21b0c1286a
A significant amount of intrinsics do not actually need backend-specific behaviors to be implemented, instead relying on methods already in rustc_codegen_ssa. So, extract those methods out to rustc_codegen_ssa, so that each backend doesn't need to reimplement the same code.
597 lines
24 KiB
Rust
597 lines
24 KiB
Rust
use super::operand::{OperandRef, OperandValue};
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use super::place::PlaceRef;
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use super::FunctionCx;
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use crate::common::{span_invalid_monomorphization_error, IntPredicate};
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use crate::glue;
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use crate::traits::*;
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use crate::MemFlags;
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use rustc_middle::ty::{self, Ty, TyCtxt};
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use rustc_span::{sym, Span};
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use rustc_target::abi::call::{FnAbi, PassMode};
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fn copy_intrinsic<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
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bx: &mut Bx,
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allow_overlap: bool,
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volatile: bool,
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ty: Ty<'tcx>,
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dst: Bx::Value,
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src: Bx::Value,
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count: Bx::Value,
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) {
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let layout = bx.layout_of(ty);
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let size = layout.size;
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let align = layout.align.abi;
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let size = bx.mul(bx.const_usize(size.bytes()), count);
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let flags = if volatile { MemFlags::VOLATILE } else { MemFlags::empty() };
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if allow_overlap {
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bx.memmove(dst, align, src, align, size, flags);
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} else {
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bx.memcpy(dst, align, src, align, size, flags);
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}
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}
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fn memset_intrinsic<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
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bx: &mut Bx,
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volatile: bool,
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ty: Ty<'tcx>,
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dst: Bx::Value,
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val: Bx::Value,
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count: Bx::Value,
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) {
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let layout = bx.layout_of(ty);
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let size = layout.size;
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let align = layout.align.abi;
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let size = bx.mul(bx.const_usize(size.bytes()), count);
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let flags = if volatile { MemFlags::VOLATILE } else { MemFlags::empty() };
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bx.memset(dst, val, size, align, flags);
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}
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impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
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pub fn codegen_intrinsic_call(
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bx: &mut Bx,
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instance: ty::Instance<'tcx>,
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fn_abi: &FnAbi<'tcx, Ty<'tcx>>,
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args: &[OperandRef<'tcx, Bx::Value>],
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llresult: Bx::Value,
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span: Span,
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) {
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let callee_ty = instance.ty(bx.tcx(), ty::ParamEnv::reveal_all());
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let (def_id, substs) = match *callee_ty.kind() {
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ty::FnDef(def_id, substs) => (def_id, substs),
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_ => bug!("expected fn item type, found {}", callee_ty),
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};
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let sig = callee_ty.fn_sig(bx.tcx());
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let sig = bx.tcx().normalize_erasing_late_bound_regions(ty::ParamEnv::reveal_all(), &sig);
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let arg_tys = sig.inputs();
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let ret_ty = sig.output();
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let name = bx.tcx().item_name(def_id);
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let name_str = &*name.as_str();
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let llret_ty = bx.backend_type(bx.layout_of(ret_ty));
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let result = PlaceRef::new_sized(llresult, fn_abi.ret.layout);
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let llval = match name {
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sym::assume => {
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bx.assume(args[0].immediate());
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return;
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}
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sym::abort => {
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bx.abort();
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return;
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}
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sym::unreachable => {
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return;
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}
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sym::va_start => bx.va_start(args[0].immediate()),
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sym::va_end => bx.va_end(args[0].immediate()),
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sym::size_of_val => {
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let tp_ty = substs.type_at(0);
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if let OperandValue::Pair(_, meta) = args[0].val {
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let (llsize, _) = glue::size_and_align_of_dst(bx, tp_ty, Some(meta));
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llsize
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} else {
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bx.const_usize(bx.layout_of(tp_ty).size.bytes())
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}
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}
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sym::min_align_of_val => {
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let tp_ty = substs.type_at(0);
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if let OperandValue::Pair(_, meta) = args[0].val {
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let (_, llalign) = glue::size_and_align_of_dst(bx, tp_ty, Some(meta));
