-use gccjit::{RValue, ToRValue, Type};
+use gccjit::{LValue, RValue, ToRValue, Type};
use rustc_ast::ast::{InlineAsmOptions, InlineAsmTemplatePiece};
use rustc_codegen_ssa::mir::operand::OperandValue;
use rustc_codegen_ssa::mir::place::PlaceRef;
use rustc_codegen_ssa::traits::{AsmBuilderMethods, AsmMethods, BaseTypeMethods, BuilderMethods, GlobalAsmOperandRef, InlineAsmOperandRef};
-use rustc_data_structures::fx::FxHashMap;
+
use rustc_hir::LlvmInlineAsmInner;
-use rustc_middle::bug;
+use rustc_middle::{bug, ty::Instance};
use rustc_span::Span;
use rustc_target::asm::*;
+use std::borrow::Cow;
+
use crate::builder::Builder;
use crate::context::CodegenCx;
use crate::type_of::LayoutGccExt;
+
+// Rust asm! and GCC Extended Asm semantics differ substantially.
+//
+// 1. Rust asm operands go along as one list of operands. Operands themselves indicate
+// if they're "in" or "out". "In" and "out" operands can interleave. One operand can be
+// both "in" and "out" (`inout(reg)`).
+//
+// GCC asm has two different lists for "in" and "out" operands. In terms of gccjit,
+// this means that all "out" operands must go before "in" operands. "In" and "out" operands
+// cannot interleave.
+//
+// 2. Operand lists in both Rust and GCC are indexed. Index starts from 0. Indexes are important
+// because the asm template refers to operands by index.
+//
+// Mapping from Rust to GCC index would be 1-1 if it wasn't for...
+//
+// 3. Clobbers. GCC has a separate list of clobbers, and clobbers don't have indexes.
+// Contrary, Rust expresses clobbers through "out" operands that aren't tied to
+// a variable (`_`), and such "clobbers" do have index.
+//
+// 4. Furthermore, GCC Extended Asm does not support explicit register constraints
+// (like `out("eax")`) directly, offering so-called "local register variables"
+// as a workaround. These variables need to be declared and initialized *before*
+// the Extended Asm block but *after* normal local variables
+// (see comment in `codegen_inline_asm` for explanation).
+//
+// With that in mind, let's see how we translate Rust syntax to GCC
+// (from now on, `CC` stands for "constraint code"):
+//
+// * `out(reg_class) var` -> translated to output operand: `"=CC"(var)`
+// * `inout(reg_class) var` -> translated to output operand: `"+CC"(var)`
+// * `in(reg_class) var` -> translated to input operand: `"CC"(var)`
+//
+// * `out(reg_class) _` -> translated to one `=r(tmp)`, where "tmp" is a temporary unused variable
+//
+// * `out("explicit register") _` -> not translated to any operands, register is simply added to clobbers list
+//
+// * `inout(reg_class) in_var => out_var` -> translated to two operands:
+// output: `"=CC"(in_var)`
+// input: `"num"(out_var)` where num is the GCC index
+// of the corresponding output operand
+//
+// * `inout(reg_class) in_var => _` -> same as `inout(reg_class) in_var => tmp`,
+// where "tmp" is a temporary unused variable
+//
+// * `out/in/inout("explicit register") var` -> translated to one or two operands as described above
+// with `"r"(var)` constraint,
+// and one register variable assigned to the desired register.
+//
+
+const ATT_SYNTAX_INS: &str = ".att_syntax noprefix\n\t";
+const INTEL_SYNTAX_INS: &str = "\n\t.intel_syntax noprefix";
+
+
+struct AsmOutOperand<'a, 'tcx, 'gcc> {
+ rust_idx: usize,
+ constraint: &'a str,
+ late: bool,
+ readwrite: bool,
+
+ tmp_var: LValue<'gcc>,
+ out_place: Option<PlaceRef<'tcx, RValue<'gcc>>>
+}
+
+struct AsmInOperand<'a, 'tcx> {
+ rust_idx: usize,
+ constraint: Cow<'a, str>,
+ val: RValue<'tcx>
+}
+
+impl AsmOutOperand<'_, '_, '_> {
+ fn to_constraint(&self) -> String {
+ let mut res = String::with_capacity(self.constraint.len() + self.late as usize + 1);
+
+ let sign = if self.readwrite { '+' } else { '=' };
+ res.push(sign);
+ if !self.late {
+ res.push('&');
+ }
+
+ res.push_str(&self.constraint);
+ res
+ }
+}
+
+enum ConstraintOrRegister {
+ Constraint(&'static str),
+ Register(&'static str)
+}
+
+
impl<'a, 'gcc, 'tcx> AsmBuilderMethods<'tcx> for Builder<'a, 'gcc, 'tcx> {
- fn codegen_llvm_inline_asm(&mut self, _ia: &LlvmInlineAsmInner, _outputs: Vec<PlaceRef<'tcx, RValue<'gcc>>>, mut _inputs: Vec<RValue<'gcc>>, _span: Span) -> bool {
- // TODO(antoyo)
- return true;
+ fn codegen_llvm_inline_asm(&mut self, _ia: &LlvmInlineAsmInner, _outputs: Vec<PlaceRef<'tcx, RValue<'gcc>>>, _inputs: Vec<RValue<'gcc>>, span: Span) -> bool {
+ self.sess().struct_span_err(span, "GCC backend does not support `llvm_asm!`")
+ .help("consider using the `asm!` macro instead")
+ .emit();
+
+ // We return `true` even if we've failed to generate the asm
+ // because we want to suppress the "malformed inline assembly" error
+ // generated by the frontend.
