bjoernager/rust
bjoernager/rust
1
Fork 0
Code Activity

make #[target_feature] work with asm register classes

Browse source
This commit is contained in:
asquared31415 2021-10-07 15:42:18 -04:00
parent d7539a6af0
commit 271da7d8bc
7 changed files with 213 additions and 112 deletions
Download patch file Download diff file Expand all files Collapse all files

64
compiler/rustc_ast_lowering/src/asm.rs
View file

@ -202,39 +202,20 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
let mut used_input_regs = FxHashMap::default();
let mut used_output_regs = FxHashMap::default();
let mut required_features: Vec<&str> = vec![];
for (idx, &(ref op, op_sp)) in operands.iter().enumerate() {
if let Some(reg) = op.reg() {
// Make sure we don't accidentally carry features from the
// previous iteration.
required_features.clear();
let reg_class = reg.reg_class();
if reg_class == asm::InlineAsmRegClass::Err {
continue;
}
// We ignore target feature requirements for clobbers: if the
// feature is disabled then the compiler doesn't care what we
// do with the registers.
//
// Note that this is only possible for explicit register
// operands, which cannot be used in the asm string.
let is_clobber = matches!(
op,
hir::InlineAsmOperand::Out {
reg: asm::InlineAsmRegOrRegClass::Reg(_),
late: _,
expr: None
}
);
// Some register classes can only be used as clobbers. This
// means that we disallow passing a value in/out of the asm and
// require that the operand name an explicit register, not a
// register class.
if reg_class.is_clobber_only(asm_arch.unwrap())
&& !(is_clobber && matches!(reg, asm::InlineAsmRegOrRegClass::Reg(_)))
&& !(op.is_clobber() && matches!(reg, asm::InlineAsmRegOrRegClass::Reg(_)))
{
let msg = format!(
"register class `{}` can only be used as a clobber, \
@ -245,47 +226,6 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
continue;
}
if !is_clobber {
// Validate register classes against currently enabled target
// features. We check that at least one type is available for
// the current target.
for &(_, feature) in reg_class.supported_types(asm_arch.unwrap()) {
if let Some(feature) = feature {
if self.sess.target_features.contains(&Symbol::intern(feature)) {
required_features.clear();
break;
} else {
required_features.push(feature);
}
} else {
required_features.clear();
break;
}
}
// We are sorting primitive strs here and can use unstable sort here
required_features.sort_unstable();
required_features.dedup();
match &required_features[..] {
[] => {}
[feature] => {
let msg = format!(
"register class `{}` requires the `{}` target feature",
reg_class.name(),
feature
);
sess.struct_span_err(op_sp, &msg).emit();
}
features => {
let msg = format!(
"register class `{}` requires at least one target feature: {}",
reg_class.name(),
features.join(", ")
);
sess.struct_span_err(op_sp, &msg).emit();
}
}
}
// Check for conflicts between explicit register operands.
if let asm::InlineAsmRegOrRegClass::Reg(reg) = reg {
let (input, output) = match op {