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llalign
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} else {
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bx.const_usize(bx.layout_of(tp_ty).align.abi.bytes())
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}
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}
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sym::size_of
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| sym::pref_align_of
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| sym::min_align_of
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| sym::needs_drop
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| sym::type_id
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| sym::type_name
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| sym::variant_count => {
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let value = bx
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.tcx()
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.const_eval_instance(ty::ParamEnv::reveal_all(), instance, None)
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.unwrap();
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OperandRef::from_const(bx, value, ret_ty).immediate_or_packed_pair(bx)
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}
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// Effectively no-op
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sym::forget => {
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return;
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}
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sym::offset => {
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let ptr = args[0].immediate();
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let offset = args[1].immediate();
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bx.inbounds_gep(ptr, &[offset])
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}
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sym::arith_offset => {
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let ptr = args[0].immediate();
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let offset = args[1].immediate();
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bx.gep(ptr, &[offset])
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}
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sym::copy_nonoverlapping => {
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copy_intrinsic(
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bx,
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false,
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false,
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substs.type_at(0),
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args[1].immediate(),
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args[0].immediate(),
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args[2].immediate(),
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);
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return;
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}
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sym::copy => {
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copy_intrinsic(
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bx,
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true,
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false,
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substs.type_at(0),
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args[1].immediate(),
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args[0].immediate(),
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args[2].immediate(),
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);
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return;
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}
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sym::write_bytes => {
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memset_intrinsic(
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bx,
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false,
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substs.type_at(0),
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args[0].immediate(),
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args[1].immediate(),
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args[2].immediate(),
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);
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return;
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}
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sym::volatile_copy_nonoverlapping_memory => {
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copy_intrinsic(
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bx,
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false,
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true,
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substs.type_at(0),
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args[0].immediate(),
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args[1].immediate(),
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args[2].immediate(),
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);
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return;
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}
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sym::volatile_copy_memory => {
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copy_intrinsic(
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bx,
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true,
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true,
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substs.type_at(0),
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args[0].immediate(),
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args[1].immediate(),
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args[2].immediate(),
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);
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return;
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}
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sym::volatile_set_memory => {
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memset_intrinsic(
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bx,
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true,
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substs.type_at(0),
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args[0].immediate(),
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args[1].immediate(),
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args[2].immediate(),
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);
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return;
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}
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sym::volatile_store => {
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let dst = args[0].deref(bx.cx());
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args[1].val.volatile_store(bx, dst);
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return;
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}
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sym::unaligned_volatile_store => {
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let dst = args[0].deref(bx.cx());
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args[1].val.unaligned_volatile_store(bx, dst);
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return;
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}
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sym::add_with_overflow
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| sym::sub_with_overflow
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| sym::mul_with_overflow
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| sym::wrapping_add