+ true
}
- fn codegen_inline_asm(&mut self, template: &[InlineAsmTemplatePiece], operands: &[InlineAsmOperandRef<'tcx, Self>], options: InlineAsmOptions, _span: &[Span]) {
+ fn codegen_inline_asm(&mut self, template: &[InlineAsmTemplatePiece], rust_operands: &[InlineAsmOperandRef<'tcx, Self>], options: InlineAsmOptions, _span: &[Span]) {
let asm_arch = self.tcx.sess.asm_arch.unwrap();
+ let is_x86 = matches!(asm_arch, InlineAsmArch::X86 | InlineAsmArch::X86_64);
+ let att_dialect = is_x86 && options.contains(InlineAsmOptions::ATT_SYNTAX);
+ let intel_dialect = is_x86 && !options.contains(InlineAsmOptions::ATT_SYNTAX);
- let intel_dialect =
- match asm_arch {
- InlineAsmArch::X86 | InlineAsmArch::X86_64 if !options.contains(InlineAsmOptions::ATT_SYNTAX) => true,
- _ => false,
- };
+ // GCC index of an output operand equals its position in the array
+ let mut outputs = vec![];
+
+ // GCC index of an input operand equals its position in the array
+ // added to `outputs.len()`
+ let mut inputs = vec![];
+
+ // Clobbers collected from `out("explicit register") _` and `inout("expl_reg") var => _`
+ let mut clobbers = vec![];
+
+ // We're trying to preallocate space for the template
+ let mut constants_len = 0;
- // Collect the types of output operands
- // FIXME(antoyo): we do this here instead of later because of a bug in libgccjit where creating the
- // variable after the extended asm expression causes a segfault:
- // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100380
- let mut output_vars = FxHashMap::default();
- let mut operand_numbers = FxHashMap::default();
- let mut current_number = 0;
- for (idx, op) in operands.iter().enumerate() {
+ // There are rules we must adhere to if we want GCC to do the right thing:
+ //
+ // * Every local variable that the asm block uses as an output must be declared *before*
+ // the asm block.
+ // * There must be no instructions whatsoever between the register variables and the asm.
+ //
+ // Therefore, the backend must generate the instructions strictly in this order:
+ //
+ // 1. Output variables.
+ // 2. Register variables.
+ // 3. The asm block.
+ //
+ // We also must make sure that no input operands are emitted before output operands.
+ //
+ // This is why we work in passes, first emitting local vars, then local register vars.
+ // Also, we don't emit any asm operands immediately; we save them to
+ // the one of the buffers to be emitted later.
+
+ // 1. Normal variables (and saving operands to buffers).
+ for (rust_idx, op) in rust_operands.iter().enumerate() {
match *op {
- InlineAsmOperandRef::Out { place, .. } => {
- let ty =
- match place {
- Some(place) => place.layout.gcc_type(self.cx, false),
- None => {
- // If the output is discarded, we don't really care what
- // type is used. We're just using this to tell GCC to
- // reserve the register.
- //dummy_output_type(self.cx, reg.reg_class())
-
- // NOTE: if no output value, we should not create one (it will be a
- // clobber).
