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Merge pull request #693 from bjorn3/abi_refactor

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Abi handling refactor
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bjorn3 2019-08-30 16:35:58 +02:00 committed by GitHub
commit f99b527e1c
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7 changed files with 478 additions and 385 deletions
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4
example/example.rs
View File

@ -202,3 +202,7 @@ fn get_sized_field_ref_from_unsized_type(u: &Unsized) -> &u8 {
fn get_unsized_field_ref_from_unsized_type(u: &Unsized) -> &str {
&u.1
}
pub fn reuse_byref_argument_storage(a: (u8, u16, u32)) -> u8 {
a.0
}

108
src/abi/comments.rs Normal file
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@ -0,0 +1,108 @@
use std::borrow::Cow;
use rustc::mir;
use crate::prelude::*;
use crate::abi::pass_mode::*;
pub fn add_args_header_comment(fx: &mut FunctionCx<impl Backend>) {
fx.add_global_comment(format!(
"kind loc.idx param pass mode ty"
));
}
pub fn add_arg_comment<'tcx>(
fx: &mut FunctionCx<'_, 'tcx, impl Backend>,
kind: &str,
local: mir::Local,
local_field: Option<usize>,
params: EmptySinglePair<Value>,
pass_mode: PassMode,
ty: Ty<'tcx>,
) {
let local_field = if let Some(local_field) = local_field {
Cow::Owned(format!(".{}", local_field))
} else {
Cow::Borrowed("")
};
let params = match params {
Empty => Cow::Borrowed("-"),
Single(param) => Cow::Owned(format!("= {:?}", param)),
Pair(param_a, param_b) => Cow::Owned(format!("= {:?}, {:?}", param_a, param_b)),
};
let pass_mode = format!("{:?}", pass_mode);
fx.add_global_comment(format!(
"{kind:5}{local:>3}{local_field:<5} {params:10} {pass_mode:36} {ty:?}",
kind = kind,
local = format!("{:?}", local),
local_field = local_field,
params = params,
pass_mode = pass_mode,
ty = ty,
));
}
pub fn add_locals_header_comment(fx: &mut FunctionCx<impl Backend>) {
fx.add_global_comment(String::new());
fx.add_global_comment(format!(
"kind local ty size align (abi,pref)"
));
}
pub fn add_local_place_comments<'tcx>(
fx: &mut FunctionCx<'_, 'tcx, impl Backend>,
place: CPlace<'tcx>,
local: Local,
) {
let TyLayout { ty, details } = place.layout();
let ty::layout::LayoutDetails {
size,
align,
abi: _,
variants: _,
fields: _,
largest_niche: _,
} = details;
match *place.inner() {
CPlaceInner::Var(var) => {
assert_eq!(local, var);
fx.add_global_comment(format!(
"ssa {:5} {:20} {:4}b {}, {}",
format!("{:?}", local),
format!("{:?}", ty),
size.bytes(),
align.abi.bytes(),
align.pref.bytes(),
));
}
CPlaceInner::Stack(stack_slot) => fx.add_entity_comment(
stack_slot,
format!(
"{:?}: {:?} size={} align={},{}",
local,
ty,
size.bytes(),
align.abi.bytes(),
align.pref.bytes(),
),
),
CPlaceInner::NoPlace => fx.add_global_comment(format!(
"zst {:5} {:20} {:4}b {}, {}",
format!("{:?}", local),
format!("{:?}", ty),
size.bytes(),
align.abi.bytes(),
align.pref.bytes(),
)),
CPlaceInner::Addr(addr, None) => fx.add_global_comment(format!(
