Expand Up @@ -1810,8 +1809,7 @@ static jl_cgval_t emit_ccall(jl_codectx_t &ctx, jl_value_t **args, size_t nargs)
++CCALL_STAT(jl_string_ptr);
assert(lrt == ctx.types().T_ptr);
assert(!isVa && !llvmcall && nccallargs == 1);
auto obj = emit_bitcast(ctx, emit_pointer_from_objref(ctx, boxed(ctx, argv[0])),
ctx.types().T_pprjlvalue);
auto obj = emit_pointer_from_objref(ctx, boxed(ctx, argv[0])); // T_pprjlvalue
// The inbounds gep makes it more clear to LLVM that the resulting value is not
// a null pointer.
auto strp = ctx.builder.CreateConstInBoundsGEP1_32(ctx.types().T_prjlvalue, obj, 1);
Expand All @@ -1823,8 +1821,7 @@ static jl_cgval_t emit_ccall(jl_codectx_t &ctx, jl_value_t **args, size_t nargs)
++CCALL_STAT(jl_symbol_name);
assert(lrt == ctx.types().T_ptr);
assert(!isVa && !llvmcall && nccallargs == 1);
auto obj = emit_bitcast(ctx, emit_pointer_from_objref(ctx, boxed(ctx, argv[0])),
ctx.types().T_pprjlvalue);
auto obj = emit_pointer_from_objref(ctx, boxed(ctx, argv[0])); // T_pprjlvalue
// The inbounds gep makes it more clear to LLVM that the resulting value is not
// a null pointer.
auto strp = ctx.builder.CreateConstInBoundsGEP1_32(
Expand Down Expand Up @@ -1929,7 +1926,7 @@ static jl_cgval_t emit_ccall(jl_codectx_t &ctx, jl_value_t **args, size_t nargs)
if (val.typ == (jl_value_t*)jl_symbol_type) {
JL_GC_POP();
const int hash_offset = offsetof(jl_sym_t, hash);
Value *ph1 = emit_bitcast(ctx, decay_derived(ctx, boxed(ctx, val)), ctx.types().T_size->getPointerTo());
Value *ph1 = decay_derived(ctx, boxed(ctx, val));
Value *ph2 = ctx.builder.CreateInBoundsGEP(ctx.types().T_size, ph1, ConstantInt::get(ctx.types().T_size, hash_offset / ctx.types().sizeof_ptr));
setName(ctx.emission_context, ph2, "object_id_ptr");
LoadInst *hashval = ctx.builder.CreateAlignedLoad(ctx.types().T_size, ph2, ctx.types().alignof_ptr);
Expand All @@ -1941,15 +1938,13 @@ static jl_cgval_t emit_ccall(jl_codectx_t &ctx, jl_value_t **args, size_t nargs)
else if (!val.isboxed) {
// If the value is not boxed, try to compute the object id without
// reboxing it.
auto T_pint8_derived = PointerType::get(getInt8Ty(ctx.builder.getContext()), AddressSpace::Derived);
auto T_p_derived = PointerType::get(ctx.builder.getContext(), AddressSpace::Derived);
if (!val.isghost && !val.ispointer())
val = value_to_pointer(ctx, val);
Value *args[] = {
emit_typeof(ctx, val, false, true),
val.isghost ? ConstantPointerNull::get(T_pint8_derived) :
ctx.builder.CreateBitCast(
decay_derived(ctx, data_pointer(ctx, val)),
T_pint8_derived)
val.isghost ? ConstantPointerNull::get(T_p_derived) :
decay_derived(ctx, data_pointer(ctx, val))
};
Value *ret = ctx.builder.CreateCall(prepare_call(jl_object_id__func), ArrayRef<Value*>(args));
setName(ctx.emission_context, ret, "object_id");
Expand Down Expand Up @@ -2043,7 +2038,7 @@ jl_cgval_t function_sig_t::emit_a_ccall(
result = emit_static_alloca(ctx, lrt);
setName(ctx.emission_context, result, "ccall_sret");
sretty = lrt;
argvals[0] = ctx.builder.CreateBitCast(result, fargt_sig[0]);
argvals[0] = result;
}
else {
// XXX: result needs to be zero'd and given a GC root here
Expand All @@ -2054,7 +2049,7 @@ jl_cgval_t function_sig_t::emit_a_ccall(
sretty = ctx.types().T_jlvalue;
sretboxed = true;
gc_uses.push_back(result);
argvals[0] = ctx.builder.CreateBitCast(emit_pointer_from_objref(ctx, result), fargt_sig[0]);
argvals[0] = emit_pointer_from_objref(ctx, result);
}
}

Expand Down Expand Up @@ -2117,8 +2112,7 @@ jl_cgval_t function_sig_t::emit_a_ccall(
else if (symarg.jl_ptr != NULL) {
++LiteralCCalls;
null_pointer_check(ctx, symarg.jl_ptr, nullptr);
Type *funcptype = PointerType::get(functype, 0);
llvmf = ctx.builder.CreateBitCast(symarg.jl_ptr, funcptype);
llvmf = symarg.jl_ptr;
}
else if (symarg.fptr != NULL) {
++LiteralCCalls;
Expand Down
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