- continue;
- },
- };
- let var = self.current_func().new_local(None, ty, "output_register");
- operand_numbers.insert(idx, current_number);
- current_number += 1;
- output_vars.insert(idx, var);
+ InlineAsmOperandRef::Out { reg, late, place } => {
+ use ConstraintOrRegister::*;
+
+ let (constraint, ty) = match (reg_to_gcc(reg), place) {
+ (Constraint(constraint), Some(place)) => (constraint, place.layout.gcc_type(self.cx, false)),
+ // When `reg` is a class and not an explicit register but the out place is not specified,
+ // we need to create an unused output variable to assign the output to. This var
+ // needs to be of a type that's "compatible" with the register class, but specific type
+ // doesn't matter.
+ (Constraint(constraint), None) => (constraint, dummy_output_type(self.cx, reg.reg_class())),
+ (Register(_), Some(_)) => {
+ // left for the next pass
+ continue
+ },
+ (Register(reg_name), None) => {
+ clobbers.push(reg_name);
+ continue
+ }
+ };
+
+ let tmp_var = self.current_func().new_local(None, ty, "output_register");
+ outputs.push(AsmOutOperand {
+ constraint,
+ rust_idx,
+ late,
+ readwrite: false,
+ tmp_var,
+ out_place: place
+ });
}
- InlineAsmOperandRef::InOut { out_place, .. } => {
- let ty =
- match out_place {
- Some(place) => place.layout.gcc_type(self.cx, false),
- None => {
- // NOTE: if no output value, we should not create one.
- continue;
- },
- };
- operand_numbers.insert(idx, current_number);
- current_number += 1;
- let var = self.current_func().new_local(None, ty, "output_register");
- output_vars.insert(idx, var);
+
+ InlineAsmOperandRef::In { reg, value } => {
+ if let ConstraintOrRegister::Constraint(constraint) = reg_to_gcc(reg) {
+ inputs.push(AsmInOperand {
+ constraint: Cow::Borrowed(constraint),
+ rust_idx,
+ val: value.immediate()
+ });
+ }
+ else {
+ // left for the next pass
+ continue
+ }
+ }
+
+ InlineAsmOperandRef::InOut { reg, late, in_value, out_place } => {
+ let constraint = if let ConstraintOrRegister::Constraint(constraint) = reg_to_gcc(reg) {
+ constraint
+ }
+ else {
+ // left for the next pass
+ continue
+ };
+
+ // Rustc frontend guarantees that input and output types are "compatible",
+ // so we can just use input var's type for the output variable.
+ //
+ // This decision is also backed by the fact that LLVM needs in and out
+ // values to be of *exactly the same type*, not just "compatible".
+ // I'm not sure if GCC is so picky too, but better safe than sorry.
+ let ty = in_value.layout.gcc_type(self.cx, false);
+ let tmp_var = self.current_func().new_local(None, ty, "output_register");
+
+ // If the out_place is None (i.e `inout(reg) _` syntax was used), we translate
+ // it to one "readwrite (+) output variable", otherwise we translate it to two
+ // "out and tied in" vars as described above.
+ let readwrite = out_place.is_none();
+ outputs.push(AsmOutOperand {
+ constraint,
+ rust_idx,
+ late,
+ readwrite,
+ tmp_var,
+ out_place,
+ });
+
+ if !readwrite {
+ let out_gcc_idx = outputs.len() - 1;
+ let constraint = Cow::Owned(out_gcc_idx.to_string());
+
+ inputs.push(AsmInOperand {
+ constraint,
+ rust_idx,
+ val: in_value.immediate()
+ });
+ }
+ }
+
+ InlineAsmOperandRef::Const { ref string } => {
+ constants_len += string.len() + att_dialect as usize;
+ }
+
+ InlineAsmOperandRef::SymFn { instance } => {
+ constants_len += self.tcx.symbol_name(instance).name.len();
+ }
+ InlineAsmOperandRef::SymStatic { def_id } => {
+ constants_len += self.tcx.symbol_name(Instance::mono(self.tcx, def_id)).name.len();
}
- _ => {}
}
}
- // All output operands must come before the input operands, hence the 2 loops.
- for (idx, op) in operands.iter().enumerate() {
+ // 2. Register variables.