"reuse {:5} {:20} {:4}b {}, {} storage={}",
format!("{:?}", local),
format!("{:?}", ty),
size.bytes(),
align.abi.bytes(),
align.pref.bytes(),
addr,
)),
CPlaceInner::Addr(_, Some(_)) => unreachable!(),
}
}

412
src/abi.rs → src/abi/mod.rs
View File

@ -1,152 +1,14 @@
use std::borrow::Cow;
#[cfg(debug_assertions)]
mod comments;
mod returning;
mod pass_mode;
use rustc::ty::layout::{FloatTy, Integer, Primitive, Scalar};
use rustc_target::spec::abi::Abi;
use crate::prelude::*;
use self::pass_mode::*;
#[derive(Copy, Clone, Debug)]
enum PassMode {
NoPass,
ByVal(Type),
ByValPair(Type, Type),
ByRef,
}
#[derive(Copy, Clone, Debug)]
enum EmptySinglePair<T> {
Empty,
Single(T),
Pair(T, T),
}
impl<T> EmptySinglePair<T> {
fn into_iter(self) -> EmptySinglePairIter<T> {
EmptySinglePairIter(self)
}
fn map<U>(self, mut f: impl FnMut(T) -> U) -> EmptySinglePair<U> {
match self {
Empty => Empty,
Single(v) => Single(f(v)),
Pair(a, b) => Pair(f(a), f(b)),
}
}
}
struct EmptySinglePairIter<T>(EmptySinglePair<T>);
impl<T> Iterator for EmptySinglePairIter<T> {
type Item = T;
fn next(&mut self) -> Option<T> {
match std::mem::replace(&mut self.0, Empty) {
Empty => None,
Single(v) => Some(v),
Pair(a, b) => {
self.0 = Single(b);
Some(a)
}
}
}
}
impl<T: std::fmt::Debug> EmptySinglePair<T> {
fn assert_single(self) -> T {
match self {
Single(v) => v,
_ => panic!("Called assert_single on {:?}", self)
}
}
fn assert_pair(self) -> (T, T) {
match self {
Pair(a, b) => (a, b),
_ => panic!("Called assert_pair on {:?}", self)
}
}
}
use EmptySinglePair::*;
impl PassMode {
fn get_param_ty(self, fx: &FunctionCx<impl Backend>) -> EmptySinglePair<Type> {
match self {
PassMode::NoPass => Empty,
PassMode::ByVal(clif_type) => Single(clif_type),
PassMode::ByValPair(a, b) => Pair(a, b),
PassMode::ByRef => Single(fx.pointer_type),
}
}
}
pub fn scalar_to_clif_type(tcx: TyCtxt, scalar: Scalar) -> Type {
match scalar.value {
Primitive::Int(int, _sign) => match int {
Integer::I8 => types::I8,
Integer::I16 => types::I16,
Integer::I32 => types::I32,
Integer::I64 => types::I64,
Integer::I128 => types::I128,
},
Primitive::Float(flt) => match flt {
FloatTy::F32 => types::F32,
FloatTy::F64 => types::F64,
},
Primitive::Pointer => pointer_ty(tcx),
}
}
fn get_pass_mode<'tcx>(
tcx: TyCtxt<'tcx>,
layout: TyLayout<'tcx>,
) -> PassMode {
assert!(!layout.is_unsized());
if layout.is_zst() {
// WARNING zst arguments must never be passed, as that will break CastKind::ClosureFnPointer
PassMode::NoPass
} else {
match &layout.abi {
layout::Abi::Uninhabited => PassMode::NoPass,
layout::Abi::Scalar(scalar) => {
PassMode::ByVal(scalar_to_clif_type(tcx, scalar.clone()))
}
layout::Abi::ScalarPair(a, b) => {
let a = scalar_to_clif_type(tcx, a.clone());
let b = scalar_to_clif_type(tcx, b.clone());
if a == types::I128 && b == types::I128 {
// Returning (i128, i128) by-val-pair would take 4 regs, while only 3 are
// available on x86_64. Cranelift gets confused when too many return params
// are used.
