rust/src/librustc_trans/trans/intrinsic.rs
2016-03-13 19:01:35 +01:00

1730 lines
71 KiB
Rust

// Copyright 2012-2014 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.
#![allow(non_upper_case_globals)]
use arena::TypedArena;
use intrinsics::{self, Intrinsic};
use libc;
use llvm;
use llvm::{ValueRef, TypeKind};
use middle::infer;
use middle::subst;
use middle::subst::FnSpace;
use trans::adt;
use trans::attributes;
use trans::base::*;
use trans::build::*;
use trans::callee::{self, Callee};
use trans::cleanup;
use trans::cleanup::CleanupMethods;
use trans::common::*;
use trans::consts;
use trans::datum::*;
use trans::debuginfo::DebugLoc;
use trans::declare;
use trans::expr;
use trans::glue;
use trans::type_of;
use trans::machine;
use trans::type_::Type;
use middle::ty::{self, Ty, TypeFoldable};
use trans::Disr;
use middle::subst::Substs;
use rustc::dep_graph::DepNode;
use rustc_front::hir;
use syntax::abi::Abi;
use syntax::ast;
use syntax::ptr::P;
use syntax::parse::token;
use rustc::lint;
use rustc::session::Session;
use syntax::codemap::Span;
use std::cmp::Ordering;
pub fn get_simple_intrinsic(ccx: &CrateContext, item: &hir::ForeignItem) -> Option<ValueRef> {
let name = match &*item.name.as_str() {
"sqrtf32" => "llvm.sqrt.f32",
"sqrtf64" => "llvm.sqrt.f64",
"powif32" => "llvm.powi.f32",
"powif64" => "llvm.powi.f64",
"sinf32" => "llvm.sin.f32",
"sinf64" => "llvm.sin.f64",
"cosf32" => "llvm.cos.f32",
"cosf64" => "llvm.cos.f64",
"powf32" => "llvm.pow.f32",
"powf64" => "llvm.pow.f64",
"expf32" => "llvm.exp.f32",
"expf64" => "llvm.exp.f64",
"exp2f32" => "llvm.exp2.f32",
"exp2f64" => "llvm.exp2.f64",
"logf32" => "llvm.log.f32",
"logf64" => "llvm.log.f64",
"log10f32" => "llvm.log10.f32",
"log10f64" => "llvm.log10.f64",
"log2f32" => "llvm.log2.f32",
"log2f64" => "llvm.log2.f64",
"fmaf32" => "llvm.fma.f32",
"fmaf64" => "llvm.fma.f64",
"fabsf32" => "llvm.fabs.f32",
"fabsf64" => "llvm.fabs.f64",
"copysignf32" => "llvm.copysign.f32",
"copysignf64" => "llvm.copysign.f64",
"floorf32" => "llvm.floor.f32",
"floorf64" => "llvm.floor.f64",
"ceilf32" => "llvm.ceil.f32",
"ceilf64" => "llvm.ceil.f64",
"truncf32" => "llvm.trunc.f32",
"truncf64" => "llvm.trunc.f64",
"rintf32" => "llvm.rint.f32",
"rintf64" => "llvm.rint.f64",
"nearbyintf32" => "llvm.nearbyint.f32",
"nearbyintf64" => "llvm.nearbyint.f64",
"roundf32" => "llvm.round.f32",
"roundf64" => "llvm.round.f64",
"assume" => "llvm.assume",
_ => return None
};
Some(ccx.get_intrinsic(&name))
}
pub fn span_transmute_size_error(a: &Session, b: Span, msg: &str) {
span_err!(a, b, E0512, "{}", msg);
}
/// Performs late verification that intrinsics are used correctly. At present,
/// the only intrinsic that needs such verification is `transmute`.
pub fn check_intrinsics(ccx: &CrateContext) {
let _task = ccx.tcx().dep_graph.in_task(DepNode::IntrinsicUseCheck);
let mut last_failing_id = None;
for transmute_restriction in ccx.tcx().transmute_restrictions.borrow().iter() {
// Sometimes, a single call to transmute will push multiple
// type pairs to test in order to exhaustively test the
// possibility around a type parameter. If one of those fails,
// there is no sense reporting errors on the others.
if last_failing_id == Some(transmute_restriction.id) {
continue;
}
debug!("transmute_restriction: {:?}", transmute_restriction);
assert!(!transmute_restriction.substituted_from.has_param_types());
assert!(!transmute_restriction.substituted_to.has_param_types());
let llfromtype = type_of::sizing_type_of(ccx,
transmute_restriction.substituted_from);
let lltotype = type_of::sizing_type_of(ccx,
transmute_restriction.substituted_to);
let from_type_size = machine::llbitsize_of_real(ccx, llfromtype);
let to_type_size = machine::llbitsize_of_real(ccx, lltotype);
if let ty::TyFnDef(..) = transmute_restriction.substituted_from.sty {
if to_type_size == machine::llbitsize_of_real(ccx, ccx.int_type()) {
// FIXME #19925 Remove this warning after a release cycle.
lint::raw_emit_lint(&ccx.tcx().sess,
&ccx.tcx().sess.lint_store.borrow(),
lint::builtin::TRANSMUTE_FROM_FN_ITEM_TYPES,
(lint::Warn, lint::LintSource::Default),
Some(transmute_restriction.span),
&format!("`{}` is now zero-sized and has to be cast \
to a pointer before transmuting to `{}`",
transmute_restriction.substituted_from,
transmute_restriction.substituted_to));
continue;
}
}
if from_type_size != to_type_size {
last_failing_id = Some(transmute_restriction.id);
if transmute_restriction.original_from != transmute_restriction.substituted_from {
span_transmute_size_error(ccx.sess(), transmute_restriction.span,
&format!("transmute called with differently sized types: \
{} (could be {} bits) to {} (could be {} bits)",
transmute_restriction.original_from,
from_type_size,
transmute_restriction.original_to,
to_type_size));
} else {
span_transmute_size_error(ccx.sess(), transmute_restriction.span,
&format!("transmute called with differently sized types: \
{} ({} bits) to {} ({} bits)",
transmute_restriction.original_from,
from_type_size,
transmute_restriction.original_to,
to_type_size));
}
}
}
ccx.sess().abort_if_errors();
}
/// Remember to add all intrinsics here, in librustc_typeck/check/mod.rs,
/// and in libcore/intrinsics.rs; if you need access to any llvm intrinsics,
/// add them to librustc_trans/trans/context.rs
pub fn trans_intrinsic_call<'a, 'blk, 'tcx>(mut bcx: Block<'blk, 'tcx>,
node: ast::NodeId,
callee_ty: Ty<'tcx>,
cleanup_scope: cleanup::CustomScopeIndex,
args: callee::CallArgs<'a, 'tcx>,
dest: expr::Dest,
substs: &'tcx subst::Substs<'tcx>,
call_info: NodeIdAndSpan)
-> Result<'blk, 'tcx> {
let fcx = bcx.fcx;
let ccx = fcx.ccx;
let tcx = bcx.tcx();
let _icx = push_ctxt("trans_intrinsic_call");
let sig = ccx.tcx().erase_late_bound_regions(callee_ty.fn_sig());
let sig = infer::normalize_associated_type(ccx.tcx(), &sig);
let arg_tys = sig.inputs;
let ret_ty = sig.output;
let foreign_item = tcx.map.expect_foreign_item(node);
let name = foreign_item.name.as_str();
let call_debug_location = DebugLoc::At(call_info.id, call_info.span);
// For `transmute` we can just trans the input expr directly into dest
if name == "transmute" {
let llret_ty = type_of::type_of(ccx, ret_ty.unwrap());
match args {
callee::ArgExprs(arg_exprs) => {
assert_eq!(arg_exprs.len(), 1);
let (in_type, out_type) = (*substs.types.get(FnSpace, 0),
*substs.types.get(FnSpace, 1));
let llintype = type_of::type_of(ccx, in_type);
let llouttype = type_of::type_of(ccx, out_type);
let in_type_size = machine::llbitsize_of_real(ccx, llintype);
let out_type_size = machine::llbitsize_of_real(ccx, llouttype);
if let ty::TyFnDef(def_id, substs, _) = in_type.sty {
if out_type_size != 0 {
// FIXME #19925 Remove this hack after a release cycle.
