Custom MIR: Support as casts

This commit is contained in:
Andy Wang 2023-03-07 11:42:34 +01:00
parent 5157d938c4
commit 7281cd0c21
No known key found for this signature in database
GPG Key ID: 181B49F9F38F3374
5 changed files with 81 additions and 1 deletions

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@ -1,5 +1,6 @@
use rustc_middle::mir::interpret::{ConstValue, Scalar};
use rustc_middle::mir::tcx::PlaceTy;
use rustc_middle::ty::cast::mir_cast_kind;
use rustc_middle::{mir::*, thir::*, ty};
use rustc_span::Span;
use rustc_target::abi::VariantIdx;
@ -142,7 +143,7 @@ fn parse_call(
}
fn parse_rvalue(&self, expr_id: ExprId) -> PResult<Rvalue<'tcx>> {
parse_by_kind!(self, expr_id, _, "rvalue",
parse_by_kind!(self, expr_id, expr, "rvalue",
@call("mir_discriminant", args) => self.parse_place(args[0]).map(Rvalue::Discriminant),
@call("mir_checked", args) => {
parse_by_kind!(self, args[0], _, "binary op",
@ -167,6 +168,12 @@ fn parse_rvalue(&self, expr_id: ExprId) -> PResult<Rvalue<'tcx>> {
ExprKind::Repeat { value, count } => Ok(
Rvalue::Repeat(self.parse_operand(*value)?, *count)
),
ExprKind::Cast { source } => {
let source = self.parse_operand(*source)?;
let source_ty = source.ty(self.body.local_decls(), self.tcx);
let cast_kind = mir_cast_kind(source_ty, expr.ty);
Ok(Rvalue::Cast(cast_kind, source, expr.ty))
},
_ => self.parse_operand(expr_id).map(Rvalue::Use),
)
}

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@ -0,0 +1,10 @@
// MIR for `float_to_int` after built
fn float_to_int(_1: f32) -> i32 {
let mut _0: i32; // return place in scope 0 at $DIR/as_cast.rs:+0:28: +0:31
bb0: {
_0 = _1 as i32 (FloatToInt); // scope 0 at $DIR/as_cast.rs:+3:13: +3:27
return; // scope 0 at $DIR/as_cast.rs:+4:13: +4:21
}
}

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@ -0,0 +1,10 @@
// MIR for `int_to_int` after built
fn int_to_int(_1: u32) -> i32 {
let mut _0: i32; // return place in scope 0 at $DIR/as_cast.rs:+0:26: +0:29
bb0: {
_0 = _1 as i32 (IntToInt); // scope 0 at $DIR/as_cast.rs:+3:13: +3:27
return; // scope 0 at $DIR/as_cast.rs:+4:13: +4:21
}
}

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@ -0,0 +1,10 @@
// MIR for `int_to_ptr` after built
fn int_to_ptr(_1: usize) -> *const i32 {
let mut _0: *const i32; // return place in scope 0 at $DIR/as_cast.rs:+0:28: +0:38
bb0: {
_0 = _1 as *const i32 (PointerFromExposedAddress); // scope 0 at $DIR/as_cast.rs:+3:13: +3:34
return; // scope 0 at $DIR/as_cast.rs:+4:13: +4:21
}
}

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@ -0,0 +1,43 @@
#![feature(custom_mir, core_intrinsics)]
extern crate core;
use core::intrinsics::mir::*;
// EMIT_MIR as_cast.int_to_int.built.after.mir
#[custom_mir(dialect = "built")]
fn int_to_int(x: u32) -> i32 {
mir!(
{
RET = x as i32;
Return()
}
)
}
// EMIT_MIR as_cast.float_to_int.built.after.mir
#[custom_mir(dialect = "built")]
fn float_to_int(x: f32) -> i32 {
mir!(
{
RET = x as i32;
Return()
}
)
}
// EMIT_MIR as_cast.int_to_ptr.built.after.mir
#[custom_mir(dialect = "built")]
fn int_to_ptr(x: usize) -> *const i32 {
mir!(
{
RET = x as *const i32;
Return()
}
)
}
fn main() {
assert_eq!(int_to_int(5), 5);
assert_eq!(float_to_int(5.), 5);
assert_eq!(int_to_ptr(0), std::ptr::null());
}