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| sym::wrapping_sub
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| sym::wrapping_mul
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| sym::unchecked_div
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| sym::unchecked_rem
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| sym::unchecked_shl
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| sym::unchecked_shr
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| sym::unchecked_add
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| sym::unchecked_sub
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| sym::unchecked_mul
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| sym::exact_div => {
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let ty = arg_tys[0];
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match int_type_width_signed(ty, bx.tcx()) {
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Some((_width, signed)) => match name {
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sym::add_with_overflow
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| sym::sub_with_overflow
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| sym::mul_with_overflow => {
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let op = match name {
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sym::add_with_overflow => OverflowOp::Add,
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sym::sub_with_overflow => OverflowOp::Sub,
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sym::mul_with_overflow => OverflowOp::Mul,
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_ => bug!(),
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};
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let (val, overflow) =
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bx.checked_binop(op, ty, args[0].immediate(), args[1].immediate());
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// Convert `i1` to a `bool`, and write it to the out parameter
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let val = bx.from_immediate(val);
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let overflow = bx.from_immediate(overflow);
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let dest = result.project_field(bx, 0);
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bx.store(val, dest.llval, dest.align);
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let dest = result.project_field(bx, 1);
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bx.store(overflow, dest.llval, dest.align);
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return;
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}
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sym::wrapping_add => bx.add(args[0].immediate(), args[1].immediate()),
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sym::wrapping_sub => bx.sub(args[0].immediate(), args[1].immediate()),
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sym::wrapping_mul => bx.mul(args[0].immediate(), args[1].immediate()),
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sym::exact_div => {
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if signed {
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bx.exactsdiv(args[0].immediate(), args[1].immediate())
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} else {
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bx.exactudiv(args[0].immediate(), args[1].immediate())
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}
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}
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sym::unchecked_div => {
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if signed {
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bx.sdiv(args[0].immediate(), args[1].immediate())
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} else {
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bx.udiv(args[0].immediate(), args[1].immediate())
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}
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}
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sym::unchecked_rem => {
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if signed {
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bx.srem(args[0].immediate(), args[1].immediate())
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} else {
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bx.urem(args[0].immediate(), args[1].immediate())
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}
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}
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sym::unchecked_shl => bx.shl(args[0].immediate(), args[1].immediate()),
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sym::unchecked_shr => {
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if signed {
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bx.ashr(args[0].immediate(), args[1].immediate())
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} else {
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bx.lshr(args[0].immediate(), args[1].immediate())
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}
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}
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sym::unchecked_add => {
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if signed {
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bx.unchecked_sadd(args[0].immediate(), args[1].immediate())
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} else {
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bx.unchecked_uadd(args[0].immediate(), args[1].immediate())
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}
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}
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sym::unchecked_sub => {
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if signed {
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bx.unchecked_ssub(args[0].immediate(), args[1].immediate())
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} else {
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bx.unchecked_usub(args[0].immediate(), args[1].immediate())
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}
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}
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sym::unchecked_mul => {
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if signed {
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bx.unchecked_smul(args[0].immediate(), args[1].immediate())
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} else {
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bx.unchecked_umul(args[0].immediate(), args[1].immediate())
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}
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}
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_ => bug!(),
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},
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None => {
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span_invalid_monomorphization_error(
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bx.tcx().sess,
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span,
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&format!(
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"invalid monomorphization of `{}` intrinsic: \
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expected basic integer type, found `{}`",
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name, ty
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),
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);
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return;
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}
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}
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}
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sym::fadd_fast | sym::fsub_fast | sym::fmul_fast | sym::fdiv_fast | sym::frem_fast => {