let _ = unpack_datum!(bcx, expr::trans(bcx, &arg_exprs[0]));
let llfn = Callee::def(ccx, def_id, substs, in_type).reify(ccx).val;
let llfnty = val_ty(llfn);
let llresult = match dest {
expr::SaveIn(d) => d,
expr::Ignore => alloc_ty(bcx, out_type, "ret")
};
Store(bcx, llfn, PointerCast(bcx, llresult, llfnty.ptr_to()));
if dest == expr::Ignore {
bcx = glue::drop_ty(bcx, llresult, out_type,
call_debug_location);
}
fcx.scopes.borrow_mut().last_mut().unwrap().drop_non_lifetime_clean();
fcx.pop_and_trans_custom_cleanup_scope(bcx, cleanup_scope);
return Result::new(bcx, llresult);
}
}
// This should be caught by the intrinsicck pass
assert_eq!(in_type_size, out_type_size);
let nonpointer_nonaggregate = |llkind: TypeKind| -> bool {
use llvm::TypeKind::*;
match llkind {
Half | Float | Double | X86_FP80 | FP128 |
PPC_FP128 | Integer | Vector | X86_MMX => true,
_ => false
}
};
// An approximation to which types can be directly cast via
// LLVM's bitcast. This doesn't cover pointer -> pointer casts,
// but does, importantly, cover SIMD types.
let in_kind = llintype.kind();
let ret_kind = llret_ty.kind();
let bitcast_compatible =
(nonpointer_nonaggregate(in_kind) && nonpointer_nonaggregate(ret_kind)) || {
in_kind == TypeKind::Pointer && ret_kind == TypeKind::Pointer
};
let dest = if bitcast_compatible {
// if we're here, the type is scalar-like (a primitive, a
// SIMD type or a pointer), and so can be handled as a
// by-value ValueRef and can also be directly bitcast to the
// target type. Doing this special case makes conversions
// like `u32x4` -> `u64x2` much nicer for LLVM and so more
// efficient (these are done efficiently implicitly in C
// with the `__m128i` type and so this means Rust doesn't
// lose out there).
let expr = &arg_exprs[0];
let datum = unpack_datum!(bcx, expr::trans(bcx, expr));
let datum = unpack_datum!(bcx, datum.to_rvalue_datum(bcx, "transmute_temp"));
let val = if datum.kind.is_by_ref() {
load_ty(bcx, datum.val, datum.ty)
} else {
from_arg_ty(bcx, datum.val, datum.ty)
};
let cast_val = BitCast(bcx, val, llret_ty);
match dest {
expr::SaveIn(d) => {
// this often occurs in a sequence like `Store(val,
// d); val2 = Load(d)`, so disappears easily.
Store(bcx, cast_val, d);
}
expr::Ignore => {}
}
dest
} else {
// The types are too complicated to do with a by-value
// bitcast, so pointer cast instead. We need to cast the
// dest so the types work out.
let dest = match dest {
expr::SaveIn(d) => expr::SaveIn(PointerCast(bcx, d, llintype.ptr_to())),
expr::Ignore => expr::Ignore
};
bcx = expr::trans_into(bcx, &arg_exprs[0], dest);
dest
};
fcx.scopes.borrow_mut().last_mut().unwrap().drop_non_lifetime_clean();
fcx.pop_and_trans_custom_cleanup_scope(bcx, cleanup_scope);
return match dest {
expr::SaveIn(d) => Result::new(bcx, d),
expr::Ignore => Result::new(bcx, C_undef(llret_ty.ptr_to()))
};
}
_ => {
ccx.sess().bug("expected expr as argument for transmute");
}
}
}
// For `move_val_init` we can evaluate the destination address
// (the first argument) and then trans the source value (the
// second argument) directly into the resulting destination
// address.
if name == "move_val_init" {
if let callee::ArgExprs(ref exprs) = args {
let (dest_expr, source_expr) = if exprs.len() != 2 {
ccx.sess().bug("expected two exprs as arguments for `move_val_init` intrinsic");
} else {
(&exprs[0], &exprs[1])
};
// evaluate destination address
let dest_datum = unpack_datum!(bcx, expr::trans(bcx, dest_expr));
let dest_datum = unpack_datum!(
bcx, dest_datum.to_rvalue_datum(bcx, "arg"));
let dest_datum = unpack_datum!(
bcx, dest_datum.to_appropriate_datum(bcx));
// `expr::trans_into(bcx, expr, dest)` is equiv to
//
// `trans(bcx, expr).store_to_dest(dest)`,
//
// which for `dest == expr::SaveIn(addr)`, is equivalent to:
//
// `trans(bcx, expr).store_to(bcx, addr)`.
let lldest = expr::Dest::SaveIn(dest_datum.val);
bcx = expr::trans_into(bcx, source_expr, lldest);
let llresult = C_nil(ccx);
fcx.pop_and_trans_custom_cleanup_scope(bcx, cleanup_scope);
return Result::new(bcx, llresult);
} else {
ccx.sess().bug("expected two exprs as arguments for `move_val_init` intrinsic");
}
}
// For `try` we need some custom control flow
if &name[..] == "try" {
if let callee::ArgExprs(ref exprs) = args {
let (func, data, local_ptr) = if exprs.len() != 3 {
ccx.sess().bug("expected three exprs as arguments for \
`try` intrinsic");
} else {
(&exprs[0], &exprs[1], &exprs[2])
};
// translate arguments
let func = unpack_datum!(bcx, expr::trans(bcx, func));
let func = unpack_datum!(bcx, func.to_rvalue_datum(bcx, "func"));
let data = unpack_datum!(bcx, expr::trans(bcx, data));
let data = unpack_datum!(bcx, data.to_rvalue_datum(bcx, "data"));
let local_ptr = unpack_datum!(bcx, expr::trans(bcx, local_ptr));
let local_ptr = local_ptr.to_rvalue_datum(bcx, "local_ptr");
let local_ptr = unpack_datum!(bcx, local_ptr);
let dest = match dest {
expr::SaveIn(d) => d,
expr::Ignore => alloc_ty(bcx, tcx.mk_mut_ptr(tcx.types.i8),
"try_result"),
};
// do the invoke
bcx = try_intrinsic(bcx, func.val, data.val, local_ptr.val, dest,
call_debug_location);
fcx.pop_and_trans_custom_cleanup_scope(bcx, cleanup_scope);
return Result::new(bcx, dest);
} else {
ccx.sess().bug("expected two exprs as arguments for \
`try` intrinsic");
}
}
// save the actual AST arguments for later (some places need to do
// const-evaluation on them)
let expr_arguments = match args {
callee::ArgExprs(args) => Some(args),
_ => None,
};
// Push the arguments.
let mut llargs = Vec::new();
bcx = callee::trans_args(bcx,
args,
callee_ty,
&mut llargs,
cleanup::CustomScope(cleanup_scope),
Abi::RustIntrinsic);
fcx.scopes.borrow_mut().last_mut().unwrap().drop_non_lifetime_clean();
// These are the only intrinsic functions that diverge.
