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| 1 | +// Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT |
| 2 | +// file at the top-level directory of this distribution and at |
| 3 | +// http://rust-lang.org/COPYRIGHT. |
| 4 | +// |
| 5 | +// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| 6 | +// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| 7 | +// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| 8 | +// option. This file may not be copied, modified, or distributed |
| 9 | +// except according to those terms. |
| 10 | + |
| 11 | +#![allow(non_upper_case_globals)] |
| 12 | + |
| 13 | +use libc::c_uint; |
| 14 | +use std::cmp; |
| 15 | +use llvm; |
| 16 | +use llvm::{Integer, Pointer, Float, Double, Vector}; |
| 17 | +use abi::{self, align_up_to, ArgType, FnType}; |
| 18 | +use context::CrateContext; |
| 19 | +use type_::Type; |
| 20 | + |
| 21 | +fn ty_align(ty: Type) -> usize { |
| 22 | + abi::ty_align(ty, 4) |
| 23 | +} |
| 24 | + |
| 25 | +fn ty_size(ty: Type) -> usize { |
| 26 | + abi::ty_size(ty, 4) |
| 27 | +} |
| 28 | + |
| 29 | +fn classify_ret_ty(ccx: &CrateContext, ret: &mut ArgType) { |
| 30 | + if is_reg_ty(ret.ty) { |
| 31 | + ret.extend_integer_width_to(32); |
| 32 | + } else { |
| 33 | + ret.make_indirect(ccx); |
| 34 | + } |
| 35 | +} |
| 36 | + |
| 37 | +fn classify_arg_ty(ccx: &CrateContext, arg: &mut ArgType, offset: &mut usize) { |
| 38 | + let orig_offset = *offset; |
| 39 | + let size = ty_size(arg.ty) * 8; |
| 40 | + let mut align = ty_align(arg.ty); |
| 41 | + |
| 42 | + align = cmp::min(cmp::max(align, 4), 8); |
| 43 | + *offset = align_up_to(*offset, align); |
| 44 | + *offset += align_up_to(size, align * 8) / 8; |
| 45 | + |
| 46 | + if !is_reg_ty(arg.ty) { |
| 47 | + arg.cast = Some(struct_ty(ccx, arg.ty)); |
| 48 | + arg.pad = padding_ty(ccx, align, orig_offset); |
| 49 | + } else { |
| 50 | + arg.extend_integer_width_to(32); |
| 51 | + } |
| 52 | +} |
| 53 | + |
| 54 | +fn is_reg_ty(ty: Type) -> bool { |
| 55 | + return match ty.kind() { |
| 56 | + Integer |
| 57 | + | Pointer |
| 58 | + | Float |
| 59 | + | Double |
| 60 | + | Vector => true, |
| 61 | + _ => false |
| 62 | + }; |
| 63 | +} |
| 64 | + |
| 65 | +fn padding_ty(ccx: &CrateContext, align: usize, offset: usize) -> Option<Type> { |
| 66 | + if ((align - 1 ) & offset) > 0 { |
| 67 | + Some(Type::i32(ccx)) |
| 68 | + } else { |
| 69 | + None |
| 70 | + } |
| 71 | +} |
| 72 | + |
| 73 | +fn coerce_to_int(ccx: &CrateContext, size: usize) -> Vec<Type> { |
| 74 | + let int_ty = Type::i32(ccx); |
| 75 | + let mut args = Vec::new(); |
| 76 | + |
| 77 | + let mut n = size / 32; |
| 78 | + while n > 0 { |
| 79 | + args.push(int_ty); |
| 80 | + n -= 1; |
| 81 | + } |
| 82 | + |
| 83 | + let r = size % 32; |
| 84 | + if r > 0 { |
| 85 | + unsafe { |
| 86 | + args.push(Type::from_ref(llvm::LLVMIntTypeInContext(ccx.llcx(), r as c_uint))); |
| 87 | + } |
| 88 | + } |
| 89 | + |
| 90 | + args |
| 91 | +} |
| 92 | + |
| 93 | +fn struct_ty(ccx: &CrateContext, ty: Type) -> Type { |
| 94 | + let size = ty_size(ty) * 8; |
| 95 | + Type::struct_(ccx, &coerce_to_int(ccx, size), false) |
| 96 | +} |
| 97 | + |
| 98 | +pub fn compute_abi_info(ccx: &CrateContext, fty: &mut FnType) { |
| 99 | + if !fty.ret.is_ignore() { |
| 100 | + classify_ret_ty(ccx, &mut fty.ret); |
| 101 | + } |
| 102 | + |
| 103 | + let mut offset = if fty.ret.is_indirect() { 4 } else { 0 }; |
| 104 | + for arg in &mut fty.args { |
| 105 | + if arg.is_ignore() { continue; } |
| 106 | + classify_arg_ty(ccx, arg, &mut offset); |
| 107 | + } |
| 108 | +} |
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