PassMode::ByRef
} else {
PassMode::ByValPair(a, b)
}
}
// FIXME implement Vector Abi in a cg_llvm compatible way
layout::Abi::Vector { .. } => PassMode::ByRef,
layout::Abi::Aggregate { .. } => PassMode::ByRef,
}
}
}
fn adjust_arg_for_abi<'tcx>(
fx: &mut FunctionCx<'_, 'tcx, impl Backend>,
arg: CValue<'tcx>,
) -> EmptySinglePair<Value> {
match get_pass_mode(fx.tcx, arg.layout()) {
PassMode::NoPass => Empty,
PassMode::ByVal(_) => Single(arg.load_scalar(fx)),
PassMode::ByValPair(_, _) => {
let (a, b) = arg.load_scalar_pair(fx);
Pair(a, b)
}
PassMode::ByRef => Single(arg.force_stack(fx)),
}
}
pub use self::returning::codegen_return;
fn clif_sig_from_fn_sig<'tcx>(tcx: TyCtxt<'tcx>, sig: FnSig<'tcx>, is_vtable_fn: bool) -> Signature {
let abi = match sig.abi {
@ -187,12 +49,7 @@ fn clif_sig_from_fn_sig<'tcx>(tcx: TyCtxt<'tcx>, sig: FnSig<'tcx>, is_vtable_fn:
// See https://github.com/rust-lang/rust/blob/37b6a5e5e82497caf5353d9d856e4eb5d14cbe06/src/librustc/ty/layout.rs#L2519-L2572 for more info
layout = tcx.layout_of(ParamEnv::reveal_all().and(tcx.mk_mut_ptr(tcx.mk_unit()))).unwrap();
}
match get_pass_mode(tcx, layout) {
PassMode::NoPass => Empty,
PassMode::ByVal(clif_ty) => Single(clif_ty),
PassMode::ByValPair(clif_ty_a, clif_ty_b) => Pair(clif_ty_a, clif_ty_b),
PassMode::ByRef => Single(pointer_ty(tcx)),
}.into_iter()
get_pass_mode(tcx, layout).get_param_ty(tcx).into_iter()
}).flatten();
let (params, returns) = match get_pass_mode(tcx, tcx.layout_of(ParamEnv::reveal_all().and(output)).unwrap()) {
@ -336,47 +193,6 @@ fn return_layout(&self) -> TyLayout<'tcx> {
}
}
#[cfg(debug_assertions)]
fn add_arg_comment<'tcx>(
fx: &mut FunctionCx<'_, 'tcx, impl Backend>,
msg: &str,
local: mir::Local,
local_field: Option<usize>,
params: EmptySinglePair<Value>,
pass_mode: PassMode,
ssa: crate::analyze::Flags,
ty: Ty<'tcx>,
) {
let local_field = if let Some(local_field) = local_field {
Cow::Owned(format!(".{}", local_field))
} else {
Cow::Borrowed("")
};
let params = match params {
Empty => Cow::Borrowed("-"),
Single(param) => Cow::Owned(format!("= {:?}", param)),
Pair(param_a, param_b) => Cow::Owned(format!("= {:?}, {:?}", param_a, param_b)),
};
let pass_mode = format!("{:?}", pass_mode);
fx.add_global_comment(format!(
"{msg:5} {local:>3}{local_field:<5} {params:10} {pass_mode:36} {ssa:10} {ty:?}",
msg = msg,
local = format!("{:?}", local),
local_field = local_field,
params = params,
pass_mode = pass_mode,
ssa = format!("{:?}", ssa),
ty = ty,
));
}
#[cfg(debug_assertions)]
fn add_local_header_comment(fx: &mut FunctionCx<impl Backend>) {
fx.add_global_comment(format!(
"msg loc.idx param pass mode ssa flags ty"
));
}
fn local_place<'tcx>(
fx: &mut FunctionCx<'_, 'tcx, impl Backend>,
local: Local,
@ -386,92 +202,17 @@ fn local_place<'tcx>(
let place = if is_ssa {
CPlace::new_var(fx, local, layout)
} else {
let place = CPlace::new_stack_slot(fx, layout.ty);
CPlace::new_stack_slot(fx, layout.ty)
};
#[cfg(debug_assertions)]
{
let TyLayout { ty, details } = layout;
let ty::layout::LayoutDetails {
size,