if name == "abort" {
let llfn = ccx.get_intrinsic(&("llvm.trap"));
Call(bcx, llfn, &[], None, call_debug_location);
fcx.pop_and_trans_custom_cleanup_scope(bcx, cleanup_scope);
Unreachable(bcx);
return Result::new(bcx, C_undef(Type::nil(ccx).ptr_to()));
} else if &name[..] == "unreachable" {
fcx.pop_and_trans_custom_cleanup_scope(bcx, cleanup_scope);
Unreachable(bcx);
return Result::new(bcx, C_nil(ccx));
}
let ret_ty = match ret_ty {
ty::FnConverging(ret_ty) => ret_ty,
ty::FnDiverging => unreachable!()
};
let llret_ty = type_of::type_of(ccx, ret_ty);
// Get location to store the result. If the user does
// not care about the result, just make a stack slot
let llresult = match dest {
expr::SaveIn(d) => d,
expr::Ignore => {
if !type_is_zero_size(ccx, ret_ty) {
let llresult = alloc_ty(bcx, ret_ty, "intrinsic_result");
call_lifetime_start(bcx, llresult);
llresult
} else {
C_undef(llret_ty.ptr_to())
}
}
};
let simple = get_simple_intrinsic(ccx, &foreign_item);
let llval = match (simple, &*name) {
(Some(llfn), _) => {
Call(bcx, llfn, &llargs, None, call_debug_location)
}
(_, "breakpoint") => {
let llfn = ccx.get_intrinsic(&("llvm.debugtrap"));
Call(bcx, llfn, &[], None, call_debug_location)
}
(_, "size_of") => {
let tp_ty = *substs.types.get(FnSpace, 0);
let lltp_ty = type_of::type_of(ccx, tp_ty);
C_uint(ccx, machine::llsize_of_alloc(ccx, lltp_ty))
}
(_, "size_of_val") => {
let tp_ty = *substs.types.get(FnSpace, 0);
if !type_is_sized(tcx, tp_ty) {
let (llsize, _) = glue::size_and_align_of_dst(bcx, tp_ty, llargs[1]);
llsize
} else {
let lltp_ty = type_of::type_of(ccx, tp_ty);
C_uint(ccx, machine::llsize_of_alloc(ccx, lltp_ty))
}
}
(_, "min_align_of") => {
let tp_ty = *substs.types.get(FnSpace, 0);
C_uint(ccx, type_of::align_of(ccx, tp_ty))
}
(_, "min_align_of_val") => {
let tp_ty = *substs.types.get(FnSpace, 0);
if !type_is_sized(tcx, tp_ty) {
let (_, llalign) = glue::size_and_align_of_dst(bcx, tp_ty, llargs[1]);
llalign
} else {
C_uint(ccx, type_of::align_of(ccx, tp_ty))
}
}
(_, "pref_align_of") => {
let tp_ty = *substs.types.get(FnSpace, 0);
let lltp_ty = type_of::type_of(ccx, tp_ty);
C_uint(ccx, machine::llalign_of_pref(ccx, lltp_ty))
}
(_, "drop_in_place") => {
let tp_ty = *substs.types.get(FnSpace, 0);
let ptr = if type_is_sized(tcx, tp_ty) {
llargs[0]
} else {
let scratch = rvalue_scratch_datum(bcx, tp_ty, "tmp");
Store(bcx, llargs[0], expr::get_dataptr(bcx, scratch.val));
Store(bcx, llargs[1], expr::get_meta(bcx, scratch.val));
fcx.schedule_lifetime_end(cleanup::CustomScope(cleanup_scope), scratch.val);
scratch.val
};
glue::drop_ty(bcx, ptr, tp_ty, call_debug_location);
C_nil(ccx)
}
(_, "type_name") => {
let tp_ty = *substs.types.get(FnSpace, 0);
let ty_name = token::intern_and_get_ident(&tp_ty.to_string());
C_str_slice(ccx, ty_name)
}
(_, "type_id") => {
let hash = ccx.tcx().hash_crate_independent(*substs.types.get(FnSpace, 0),
&ccx.link_meta().crate_hash);
C_u64(ccx, hash)
}
(_, "init_dropped") => {
let tp_ty = *substs.types.get(FnSpace, 0);
if !return_type_is_void(ccx, tp_ty) {
drop_done_fill_mem(bcx, llresult, tp_ty);
}
C_nil(ccx)
}
(_, "init") => {
let tp_ty = *substs.types.get(FnSpace, 0);
if !return_type_is_void(ccx, tp_ty) {
// Just zero out the stack slot. (See comment on base::memzero for explanation)
init_zero_mem(bcx, llresult, tp_ty);
}
C_nil(ccx)
}
// Effectively no-ops
(_, "uninit") | (_, "forget") => {
C_nil(ccx)
}
(_, "needs_drop") => {
let tp_ty = *substs.types.get(FnSpace, 0);
C_bool(ccx, bcx.fcx.type_needs_drop(tp_ty))
}
(_, "offset") => {
let ptr = llargs[0];
let offset = llargs[1];
InBoundsGEP(bcx, ptr, &[offset])
}
(_, "arith_offset") => {
let ptr = llargs[0];
let offset = llargs[1];
GEP(bcx, ptr, &[offset])
}
(_, "copy_nonoverlapping") => {
copy_intrinsic(bcx,
false,
false,
*substs.types.get(FnSpace, 0),
llargs[1],
llargs[0],
llargs[2],
call_debug_location)
}
(_, "copy") => {
copy_intrinsic(bcx,
true,
false,
*substs.types.get(FnSpace, 0),
llargs[1],
llargs[0],
llargs[2],
call_debug_location)
}
(_, "write_bytes") => {
memset_intrinsic(bcx,
false,
*substs.types.get(FnSpace, 0),
llargs[0],
llargs[1],
llargs[2],
call_debug_location)
}
(_, "volatile_copy_nonoverlapping_memory") => {
copy_intrinsic(bcx,
false,
true,
*substs.types.get(FnSpace, 0),
llargs[0],
llargs[1],
llargs[2],
call_debug_location)
}
(_, "volatile_copy_memory") => {
copy_intrinsic(bcx,
true,
true,
*substs.types.get(FnSpace, 0),
llargs[0],
llargs[1],
llargs[2],
call_debug_location)
}
(_, "volatile_set_memory") => {
memset_intrinsic(bcx,
true,
*substs.types.get(FnSpace, 0),
llargs[0],
llargs[1],
llargs[2],
call_debug_location)
}
(_, "volatile_load") => {
let tp_ty = *substs.types.get(FnSpace, 0);
let ptr = to_arg_ty_ptr(bcx, llargs[0], tp_ty);
let load = VolatileLoad(bcx, ptr);
unsafe {
llvm::LLVMSetAlignment(load, type_of::align_of(ccx, tp_ty));
}
to_arg_ty(bcx, load, tp_ty)
},
(_, "volatile_store") => {
let tp_ty = *substs.types.get(FnSpace, 0);
let ptr = to_arg_ty_ptr(bcx, llargs[0], tp_ty);
let val = if type_is_immediate(bcx.ccx(), tp_ty) {
from_arg_ty(bcx, llargs[1], tp_ty)
} else {
Load(bcx, llargs[1])
};
let store = VolatileStore(bcx, val, ptr);
unsafe {
llvm::LLVMSetAlignment(store, type_of::align_of(ccx, tp_ty));
}
C_nil(ccx)
},
(_, "ctlz") | (_, "cttz") | (_, "ctpop") | (_, "bswap") |
(_, "add_with_overflow") | (_, "sub_with_overflow") | (_, "mul_with_overflow") |
(_, "overflowing_add") | (_, "overflowing_sub") | (_, "overflowing_mul") |
(_, "unchecked_div") | (_, "unchecked_rem") => {
let sty = &arg_tys[0].sty;
match int_type_width_signed(sty, ccx) {
Some((width, signed)) =>
match &*name {
"ctlz" => count_zeros_intrinsic(bcx, &format!("llvm.ctlz.i{}", width),
llargs[0], call_debug_location),
"cttz" => count_zeros_intrinsic(bcx, &format!("llvm.cttz.i{}", width),
llargs[0], call_debug_location),
"ctpop" => Call(bcx, ccx.get_intrinsic(&format!("llvm.ctpop.i{}", width)),
&llargs, None, call_debug_location),
"bswap" => {
if width == 8 {
llargs[0] // byte swap a u8/i8 is just a no-op
} else {
Call(bcx, ccx.get_intrinsic(&format!("llvm.bswap.i{}", width)),
&llargs, None, call_debug_location)
}
}
"add_with_overflow" | "sub_with_overflow" | "mul_with_overflow" => {
let intrinsic = format!("llvm.{}{}.with.overflow.i{}",
if signed { 's' } else { 'u' },
&name[..3], width);
with_overflow_intrinsic(bcx, &intrinsic, llargs[0], llargs[1], llresult,
