use crate::builder::Builder;
use crate::type_::Type;
use crate::type_of::LayoutLlvmExt;
use crate::value::Value;
use rustc_codegen_ssa::mir::operand::OperandRef;
use rustc_codegen_ssa::{
common::IntPredicate,
traits::{BaseTypeMethods, BuilderMethods, ConstMethods},
};
use rustc_middle::ty::layout::{HasTyCtxt, LayoutOf};
use rustc_middle::ty::Ty;
use rustc_target::abi::{Align, Endian, HasDataLayout, Size};
fn round_pointer_up_to_alignment<'ll>(
bx: &mut Builder<'_, 'll, '_>,
addr: &'ll Value,
align: Align,
ptr_ty: &'ll Type,
) -> &'ll Value {
let mut ptr_as_int = bx.ptrtoint(addr, bx.cx().type_isize());
ptr_as_int = bx.add(ptr_as_int, bx.cx().const_i32(align.bytes() as i32 - 1));
ptr_as_int = bx.and(ptr_as_int, bx.cx().const_i32(-(align.bytes() as i32)));
bx.inttoptr(ptr_as_int, ptr_ty)
}
fn emit_direct_ptr_va_arg<'ll, 'tcx>(
bx: &mut Builder<'_, 'll, 'tcx>,
list: OperandRef<'tcx, &'ll Value>,
size: Size,
align: Align,
slot_size: Align,
allow_higher_align: bool,
) -> (&'ll Value, Align) {
let va_list_ty = bx.type_ptr();
let va_list_addr = list.immediate();
let ptr = bx.load(va_list_ty, va_list_addr, bx.tcx().data_layout.pointer_align.abi);
let (addr, addr_align) = if allow_higher_align && align > slot_size {
(round_pointer_up_to_alignment(bx, ptr, align, bx.type_ptr()), align)
} else {
(ptr, slot_size)
};
let aligned_size = size.align_to(slot_size).bytes() as i32;
let full_direct_size = bx.cx().const_i32(aligned_size);
let next = bx.inbounds_gep(bx.type_i8(), addr, &[full_direct_size]);
bx.store(next, va_list_addr, bx.tcx().data_layout.pointer_align.abi);
if size.bytes() < slot_size.bytes() && bx.tcx().sess.target.endian == Endian::Big {
let adjusted_size = bx.cx().const_i32((slot_size.bytes() - size.bytes()) as i32);
let adjusted = bx.inbounds_gep(bx.type_i8(), addr, &[adjusted_size]);
(adjusted, addr_align)
} else {
(addr, addr_align)
}
}
fn emit_ptr_va_arg<'ll, 'tcx>(
bx: &mut Builder<'_, 'll, 'tcx>,
list: OperandRef<'tcx, &'ll Value>,
target_ty: Ty<'tcx>,
indirect: bool,
slot_size: Align,
allow_higher_align: bool,
) -> &'ll Value {
let layout = bx.cx.layout_of(target_ty);
let (llty, size, align) = if indirect {
(
bx.cx.layout_of(Ty::new_imm_ptr(bx.cx.tcx, target_ty)).llvm_type(bx.cx),
bx.cx.data_layout().pointer_size,
bx.cx.data_layout().pointer_align,
)
} else {
(layout.llvm_type(bx.cx), layout.size, layout.align)
};
let (addr, addr_align) =
emit_direct_ptr_va_arg(bx, list, size, align.abi, slot_size, allow_higher_align);
if indirect {
let tmp_ret = bx.load(llty, addr, addr_align);
bx.load(bx.cx.layout_of(target_ty).llvm_type(bx.cx), tmp_ret, align.abi)
} else {
bx.load(llty, addr, addr_align)
}
}
fn emit_aapcs_va_arg<'ll, 'tcx>(
bx: &mut Builder<'_, 'll, 'tcx>,
list: OperandRef<'tcx, &'ll Value>,
target_ty: Ty<'tcx>,
) -> &'ll Value {
let va_list_addr = list.immediate();
let va_list_layout = list.deref(bx.cx).layout;
let va_list_ty = va_list_layout.llvm_type(bx);
let layout = bx.cx.layout_of(target_ty);
let maybe_reg = bx.append_sibling_block("va_arg.maybe_reg");