align,
abi: _,
variants: _,
fields: _,
largest_niche: _,
} = details;
match *place.inner() {
CPlaceInner::Stack(stack_slot) => fx.add_entity_comment(
stack_slot,
format!(
"{:?}: {:?} size={} align={},{}",
local,
ty,
size.bytes(),
align.abi.bytes(),
align.pref.bytes(),
),
),
CPlaceInner::NoPlace => fx.add_global_comment(format!(
"zst {:?}: {:?} size={} align={}, {}",
local,
ty,
size.bytes(),
align.abi.bytes(),
align.pref.bytes(),
)),
_ => unreachable!(),
}
}
place
};
self::comments::add_local_place_comments(fx, place, local);
let prev_place = fx.local_map.insert(local, place);
debug_assert!(prev_place.is_none());
fx.local_map[&local]
}
fn cvalue_for_param<'tcx>(
fx: &mut FunctionCx<'_, 'tcx, impl Backend>,
start_ebb: Ebb,
local: mir::Local,
local_field: Option<usize>,
arg_ty: Ty<'tcx>,
ssa_flags: crate::analyze::Flags,
) -> Option<CValue<'tcx>> {
let layout = fx.layout_of(arg_ty);
let pass_mode = get_pass_mode(fx.tcx, fx.layout_of(arg_ty));
if let PassMode::NoPass = pass_mode {
return None;
}
let clif_types = pass_mode.get_param_ty(fx);
let ebb_params = clif_types.map(|t| fx.bcx.append_ebb_param(start_ebb, t));
#[cfg(debug_assertions)]
add_arg_comment(
fx,
"arg",
local,
local_field,
ebb_params,
pass_mode,
ssa_flags,
arg_ty,
);
match pass_mode {
PassMode::NoPass => unreachable!(),
PassMode::ByVal(_) => Some(CValue::by_val(ebb_params.assert_single(), layout)),
PassMode::ByValPair(_, _) => {
let (a, b) = ebb_params.assert_pair();
Some(CValue::by_val_pair(a, b, layout))
}
PassMode::ByRef => Some(CValue::by_ref(ebb_params.assert_single(), layout)),
}
}
pub fn codegen_fn_prelude(
fx: &mut FunctionCx<'_, '_, impl Backend>,
start_ebb: Ebb,
@ -479,33 +220,9 @@ pub fn codegen_fn_prelude(
let ssa_analyzed = crate::analyze::analyze(fx);
#[cfg(debug_assertions)]
fx.add_global_comment(format!("ssa {:?}", ssa_analyzed));
self::comments::add_args_header_comment(fx);
let ret_layout = fx.return_layout();
let output_pass_mode = get_pass_mode(fx.tcx, fx.return_layout());
let ret_param = match output_pass_mode {
PassMode::NoPass | PassMode::ByVal(_) | PassMode::ByValPair(_, _) => None,
PassMode::ByRef => Some(fx.bcx.append_ebb_param(start_ebb, fx.pointer_type)),
};
#[cfg(debug_assertions)]
{
add_local_header_comment(fx);
let ret_param = match ret_param {
Some(param) => Single(param),
None => Empty,
};
add_arg_comment(
fx,
"ret",
RETURN_PLACE,
None,
ret_param,
output_pass_mode,
ssa_analyzed[&RETURN_PLACE],
ret_layout.ty,
);
}
self::returning::codegen_return_param(fx, &ssa_analyzed, start_ebb);
// None means pass_mode == NoPass
enum ArgKind<'tcx> {
@ -539,7 +256,6 @@ enum ArgKind<'tcx> {
local,
Some(i),
arg_ty,
ssa_analyzed[&local],
);
params.push(param);
}
@ -547,7 +263,7 @@ enum ArgKind<'tcx> {
(local, ArgKind::Spread(params), arg_ty)
} else {
let param =
cvalue_for_param(fx, start_ebb, local, None, arg_ty, ssa_analyzed[&local]);
cvalue_for_param(fx, start_ebb, local, None, arg_ty);
(local, ArgKind::Normal(param), arg_ty)
}
})
@ -555,26 +271,8 @@ enum ArgKind<'tcx> {
fx.bcx.switch_to_block(start_ebb);
