| // Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT |
| // file at the top-level directory of this distribution and at |
| // http://rust-lang.org/COPYRIGHT. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| // Information concerning the machine representation of various types. |
| |
| #![allow(non_camel_case_types)] |
| |
| use llvm::{self, ValueRef}; |
| use common::*; |
| |
| use type_::Type; |
| |
| pub type llbits = u64; |
| pub type llsize = u64; |
| pub type llalign = u32; |
| |
| // ______________________________________________________________________ |
| // compute sizeof / alignof |
| |
| // Returns the number of bytes between successive elements of type T in an |
| // array of T. This is the "ABI" size. It includes any ABI-mandated padding. |
| pub fn llsize_of_alloc(cx: &CrateContext, ty: Type) -> llsize { |
| unsafe { |
| return llvm::LLVMABISizeOfType(cx.td(), ty.to_ref()); |
| } |
| } |
| |
| /// Returns the "real" size of the type in bits. |
| pub fn llbitsize_of_real(cx: &CrateContext, ty: Type) -> llbits { |
| unsafe { |
| llvm::LLVMSizeOfTypeInBits(cx.td(), ty.to_ref()) |
| } |
| } |
| |
| /// Returns the size of the type as an LLVM constant integer value. |
| pub fn llsize_of(cx: &CrateContext, ty: Type) -> ValueRef { |
| // Once upon a time, this called LLVMSizeOf, which does a |
| // getelementptr(1) on a null pointer and casts to an int, in |
| // order to obtain the type size as a value without requiring the |
| // target data layout. But we have the target data layout, so |
| // there's no need for that contrivance. The instruction |
| // selection DAG generator would flatten that GEP(1) node into a |
| // constant of the type's alloc size, so let's save it some work. |
| return C_uint(cx, llsize_of_alloc(cx, ty)); |
| } |
| |
| // Returns the preferred alignment of the given type for the current target. |
| // The preferred alignment may be larger than the alignment used when |
| // packing the type into structs. This will be used for things like |
| // allocations inside a stack frame, which LLVM has a free hand in. |
| pub fn llalign_of_pref(cx: &CrateContext, ty: Type) -> llalign { |
| unsafe { |
| return llvm::LLVMPreferredAlignmentOfType(cx.td(), ty.to_ref()); |
| } |
| } |
| |
| // Returns the minimum alignment of a type required by the platform. |
| // This is the alignment that will be used for struct fields, arrays, |
| // and similar ABI-mandated things. |
| pub fn llalign_of_min(cx: &CrateContext, ty: Type) -> llalign { |
| unsafe { |
| return llvm::LLVMABIAlignmentOfType(cx.td(), ty.to_ref()); |
| } |
| } |
| |
| pub fn llelement_offset(cx: &CrateContext, struct_ty: Type, element: usize) -> u64 { |
| unsafe { |
| return llvm::LLVMOffsetOfElement(cx.td(), |
| struct_ty.to_ref(), |
| element as u32); |
| } |
| } |