| // Copyright 2014-2016 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. |
| |
| // FIXME: The PowerPC64 ABI needs to zero or sign extend function |
| // call parameters, but compute_abi_info() is passed LLVM types |
| // which have no sign information. |
| // |
| // Alignment of 128 bit types is not currently handled, this will |
| // need to be fixed when PowerPC vector support is added. |
| |
| use llvm::{Integer, Pointer, Float, Double, Struct, Array}; |
| use abi::{FnType, ArgType}; |
| use context::CrateContext; |
| use type_::Type; |
| |
| use std::cmp; |
| |
| fn align_up_to(off: usize, a: usize) -> usize { |
| return (off + a - 1) / a * a; |
| } |
| |
| fn align(off: usize, ty: Type) -> usize { |
| let a = ty_align(ty); |
| return align_up_to(off, a); |
| } |
| |
| fn ty_align(ty: Type) -> usize { |
| match ty.kind() { |
| Integer => ((ty.int_width() as usize) + 7) / 8, |
| Pointer => 8, |
| Float => 4, |
| Double => 8, |
| Struct => { |
| if ty.is_packed() { |
| 1 |
| } else { |
| let str_tys = ty.field_types(); |
| str_tys.iter().fold(1, |a, t| cmp::max(a, ty_align(*t))) |
| } |
| } |
| Array => { |
| let elt = ty.element_type(); |
| ty_align(elt) |
| } |
| _ => bug!("ty_align: unhandled type") |
| } |
| } |
| |
| fn ty_size(ty: Type) -> usize { |
| match ty.kind() { |
| Integer => ((ty.int_width() as usize) + 7) / 8, |
| Pointer => 8, |
| Float => 4, |
| Double => 8, |
| Struct => { |
| if ty.is_packed() { |
| let str_tys = ty.field_types(); |
| str_tys.iter().fold(0, |s, t| s + ty_size(*t)) |
| } else { |
| let str_tys = ty.field_types(); |
| let size = str_tys.iter().fold(0, |s, t| align(s, *t) + ty_size(*t)); |
| align(size, ty) |
| } |
| } |
| Array => { |
| let len = ty.array_length(); |
| let elt = ty.element_type(); |
| let eltsz = ty_size(elt); |
| len * eltsz |
| } |
| _ => bug!("ty_size: unhandled type") |
| } |
| } |
| |
| fn is_homogenous_aggregate_ty(ty: Type) -> Option<(Type, u64)> { |
| fn check_array(ty: Type) -> Option<(Type, u64)> { |
| let len = ty.array_length() as u64; |
| if len == 0 { |
| return None |
| } |
| let elt = ty.element_type(); |
| |
| // if our element is an HFA/HVA, so are we; multiply members by our len |
| is_homogenous_aggregate_ty(elt).map(|(base_ty, members)| (base_ty, len * members)) |
| } |
| |
| fn check_struct(ty: Type) -> Option<(Type, u64)> { |
| let str_tys = ty.field_types(); |
| if str_tys.len() == 0 { |
| return None |
| } |
| |
| let mut prev_base_ty = None; |
| let mut members = 0; |
| for opt_homog_agg in str_tys.iter().map(|t| is_homogenous_aggregate_ty(*t)) { |
| match (prev_base_ty, opt_homog_agg) { |
| // field isn't itself an HFA, so we aren't either |
| (_, None) => return None, |
| |
| // first field - store its type and number of members |
| (None, Some((field_ty, field_members))) => { |
| prev_base_ty = Some(field_ty); |
| members = field_members; |
| }, |
| |
| // 2nd or later field - give up if it's a different type; otherwise incr. members |
| (Some(prev_ty), Some((field_ty, field_members))) => { |
| if prev_ty != field_ty { |
| return None; |
| } |
| members += field_members; |
| } |
| } |
| } |
| |
| // Because of previous checks, we know prev_base_ty is Some(...) because |
| // 1. str_tys has at least one element; and |
| // 2. prev_base_ty was filled in (or we would've returned early) |
| let (base_ty, members) = (prev_base_ty.unwrap(), members); |
| |
| // Ensure there is no padding. |
| if ty_size(ty) == ty_size(base_ty) * (members as usize) { |
| Some((base_ty, members)) |
| } else { |
| None |
| } |
| } |
| |
| let homog_agg = match ty.kind() { |
| Float => Some((ty, 1)), |
| Double => Some((ty, 1)), |
| Array => check_array(ty), |
| Struct => check_struct(ty), |
| _ => None |
| }; |
| |
| // Ensure we have at most eight uniquely addressable members |
| homog_agg.and_then(|(base_ty, members)| { |
| if members > 0 && members <= 8 { |
| Some((base_ty, members)) |
| } else { |
| None |
| } |
| }) |
| } |
| |
| fn classify_ret_ty(ccx: &CrateContext, ret: &mut ArgType) { |
| if is_reg_ty(ret.ty) { |
| ret.extend_integer_width_to(64); |
| return; |
| } |
| |
| // The PowerPC64 big endian ABI doesn't return aggregates in registers |
| if ccx.sess().target.target.target_endian == "big" { |
| ret.make_indirect(ccx); |
| } |
| |
| if let Some((base_ty, members)) = is_homogenous_aggregate_ty(ret.ty) { |
| ret.cast = Some(Type::array(&base_ty, members)); |
| return; |
| } |
| let size = ty_size(ret.ty); |
| if size <= 16 { |
| let llty = if size <= 1 { |
| Type::i8(ccx) |
| } else if size <= 2 { |
| Type::i16(ccx) |
| } else if size <= 4 { |
| Type::i32(ccx) |
| } else if size <= 8 { |
| Type::i64(ccx) |
| } else { |
| Type::array(&Type::i64(ccx), ((size + 7 ) / 8 ) as u64) |
| }; |
| ret.cast = Some(llty); |
| return; |
| } |
| |
| ret.make_indirect(ccx); |
| } |
| |
| fn classify_arg_ty(ccx: &CrateContext, arg: &mut ArgType) { |
| if is_reg_ty(arg.ty) { |
| arg.extend_integer_width_to(64); |
| return; |
| } |
| |
| if let Some((base_ty, members)) = is_homogenous_aggregate_ty(arg.ty) { |
| arg.cast = Some(Type::array(&base_ty, members)); |
| return; |
| } |
| |
| arg.cast = Some(struct_ty(ccx, arg.ty)); |
| } |
| |
| fn is_reg_ty(ty: Type) -> bool { |
| match ty.kind() { |
| Integer |
| | Pointer |
| | Float |
| | Double => true, |
| _ => false |
| } |
| } |
| |
| fn coerce_to_long(ccx: &CrateContext, size: usize) -> Vec<Type> { |
| let long_ty = Type::i64(ccx); |
| let mut args = Vec::new(); |
| |
| let mut n = size / 64; |
| while n > 0 { |
| args.push(long_ty); |
| n -= 1; |
| } |
| |
| let r = size % 64; |
| if r > 0 { |
| args.push(Type::ix(ccx, r as u64)); |
| } |
| |
| args |
| } |
| |
| fn struct_ty(ccx: &CrateContext, ty: Type) -> Type { |
| let size = ty_size(ty) * 8; |
| Type::struct_(ccx, &coerce_to_long(ccx, size), false) |
| } |
| |
| pub fn compute_abi_info(ccx: &CrateContext, fty: &mut FnType) { |
| 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); |
| } |
| } |