match output_pass_mode {
PassMode::NoPass => {
fx.local_map
.insert(RETURN_PLACE, CPlace::no_place(ret_layout));
}
PassMode::ByVal(_) | PassMode::ByValPair(_, _) => {
let is_ssa = !ssa_analyzed
.get(&RETURN_PLACE)
.unwrap()
.contains(crate::analyze::Flags::NOT_SSA);
local_place(fx, RETURN_PLACE, ret_layout, is_ssa);
}
PassMode::ByRef => {
fx.local_map.insert(
RETURN_PLACE,
CPlace::for_addr(ret_param.unwrap(), ret_layout),
);
}
}
#[cfg(debug_assertions)]
self::comments::add_locals_header_comment(fx);
for (local, arg_kind, ty) in func_params {
let layout = fx.layout_of(ty);
@ -584,6 +282,34 @@ enum ArgKind<'tcx> {
.unwrap()
.contains(crate::analyze::Flags::NOT_SSA);
match arg_kind {
ArgKind::Normal(Some(val)) => {
if let Some(addr) = val.try_to_addr() {
let local_decl = &fx.mir.local_decls[local];
// v this ! is important
let internally_mutable = !val.layout().ty.is_freeze(
fx.tcx,
ParamEnv::reveal_all(),
local_decl.source_info.span,
);
if local_decl.mutability == mir::Mutability::Not && internally_mutable {
// We wont mutate this argument, so it is fine to borrow the backing storage
// of this argument, to prevent a copy.
let place = CPlace::for_addr(addr, val.layout());
#[cfg(debug_assertions)]
self::comments::add_local_place_comments(fx, place, local);
let prev_place = fx.local_map.insert(local, place);
debug_assert!(prev_place.is_none());
continue;
}
}
}
_ => {}
}
let place = local_place(fx, local, layout, is_ssa);
match arg_kind {
@ -706,18 +432,6 @@ fn codegen_call_inner<'tcx>(
) {
let fn_sig = fx.tcx.normalize_erasing_late_bound_regions(ParamEnv::reveal_all(), &fn_ty.fn_sig(fx.tcx));
let ret_layout = fx.layout_of(fn_sig.output());
let output_pass_mode = get_pass_mode(fx.tcx, fx.layout_of(fn_sig.output()));
let return_ptr = match output_pass_mode {
PassMode::NoPass => None,
PassMode::ByRef => match ret_place {
Some(ret_place) => Some(ret_place.to_addr(fx)),
None => Some(fx.bcx.ins().iconst(fx.pointer_type, 43)),
},
PassMode::ByVal(_) | PassMode::ByValPair(_, _) => None,
};
let instance = match fn_ty.sty {
ty::FnDef(def_id, substs) => {
Some(Instance::resolve(fx.tcx, ParamEnv::reveal_all(), def_id, substs).unwrap())
@ -766,6 +480,7 @@ fn codegen_call_inner<'tcx>(
}
};
let (call_inst, call_args) = self::returning::codegen_with_call_return_arg(fx, fn_sig, ret_place, |fx, return_ptr| {
let call_args: Vec<Value> = return_ptr
.into_iter()
.chain(first_arg.into_iter())
@ -787,6 +502,9 @@ fn codegen_call_inner<'tcx>(
fx.bcx.ins().call(func_ref, &call_args)
};
(call_inst, call_args)
});
// FIXME find a cleaner way to support varargs
if fn_sig.c_variadic {
if fn_sig.abi != Abi::C {
@ -806,24 +524,6 @@ fn codegen_call_inner<'tcx>(
.collect::<Vec<AbiParam>>();
fx.bcx.func.dfg.signatures[sig_ref].params = abi_params;
}
match output_pass_mode {
PassMode::NoPass => {}
PassMode::ByVal(_) => {
if let Some(ret_place) = ret_place {
let ret_val = fx.bcx.inst_results(call_inst)[0];
ret_place.write_cvalue(fx, CValue::by_val(ret_val, ret_layout));
}
}
PassMode::ByValPair(_, _) => {