call_debug_location)
},
"overflowing_add" => Add(bcx, llargs[0], llargs[1], call_debug_location),
"overflowing_sub" => Sub(bcx, llargs[0], llargs[1], call_debug_location),
"overflowing_mul" => Mul(bcx, llargs[0], llargs[1], call_debug_location),
"unchecked_div" =>
if signed {
SDiv(bcx, llargs[0], llargs[1], call_debug_location)
} else {
UDiv(bcx, llargs[0], llargs[1], call_debug_location)
},
"unchecked_rem" =>
if signed {
SRem(bcx, llargs[0], llargs[1], call_debug_location)
} else {
URem(bcx, llargs[0], llargs[1], call_debug_location)
},
_ => unreachable!(),
},
None => {
span_invalid_monomorphization_error(
tcx.sess, call_info.span,
&format!("invalid monomorphization of `{}` intrinsic: \
expected basic integer type, found `{}`", name, sty));
C_null(llret_ty)
}
}
},
(_, "return_address") => {
if !fcx.caller_expects_out_pointer {
span_err!(tcx.sess, call_info.span, E0510,
"invalid use of `return_address` intrinsic: function \
does not use out pointer");
C_null(Type::i8p(ccx))
} else {
PointerCast(bcx, llvm::get_param(fcx.llfn, 0), Type::i8p(ccx))
}
}
(_, "discriminant_value") => {
let val_ty = substs.types.get(FnSpace, 0);
match val_ty.sty {
ty::TyEnum(..) => {
let repr = adt::represent_type(ccx, *val_ty);
adt::trans_get_discr(bcx, &repr, llargs[0],
Some(llret_ty), true)
}
_ => C_null(llret_ty)
}
}
(_, name) if name.starts_with("simd_") => {
generic_simd_intrinsic(bcx, name,
substs,
callee_ty,
expr_arguments,
&llargs,
ret_ty, llret_ty,
call_debug_location,
call_info)
}
// This requires that atomic intrinsics follow a specific naming pattern:
// "atomic_<operation>[_<ordering>]", and no ordering means SeqCst
(_, name) if name.starts_with("atomic_") => {
let split: Vec<&str> = name.split('_').collect();
let (order, failorder) = match split.len() {
2 => (llvm::SequentiallyConsistent, llvm::SequentiallyConsistent),
3 => match split[2] {
"unordered" => (llvm::Unordered, llvm::Unordered),
"relaxed" => (llvm::Monotonic, llvm::Monotonic),
"acq" => (llvm::Acquire, llvm::Acquire),
"rel" => (llvm::Release, llvm::Monotonic),
"acqrel" => (llvm::AcquireRelease, llvm::Acquire),
"failrelaxed" if split[1] == "cxchg" || split[1] == "cxchgweak" =>
(llvm::SequentiallyConsistent, llvm::Monotonic),
"failacq" if split[1] == "cxchg" || split[1] == "cxchgweak" =>
(llvm::SequentiallyConsistent, llvm::Acquire),
_ => ccx.sess().fatal("unknown ordering in atomic intrinsic")
},
4 => match (split[2], split[3]) {
("acq", "failrelaxed") if split[1] == "cxchg" || split[1] == "cxchgweak" =>
(llvm::Acquire, llvm::Monotonic),
("acqrel", "failrelaxed") if split[1] == "cxchg" || split[1] == "cxchgweak" =>
(llvm::AcquireRelease, llvm::Monotonic),
_ => ccx.sess().fatal("unknown ordering in atomic intrinsic")
},
_ => ccx.sess().fatal("Atomic intrinsic not in correct format"),
};
match split[1] {
"cxchg" => {
let tp_ty = *substs.types.get(FnSpace, 0);
let ptr = to_arg_ty_ptr(bcx, llargs[0], tp_ty);
let cmp = from_arg_ty(bcx, llargs[1], tp_ty);
let src = from_arg_ty(bcx, llargs[2], tp_ty);
let res = AtomicCmpXchg(bcx, ptr, cmp, src, order, failorder, llvm::False);
ExtractValue(bcx, res, 0)
}
"cxchgweak" => {
let tp_ty = *substs.types.get(FnSpace, 0);
let ptr = to_arg_ty_ptr(bcx, llargs[0], tp_ty);
let cmp = from_arg_ty(bcx, llargs[1], tp_ty);
let src = from_arg_ty(bcx, llargs[2], tp_ty);
let val = AtomicCmpXchg(bcx, ptr, cmp, src, order, failorder, llvm::True);
let result = ExtractValue(bcx, val, 0);
let success = ZExt(bcx, ExtractValue(bcx, val, 1), Type::bool(bcx.ccx()));
Store(bcx, result, StructGEP(bcx, llresult, 0));
Store(bcx, success, StructGEP(bcx, llresult, 1));
C_nil(ccx)
}
"load" => {
let tp_ty = *substs.types.get(FnSpace, 0);
let ptr = to_arg_ty_ptr(bcx, llargs[0], tp_ty);
to_arg_ty(bcx, AtomicLoad(bcx, ptr, order), tp_ty)
}
"store" => {
let tp_ty = *substs.types.get(FnSpace, 0);
let ptr = to_arg_ty_ptr(bcx, llargs[0], tp_ty);
let val = from_arg_ty(bcx, llargs[1], tp_ty);
AtomicStore(bcx, val, ptr, order);
C_nil(ccx)
}
"fence" => {
AtomicFence(bcx, order, llvm::CrossThread);
C_nil(ccx)
}
"singlethreadfence" => {
AtomicFence(bcx, order, llvm::SingleThread);
C_nil(ccx)
}
// These are all AtomicRMW ops
op => {
let atom_op = match op {
"xchg" => llvm::AtomicXchg,
"xadd" => llvm::AtomicAdd,
"xsub" => llvm::AtomicSub,
"and" => llvm::AtomicAnd,
"nand" => llvm::AtomicNand,
"or" => llvm::AtomicOr,
"xor" => llvm::AtomicXor,
"max" => llvm::AtomicMax,
"min" => llvm::AtomicMin,
"umax" => llvm::AtomicUMax,
"umin" => llvm::AtomicUMin,
_ => ccx.sess().fatal("unknown atomic operation")
};
let tp_ty = *substs.types.get(FnSpace, 0);
let ptr = to_arg_ty_ptr(bcx, llargs[0], tp_ty);
let val = from_arg_ty(bcx, llargs[1], tp_ty);
AtomicRMW(bcx, atom_op, ptr, val, order)
}
}
}
(_, _) => {
let intr = match Intrinsic::find(tcx, &name) {
Some(intr) => intr,
None => ccx.sess().span_bug(foreign_item.span,
&format!("unknown intrinsic '{}'", name)),
};
fn one<T>(x: Vec<T>) -> T {
assert_eq!(x.len(), 1);
x.into_iter().next().unwrap()
}
fn ty_to_type(ccx: &CrateContext, t: &intrinsics::Type,
any_changes_needed: &mut bool) -> Vec<Type> {
use intrinsics::Type::*;
match *t {
Void => vec![Type::void(ccx)],
Integer(_signed, width, llvm_width) => {
*any_changes_needed |= width != llvm_width;
vec![Type::ix(ccx, llvm_width as u64)]
}
Float(x) => {
match x {
32 => vec![Type::f32(ccx)],
64 => vec![Type::f64(ccx)],
_ => unreachable!()
}
}
Pointer(ref t, ref llvm_elem, _const) => {
*any_changes_needed |= llvm_elem.is_some();
let t = llvm_elem.as_ref().unwrap_or(t);
let elem = one(ty_to_type(ccx, t,
any_changes_needed));
vec![elem.ptr_to()]
}
Vector(ref t, ref llvm_elem, length) => {
*any_changes_needed |= llvm_elem.is_some();
let t = llvm_elem.as_ref().unwrap_or(t);
let elem = one(ty_to_type(ccx, t,
any_changes_needed));
vec![Type::vector(&elem,
length as u64)]
}
Aggregate(false, ref contents) => {
let elems = contents.iter()
.map(|t| one(ty_to_type(ccx, t, any_changes_needed)))
.collect::<Vec<_>>();
vec![Type::struct_(ccx, &elems, false)]
}
Aggregate(true, ref contents) => {
*any_changes_needed = true;
contents.iter()
.flat_map(|t| ty_to_type(ccx, t, any_changes_needed))
.collect()
}
}
}
// This allows an argument list like `foo, (bar, baz),
// qux` to be converted into `foo, bar, baz, qux`, integer
// arguments to be truncated as needed and pointers to be
// cast.
