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Allow MaybeUninit in input and output of inline assembly

This commit is contained in:
Taiki Endo 2023-08-23 21:57:18 +09:00
parent 6046aa06b6
commit 03fd2d4379
2 changed files with 61 additions and 19 deletions
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53
compiler/rustc_hir_analysis/src/check/intrinsicck.rs
View File

@ -44,20 +44,7 @@ impl<'a, 'tcx> InlineAsmCtxt<'a, 'tcx> {
false
}
fn check_asm_operand_type(
&self,
idx: usize,
reg: InlineAsmRegOrRegClass,
expr: &'tcx hir::Expr<'tcx>,
template: &[InlineAsmTemplatePiece],
is_input: bool,
tied_input: Option<(&'tcx hir::Expr<'tcx>, Option<InlineAsmType>)>,
target_features: &FxIndexSet<Symbol>,
) -> Option<InlineAsmType> {
let ty = (self.get_operand_ty)(expr);
if ty.has_non_region_infer() {
bug!("inference variable in asm operand ty: {:?} {:?}", expr, ty);
}
fn get_asm_ty(&self, ty: Ty<'tcx>) -> Option<InlineAsmType> {
let asm_ty_isize = match self.tcx.sess.target.pointer_width {
16 => InlineAsmType::I16,
32 => InlineAsmType::I32,
@ -65,10 +52,7 @@ impl<'a, 'tcx> InlineAsmCtxt<'a, 'tcx> {
_ => unreachable!(),
};
let asm_ty = match *ty.kind() {
// `!` is allowed for input but not for output (issue #87802)
ty::Never if is_input => return None,
_ if ty.references_error() => return None,
match *ty.kind() {
ty::Int(IntTy::I8) | ty::Uint(UintTy::U8) => Some(InlineAsmType::I8),
ty::Int(IntTy::I16) | ty::Uint(UintTy::U16) => Some(InlineAsmType::I16),
ty::Int(IntTy::I32) | ty::Uint(UintTy::U32) => Some(InlineAsmType::I32),
@ -99,7 +83,6 @@ impl<'a, 'tcx> InlineAsmCtxt<'a, 'tcx> {
};
match ty.kind() {
ty::Never | ty::Error(_) => return None,
ty::Int(IntTy::I8) | ty::Uint(UintTy::U8) => Some(InlineAsmType::VecI8(size)),
ty::Int(IntTy::I16) | ty::Uint(UintTy::U16) => {
Some(InlineAsmType::VecI16(size))
@ -128,6 +111,38 @@ impl<'a, 'tcx> InlineAsmCtxt<'a, 'tcx> {
}
ty::Infer(_) => unreachable!(),
_ => None,
}
}
fn check_asm_operand_type(
&self,
idx: usize,
reg: InlineAsmRegOrRegClass,
expr: &'tcx hir::Expr<'tcx>,
template: &[InlineAsmTemplatePiece],
is_input: bool,
tied_input: Option<(&'tcx hir::Expr<'tcx>, Option<InlineAsmType>)>,
target_features: &FxIndexSet<Symbol>,
) -> Option<InlineAsmType> {
let ty = (self.get_operand_ty)(expr);
if ty.has_non_region_infer() {
bug!("inference variable in asm operand ty: {:?} {:?}", expr, ty);
}
let asm_ty = match *ty.kind() {
// `!` is allowed for input but not for output (issue #87802)
ty::Never if is_input => return None,
_ if ty.references_error() => return None,
ty::Adt(adt, args) if Some(adt.did()) == self.tcx.lang_items().maybe_uninit() => {
let fields = &adt.non_enum_variant().fields;
let ty = fields[FieldIdx::from_u32(1)].ty(self.tcx, args);
let ty::Adt(ty, args) = ty.kind() else { unreachable!() };
assert!(ty.is_manually_drop());
let fields = &ty.non_enum_variant().fields;
let ty = fields[FieldIdx::from_u32(0)].ty(self.tcx, args);
self.get_asm_ty(ty)
}
_ => self.get_asm_ty(ty),
};
let Some(asm_ty) = asm_ty else {
let msg = format!("cannot use value of type `{ty}` for inline assembly");

27
tests/codegen/asm-maybe-uninit.rs Normal file
View File

@ -0,0 +1,27 @@
// compile-flags: -O
// only-x86_64
#![crate_type = "rlib"]
#![allow(asm_sub_register)]
use std::mem::MaybeUninit;
use std::arch::asm;
// CHECK-LABEL: @int
#[no_mangle]
pub unsafe fn int(x: MaybeUninit<i32>) -> MaybeUninit<i32> {
let y: MaybeUninit<i32>;
asm!("/*{}{}*/", in(reg) x, out(reg) y);
y
}
// CHECK-LABEL: @inout
#[no_mangle]
pub unsafe fn inout(mut x: i32) -> MaybeUninit<u32> {
let mut y: MaybeUninit<u32>;
asm!("/*{}*/", inout(reg) x => y);
asm!("/*{}*/", inout(reg) y => x);
asm!("/*{}*/", inlateout(reg) x => y);
asm!("/*{}*/", inlateout(reg) y => x);
y
}