if let Some(ret_place) = ret_place {
let ret_val_a = fx.bcx.inst_results(call_inst)[0];
let ret_val_b = fx.bcx.inst_results(call_inst)[1];
ret_place.write_cvalue(fx, CValue::by_val_pair(ret_val_a, ret_val_b, ret_layout));
}
}
PassMode::ByRef => {}
}
}
pub fn codegen_drop<'tcx>(
@ -875,21 +575,3 @@ pub fn codegen_drop<'tcx>(
}
}
}
pub fn codegen_return(fx: &mut FunctionCx<impl Backend>) {
match get_pass_mode(fx.tcx, fx.return_layout()) {
PassMode::NoPass | PassMode::ByRef => {
fx.bcx.ins().return_(&[]);
}
PassMode::ByVal(_) => {
let place = fx.get_local_place(RETURN_PLACE);
let ret_val = place.to_cvalue(fx).load_scalar(fx);
fx.bcx.ins().return_(&[ret_val]);
}
PassMode::ByValPair(_, _) => {
let place = fx.get_local_place(RETURN_PLACE);
let (ret_val_a, ret_val_b) = place.to_cvalue(fx).load_scalar_pair(fx);
fx.bcx.ins().return_(&[ret_val_a, ret_val_b]);
}
}
}

166
src/abi/pass_mode.rs Normal file
View File

@ -0,0 +1,166 @@
use crate::prelude::*;
#[derive(Copy, Clone, Debug)]
pub enum PassMode {
NoPass,
ByVal(Type),
ByValPair(Type, Type),
ByRef,
}
#[derive(Copy, Clone, Debug)]
pub enum EmptySinglePair<T> {
Empty,
Single(T),
Pair(T, T),
}
impl<T> EmptySinglePair<T> {
pub fn into_iter(self) -> EmptySinglePairIter<T> {
EmptySinglePairIter(self)
}
pub fn map<U>(self, mut f: impl FnMut(T) -> U) -> EmptySinglePair<U> {
match self {
Empty => Empty,
Single(v) => Single(f(v)),
Pair(a, b) => Pair(f(a), f(b)),
}
}
}
pub struct EmptySinglePairIter<T>(EmptySinglePair<T>);
impl<T> Iterator for EmptySinglePairIter<T> {
type Item = T;
fn next(&mut self) -> Option<T> {
match std::mem::replace(&mut self.0, Empty) {
Empty => None,
Single(v) => Some(v),
Pair(a, b) => {
self.0 = Single(b);
Some(a)
}
}
}
}
impl<T: std::fmt::Debug> EmptySinglePair<T> {
pub fn assert_single(self) -> T {
match self {
Single(v) => v,
_ => panic!("Called assert_single on {:?}", self)
}
}
pub fn assert_pair(self) -> (T, T) {
match self {
Pair(a, b) => (a, b),
_ => panic!("Called assert_pair on {:?}", self)
}
}
}
pub use EmptySinglePair::*;
impl PassMode {
pub fn get_param_ty(self, tcx: TyCtxt<'_>) -> EmptySinglePair<Type> {
match self {
PassMode::NoPass => Empty,
PassMode::ByVal(clif_type) => Single(clif_type),
PassMode::ByValPair(a, b) => Pair(a, b),
PassMode::ByRef => Single(pointer_ty(tcx)),
}
}
}
pub fn get_pass_mode<'tcx>(
tcx: TyCtxt<'tcx>,
layout: TyLayout<'tcx>,
) -> PassMode {
assert!(!layout.is_unsized());
if layout.is_zst() {
// WARNING zst arguments must never be passed, as that will break CastKind::ClosureFnPointer
PassMode::NoPass
} else {
match &layout.abi {
layout::Abi::Uninhabited => PassMode::NoPass,
layout::Abi::Scalar(scalar) => {
PassMode::ByVal(scalar_to_clif_type(tcx, scalar.clone()))
}
layout::Abi::ScalarPair(a, b) => {
let a = scalar_to_clif_type(tcx, a.clone());
let b = scalar_to_clif_type(tcx, b.clone());
if a == types::I128 && b == types::I128 {
// Returning (i128, i128) by-val-pair would take 4 regs, while only 3 are
// available on x86_64. Cranelift gets confused when too many return params
// are used.