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match float_type_width(arg_tys[0]) {
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Some(_width) => match name {
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sym::fadd_fast => bx.fadd_fast(args[0].immediate(), args[1].immediate()),
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sym::fsub_fast => bx.fsub_fast(args[0].immediate(), args[1].immediate()),
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sym::fmul_fast => bx.fmul_fast(args[0].immediate(), args[1].immediate()),
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sym::fdiv_fast => bx.fdiv_fast(args[0].immediate(), args[1].immediate()),
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sym::frem_fast => bx.frem_fast(args[0].immediate(), args[1].immediate()),
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_ => bug!(),
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},
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None => {
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span_invalid_monomorphization_error(
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bx.tcx().sess,
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span,
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&format!(
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"invalid monomorphization of `{}` intrinsic: \
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expected basic float type, found `{}`",
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name, arg_tys[0]
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),
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);
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return;
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}
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}
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}
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sym::float_to_int_unchecked => {
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if float_type_width(arg_tys[0]).is_none() {
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span_invalid_monomorphization_error(
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bx.tcx().sess,
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span,
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&format!(
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"invalid monomorphization of `float_to_int_unchecked` \
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intrinsic: expected basic float type, \
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found `{}`",
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arg_tys[0]
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),
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);
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return;
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}
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let (_width, signed) = match int_type_width_signed(ret_ty, bx.tcx()) {
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Some(pair) => pair,
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None => {
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span_invalid_monomorphization_error(
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bx.tcx().sess,
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span,
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&format!(
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"invalid monomorphization of `float_to_int_unchecked` \
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intrinsic: expected basic integer type, \
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found `{}`",
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ret_ty
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),
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);
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return;
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}
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};
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if signed {
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bx.fptosi(args[0].immediate(), llret_ty)
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} else {
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bx.fptoui(args[0].immediate(), llret_ty)
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}
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}
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sym::discriminant_value => {
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if ret_ty.is_integral() {
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args[0].deref(bx.cx()).codegen_get_discr(bx, ret_ty)
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} else {
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span_bug!(span, "Invalid discriminant type for `{:?}`", arg_tys[0])
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}
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}
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// This requires that atomic intrinsics follow a specific naming pattern:
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// "atomic_<operation>[_<ordering>]", and no ordering means SeqCst
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name if name_str.starts_with("atomic_") => {
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use crate::common::AtomicOrdering::*;
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use crate::common::{AtomicRmwBinOp, SynchronizationScope};
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let split: Vec<&str> = name_str.split('_').collect();
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let is_cxchg = split[1] == "cxchg" || split[1] == "cxchgweak";
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let (order, failorder) = match split.len() {
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2 => (SequentiallyConsistent, SequentiallyConsistent),
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3 => match split[2] {
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"unordered" => (Unordered, Unordered),
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"relaxed" => (Monotonic, Monotonic),
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"acq" => (Acquire, Acquire),
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"rel" => (Release, Monotonic),
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"acqrel" => (AcquireRelease, Acquire),
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"failrelaxed" if is_cxchg => (SequentiallyConsistent, Monotonic),
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"failacq" if is_cxchg => (SequentiallyConsistent, Acquire),
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_ => bx.sess().fatal("unknown ordering in atomic intrinsic"),
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},
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4 => match (split[2], split[3]) {
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("acq", "failrelaxed") if is_cxchg => (Acquire, Monotonic),
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("acqrel", "failrelaxed") if is_cxchg => (AcquireRelease, Monotonic),
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_ => bx.sess().fatal("unknown ordering in atomic intrinsic"),
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},
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_ => bx.sess().fatal("Atomic intrinsic not in correct format"),
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};
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let invalid_monomorphization = |ty| {
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span_invalid_monomorphization_error(
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bx.tcx().sess,
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span,
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&format!(