+ for (rust_idx, op) in rust_operands.iter().enumerate() {
match *op {
- InlineAsmOperandRef::In { .. } | InlineAsmOperandRef::InOut { .. } => {
- operand_numbers.insert(idx, current_number);
- current_number += 1;
- },
- _ => (),
+ // `out("explicit register") var`
+ InlineAsmOperandRef::Out { reg, late, place } => {
+ if let ConstraintOrRegister::Register(reg_name) = reg_to_gcc(reg) {
+ let out_place = if let Some(place) = place {
+ place
+ }
+ else {
+ // processed in the previous pass
+ continue
+ };
+
+ let ty = out_place.layout.gcc_type(self.cx, false);
+ let tmp_var = self.current_func().new_local(None, ty, "output_register");
+ tmp_var.set_register_name(reg_name);
+
+ outputs.push(AsmOutOperand {
+ constraint: "r".into(),
+ rust_idx,
+ late,
+ readwrite: false,
+ tmp_var,
+ out_place: Some(out_place)
+ });
+ }
+
+ // processed in the previous pass
+ }
+
+ // `in("explicit register") var`
+ InlineAsmOperandRef::In { reg, value } => {
+ if let ConstraintOrRegister::Register(reg_name) = reg_to_gcc(reg) {
+ let ty = value.layout.gcc_type(self.cx, false);
+ let reg_var = self.current_func().new_local(None, ty, "input_register");
+ reg_var.set_register_name(reg_name);
+ self.llbb().add_assignment(None, reg_var, value.immediate());
+
+ inputs.push(AsmInOperand {
+ constraint: "r".into(),
+ rust_idx,
+ val: reg_var.to_rvalue()
+ });
+ }
+
+ // processed in the previous pass
+ }
+
+ // `inout("explicit register") in_var => out_var`
+ InlineAsmOperandRef::InOut { reg, late, in_value, out_place } => {
+ if let ConstraintOrRegister::Register(reg_name) = reg_to_gcc(reg) {
+ let out_place = if let Some(place) = out_place {
+ place
+ }
+ else {
+ // processed in the previous pass
+ continue
+ };
+
+ // See explanation in the first pass.
+ let ty = in_value.layout.gcc_type(self.cx, false);
+ let tmp_var = self.current_func().new_local(None, ty, "output_register");
+ tmp_var.set_register_name(reg_name);
+
+ outputs.push(AsmOutOperand {
+ constraint: "r".into(),
+ rust_idx,
+ late,
+ readwrite: false,
+ tmp_var,
+ out_place: Some(out_place)
+ });
+
+ let constraint = Cow::Owned((outputs.len() - 1).to_string());
+ inputs.push(AsmInOperand {
+ constraint,
+ rust_idx,
+ val: in_value.immediate()
+ });
+ }
+
+ // processed in the previous pass
+ }
+
+ InlineAsmOperandRef::Const { .. }
+ | InlineAsmOperandRef::SymFn { .. }
+ | InlineAsmOperandRef::SymStatic { .. } => {
+ // processed in the previous pass
+ }
}
}
- // Build the template string
- let mut template_str = String::new();
+ // 3. Build the template string
+
+ let mut template_str = String::with_capacity(estimate_template_length(template, constants_len, att_dialect));
+ if !intel_dialect {
+ template_str.push_str(ATT_SYNTAX_INS);
+ }
+
for piece in template {
match *piece {
InlineAsmTemplatePiece::String(ref string) => {
- if string.contains('%') {
- for c in string.chars() {
- if c == '%' {
- template_str.push_str("%%");
- }
- else {
- template_str.push(c);
- }
- }
+ // TODO(@Commeownist): switch to `Iterator::intersperse` once it's stable
+ let mut iter = string.split('%');
+ if let Some(s) = iter.next() {
+ template_str.push_str(s);
}
- else {
- template_str.push_str(string)
+
+ for s in iter {
+ template_str.push_str("%%");
+ template_str.push_str(s);
}
}
InlineAsmTemplatePiece::Placeholder { operand_idx, modifier, span: _ } => {
- match operands[operand_idx] {
- InlineAsmOperandRef::Out { reg, place: Some(_), .. } => {
+ let mut push_to_template = |modifier, gcc_idx| {
+ use std::fmt::Write;
+
+ template_str.push('%');
+ if let Some(modifier) = modifier {
+ template_str.push(modifier);
+ }
+ write!(template_str, "{}", gcc_idx).expect("pushing to string failed");
+ };
+
+ match rust_operands[operand_idx] {
+ InlineAsmOperandRef::Out { reg, .. } => {
let modifier = modifier_to_gcc(asm_arch, reg.reg_class(), modifier);
- if let Some(modifier) = modifier {
- template_str.push_str(&format!("%{}{}", modifier, operand_numbers[&operand_idx]));
- } else {