fn modify_as_needed<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
t: &intrinsics::Type,
arg_type: Ty<'tcx>,
llarg: ValueRef)
-> Vec<ValueRef>
{
match *t {
intrinsics::Type::Aggregate(true, ref contents) => {
// We found a tuple that needs squishing! So
// run over the tuple and load each field.
//
// This assumes the type is "simple", i.e. no
// destructors, and the contents are SIMD
// etc.
assert!(!bcx.fcx.type_needs_drop(arg_type));
let repr = adt::represent_type(bcx.ccx(), arg_type);
let repr_ptr = &repr;
let arg = adt::MaybeSizedValue::sized(llarg);
(0..contents.len())
.map(|i| {
Load(bcx, adt::trans_field_ptr(bcx, repr_ptr, arg, Disr(0), i))
})
.collect()
}
intrinsics::Type::Pointer(_, Some(ref llvm_elem), _) => {
let llvm_elem = one(ty_to_type(bcx.ccx(), llvm_elem, &mut false));
vec![PointerCast(bcx, llarg,
llvm_elem.ptr_to())]
}
intrinsics::Type::Vector(_, Some(ref llvm_elem), length) => {
let llvm_elem = one(ty_to_type(bcx.ccx(), llvm_elem, &mut false));
vec![BitCast(bcx, llarg,
Type::vector(&llvm_elem, length as u64))]
}
intrinsics::Type::Integer(_, width, llvm_width) if width != llvm_width => {
// the LLVM intrinsic uses a smaller integer
// size than the C intrinsic's signature, so
// we have to trim it down here.
vec![Trunc(bcx, llarg, Type::ix(bcx.ccx(), llvm_width as u64))]
}
_ => vec![llarg],
}
}
let mut any_changes_needed = false;
let inputs = intr.inputs.iter()
.flat_map(|t| ty_to_type(ccx, t, &mut any_changes_needed))
.collect::<Vec<_>>();
let mut out_changes = false;
let outputs = one(ty_to_type(ccx, &intr.output, &mut out_changes));
// outputting a flattened aggregate is nonsense
assert!(!out_changes);
let llargs = if !any_changes_needed {
// no aggregates to flatten, so no change needed
llargs
} else {
// there are some aggregates that need to be flattened
// in the LLVM call, so we need to run over the types
// again to find them and extract the arguments
intr.inputs.iter()
.zip(&llargs)
.zip(&arg_tys)
.flat_map(|((t, llarg), ty)| modify_as_needed(bcx, t, ty, *llarg))
.collect()
};
assert_eq!(inputs.len(), llargs.len());
let val = match intr.definition {
intrinsics::IntrinsicDef::Named(name) => {
let f = declare::declare_cfn(ccx,
name,
Type::func(&inputs, &outputs),
tcx.mk_nil());
Call(bcx, f, &llargs, None, call_debug_location)
}
};
match intr.output {
intrinsics::Type::Aggregate(flatten, ref elems) => {
// the output is a tuple so we need to munge it properly
assert!(!flatten);
for i in 0..elems.len() {
let val = ExtractValue(bcx, val, i);
Store(bcx, val, StructGEP(bcx, llresult, i));
}
C_nil(ccx)
}
_ => val,
}
}
};
if val_ty(llval) != Type::void(ccx) &&
machine::llsize_of_alloc(ccx, val_ty(llval)) != 0 {
store_ty(bcx, llval, llresult, ret_ty);
}
// If we made a temporary stack slot, let's clean it up
match dest {
expr::Ignore => {
bcx = glue::drop_ty(bcx, llresult, ret_ty, call_debug_location);
call_lifetime_end(bcx, llresult);
}
expr::SaveIn(_) => {}
}
fcx.pop_and_trans_custom_cleanup_scope(bcx, cleanup_scope);
Result::new(bcx, llresult)
}
fn copy_intrinsic<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
allow_overlap: bool,
volatile: bool,
tp_ty: Ty<'tcx>,
dst: ValueRef,
src: ValueRef,
count: ValueRef,
call_debug_location: DebugLoc)
-> ValueRef {
let ccx = bcx.ccx();
let lltp_ty = type_of::type_of(ccx, tp_ty);
let align = C_i32(ccx, type_of::align_of(ccx, tp_ty) as i32);
let size = machine::llsize_of(ccx, lltp_ty);
let int_size = machine::llbitsize_of_real(ccx, ccx.int_type());
let operation = if allow_overlap {
"memmove"
} else {
"memcpy"
};
let name = format!("llvm.{}.p0i8.p0i8.i{}", operation, int_size);
let dst_ptr = PointerCast(bcx, dst, Type::i8p(ccx));
let src_ptr = PointerCast(bcx, src, Type::i8p(ccx));
let llfn = ccx.get_intrinsic(&name);
Call(bcx,
llfn,
&[dst_ptr,
src_ptr,
Mul(bcx, size, count, DebugLoc::None),
align,
C_bool(ccx, volatile)],
None,
call_debug_location)
}
fn memset_intrinsic<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
volatile: bool,
tp_ty: Ty<'tcx>,
dst: ValueRef,
val: ValueRef,
count: ValueRef,
call_debug_location: DebugLoc)
-> ValueRef {
let ccx = bcx.ccx();
let lltp_ty = type_of::type_of(ccx, tp_ty);
let align = C_i32(ccx, type_of::align_of(ccx, tp_ty) as i32);
let size = machine::llsize_of(ccx, lltp_ty);
let int_size = machine::llbitsize_of_real(ccx, ccx.int_type());
let name = format!("llvm.memset.p0i8.i{}", int_size);
let dst_ptr = PointerCast(bcx, dst, Type::i8p(ccx));
let llfn = ccx.get_intrinsic(&name);
Call(bcx,
llfn,
&[dst_ptr,
val,
Mul(bcx, size, count, DebugLoc::None),
align,
C_bool(ccx, volatile)],
None,
call_debug_location)
}
fn count_zeros_intrinsic(bcx: Block,
name: &str,
val: ValueRef,
call_debug_location: DebugLoc)
-> ValueRef {
let y = C_bool(bcx.ccx(), false);
let llfn = bcx.ccx().get_intrinsic(&name);
Call(bcx, llfn, &[val, y], None, call_debug_location)
}
fn with_overflow_intrinsic<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
name: &str,
a: ValueRef,
b: ValueRef,
out: ValueRef,
call_debug_location: DebugLoc)
-> ValueRef {
let llfn = bcx.ccx().get_intrinsic(&name);
// Convert `i1` to a `bool`, and write it to the out parameter
let val = Call(bcx, llfn, &[a, b], None, call_debug_location);
let result = ExtractValue(bcx, val, 0);
let overflow = ZExt(bcx, ExtractValue(bcx, val, 1), Type::bool(bcx.ccx()));
Store(bcx, result, StructGEP(bcx, out, 0));
Store(bcx, overflow, StructGEP(bcx, out, 1));
C_nil(bcx.ccx())
}
fn try_intrinsic<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
func: ValueRef,
data: ValueRef,
local_ptr: ValueRef,
dest: ValueRef,
dloc: DebugLoc) -> Block<'blk, 'tcx> {
if bcx.sess().no_landing_pads() {
Call(bcx, func, &[data], None, dloc);
Store(bcx, C_null(Type::i8p(bcx.ccx())), dest);
bcx
} else if wants_msvc_seh(bcx.sess()) {
trans_msvc_try(bcx, func, data, local_ptr, dest, dloc)
} else {
trans_gnu_try(bcx, func, data, local_ptr, dest, dloc)
}
}
// MSVC's definition of the `rust_try` function.
