auto merge of #9136 : thestinger/rust/ptr, r=alexcrichton

This is mostly for consistency, as you can now compare raw pointers in
constant expressions or without the standard library.

It also reduces the number of `ptrtoint` instructions in the IR, making
tracking down culprits of what's usually an anti-pattern easier.

Author: bors

src/librustc/middle/ty.rs

@@ -4267,6 +4267,7 @@ pub fn is_binopable(cx: ctxt, ty: t, op: ast::BinOp) -> bool {
     static tycat_int: int = 3;
     static tycat_float: int = 4;
     static tycat_bot: int = 5;
+    static tycat_raw_ptr: int = 6;
 
     static opcat_add: int = 0;
     static opcat_sub: int = 1;
@@ -4310,6 +4311,7 @@ pub fn is_binopable(cx: ctxt, ty: t, op: ast::BinOp) -> bool {
           ty_int(_) | ty_uint(_) | ty_infer(IntVar(_)) => tycat_int,
           ty_float(_) | ty_infer(FloatVar(_)) => tycat_float,
           ty_bot => tycat_bot,
+          ty_ptr(_) => tycat_raw_ptr,
           _ => tycat_other
         }
     }
@@ -4324,7 +4326,8 @@ pub fn is_binopable(cx: ctxt, ty: t, op: ast::BinOp) -> bool {
     /*char*/    [f, f, f, f,     t,   t,  f,   f],
     /*int*/     [t, t, t, t,     t,   t,  t,   f],
     /*float*/   [t, t, t, f,     t,   t,  f,   f],
-    /*bot*/     [t, t, t, t,     f,   f,  t,   t]];
+    /*bot*/     [t, t, t, t,     f,   f,  t,   t],
+    /*raw ptr*/ [f, f, f, f,     t,   t,  f,   f]];
 
     return tbl[tycat(cx, ty)][opcat(op)];
 }

src/libstd/ptr.rs

@@ -383,7 +383,7 @@ impl<T> RawPtr<T> for *mut T {
 }
 
 // Equality for pointers
-#[cfg(not(test))]
+#[cfg(stage0, not(test))]
 impl<T> Eq for *T {
     #[inline]
     fn eq(&self, other: &*T) -> bool {
@@ -393,7 +393,17 @@ impl<T> Eq for *T {
     fn ne(&self, other: &*T) -> bool { !self.eq(other) }
 }
 
-#[cfg(not(test))]
+#[cfg(not(stage0), not(test))]
+impl<T> Eq for *T {
+    #[inline]
+    fn eq(&self, other: &*T) -> bool {
+        *self == *other
+    }
+    #[inline]
+    fn ne(&self, other: &*T) -> bool { !self.eq(other) }
+}
+
+#[cfg(stage0, not(test))]
 impl<T> Eq for *mut T {
     #[inline]
     fn eq(&self, other: &*mut T) -> bool {
@@ -403,6 +413,16 @@ impl<T> Eq for *mut T {
     fn ne(&self, other: &*mut T) -> bool { !self.eq(other) }
 }
 
+#[cfg(not(stage0), not(test))]
+impl<T> Eq for *mut T {
+    #[inline]
+    fn eq(&self, other: &*mut T) -> bool {
+        *self == *other
+    }
+    #[inline]
+    fn ne(&self, other: &*mut T) -> bool { !self.eq(other) }
+}
+
 // Equivalence for pointers
 #[cfg(not(test))]
 impl<T> Equiv<*mut T> for *T {
@@ -460,7 +480,7 @@ mod externfnpointers {
 }
 
 // Comparison for pointers
-#[cfg(not(test))]
+#[cfg(stage0, not(test))]
 impl<T> Ord for *T {
     #[inline]
     fn lt(&self, other: &*T) -> bool {
@@ -480,7 +500,27 @@ impl<T> Ord for *T {
     }
 }
 
-#[cfg(not(test))]
+#[cfg(not(stage0), not(test))]
+impl<T> Ord for *T {
+    #[inline]
+    fn lt(&self, other: &*T) -> bool {
+        *self < *other
+    }
+    #[inline]
+    fn le(&self, other: &*T) -> bool {
+        *self <= *other
+    }
+    #[inline]
+    fn ge(&self, other: &*T) -> bool {
+        *self >= *other
+    }
+    #[inline]
+    fn gt(&self, other: &*T) -> bool {
+        *self > *other
+    }
+}
+
+#[cfg(stage0, not(test))]
 impl<T> Ord for *mut T {
     #[inline]
     fn lt(&self, other: &*mut T) -> bool {
@@ -500,6 +540,26 @@ impl<T> Ord for *mut T {
     }
 }
 
+#[cfg(not(stage0), not(test))]
+impl<T> Ord for *mut T {
+    #[inline]
+    fn lt(&self, other: &*mut T) -> bool {
+        *self < *other
+    }
+    #[inline]
+    fn le(&self, other: &*mut T) -> bool {
+        *self <= *other
+    }
+    #[inline]
+    fn ge(&self, other: &*mut T) -> bool {
+        *self >= *other
+    }
+    #[inline]
+    fn gt(&self, other: &*mut T) -> bool {
+        *self > *other
+    }
+}
+
 #[cfg(test)]
 pub mod ptr_tests {
     use super::*;