- template_str.push_str(&format!("%{}", operand_numbers[&operand_idx]));
- }
- },
- InlineAsmOperandRef::Out { place: None, .. } => {
- unimplemented!("Out None");
- },
- InlineAsmOperandRef::In { reg, .. }
- | InlineAsmOperandRef::InOut { reg, .. } => {
+ let gcc_index = outputs.iter()
+ .position(|op| operand_idx == op.rust_idx)
+ .expect("wrong rust index");
+ push_to_template(modifier, gcc_index);
+ }
+
+ InlineAsmOperandRef::In { reg, .. } => {
let modifier = modifier_to_gcc(asm_arch, reg.reg_class(), modifier);
- if let Some(modifier) = modifier {
- template_str.push_str(&format!("%{}{}", modifier, operand_numbers[&operand_idx]));
- } else {
- template_str.push_str(&format!("%{}", operand_numbers[&operand_idx]));
- }
+ let in_gcc_index = inputs.iter()
+ .position(|op| operand_idx == op.rust_idx)
+ .expect("wrong rust index");
+ let gcc_index = in_gcc_index + outputs.len();
+ push_to_template(modifier, gcc_index);
}
+
+ InlineAsmOperandRef::InOut { reg, .. } => {
+ let modifier = modifier_to_gcc(asm_arch, reg.reg_class(), modifier);
+
+ // The input register is tied to the output, so we can just use the index of the output register
+ let gcc_index = outputs.iter()
+ .position(|op| operand_idx == op.rust_idx)
+ .expect("wrong rust index");
+ push_to_template(modifier, gcc_index);
+ }
+
+ InlineAsmOperandRef::SymFn { instance } => {
+ let name = self.tcx.symbol_name(instance).name;
+ template_str.push_str(name);
+ }
+
+ InlineAsmOperandRef::SymStatic { def_id } => {
+ // TODO(@Commeownist): This may not be sufficient for all kinds of statics.
+ // Some statics may need the `@plt` suffix, like thread-local vars.
+ let instance = Instance::mono(self.tcx, def_id);
+ let name = self.tcx.symbol_name(instance).name;
+ template_str.push_str(name);
+ }
+
InlineAsmOperandRef::Const { ref string } => {
// Const operands get injected directly into the template
+ if att_dialect {
+ template_str.push('$');
+ }
template_str.push_str(string);
}
- InlineAsmOperandRef::SymFn { .. }
- | InlineAsmOperandRef::SymStatic { .. } => {
- unimplemented!();
- // Only emit the raw symbol name
- //template_str.push_str(&format!("${{{}:c}}", op_idx[&operand_idx]));
- }
}
}
}
}
+ if !intel_dialect {
+ template_str.push_str(INTEL_SYNTAX_INS);
+ }
+
+ // 4. Generate Extended Asm block
+
let block = self.llbb();
- let template_str =
- if intel_dialect {
- template_str
- }
- else {
- // FIXME(antoyo): this might break the "m" memory constraint:
- // https://stackoverflow.com/a/9347957/389119
- // TODO(antoyo): only set on x86 platforms.
- format!(".att_syntax noprefix\n\t{}\n\t.intel_syntax noprefix", template_str)
- };
let extended_asm = block.add_extended_asm(None, &template_str);
- // Collect the types of output operands
- let mut output_types = vec![];
- for (idx, op) in operands.iter().enumerate() {
- match *op {
- InlineAsmOperandRef::Out { reg, late, place } => {
- let ty =
- match place {
- Some(place) => place.layout.gcc_type(self.cx, false),
- None => {
- // If the output is discarded, we don't really care what
- // type is used. We're just using this to tell GCC to
- // reserve the register.
- dummy_output_type(self.cx, reg.reg_class())
- },
- };
- output_types.push(ty);
- let prefix = if late { "=" } else { "=&" };
- let constraint = format!("{}{}", prefix, reg_to_gcc(reg));
+ for op in &outputs {
+ extended_asm.add_output_operand(None, &op.to_constraint(), op.tmp_var);
+ }
- if place.is_some() {
- let var = output_vars[&idx];
- extended_asm.add_output_operand(None, &constraint, var);
- }
- else {
- // NOTE: reg.to_string() returns the register name with quotes around it so
- // remove them.
- extended_asm.add_clobber(reg.to_string().trim_matches('"'));
- }
- }
- InlineAsmOperandRef::InOut { reg, late, in_value, out_place } => {
- let ty =
- match out_place {
- Some(out_place) => out_place.layout.gcc_type(self.cx, false),
- None => dummy_output_type(self.cx, reg.reg_class())
- };
- output_types.push(ty);
- // TODO(antoyo): prefix of "+" for reading and writing?
