bjoernager/rust
bjoernager/rust
1
Fork 0
Code Activity

Rollup merge of #104605 - RalfJung:clf_consts, r=bjorn3

Browse source 
deduplicate constant evaluation in cranelift backend

The cranelift backend had two matches on `ConstantKind`, which can be avoided, and used this `eval_for_mir` that nothing else uses... this makes things more consistent with the (better-tested) LLVM backend.

I noticed this because cranelift was the only user of `eval_for_mir`. However `try_eval_for_mir` still has one other user in `eval`... the odd thing is that the interpreter has its own `eval_mir_constant` which seems to duplicate the same functionality and does not use `try_eval_for_mir`. No idea what is happening here.

r? ``@bjorn3``
Cc ``@lcnr``
This commit is contained in:
Matthias Krüger 2022-11-21 14:11:12 +01:00 • committed by GitHub
commit ed22bdc18f
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
3 changed files with 31 additions and 51 deletions
Download patch file Download diff file Expand all files Collapse all files

15
compiler/rustc_middle/src/ty/consts.rs
View file

@ -1,5 +1,4 @@
use crate::mir::interpret::LitToConstInput;
use crate::mir::ConstantKind;
use crate::ty::{self, DefIdTree, InternalSubsts, ParamEnv, ParamEnvAnd, Ty, TyCtxt};
use rustc_data_structures::intern::Interned;
use rustc_hir as hir;
@ -230,20 +229,6 @@ impl<'tcx> Const<'tcx> {
}
}
#[inline]
/// Tries to evaluate the constant if it is `Unevaluated` and creates a ConstValue if the
/// evaluation succeeds. If it doesn't succeed, returns the unevaluated constant.
pub fn eval_for_mir(self, tcx: TyCtxt<'tcx>, param_env: ParamEnv<'tcx>) -> ConstantKind<'tcx> {
if let Some(val) = self.kind().try_eval_for_mir(tcx, param_env) {
match val {
Ok(const_val) => ConstantKind::from_value(const_val, self.ty()),
Err(guar) => ConstantKind::Ty(tcx.const_error_with_guaranteed(self.ty(), guar)),
}
} else {
ConstantKind::Ty(self)
}
}
#[inline]
/// Panics if the value cannot be evaluated or doesn't contain a valid integer of the given type.
pub fn eval_bits(self, tcx: TyCtxt<'tcx>, param_env: ParamEnv<'tcx>, ty: Ty<'tcx>) -> u128 {