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"invalid monomorphization of `{}` intrinsic: \
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expected basic integer type, found `{}`",
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name, ty
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),
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);
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};
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match split[1] {
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"cxchg" | "cxchgweak" => {
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let ty = substs.type_at(0);
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if int_type_width_signed(ty, bx.tcx()).is_some() {
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let weak = split[1] == "cxchgweak";
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let pair = bx.atomic_cmpxchg(
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args[0].immediate(),
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args[1].immediate(),
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args[2].immediate(),
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order,
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failorder,
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weak,
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);
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let val = bx.extract_value(pair, 0);
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let success = bx.extract_value(pair, 1);
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let val = bx.from_immediate(val);
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let success = bx.from_immediate(success);
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let dest = result.project_field(bx, 0);
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bx.store(val, dest.llval, dest.align);
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let dest = result.project_field(bx, 1);
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bx.store(success, dest.llval, dest.align);
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return;
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} else {
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return invalid_monomorphization(ty);
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}
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}
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"load" => {
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let ty = substs.type_at(0);
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if int_type_width_signed(ty, bx.tcx()).is_some() {
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let size = bx.layout_of(ty).size;
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bx.atomic_load(args[0].immediate(), order, size)
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} else {
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return invalid_monomorphization(ty);
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}
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}
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"store" => {
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let ty = substs.type_at(0);
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if int_type_width_signed(ty, bx.tcx()).is_some() {
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let size = bx.layout_of(ty).size;
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bx.atomic_store(args[1].immediate(), args[0].immediate(), order, size);
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return;
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} else {
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return invalid_monomorphization(ty);
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}
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}
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"fence" => {
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bx.atomic_fence(order, SynchronizationScope::CrossThread);
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return;
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}
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"singlethreadfence" => {
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bx.atomic_fence(order, SynchronizationScope::SingleThread);
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return;
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}
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// These are all AtomicRMW ops
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op => {
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||
let atom_op = match op {
|
||
"xchg" => AtomicRmwBinOp::AtomicXchg,
|
||
"xadd" => AtomicRmwBinOp::AtomicAdd,
|
||
"xsub" => AtomicRmwBinOp::AtomicSub,
|
||
"and" => AtomicRmwBinOp::AtomicAnd,
|
||
"nand" => AtomicRmwBinOp::AtomicNand,
|
||
"or" => AtomicRmwBinOp::AtomicOr,
|
||
"xor" => AtomicRmwBinOp::AtomicXor,
|
||
"max" => AtomicRmwBinOp::AtomicMax,
|
||
"min" => AtomicRmwBinOp::AtomicMin,
|
||
"umax" => AtomicRmwBinOp::AtomicUMax,
|
||
"umin" => AtomicRmwBinOp::AtomicUMin,
|
||
_ => bx.sess().fatal("unknown atomic operation"),
|
||
};
|
||
|
||
let ty = substs.type_at(0);
|
||
if int_type_width_signed(ty, bx.tcx()).is_some() {
|
||
bx.atomic_rmw(atom_op, args[0].immediate(), args[1].immediate(), order)
|
||
} else {
|
||
return invalid_monomorphization(ty);
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
sym::nontemporal_store => {
|
||
let dst = args[0].deref(bx.cx());
|
||
args[1].val.nontemporal_store(bx, dst);
|
||
return;
|
||
}
|
||
|
||
sym::ptr_guaranteed_eq | sym::ptr_guaranteed_ne => {
|
||
let a = args[0].immediate();
|
||
let b = args[1].immediate();
|
||
if name == sym::ptr_guaranteed_eq {
|
||
bx.icmp(IntPredicate::IntEQ, a, b)
|
||
} else {
|
||
bx.icmp(IntPredicate::IntNE, a, b)
|
||
}
|
||
}
|
||
|
||
sym::ptr_offset_from => {
|
||
let ty = substs.type_at(0);
|
||
let pointee_size = bx.layout_of(ty).size;
|
||
|
||
// This is the same sequence that Clang emits for pointer subtraction.
|
||
// It can be neither `nsw` nor `nuw` because the input is treated as
|
||
// unsigned but then the output is treated as signed, so neither works.
|
||
let a = args[0].immediate();
|
||
let b = args[1].immediate();
|
||
let a = bx.ptrtoint(a, bx.type_isize());
|
||
let b = bx.ptrtoint(b, bx.type_isize());
|
||
let d = bx.sub(a, b);
|
||
let pointee_size = bx.const_usize(pointee_size.bytes());
|
||
// this is where the signed magic happens (notice the `s` in `exactsdiv`)
|
||
bx.exactsdiv(d, pointee_size)
|
||
}
|
||
|
||
_ => {
|
||
// Need to use backend-specific things in the implementation.
|
||
bx.codegen_intrinsic_call(instance, fn_abi, args, llresult, span);
|
||
return;
|
||
}
|
||
};
|
||
|
||
if !fn_abi.ret.is_ignore() {
|
||
if let PassMode::Cast(ty) = fn_abi.ret.mode {
|
||
let ptr_llty = bx.type_ptr_to(bx.cast_backend_type(&ty));
|
||
let ptr = bx.pointercast(result.llval, ptr_llty);
|
||
bx.store(llval, ptr, result.align);
|
||
} else {
|
||
OperandRef::from_immediate_or_packed_pair(bx, llval, result.layout)
|
||
.val
|
||
.store(bx, result);
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
// Returns the width of an int Ty, and if it's signed or not
|
||
// Returns None if the type is not an integer
|
||
// FIXME: there’s multiple of this functions, investigate using some of the already existing
|
||
// stuffs.
|
||
fn int_type_width_signed(ty: Ty<'_>, tcx: TyCtxt<'_>) -> Option<(u64, bool)> {
|
||
match ty.kind() {
|
||
ty::Int(t) => Some((t.bit_width().unwrap_or(u64::from(tcx.sess.target.ptr_width)), true)),
|
||
ty::Uint(t) => Some((t.bit_width().unwrap_or(u64::from(tcx.sess.target.ptr_width)), false)),
|
||
_ => None,
|
||
}
|
||
}
|
||
|
||
// Returns the width of a float Ty
|
||
// Returns None if the type is not a float
|
||
fn float_type_width(ty: Ty<'_>) -> Option<u64> {
|
||
match ty.kind() {
|
||
ty::Float(t) => Some(t.bit_width()),
|
||
_ => None,
|
||
}
|
||
}
|