- let prefix = if late { "=" } else { "=&" };
- let constraint = format!("{}{}", prefix, reg_to_gcc(reg));
-
- if out_place.is_some() {
- let var = output_vars[&idx];
- // TODO(antoyo): also specify an output operand when out_place is none: that would
- // be the clobber but clobbers do not support general constraint like reg;
- // they only support named registers.
- // Not sure how we can do this. And the LLVM backend does not seem to add a
- // clobber.
- extended_asm.add_output_operand(None, &constraint, var);
- }
+ for op in &inputs {
+ extended_asm.add_input_operand(None, &op.constraint, op.val);
+ }
- let constraint = reg_to_gcc(reg);
- extended_asm.add_input_operand(None, &constraint, in_value.immediate());
- }
- InlineAsmOperandRef::In { reg, value } => {
- let constraint = reg_to_gcc(reg);
- extended_asm.add_input_operand(None, &constraint, value.immediate());
- }
- _ => {}
+ for clobber in clobbers.iter() {
+ extended_asm.add_clobber(clobber);
+ }
+
+ if !options.contains(InlineAsmOptions::PRESERVES_FLAGS) {
+ // TODO(@Commeownist): I'm not 100% sure this one clobber is sufficient
+ // on all architectures. For instance, what about FP stack?
+ extended_asm.add_clobber("cc");
+ }
+ if !options.contains(InlineAsmOptions::NOMEM) {
+ extended_asm.add_clobber("memory");
+ }
+ if !options.contains(InlineAsmOptions::PURE) {
+ extended_asm.set_volatile_flag(true);
+ }
+ if !options.contains(InlineAsmOptions::NOSTACK) {
+ // TODO(@Commeownist): figure out how to align stack
+ }
+ if options.contains(InlineAsmOptions::NORETURN) {
+ let builtin_unreachable = self.context.get_builtin_function("__builtin_unreachable");
+ let builtin_unreachable: RValue<'gcc> = unsafe { std::mem::transmute(builtin_unreachable) };
+ self.call(self.type_void(), builtin_unreachable, &[], None);
+ }
+
+ // Write results to outputs.
+ //
+ // We need to do this because:
+ // 1. Turning `PlaceRef` into `RValue` is error-prone and has nasty edge cases
+ // (especially with current `rustc_backend_ssa` API).
+ // 2. Not every output operand has an `out_place`, and it's required by `add_output_operand`.
+ //
+ // Instead, we generate a temporary output variable for each output operand, and then this loop,
+ // generates `out_place = tmp_var;` assignments if out_place exists.
+ for op in &outputs {
+ if let Some(place) = op.out_place {
+ OperandValue::Immediate(op.tmp_var.to_rvalue()).store(self, place);
}
}
- // Write results to outputs
- for (idx, op) in operands.iter().enumerate() {
- if let InlineAsmOperandRef::Out { place: Some(place), .. }
- | InlineAsmOperandRef::InOut { out_place: Some(place), .. } = *op
- {
- OperandValue::Immediate(output_vars[&idx].to_rvalue()).store(self, place);
+ }
+}
+
+fn estimate_template_length(template: &[InlineAsmTemplatePiece], constants_len: usize, att_dialect: bool) -> usize {
+ let len: usize = template.iter().map(|piece| {
+ match *piece {
+ InlineAsmTemplatePiece::String(ref string) => {
+ string.len()
+ }
+ InlineAsmTemplatePiece::Placeholder { .. } => {
+ // '%' + 1 char modifier + 1 char index
+ 3
}
}
+ })
+ .sum();
+
+ // increase it by 5% to account for possible '%' signs that'll be duplicated
+ // I pulled the number out of blue, but should be fair enough
+ // as the upper bound
+ let mut res = (len as f32 * 1.05) as usize + constants_len;
+
+ if att_dialect {
+ res += INTEL_SYNTAX_INS.len() + ATT_SYNTAX_INS.len();
}
+ res
}
/// Converts a register class to a GCC constraint code.
-// TODO(antoyo): return &'static str instead?
-fn reg_to_gcc(reg: InlineAsmRegOrRegClass) -> String {
- match reg {
+fn reg_to_gcc(reg: InlineAsmRegOrRegClass) -> ConstraintOrRegister {
+ let constraint = match reg {
// For vector registers LLVM wants the register name to match the type size.
InlineAsmRegOrRegClass::Reg(reg) => {
// TODO(antoyo): add support for vector register.
