bjoernager/rust
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Use layout::Integer over manual *size resolving

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Oliver Schneider 2018-01-26 13:37:46 +01:00 • committed by Oliver Schneider
parent 9857eaa4df
commit bdda1196f2
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1 changed files with 26 additions and 27 deletions
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53
src/librustc/ty/util.rs
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@ -22,6 +22,7 @@ use ty::fold::TypeVisitor;
use ty::subst::{Subst, UnpackedKind};
use ty::maps::TyCtxtAt;
use ty::TypeVariants::*;
use ty::layout::Integer;
use util::common::ErrorReported;
use middle::lang_items;
use mir::interpret::{Value, PrimVal};
@ -32,7 +33,7 @@ use rustc_data_structures::fx::FxHashMap;
use std::{cmp, fmt};
use std::hash::Hash;
use std::intrinsics;
use syntax::ast::{self, Name, UintTy, IntTy};
use syntax::ast::{self, Name};
use syntax::attr::{self, SignedInt, UnsignedInt};
use syntax_pos::{Span, DUMMY_SP};
@ -58,31 +59,21 @@ impl<'tcx> Discr<'tcx> {
self.checked_add(tcx, 1).0
}
pub fn checked_add<'a, 'gcx>(self, tcx: TyCtxt<'a, 'gcx, 'tcx>, n: u128) -> (Self, bool) {
let ty = match self.ty.sty {
TyInt(IntTy::Isize) => tcx.mk_mach_int(tcx.sess.target.isize_ty),
TyUint(UintTy::Usize) => tcx.mk_mach_uint(tcx.sess.target.usize_ty),
_ => self.ty,
let (int, signed) = match self.ty.sty {
TyInt(ity) => (Integer::from_attr(tcx, SignedInt(ity)), true),
TyUint(uty) => (Integer::from_attr(tcx, UnsignedInt(uty)), false),
_ => bug!("non integer discriminant"),
};
let (min, max) = match ty.sty {
TyInt(IntTy::I8) => (i8::min_value() as i128 as u128, i8::max_value() as u128),
TyInt(IntTy::I16) => (i16::min_value() as i128 as u128, i16::max_value() as u128),
TyInt(IntTy::I32) => (i32::min_value() as i128 as u128, i32::max_value() as u128),
TyInt(IntTy::I64) => (i64::min_value() as i128 as u128, i64::max_value() as u128),
TyInt(IntTy::I128) => (i128::min_value() as i128 as u128, i128::max_value() as u128),
TyInt(IntTy::Isize) => unreachable!(),
TyUint(UintTy::U8) => (u8::min_value() as u128, u8::max_value() as u128),
TyUint(UintTy::U16) => (u16::min_value() as u128, u16::max_value() as u128),
TyUint(UintTy::U32) => (u32::min_value() as u128, u32::max_value() as u128),
TyUint(UintTy::U64) => (u64::min_value() as u128, u64::max_value() as u128),
TyUint(UintTy::U128) => (u128::min_value() as u128, u128::max_value()),
TyUint(UintTy::Usize) => unreachable!(),
_ => bug!("not a valid discriminant type: {}", ty)
};
if ty.is_signed() {
if signed {
let (min, max) = match int {
Integer::I8 => (i8::min_value() as i128, i8::max_value() as i128),
Integer::I16 => (i16::min_value() as i128, i16::max_value() as i128),
Integer::I32 => (i32::min_value() as i128, i32::max_value() as i128),
Integer::I64 => (i64::min_value() as i128, i64::max_value() as i128),
Integer::I128 => (i128::min_value(), i128::max_value()),
};
let val = self.val as i128;
let n = n as i128;
let max = max as i128;
let min = min as i128;
let oflo = val > max - n;
let val = if oflo {
min + (n - (max - val))
@ -94,14 +85,22 @@ impl<'tcx> Discr<'tcx> {
ty: self.ty,
}, oflo)
} else {
let oflo = self.val > max - n;
let (min, max) = match int {
Integer::I8 => (u8::min_value() as u128, u8::max_value() as u128),
Integer::I16 => (u16::min_value() as u128, u16::max_value() as u128),
Integer::I32 => (u32::min_value() as u128, u32::max_value() as u128),
Integer::I64 => (u64::min_value() as u128, u64::max_value() as u128),
Integer::I128 => (u128::min_value(), u128::max_value()),
};
let val = self.val;
let oflo = val > max - n;
let val = if oflo {
min + (n - (max - self.val))
min + (n - (max - val))
} else {
self.val + n
val + n
};
(Self {
val,
val: val,
ty: self.ty,
}, oflo)
}