//
// This implementation uses the new exception handling instructions in LLVM
// which have support in LLVM for SEH on MSVC targets. Although these
// instructions are meant to work for all targets, as of the time of this
// writing, however, LLVM does not recommend the usage of these new instructions
// as the old ones are still more optimized.
fn trans_msvc_try<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
func: ValueRef,
data: ValueRef,
local_ptr: ValueRef,
dest: ValueRef,
dloc: DebugLoc) -> Block<'blk, 'tcx> {
let llfn = get_rust_try_fn(bcx.fcx, &mut |bcx| {
let ccx = bcx.ccx();
let dloc = DebugLoc::None;
SetPersonalityFn(bcx, bcx.fcx.eh_personality());
let normal = bcx.fcx.new_temp_block("normal");
let catchswitch = bcx.fcx.new_temp_block("catchswitch");
let catchpad = bcx.fcx.new_temp_block("catchpad");
let caught = bcx.fcx.new_temp_block("caught");
let func = llvm::get_param(bcx.fcx.llfn, 0);
let data = llvm::get_param(bcx.fcx.llfn, 1);
let local_ptr = llvm::get_param(bcx.fcx.llfn, 2);
// We're generating an IR snippet that looks like:
//
// declare i32 @rust_try(%func, %data, %ptr) {
// %slot = alloca i8*
// call @llvm.localescape(%slot)
// store %ptr, %slot
// invoke %func(%data) to label %normal unwind label %catchswitch
//
// normal:
// ret i32 0
//
// catchswitch:
// %cs = catchswitch within none [%catchpad] unwind to caller
//
// catchpad:
// %tok = catchpad within %cs [%rust_try_filter]
// catchret from %tok to label %caught
//
// caught:
// ret i32 1
// }
//
// This structure follows the basic usage of the instructions in LLVM
// (see their documentation/test cases for examples), but a
// perhaps-surprising part here is the usage of the `localescape`
// intrinsic. This is used to allow the filter function (also generated
// here) to access variables on the stack of this intrinsic. This
// ability enables us to transfer information about the exception being
// thrown to this point, where we're catching the exception.
//
// More information can be found in libstd's seh.rs implementation.
let slot = Alloca(bcx, Type::i8p(ccx), "slot");
let localescape = ccx.get_intrinsic(&"llvm.localescape");
Call(bcx, localescape, &[slot], None, dloc);
Store(bcx, local_ptr, slot);
Invoke(bcx, func, &[data], normal.llbb, catchswitch.llbb, None, dloc);
Ret(normal, C_i32(ccx, 0), dloc);
let cs = CatchSwitch(catchswitch, None, None, 1);
AddHandler(catchswitch, cs, catchpad.llbb);
let filter = generate_filter_fn(bcx.fcx, bcx.fcx.llfn);
let filter = BitCast(catchpad, filter, Type::i8p(ccx));
let tok = CatchPad(catchpad, cs, &[filter]);
CatchRet(catchpad, tok, caught.llbb);
Ret(caught, C_i32(ccx, 1), dloc);
});
// Note that no invoke is used here because by definition this function
// can't panic (that's what it's catching).
let ret = Call(bcx, llfn, &[func, data, local_ptr], None, dloc);
Store(bcx, ret, dest);
return bcx
}
// Definition of the standard "try" function for Rust using the GNU-like model
// of exceptions (e.g. the normal semantics of LLVM's landingpad and invoke
// instructions).
//
// This translation is a little surprising because we always call a shim
// function instead of inlining the call to `invoke` manually here. This is done
// because in LLVM we're only allowed to have one personality per function
// definition. The call to the `try` intrinsic is being inlined into the
// function calling it, and that function may already have other personality
// functions in play. By calling a shim we're guaranteed that our shim will have
// the right personality function.
fn trans_gnu_try<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
func: ValueRef,
data: ValueRef,
local_ptr: ValueRef,
dest: ValueRef,
dloc: DebugLoc) -> Block<'blk, 'tcx> {
let llfn = get_rust_try_fn(bcx.fcx, &mut |bcx| {
let ccx = bcx.ccx();
let dloc = DebugLoc::None;
// Translates the shims described above:
//
// bcx:
// invoke %func(%args...) normal %normal unwind %catch
//
// normal:
// ret 0
//
// catch:
// (ptr, _) = landingpad
// store ptr, %local_ptr
// ret 1
//
// Note that the `local_ptr` data passed into the `try` intrinsic is
// expected to be `*mut *mut u8` for this to actually work, but that's
// managed by the standard library.
attributes::emit_uwtable(bcx.fcx.llfn, true);
let catch_pers = match bcx.tcx().lang_items.eh_personality_catch() {
Some(did) => callee::trans_fn_ref(ccx, did, ExprId(0),
bcx.fcx.param_substs).val,
None => bcx.tcx().sess.bug("eh_personality_catch not defined"),
};
let then = bcx.fcx.new_temp_block("then");
let catch = bcx.fcx.new_temp_block("catch");
let func = llvm::get_param(bcx.fcx.llfn, 0);
let data = llvm::get_param(bcx.fcx.llfn, 1);
let local_ptr = llvm::get_param(bcx.fcx.llfn, 2);
Invoke(bcx, func, &[data], then.llbb, catch.llbb, None, dloc);
Ret(then, C_i32(ccx, 0), dloc);
// Type indicator for the exception being thrown.
//
// The first value in this tuple is a pointer to the exception object
// being thrown. The second value is a "selector" indicating which of
// the landing pad clauses the exception's type had been matched to.
// rust_try ignores the selector.
let lpad_ty = Type::struct_(ccx, &[Type::i8p(ccx), Type::i32(ccx)],
false);
let vals = LandingPad(catch, lpad_ty, catch_pers, 1);
AddClause(catch, vals, C_null(Type::i8p(ccx)));
let ptr = ExtractValue(catch, vals, 0);
Store(catch, ptr, BitCast(catch, local_ptr, Type::i8p(ccx).ptr_to()));
Ret(catch, C_i32(ccx, 1), dloc);
});
// Note that no invoke is used here because by definition this function
// can't panic (that's what it's catching).
let ret = Call(bcx, llfn, &[func, data, local_ptr], None, dloc);
Store(bcx, ret, dest);
return bcx;
}
// Helper function to give a Block to a closure to translate a shim function.
// This is currently primarily used for the `try` intrinsic functions above.
fn gen_fn<'a, 'tcx>(fcx: &FunctionContext<'a, 'tcx>,
name: &str,
ty: Ty<'tcx>,
output: ty::FnOutput<'tcx>,
trans: &mut for<'b> FnMut(Block<'b, 'tcx>))
-> ValueRef {
let ccx = fcx.ccx;
let llfn = declare::define_internal_rust_fn(ccx, name, ty);
let (fcx, block_arena);
block_arena = TypedArena::new();
fcx = new_fn_ctxt(ccx, llfn, ast::DUMMY_NODE_ID, false,
output, ccx.tcx().mk_substs(Substs::trans_empty()),
None, &block_arena);
let bcx = init_function(&fcx, true, output);
trans(bcx);
fcx.cleanup();
return llfn
}
// Helper function used to get a handle to the `__rust_try` function used to
// catch exceptions.