- let constraint =
- match reg.name() {
- "ax" => "a",
- "bx" => "b",
- "cx" => "c",
- "dx" => "d",
- "si" => "S",
- "di" => "D",
- // TODO(antoyo): for registers like r11, we have to create a register variable: https://stackoverflow.com/a/31774784/389119
- // TODO(antoyo): in this case though, it's a clobber, so it should work as r11.
- // Recent nightly supports clobber() syntax, so update to it. It does not seem
- // like it's implemented yet.
- name => name, // FIXME(antoyo): probably wrong.
- };
- constraint.to_string()
+ match reg.name() {
+ "ax" => "a",
+ "bx" => "b",
+ "cx" => "c",
+ "dx" => "d",
+ "si" => "S",
+ "di" => "D",
+ // For registers like r11, we have to create a register variable: https://stackoverflow.com/a/31774784/389119
+ name => return ConstraintOrRegister::Register(name),
+ }
},
InlineAsmRegOrRegClass::RegClass(reg) => match reg {
InlineAsmRegClass::AArch64(AArch64InlineAsmRegClass::preg) => unimplemented!(),
InlineAsmRegClass::PowerPC(PowerPCInlineAsmRegClass::reg) => unimplemented!(),
InlineAsmRegClass::PowerPC(PowerPCInlineAsmRegClass::reg_nonzero) => unimplemented!(),
InlineAsmRegClass::PowerPC(PowerPCInlineAsmRegClass::freg) => unimplemented!(),
+ InlineAsmRegClass::PowerPC(PowerPCInlineAsmRegClass::cr)
+ | InlineAsmRegClass::PowerPC(PowerPCInlineAsmRegClass::xer) => {
+ unreachable!("clobber-only")
+ },
InlineAsmRegClass::RiscV(RiscVInlineAsmRegClass::reg) => unimplemented!(),
InlineAsmRegClass::RiscV(RiscVInlineAsmRegClass::freg) => unimplemented!(),
InlineAsmRegClass::RiscV(RiscVInlineAsmRegClass::vreg) => unimplemented!(),
- InlineAsmRegClass::X86(X86InlineAsmRegClass::mmx_reg) => unimplemented!(),
InlineAsmRegClass::X86(X86InlineAsmRegClass::reg) => "r",
- InlineAsmRegClass::X86(X86InlineAsmRegClass::reg_abcd) => unimplemented!(),
- InlineAsmRegClass::X86(X86InlineAsmRegClass::reg_byte) => unimplemented!(),
+ InlineAsmRegClass::X86(X86InlineAsmRegClass::reg_abcd) => "Q",
+ InlineAsmRegClass::X86(X86InlineAsmRegClass::reg_byte) => "q",
InlineAsmRegClass::X86(X86InlineAsmRegClass::xmm_reg)
- | InlineAsmRegClass::X86(X86InlineAsmRegClass::ymm_reg) => unimplemented!(),
- InlineAsmRegClass::X86(X86InlineAsmRegClass::x87_reg) => unimplemented!(),
- InlineAsmRegClass::X86(X86InlineAsmRegClass::zmm_reg) => unimplemented!(),
+ | InlineAsmRegClass::X86(X86InlineAsmRegClass::ymm_reg) => "x",
+ InlineAsmRegClass::X86(X86InlineAsmRegClass::zmm_reg) => "v",
InlineAsmRegClass::X86(X86InlineAsmRegClass::kreg) => unimplemented!(),
InlineAsmRegClass::Wasm(WasmInlineAsmRegClass::local) => unimplemented!(),
+ InlineAsmRegClass::X86(
+ X86InlineAsmRegClass::x87_reg | X86InlineAsmRegClass::mmx_reg,
+ ) => unreachable!("clobber-only"),
InlineAsmRegClass::SpirV(SpirVInlineAsmRegClass::reg) => {
bug!("GCC backend does not support SPIR-V")
}
+ InlineAsmRegClass::S390x(S390xInlineAsmRegClass::reg) => unimplemented!(),
+ InlineAsmRegClass::S390x(S390xInlineAsmRegClass::freg) => unimplemented!(),
InlineAsmRegClass::Err => unreachable!(),
}
- .to_string(),
- }
+ };
+
+ ConstraintOrRegister::Constraint(constraint)
}
/// Type to use for outputs that are discarded. It doesn't really matter what
InlineAsmRegClass::PowerPC(PowerPCInlineAsmRegClass::reg) => cx.type_i32(),
InlineAsmRegClass::PowerPC(PowerPCInlineAsmRegClass::reg_nonzero) => cx.type_i32(),
InlineAsmRegClass::PowerPC(PowerPCInlineAsmRegClass::freg) => cx.type_f64(),
+ InlineAsmRegClass::PowerPC(PowerPCInlineAsmRegClass::cr)
+ | InlineAsmRegClass::PowerPC(PowerPCInlineAsmRegClass::xer) => {
+ unreachable!("clobber-only")
+ },
InlineAsmRegClass::RiscV(RiscVInlineAsmRegClass::reg) => cx.type_i32(),
InlineAsmRegClass::RiscV(RiscVInlineAsmRegClass::freg) => cx.type_f32(),
InlineAsmRegClass::RiscV(RiscVInlineAsmRegClass::vreg) => cx.type_f32(),
InlineAsmRegClass::SpirV(SpirVInlineAsmRegClass::reg) => {
bug!("LLVM backend does not support SPIR-V")
},
+ InlineAsmRegClass::S390x(S390xInlineAsmRegClass::reg) => cx.type_i32(),
+ InlineAsmRegClass::S390x(S390xInlineAsmRegClass::freg) => cx.type_f64(),
InlineAsmRegClass::Err => unreachable!(),
}
}
match operands[operand_idx] {
GlobalAsmOperandRef::Const { ref string } => {
// Const operands get injected directly into the
- // template. Note that we don't need to escape $
+ // template. Note that we don't need to escape %
// here unlike normal inline assembly.
