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Remove ancient register allocation (#3401)

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This commit is contained in:
Benjamin Bouvier
2021-09-30 21:27:23 +02:00
committed by GitHub
parent 80336f4535
commit bae4ec6427
66 changed files with 112 additions and 15380 deletions
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66
cranelift/codegen/src/isa/constraints.rs
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@@ -8,9 +8,8 @@
//! are satisfied.
use crate::binemit::CodeOffset;
use crate::ir::{Function, Inst, ValueLoc};
use crate::ir::ValueLoc;
use crate::isa::{RegClass, RegUnit};
use crate::regalloc::RegDiversions;
/// Register constraint for a single value operand or instruction result.
#[derive(PartialEq, Debug)]
@@ -87,69 +86,6 @@ pub enum ConstraintKind {
Stack,
}
/// Value operand constraints for an encoding recipe.
#[derive(PartialEq, Clone)]
pub struct RecipeConstraints {
/// Constraints for the instruction's fixed value operands.
///
/// If the instruction takes a variable number of operands, the register constraints for those
/// operands must be computed dynamically.
///
/// - For branches and jumps, block arguments must match the expectations of the destination block.
/// - For calls and returns, the calling convention ABI specifies constraints.
pub ins: &'static [OperandConstraint],
/// Constraints for the instruction's fixed results.
///
/// If the instruction produces a variable number of results, it's probably a call and the
/// constraints must be derived from the calling convention ABI.
pub outs: &'static [OperandConstraint],
/// Are any of the input constraints `FixedReg` or `FixedTied`?
pub fixed_ins: bool,
/// Are any of the output constraints `FixedReg` or `FixedTied`?
pub fixed_outs: bool,
/// Are any of the input/output constraints `Tied` (but not `FixedTied`)?
pub tied_ops: bool,
/// Does this instruction clobber the CPU flags?
///
/// When true, SSA values of type `iflags` or `fflags` can not be live across the instruction.
pub clobbers_flags: bool,
}
impl RecipeConstraints {
/// Check that these constraints are satisfied by the operands on `inst`.
pub fn satisfied(&self, inst: Inst, divert: &RegDiversions, func: &Function) -> bool {
for (&arg, constraint) in func.dfg.inst_args(inst).iter().zip(self.ins) {
let loc = divert.get(arg, &func.locations);
if let ConstraintKind::Tied(out_index) = constraint.kind {
let out_val = func.dfg.inst_results(inst)[out_index as usize];
let out_loc = func.locations[out_val];
if loc != out_loc {
return false;
}
}
if !constraint.satisfied(loc) {
return false;
}
}
for (&arg, constraint) in func.dfg.inst_results(inst).iter().zip(self.outs) {
let loc = divert.get(arg, &func.locations);
if !constraint.satisfied(loc) {
return false;
}
}
true
}
}
/// Constraints on the range of a branch instruction.
///
/// A branch instruction usually encodes its destination as a signed n-bit offset from an origin.