//
// This function is only generated once and is then cached.
fn get_rust_try_fn<'a, 'tcx>(fcx: &FunctionContext<'a, 'tcx>,
trans: &mut for<'b> FnMut(Block<'b, 'tcx>))
-> ValueRef {
let ccx = fcx.ccx;
if let Some(llfn) = *ccx.rust_try_fn().borrow() {
return llfn
}
// Define the type up front for the signature of the rust_try function.
let tcx = ccx.tcx();
let i8p = tcx.mk_mut_ptr(tcx.types.i8);
let fn_ty = tcx.mk_fn_ptr(ty::BareFnTy {
unsafety: hir::Unsafety::Unsafe,
abi: Abi::Rust,
sig: ty::Binder(ty::FnSig {
inputs: vec![i8p],
output: ty::FnOutput::FnConverging(tcx.mk_nil()),
variadic: false,
}),
});
let output = ty::FnOutput::FnConverging(tcx.types.i32);
let try_fn_ty = ty::BareFnTy {
unsafety: hir::Unsafety::Unsafe,
abi: Abi::Rust,
sig: ty::Binder(ty::FnSig {
inputs: vec![fn_ty, i8p, i8p],
output: output,
variadic: false,
}),
};
let rust_try = gen_fn(fcx, "__rust_try", tcx.mk_fn_ptr(try_fn_ty), output,
trans);
*ccx.rust_try_fn().borrow_mut() = Some(rust_try);
return rust_try
}
// For MSVC-style exceptions (SEH), the compiler generates a filter function
// which is used to determine whether an exception is being caught (e.g. if it's
// a Rust exception or some other).
//
// This function is used to generate said filter function. The shim generated
// here is actually just a thin wrapper to call the real implementation in the
// standard library itself. For reasons as to why, see seh.rs in the standard
// library.
fn generate_filter_fn<'a, 'tcx>(fcx: &FunctionContext<'a, 'tcx>,
rust_try_fn: ValueRef)
-> ValueRef {
let ccx = fcx.ccx;
let tcx = ccx.tcx();
let dloc = DebugLoc::None;
let rust_try_filter = match ccx.tcx().lang_items.msvc_try_filter() {
Some(did) => callee::trans_fn_ref(ccx, did, ExprId(0),
fcx.param_substs).val,
None => ccx.sess().bug("msvc_try_filter not defined"),
};
let output = ty::FnOutput::FnConverging(tcx.types.i32);
let i8p = tcx.mk_mut_ptr(tcx.types.i8);
let frameaddress = ccx.get_intrinsic(&"llvm.frameaddress");
let recoverfp = ccx.get_intrinsic(&"llvm.x86.seh.recoverfp");
let localrecover = ccx.get_intrinsic(&"llvm.localrecover");
// On all platforms, once we have the EXCEPTION_POINTERS handle as well as
// the base pointer, we follow the standard layout of:
//
// block:
// %parentfp = call i8* llvm.x86.seh.recoverfp(@rust_try_fn, %bp)
// %arg = call i8* llvm.localrecover(@rust_try_fn, %parentfp, 0)
// %ret = call i32 @the_real_filter_function(%ehptrs, %arg)
// ret i32 %ret
//
// The recoverfp intrinsic is used to recover the frame frame pointer of the
// `rust_try_fn` function, which is then in turn passed to the
// `localrecover` intrinsic (pairing with the `localescape` intrinsic
// mentioned above). Putting all this together means that we now have a
// handle to the arguments passed into the `try` function, allowing writing
// to the stack over there.
//
// For more info, see seh.rs in the standard library.
let do_trans = |bcx: Block, ehptrs, base_pointer| {
let rust_try_fn = BitCast(bcx, rust_try_fn, Type::i8p(ccx));
let parentfp = Call(bcx, recoverfp, &[rust_try_fn, base_pointer],
None, dloc);
let arg = Call(bcx, localrecover,
&[rust_try_fn, parentfp, C_i32(ccx, 0)], None, dloc);
let ret = Call(bcx, rust_try_filter, &[ehptrs, arg], None, dloc);
Ret(bcx, ret, dloc);
};
if ccx.tcx().sess.target.target.arch == "x86" {
// On x86 the filter function doesn't actually receive any arguments.
// Instead the %ebp register contains some contextual information.
//
// Unfortunately I don't know of any great documentation as to what's
// going on here, all I can say is that there's a few tests cases in
// LLVM's test suite which follow this pattern of instructions, so we
// just do the same.
let filter_fn_ty = tcx.mk_fn_ptr(ty::BareFnTy {
unsafety: hir::Unsafety::Unsafe,
abi: Abi::Rust,
sig: ty::Binder(ty::FnSig {
inputs: vec![],
output: output,
variadic: false,
}),
});
gen_fn(fcx, "__rustc_try_filter", filter_fn_ty, output, &mut |bcx| {
let ebp = Call(bcx, frameaddress, &[C_i32(ccx, 1)], None, dloc);
let exn = InBoundsGEP(bcx, ebp, &[C_i32(ccx, -20)]);
let exn = Load(bcx, BitCast(bcx, exn, Type::i8p(ccx).ptr_to()));
do_trans(bcx, exn, ebp);
})
} else if ccx.tcx().sess.target.target.arch == "x86_64" {
// Conveniently on x86_64 the EXCEPTION_POINTERS handle and base pointer
// are passed in as arguments to the filter function, so we just pass
// those along.
let filter_fn_ty = tcx.mk_fn_ptr(ty::BareFnTy {
unsafety: hir::Unsafety::Unsafe,
abi: Abi::Rust,
sig: ty::Binder(ty::FnSig {
inputs: vec![i8p, i8p],
output: output,
variadic: false,
}),
});
gen_fn(fcx, "__rustc_try_filter", filter_fn_ty, output, &mut |bcx| {
let exn = llvm::get_param(bcx.fcx.llfn, 0);
let rbp = llvm::get_param(bcx.fcx.llfn, 1);
do_trans(bcx, exn, rbp);
})
} else {
panic!("unknown target to generate a filter function")
}
}
fn span_invalid_monomorphization_error(a: &Session, b: Span, c: &str) {
span_err!(a, b, E0511, "{}", c);
}
fn generic_simd_intrinsic<'blk, 'tcx, 'a>
(bcx: Block<'blk, 'tcx>,
name: &str,
substs: &'tcx subst::Substs<'tcx>,
callee_ty: Ty<'tcx>,
args: Option<&[P<hir::Expr>]>,
llargs: &[ValueRef],
ret_ty: Ty<'tcx>,
llret_ty: Type,
call_debug_location: DebugLoc,
call_info: NodeIdAndSpan) -> ValueRef
{
// macros for error handling:
macro_rules! emit_error {
($msg: tt) => {
emit_error!($msg, )
};
($msg: tt, $($fmt: tt)*) => {
span_invalid_monomorphization_error(
bcx.sess(), call_info.span,
&format!(concat!("invalid monomorphization of `{}` intrinsic: ",
$msg),
name, $($fmt)*));
}
}
macro_rules! require {
($cond: expr, $($fmt: tt)*) => {
if !$cond {
emit_error!($($fmt)*);
return C_null(llret_ty)
}
}
}
macro_rules! require_simd {
($ty: expr, $position: expr) => {
require!($ty.is_simd(), "expected SIMD {} type, found non-SIMD `{}`", $position, $ty)
}
}
let tcx = bcx.tcx();
let sig = tcx.erase_late_bound_regions(callee_ty.fn_sig());
let sig = infer::normalize_associated_type(tcx, &sig);
let arg_tys = sig.inputs;
// every intrinsic takes a SIMD vector as its first argument
require_simd!(arg_tys[0], "input");
let in_ty = arg_tys[0];
let in_elem = arg_tys[0].simd_type(tcx);
let in_len = arg_tys[0].simd_size(tcx);
let comparison = match name {
"simd_eq" => Some(hir::BiEq),
"simd_ne" => Some(hir::BiNe),
"simd_lt" => Some(hir::BiLt),
"simd_le" => Some(hir::BiLe),
"simd_gt" => Some(hir::BiGt),
"simd_ge" => Some(hir::BiGe),
_ => None
};
if let Some(cmp_op) = comparison {
require_simd!(ret_ty, "return");
let out_len = ret_ty.simd_size(tcx);
require!(in_len == out_len,
"expected return type with length {} (same as input type `{}`), \
found `{}` with length {}",
in_len, in_ty,
ret_ty, out_len);
require!(llret_ty.element_type().kind() == llvm::Integer,
"expected return type with integer elements, found `{}` with non-integer `{}`",
ret_ty,
ret_ty.simd_type(tcx));
return compare_simd_types(bcx,
llargs[0],
llargs[1],
in_elem,
llret_ty,
cmp_op,
call_debug_location)
}
if name.starts_with("simd_shuffle") {
let n: usize = match name["simd_shuffle".len()..].parse() {
Ok(n) => n,
Err(_) => tcx.sess.span_bug(call_info.span,
"bad `simd_shuffle` instruction only caught in trans?")