template_str.push_str(string);
}
InlineAsmRegClass::RiscV(RiscVInlineAsmRegClass::vreg) => unimplemented!(),
InlineAsmRegClass::X86(X86InlineAsmRegClass::reg)
| InlineAsmRegClass::X86(X86InlineAsmRegClass::reg_abcd) => match modifier {
- None if arch == InlineAsmArch::X86_64 => Some('q'),
- None => Some('k'),
+ None => if arch == InlineAsmArch::X86_64 { Some('q') } else { Some('k') },
Some('l') => Some('b'),
Some('h') => Some('h'),
Some('x') => Some('w'),
Some('r') => Some('q'),
_ => unreachable!(),
},
- InlineAsmRegClass::X86(X86InlineAsmRegClass::mmx_reg) => unimplemented!(),
- InlineAsmRegClass::X86(X86InlineAsmRegClass::reg_byte) => unimplemented!(),
- InlineAsmRegClass::X86(X86InlineAsmRegClass::xmm_reg)
- | InlineAsmRegClass::X86(X86InlineAsmRegClass::ymm_reg)
- | InlineAsmRegClass::X86(X86InlineAsmRegClass::zmm_reg) => unimplemented!(),
- InlineAsmRegClass::X86(X86InlineAsmRegClass::x87_reg) => unimplemented!(),
- InlineAsmRegClass::X86(X86InlineAsmRegClass::kreg) => unimplemented!(),
+ InlineAsmRegClass::X86(X86InlineAsmRegClass::reg_byte) => None,
+ InlineAsmRegClass::X86(reg @ X86InlineAsmRegClass::xmm_reg)
+ | InlineAsmRegClass::X86(reg @ X86InlineAsmRegClass::ymm_reg)
+ | InlineAsmRegClass::X86(reg @ X86InlineAsmRegClass::zmm_reg) => match (reg, modifier) {
+ (X86InlineAsmRegClass::xmm_reg, None) => Some('x'),
+ (X86InlineAsmRegClass::ymm_reg, None) => Some('t'),
+ (X86InlineAsmRegClass::zmm_reg, None) => Some('g'),
+ (_, Some('x')) => Some('x'),
+ (_, Some('y')) => Some('t'),
+ (_, Some('z')) => Some('g'),
+ _ => unreachable!(),
+ },
+ InlineAsmRegClass::X86(X86InlineAsmRegClass::kreg) => None,
+ InlineAsmRegClass::X86(X86InlineAsmRegClass::x87_reg | X86InlineAsmRegClass::mmx_reg) => {
+ unreachable!("clobber-only")
+ }
InlineAsmRegClass::Wasm(WasmInlineAsmRegClass::local) => unimplemented!(),
InlineAsmRegClass::SpirV(SpirVInlineAsmRegClass::reg) => {
bug!("LLVM backend does not support SPIR-V")
},
+ InlineAsmRegClass::S390x(S390xInlineAsmRegClass::reg) => unimplemented!(),
+ InlineAsmRegClass::S390x(S390xInlineAsmRegClass::freg) => unimplemented!(),
InlineAsmRegClass::Err => unreachable!(),
}
}
projects / rust.git / commitdiff