let in_reg = bx.append_sibling_block("va_arg.in_reg");
let on_stack = bx.append_sibling_block("va_arg.on_stack");
let end = bx.append_sibling_block("va_arg.end");
let zero = bx.const_i32(0);
let offset_align = Align::from_bytes(4).unwrap();
let gr_type = target_ty.is_any_ptr() || target_ty.is_integral();
let (reg_off, reg_top_index, slot_size) = if gr_type {
let gr_offs =
bx.struct_gep(va_list_ty, va_list_addr, va_list_layout.llvm_field_index(bx.cx, 3));
let nreg = (layout.size.bytes() + 7) / 8;
(gr_offs, va_list_layout.llvm_field_index(bx.cx, 1), nreg * 8)
} else {
let vr_off =
bx.struct_gep(va_list_ty, va_list_addr, va_list_layout.llvm_field_index(bx.cx, 4));
let nreg = (layout.size.bytes() + 15) / 16;
(vr_off, va_list_layout.llvm_field_index(bx.cx, 2), nreg * 16)
};
let mut reg_off_v = bx.load(bx.type_i32(), reg_off, offset_align);
let use_stack = bx.icmp(IntPredicate::IntSGE, reg_off_v, zero);
bx.cond_br(use_stack, on_stack, maybe_reg);
bx.switch_to_block(maybe_reg);
if gr_type && layout.align.abi.bytes() > 8 {
reg_off_v = bx.add(reg_off_v, bx.const_i32(15));
reg_off_v = bx.and(reg_off_v, bx.const_i32(-16));
}
let new_reg_off_v = bx.add(reg_off_v, bx.const_i32(slot_size as i32));
bx.store(new_reg_off_v, reg_off, offset_align);
let use_stack = bx.icmp(IntPredicate::IntSGT, new_reg_off_v, zero);
bx.cond_br(use_stack, on_stack, in_reg);
bx.switch_to_block(in_reg);
let top_type = bx.type_ptr();
let top = bx.struct_gep(va_list_ty, va_list_addr, reg_top_index);
let top = bx.load(top_type, top, bx.tcx().data_layout.pointer_align.abi);
let mut reg_addr = bx.gep(bx.type_i8(), top, &[reg_off_v]);
if bx.tcx().sess.target.endian == Endian::Big && layout.size.bytes() != slot_size {
let offset = bx.const_i32((slot_size - layout.size.bytes()) as i32);
reg_addr = bx.gep(bx.type_i8(), reg_addr, &[offset]);
}
let reg_type = layout.llvm_type(bx);
let reg_value = bx.load(reg_type, reg_addr, layout.align.abi);
bx.br(end);
bx.switch_to_block(on_stack);
let stack_value =
emit_ptr_va_arg(bx, list, target_ty, false, Align::from_bytes(8).unwrap(), true);
bx.br(end);
bx.switch_to_block(end);
let val =
bx.phi(layout.immediate_llvm_type(bx), &[reg_value, stack_value], &[in_reg, on_stack]);
val
}
fn emit_s390x_va_arg<'ll, 'tcx>(
bx: &mut Builder<'_, 'll, 'tcx>,
list: OperandRef<'tcx, &'ll Value>,
target_ty: Ty<'tcx>,
) -> &'ll Value {
let va_list_addr = list.immediate();
let va_list_layout = list.deref(bx.cx).layout;
let va_list_ty = va_list_layout.llvm_type(bx);
let layout = bx.cx.layout_of(target_ty);
let in_reg = bx.append_sibling_block("va_arg.in_reg");
let in_mem = bx.append_sibling_block("va_arg.in_mem");
let end = bx.append_sibling_block("va_arg.end");
let target_ty_size = bx.cx.size_of(target_ty).bytes();
let indirect: bool = target_ty_size > 8 || !target_ty_size.is_power_of_two();
let unpadded_size = if indirect { 8 } else { target_ty_size };
let padded_size = 8;
let padding = padded_size - unpadded_size;
let gpr_type = indirect || !layout.is_single_fp_element(bx.cx);
