bjoernager/rust
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explain PassMode::Cast

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This commit is contained in:
Ralf Jung 2023-09-07 22:06:37 +02:00
parent 9cbc90c0ae
commit 7740476a43
7 changed files with 38 additions and 27 deletions
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18
compiler/rustc_codegen_llvm/src/abi.rs
View file

@ -211,7 +211,7 @@ impl<'ll, 'tcx> ArgAbiExt<'ll, 'tcx> for ArgAbi<'tcx, Ty<'tcx>> {
OperandValue::Ref(val, None, self.layout.align.abi).store(bx, dst)
} else if self.is_unsized_indirect() {
bug!("unsized `ArgAbi` must be handled through `store_fn_arg`");
} else if let PassMode::Cast(cast, _) = &self.mode {
} else if let PassMode::Cast { cast, pad_i32: _ } = &self.mode {
// FIXME(eddyb): Figure out when the simpler Store is safe, clang
// uses it for i16 -> {i8, i8}, but not for i24 -> {i8, i8, i8}.
let can_store_through_cast_ptr = false;
@ -279,7 +279,7 @@ impl<'ll, 'tcx> ArgAbiExt<'ll, 'tcx> for ArgAbi<'tcx, Ty<'tcx>> {
}
PassMode::Direct(_)
| PassMode::Indirect { attrs: _, extra_attrs: None, on_stack: _ }
| PassMode::Cast(..) => {
| PassMode::Cast { .. } => {
let next_arg = next();
self.store(bx, next_arg, dst);
}
@ -332,7 +332,7 @@ impl<'ll, 'tcx> FnAbiLlvmExt<'ll, 'tcx> for FnAbi<'tcx, Ty<'tcx>> {
let llreturn_ty = match &self.ret.mode {
PassMode::Ignore => cx.type_void(),
PassMode::Direct(_) | PassMode::Pair(..) => self.ret.layout.immediate_llvm_type(cx),
PassMode::Cast(cast, _) => cast.llvm_type(cx),
PassMode::Cast { cast, pad_i32: _ } => cast.llvm_type(cx),
PassMode::Indirect { .. } => {
llargument_tys.push(cx.type_ptr());
cx.type_void()
@ -390,7 +390,9 @@ impl<'ll, 'tcx> FnAbiLlvmExt<'ll, 'tcx> for FnAbi<'tcx, Ty<'tcx>> {
llargument_tys.push(ptr_layout.scalar_pair_element_llvm_type(cx, 1, true));
continue;
}
PassMode::Cast(cast, pad_i32) => {
PassMode::Cast { cast, pad_i32 } => {
// `Cast` means "transmute to `CastType`"; that only makes sense for sized types.
assert!(arg.layout.is_sized());
// add padding
if *pad_i32 {
llargument_tys.push(Reg::i32().llvm_type(cx));
@ -448,7 +450,7 @@ impl<'ll, 'tcx> FnAbiLlvmExt<'ll, 'tcx> for FnAbi<'tcx, Ty<'tcx>> {
let sret = llvm::CreateStructRetAttr(cx.llcx, self.ret.layout.llvm_type(cx));
attributes::apply_to_llfn(llfn, llvm::AttributePlace::Argument(i), &[sret]);
}
PassMode::Cast(cast, _) => {
PassMode::Cast { cast, pad_i32: _ } => {
cast.attrs.apply_attrs_to_llfn(llvm::AttributePlace::ReturnValue, cx, llfn);
}
_ => {}
@ -474,7 +476,7 @@ impl<'ll, 'tcx> FnAbiLlvmExt<'ll, 'tcx> for FnAbi<'tcx, Ty<'tcx>> {
apply(a);
apply(b);
}
PassMode::Cast(cast, pad_i32) => {
PassMode::Cast { cast, pad_i32 } => {
if *pad_i32 {
apply(&ArgAttributes::new());
}
@ -510,7 +512,7 @@ impl<'ll, 'tcx> FnAbiLlvmExt<'ll, 'tcx> for FnAbi<'tcx, Ty<'tcx>> {
let sret = llvm::CreateStructRetAttr(bx.cx.llcx, self.ret.layout.llvm_type(bx));
attributes::apply_to_callsite(callsite, llvm::AttributePlace::Argument(i), &[sret]);
}
PassMode::Cast(cast, _) => {
PassMode::Cast { cast, pad_i32: _ } => {
cast.attrs.apply_attrs_to_callsite(
llvm::AttributePlace::ReturnValue,
&bx.cx,
@ -553,7 +555,7 @@ impl<'ll, 'tcx> FnAbiLlvmExt<'ll, 'tcx> for FnAbi<'tcx, Ty<'tcx>> {
apply(bx.cx, a);
apply(bx.cx, b);
}
PassMode::Cast(cast, pad_i32) => {
PassMode::Cast { cast, pad_i32 } => {
if *pad_i32 {
apply(bx.cx, &ArgAttributes::new());
}

4
compiler/rustc_codegen_llvm/src/intrinsic.rs
View file

@ -165,7 +165,7 @@ impl<'ll, 'tcx> IntrinsicCallMethods<'tcx> for Builder<'_, 'll, 'tcx> {
sym::volatile_load | sym::unaligned_volatile_load => {
let tp_ty = fn_args.type_at(0);
let ptr = args[0].immediate();
let load = if let PassMode::Cast(ty, _) = &fn_abi.ret.mode {
let load = if let PassMode::Cast { cast: ty, pad_i32: _ } = &fn_abi.ret.mode {
let llty = ty.llvm_type(self);
self.volatile_load(llty, ptr)
} else {
@ -386,7 +386,7 @@ impl<'ll, 'tcx> IntrinsicCallMethods<'tcx> for Builder<'_, 'll, 'tcx> {
};
if !fn_abi.ret.is_ignore() {
if let PassMode::Cast(_, _) = &fn_abi.ret.mode {
if let PassMode::Cast { .. } = &fn_abi.ret.mode {
self.store(llval, result.llval, result.align);
} else {
OperandRef::from_immediate_or_packed_pair(self, llval, result.layout)