From f23fb19ee508515912e136c948a0242cc88a2d4e Mon Sep 17 00:00:00 2001 From: Daniel Micay Date: Tue, 6 Aug 2013 17:15:43 -0400 Subject: [PATCH] vec: avoid `ptrtoint`/`inttoptr` in the iterators This results in throwing away alias analysis information, because LLVM does *not* implement reasoning about these conversions yet. We specialize zero-size types since a `getelementptr` offset will return us the same pointer, making it broken as a simple counter. --- src/libstd/vec.rs | 26 ++++++++++++++++++-------- 1 file changed, 18 insertions(+), 8 deletions(-) diff --git a/src/libstd/vec.rs b/src/libstd/vec.rs index 0259b547ab3..8dbfb3ec543 100644 --- a/src/libstd/vec.rs +++ b/src/libstd/vec.rs @@ -849,10 +849,15 @@ fn slice_to(&self, end: uint) -> &'self [T] { fn iter(self) -> VecIterator<'self, T> { unsafe { let p = vec::raw::to_ptr(self); - VecIterator{ptr: p, - end: (p as uint + self.len() * - sys::nonzero_size_of::()) as *T, - lifetime: cast::transmute(p)} + if sys::size_of::() == 0 { + VecIterator{ptr: p, + end: (p as uint + self.len()) as *T, + lifetime: cast::transmute(p)} + } else { + VecIterator{ptr: p, + end: p.offset(self.len() as int), + lifetime: cast::transmute(p)} + } } } @@ -1826,10 +1831,15 @@ fn mut_split(self, mid: uint) -> (&'self mut [T], &'self mut [T]) { fn mut_iter(self) -> VecMutIterator<'self, T> { unsafe { let p = vec::raw::to_mut_ptr(self); - VecMutIterator{ptr: p, - end: (p as uint + self.len() * - sys::nonzero_size_of::()) as *mut T, - lifetime: cast::transmute(p)} + if sys::size_of::() == 0 { + VecMutIterator{ptr: p, + end: (p as uint + self.len()) as *mut T, + lifetime: cast::transmute(p)} + } else { + VecMutIterator{ptr: p, + end: p.offset(self.len() as int), + lifetime: cast::transmute(p)} + } } } -- 2.44.0