From 7d982fdcf439799efbcc9f0cfcda99fa87b07460 Mon Sep 17 00:00:00 2001
From: Oliver Schneider <git-spam-no-reply9815368754983@oli-obk.de>
Date: Tue, 24 Apr 2018 14:42:30 +0200
Subject: [PATCH] Implement `PartialCmp` for `ConstFloat`
---
src/librustc/ich/impls_const_math.rs | 1 -
src/librustc_const_math/err.rs | 2 --
src/librustc_const_math/float.rs | 14 ++++++++++----
src/librustc_mir/hair/pattern/mod.rs | 3 +--
src/librustc_mir/interpret/operator.rs | 12 ++++++------
5 files changed, 17 insertions(+), 15 deletions(-)
diff --git a/src/librustc/ich/impls_const_math.rs b/src/librustc/ich/impls_const_math.rs
index afa28ae319c..387a6d5f35c 100644
--- a/src/librustc/ich/impls_const_math.rs
+++ b/src/librustc/ich/impls_const_math.rs
@@ -17,7 +17,6 @@ impl_stable_hash_for!(struct ::rustc_const_math::ConstFloat {
});
impl_stable_hash_for!(enum ::rustc_const_math::ConstMathErr {
- CmpBetweenUnequalTypes,
UnequalTypes(op),
Overflow(op),
DivisionByZero,
diff --git a/src/librustc_const_math/err.rs b/src/librustc_const_math/err.rs
index dee8813e86f..5d442ee7b97 100644
--- a/src/librustc_const_math/err.rs
+++ b/src/librustc_const_math/err.rs
@@ -10,7 +10,6 @@
#[derive(Debug, PartialEq, Eq, Clone, RustcEncodable, RustcDecodable)]
pub enum ConstMathErr {
- CmpBetweenUnequalTypes,
UnequalTypes(Op),
Overflow(Op),
DivisionByZero,
@@ -37,7 +36,6 @@ impl ConstMathErr {
pub fn description(&self) -> &'static str {
use self::Op::*;
match *self {
- CmpBetweenUnequalTypes => "compared two values of different types",
UnequalTypes(Add) => "tried to add two values of different types",
UnequalTypes(Sub) => "tried to subtract two values of different types",
UnequalTypes(Mul) => "tried to multiply two values of different types",
diff --git a/src/librustc_const_math/float.rs b/src/librustc_const_math/float.rs
index 9d820ea8cbe..61e9b34f06a 100644
--- a/src/librustc_const_math/float.rs
+++ b/src/librustc_const_math/float.rs
@@ -31,6 +31,12 @@ pub struct ConstFloat {
pub bits: u128,
}
+impl PartialOrd<ConstFloat> for ConstFloat {
+ fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+ self.try_cmp(*other)
+ }
+}
+
impl ConstFloat {
/// Description of the type, not the value
pub fn description(&self) -> &'static str {
@@ -38,22 +44,22 @@ impl ConstFloat {
}
/// Compares the values if they are of the same type
- pub fn try_cmp(self, rhs: Self) -> Result<Ordering, ConstMathErr> {
+ fn try_cmp(self, rhs: Self) -> Option<Ordering> {
match (self.ty, rhs.ty) {
(ast::FloatTy::F64, ast::FloatTy::F64) => {
let a = Double::from_bits(self.bits);
let b = Double::from_bits(rhs.bits);
// This is pretty bad but it is the existing behavior.
- Ok(a.partial_cmp(&b).unwrap_or(Ordering::Greater))
+ Some(a.partial_cmp(&b).unwrap_or(Ordering::Greater))
}
(ast::FloatTy::F32, ast::FloatTy::F32) => {
let a = Single::from_bits(self.bits);
let b = Single::from_bits(rhs.bits);
- Ok(a.partial_cmp(&b).unwrap_or(Ordering::Greater))
+ Some(a.partial_cmp(&b).unwrap_or(Ordering::Greater))
}
- _ => Err(CmpBetweenUnequalTypes),
+ _ => None,
}
}
diff --git a/src/librustc_mir/hair/pattern/mod.rs b/src/librustc_mir/hair/pattern/mod.rs
index c2da8c11d87..776b24a8648 100644
--- a/src/librustc_mir/hair/pattern/mod.rs
+++ b/src/librustc_mir/hair/pattern/mod.rs
@@ -1069,8 +1069,7 @@ pub fn compare_const_vals<'a, 'tcx>(
bits: b,
ty,
};
- // FIXME(oli-obk): report cmp errors?
- l.try_cmp(r).ok()
+ l.partial_cmp(&r)
},
ty::TyInt(_) => {
let a = interpret::sign_extend(tcx, a, ty).expect("layout error for TyInt");
diff --git a/src/librustc_mir/interpret/operator.rs b/src/librustc_mir/interpret/operator.rs
index dfc0c4a824a..0c748f818cc 100644
--- a/src/librustc_mir/interpret/operator.rs
+++ b/src/librustc_mir/interpret/operator.rs
@@ -135,12 +135,12 @@ impl<'a, 'mir, 'tcx, M: Machine<'mir, 'tcx>> EvalContext<'a, 'mir, 'tcx, M> {
ty,
};
match op {
- Eq => PrimVal::from_bool(l.try_cmp(r).unwrap() == Ordering::Equal),
- Ne => PrimVal::from_bool(l.try_cmp(r).unwrap() != Ordering::Equal),
- Lt => PrimVal::from_bool(l.try_cmp(r).unwrap() == Ordering::Less),
- Le => PrimVal::from_bool(l.try_cmp(r).unwrap() != Ordering::Greater),
- Gt => PrimVal::from_bool(l.try_cmp(r).unwrap() == Ordering::Greater),
- Ge => PrimVal::from_bool(l.try_cmp(r).unwrap() != Ordering::Less),
+ Eq => PrimVal::from_bool(l.partial_cmp(&r).unwrap() == Ordering::Equal),
+ Ne => PrimVal::from_bool(l.partial_cmp(&r).unwrap() != Ordering::Equal),
+ Lt => PrimVal::from_bool(l.partial_cmp(&r).unwrap() == Ordering::Less),
+ Le => PrimVal::from_bool(l.partial_cmp(&r).unwrap() != Ordering::Greater),
+ Gt => PrimVal::from_bool(l.partial_cmp(&r).unwrap() == Ordering::Greater),
+ Ge => PrimVal::from_bool(l.partial_cmp(&r).unwrap() != Ordering::Less),
Add => PrimVal::Bytes((l + r).unwrap().bits),
Sub => PrimVal::Bytes((l - r).unwrap().bits),
Mul => PrimVal::Bytes((l * r).unwrap().bits),