let (max_regs, reg_count_field, reg_save_index, reg_padding) =
if gpr_type { (5, 0, 2, padding) } else { (4, 1, 16, 0) };
let reg_count = bx.struct_gep(
va_list_ty,
va_list_addr,
va_list_layout.llvm_field_index(bx.cx, reg_count_field),
);
let reg_count_v = bx.load(bx.type_i64(), reg_count, Align::from_bytes(8).unwrap());
let use_regs = bx.icmp(IntPredicate::IntULT, reg_count_v, bx.const_u64(max_regs));
bx.cond_br(use_regs, in_reg, in_mem);
bx.switch_to_block(in_reg);
let reg_ptr =
bx.struct_gep(va_list_ty, va_list_addr, va_list_layout.llvm_field_index(bx.cx, 3));
let reg_ptr_v = bx.load(bx.type_ptr(), reg_ptr, bx.tcx().data_layout.pointer_align.abi);
let scaled_reg_count = bx.mul(reg_count_v, bx.const_u64(8));
let reg_off = bx.add(scaled_reg_count, bx.const_u64(reg_save_index * 8 + reg_padding));
let reg_addr = bx.gep(bx.type_i8(), reg_ptr_v, &[reg_off]);
let new_reg_count_v = bx.add(reg_count_v, bx.const_u64(1));
bx.store(new_reg_count_v, reg_count, Align::from_bytes(8).unwrap());
bx.br(end);
bx.switch_to_block(in_mem);
let arg_ptr =
bx.struct_gep(va_list_ty, va_list_addr, va_list_layout.llvm_field_index(bx.cx, 2));
let arg_ptr_v = bx.load(bx.type_ptr(), arg_ptr, bx.tcx().data_layout.pointer_align.abi);
let arg_off = bx.const_u64(padding);
let mem_addr = bx.gep(bx.type_i8(), arg_ptr_v, &[arg_off]);
let arg_size = bx.cx().const_u64(padded_size);
let new_arg_ptr_v = bx.inbounds_gep(bx.type_i8(), arg_ptr_v, &[arg_size]);
bx.store(new_arg_ptr_v, arg_ptr, bx.tcx().data_layout.pointer_align.abi);
bx.br(end);
bx.switch_to_block(end);
let val_addr = bx.phi(bx.type_ptr(), &[reg_addr, mem_addr], &[in_reg, in_mem]);
let val_type = layout.llvm_type(bx);
let val_addr = if indirect {
bx.load(bx.cx.type_ptr(), val_addr, bx.tcx().data_layout.pointer_align.abi)
} else {
val_addr
};
bx.load(val_type, val_addr, layout.align.abi)
}
pub(super) fn emit_va_arg<'ll, 'tcx>(
bx: &mut Builder<'_, 'll, 'tcx>,
addr: OperandRef<'tcx, &'ll Value>,
target_ty: Ty<'tcx>,
) -> &'ll Value {
let target = &bx.cx.tcx.sess.target;
let arch = &bx.cx.tcx.sess.target.arch;
match &**arch {
"x86" if target.is_like_windows => {
emit_ptr_va_arg(bx, addr, target_ty, false, Align::from_bytes(4).unwrap(), false)
}
"x86" => emit_ptr_va_arg(bx, addr, target_ty, false, Align::from_bytes(4).unwrap(), true),
"aarch64" if target.is_like_windows => {
emit_ptr_va_arg(bx, addr, target_ty, false, Align::from_bytes(8).unwrap(), false)
}
"aarch64" if target.is_like_osx => {
emit_ptr_va_arg(bx, addr, target_ty, false, Align::from_bytes(8).unwrap(), true)
}
"aarch64" => emit_aapcs_va_arg(bx, addr, target_ty),
"s390x" => emit_s390x_va_arg(bx, addr, target_ty),
"x86_64" if target.is_like_windows => {
let target_ty_size = bx.cx.size_of(target_ty).bytes();
let indirect: bool = target_ty_size > 8 || !target_ty_size.is_power_of_two();
emit_ptr_va_arg(bx, addr, target_ty, indirect, Align::from_bytes(8).unwrap(), false)
}
_ => bx.va_arg(addr.immediate(), bx.cx.layout_of(target_ty).llvm_type(bx.cx)),
}
}