| // Copyright 2015 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. |
| |
| use abi::{FnType, ArgType, LayoutExt, Reg, RegKind, Uniform}; |
| use context::CrateContext; |
| |
| fn is_homogeneous_aggregate<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, arg: &mut ArgType<'tcx>) |
| -> Option<Uniform> { |
| arg.layout.homogeneous_aggregate(ccx).and_then(|unit| { |
| let size = arg.layout.size; |
| |
| // Ensure we have at most four uniquely addressable members. |
| if size > unit.size.checked_mul(4, ccx).unwrap() { |
| return None; |
| } |
| |
| let valid_unit = match unit.kind { |
| RegKind::Integer => false, |
| RegKind::Float => true, |
| RegKind::Vector => size.bits() == 64 || size.bits() == 128 |
| }; |
| |
| if valid_unit { |
| Some(Uniform { |
| unit, |
| total: size |
| }) |
| } else { |
| None |
| } |
| }) |
| } |
| |
| fn classify_ret_ty<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, ret: &mut ArgType<'tcx>) { |
| if !ret.layout.is_aggregate() { |
| ret.extend_integer_width_to(32); |
| return; |
| } |
| if let Some(uniform) = is_homogeneous_aggregate(ccx, ret) { |
| ret.cast_to(uniform); |
| return; |
| } |
| let size = ret.layout.size; |
| let bits = size.bits(); |
| if bits <= 128 { |
| let unit = if bits <= 8 { |
| Reg::i8() |
| } else if bits <= 16 { |
| Reg::i16() |
| } else if bits <= 32 { |
| Reg::i32() |
| } else { |
| Reg::i64() |
| }; |
| |
| ret.cast_to(Uniform { |
| unit, |
| total: size |
| }); |
| return; |
| } |
| ret.make_indirect(); |
| } |
| |
| fn classify_arg_ty<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, arg: &mut ArgType<'tcx>) { |
| if !arg.layout.is_aggregate() { |
| arg.extend_integer_width_to(32); |
| return; |
| } |
| if let Some(uniform) = is_homogeneous_aggregate(ccx, arg) { |
| arg.cast_to(uniform); |
| return; |
| } |
| let size = arg.layout.size; |
| let bits = size.bits(); |
| if bits <= 128 { |
| let unit = if bits <= 8 { |
| Reg::i8() |
| } else if bits <= 16 { |
| Reg::i16() |
| } else if bits <= 32 { |
| Reg::i32() |
| } else { |
| Reg::i64() |
| }; |
| |
| arg.cast_to(Uniform { |
| unit, |
| total: size |
| }); |
| return; |
| } |
| arg.make_indirect(); |
| } |
| |
| pub fn compute_abi_info<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, fty: &mut FnType<'tcx>) { |
| if !fty.ret.is_ignore() { |
| classify_ret_ty(ccx, &mut fty.ret); |
| } |
| |
| for arg in &mut fty.args { |
| if arg.is_ignore() { continue; } |
| classify_arg_ty(ccx, arg); |
| } |
| } |