};
require_simd!(ret_ty, "return");
let out_len = ret_ty.simd_size(tcx);
require!(out_len == n,
"expected return type of length {}, found `{}` with length {}",
n, ret_ty, out_len);
require!(in_elem == ret_ty.simd_type(tcx),
"expected return element type `{}` (element of input `{}`), \
found `{}` with element type `{}`",
in_elem, in_ty,
ret_ty, ret_ty.simd_type(tcx));
let total_len = in_len as u64 * 2;
let vector = match args {
Some(args) => &args[2],
None => bcx.sess().span_bug(call_info.span,
"intrinsic call with unexpected argument shape"),
};
let vector = match consts::const_expr(bcx.ccx(), vector, substs, None,
consts::TrueConst::Yes, // this should probably help simd error reporting
) {
Ok((vector, _)) => vector,
Err(err) => bcx.sess().span_fatal(call_info.span, &err.description()),
};
let indices: Option<Vec<_>> = (0..n)
.map(|i| {
let arg_idx = i;
let val = const_get_elt(bcx.ccx(), vector, &[i as libc::c_uint]);
let c = const_to_opt_uint(val);
match c {
None => {
emit_error!("shuffle index #{} is not a constant", arg_idx);
None
}
Some(idx) if idx >= total_len => {
emit_error!("shuffle index #{} is out of bounds (limit {})",
arg_idx, total_len);
None
}
Some(idx) => Some(C_i32(bcx.ccx(), idx as i32)),
}
})
.collect();
let indices = match indices {
Some(i) => i,
None => return C_null(llret_ty)
};
return ShuffleVector(bcx, llargs[0], llargs[1], C_vector(&indices))
}
if name == "simd_insert" {
require!(in_elem == arg_tys[2],
"expected inserted type `{}` (element of input `{}`), found `{}`",
in_elem, in_ty, arg_tys[2]);
return InsertElement(bcx, llargs[0], llargs[2], llargs[1])
}
if name == "simd_extract" {
require!(ret_ty == in_elem,
"expected return type `{}` (element of input `{}`), found `{}`",
in_elem, in_ty, ret_ty);
return ExtractElement(bcx, llargs[0], llargs[1])
}
if name == "simd_cast" {
require_simd!(ret_ty, "return");
let out_len = ret_ty.simd_size(tcx);
require!(in_len == out_len,
"expected return type with length {} (same as input type `{}`), \
found `{}` with length {}",
in_len, in_ty,
ret_ty, out_len);
// casting cares about nominal type, not just structural type
let out_elem = ret_ty.simd_type(tcx);
if in_elem == out_elem { return llargs[0]; }
enum Style { Float, Int(/* is signed? */ bool), Unsupported }
let (in_style, in_width) = match in_elem.sty {
// vectors of pointer-sized integers should've been
// disallowed before here, so this unwrap is safe.
ty::TyInt(i) => (Style::Int(true), i.bit_width().unwrap()),
ty::TyUint(u) => (Style::Int(false), u.bit_width().unwrap()),
ty::TyFloat(f) => (Style::Float, f.bit_width()),
_ => (Style::Unsupported, 0)
};
let (out_style, out_width) = match out_elem.sty {
ty::TyInt(i) => (Style::Int(true), i.bit_width().unwrap()),
ty::TyUint(u) => (Style::Int(false), u.bit_width().unwrap()),
ty::TyFloat(f) => (Style::Float, f.bit_width()),
_ => (Style::Unsupported, 0)
};
match (in_style, out_style) {
(Style::Int(in_is_signed), Style::Int(_)) => {
return match in_width.cmp(&out_width) {
Ordering::Greater => Trunc(bcx, llargs[0], llret_ty),
Ordering::Equal => llargs[0],
Ordering::Less => if in_is_signed {
SExt(bcx, llargs[0], llret_ty)
} else {
ZExt(bcx, llargs[0], llret_ty)
}
}
}
(Style::Int(in_is_signed), Style::Float) => {
return if in_is_signed {
SIToFP(bcx, llargs[0], llret_ty)
} else {
UIToFP(bcx, llargs[0], llret_ty)
}
}
(Style::Float, Style::Int(out_is_signed)) => {
return if out_is_signed {
FPToSI(bcx, llargs[0], llret_ty)
} else {
FPToUI(bcx, llargs[0], llret_ty)
}
}
(Style::Float, Style::Float) => {
return match in_width.cmp(&out_width) {
Ordering::Greater => FPTrunc(bcx, llargs[0], llret_ty),
Ordering::Equal => llargs[0],
Ordering::Less => FPExt(bcx, llargs[0], llret_ty)
}
}
_ => {/* Unsupported. Fallthrough. */}
}
require!(false,
"unsupported cast from `{}` with element `{}` to `{}` with element `{}`",
in_ty, in_elem,
ret_ty, out_elem);
}
macro_rules! arith {
($($name: ident: $($($p: ident),* => $call: expr),*;)*) => {
$(
if name == stringify!($name) {
match in_elem.sty {
$(
$(ty::$p(_))|* => {
return $call(bcx, llargs[0], llargs[1], call_debug_location)
}
)*
_ => {},
}
require!(false,
"unsupported operation on `{}` with element `{}`",
in_ty,
in_elem)
})*
}
}
arith! {
simd_add: TyUint, TyInt => Add, TyFloat => FAdd;
simd_sub: TyUint, TyInt => Sub, TyFloat => FSub;
simd_mul: TyUint, TyInt => Mul, TyFloat => FMul;
simd_div: TyFloat => FDiv;
simd_shl: TyUint, TyInt => Shl;
simd_shr: TyUint => LShr, TyInt => AShr;
simd_and: TyUint, TyInt => And;
simd_or: TyUint, TyInt => Or;
simd_xor: TyUint, TyInt => Xor;
}
bcx.sess().span_bug(call_info.span, "unknown SIMD intrinsic");
}
// Returns the width of an int TypeVariant, and if it's signed or not
// Returns None if the type is not an integer
fn int_type_width_signed<'tcx>(sty: &ty::TypeVariants<'tcx>, ccx: &CrateContext)
-> Option<(u64, bool)> {
use rustc::middle::ty::{TyInt, TyUint};
match *sty {
TyInt(t) => Some((match t {
ast::IntTy::Is => {
match &ccx.tcx().sess.target.target.target_pointer_width[..] {
"32" => 32,
"64" => 64,
tws => panic!("Unsupported target word size for isize: {}", tws),
}
},
ast::IntTy::I8 => 8,
ast::IntTy::I16 => 16,
ast::IntTy::I32 => 32,
ast::IntTy::I64 => 64,
}, true)),
TyUint(t) => Some((match t {
ast::UintTy::Us => {
match &ccx.tcx().sess.target.target.target_pointer_width[..] {
"32" => 32,
"64" => 64,
tws => panic!("Unsupported target word size for usize: {}", tws),
}
},
ast::UintTy::U8 => 8,
ast::UintTy::U16 => 16,
ast::UintTy::U32 => 32,
ast::UintTy::U64 => 64,
}, false)),
_ => None,
}
}