PassMode::ByRef
} else {
PassMode::ByValPair(a, b)
}
}
// FIXME implement Vector Abi in a cg_llvm compatible way
layout::Abi::Vector { .. } => PassMode::ByRef,
layout::Abi::Aggregate { .. } => PassMode::ByRef,
}
}
}
pub fn adjust_arg_for_abi<'tcx>(
fx: &mut FunctionCx<'_, 'tcx, impl Backend>,
arg: CValue<'tcx>,
) -> EmptySinglePair<Value> {
match get_pass_mode(fx.tcx, arg.layout()) {
PassMode::NoPass => Empty,
PassMode::ByVal(_) => Single(arg.load_scalar(fx)),
PassMode::ByValPair(_, _) => {
let (a, b) = arg.load_scalar_pair(fx);
Pair(a, b)
}
PassMode::ByRef => Single(arg.force_stack(fx)),
}
}
pub fn cvalue_for_param<'tcx>(
fx: &mut FunctionCx<'_, 'tcx, impl Backend>,
start_ebb: Ebb,
local: mir::Local,
local_field: Option<usize>,
arg_ty: Ty<'tcx>,
) -> Option<CValue<'tcx>> {
let layout = fx.layout_of(arg_ty);
let pass_mode = get_pass_mode(fx.tcx, fx.layout_of(arg_ty));
if let PassMode::NoPass = pass_mode {
return None;
}
let clif_types = pass_mode.get_param_ty(fx.tcx);
let ebb_params = clif_types.map(|t| fx.bcx.append_ebb_param(start_ebb, t));
#[cfg(debug_assertions)]
crate::abi::comments::add_arg_comment(
fx,
"arg",
local,
local_field,
ebb_params,
pass_mode,
arg_ty,
);
match pass_mode {
PassMode::NoPass => unreachable!(),
PassMode::ByVal(_) => Some(CValue::by_val(ebb_params.assert_single(), layout)),
PassMode::ByValPair(_, _) => {
let (a, b) = ebb_params.assert_pair();
Some(CValue::by_val_pair(a, b, layout))
}
PassMode::ByRef => Some(CValue::by_ref(ebb_params.assert_single(), layout)),
}
}

108
src/abi/returning.rs Normal file
View File

@ -0,0 +1,108 @@
use crate::prelude::*;
use crate::abi::pass_mode::*;
pub fn codegen_return_param(
fx: &mut FunctionCx<impl Backend>,
ssa_analyzed: &HashMap<Local, crate::analyze::Flags>,
start_ebb: Ebb,
) {
let ret_layout = fx.return_layout();
let output_pass_mode = get_pass_mode(fx.tcx, fx.return_layout());
let ret_param = match output_pass_mode {
PassMode::NoPass => {
fx.local_map
.insert(RETURN_PLACE, CPlace::no_place(ret_layout));
Empty
}
PassMode::ByVal(_) | PassMode::ByValPair(_, _) => {
let is_ssa = !ssa_analyzed
.get(&RETURN_PLACE)
.unwrap()
.contains(crate::analyze::Flags::NOT_SSA);
super::local_place(fx, RETURN_PLACE, ret_layout, is_ssa);
Empty
}
PassMode::ByRef => {
let ret_param = fx.bcx.append_ebb_param(start_ebb, fx.pointer_type);
fx.local_map.insert(
RETURN_PLACE,
CPlace::for_addr(ret_param, ret_layout),
);
Single(ret_param)
}
};
#[cfg(debug_assertions)]
crate::abi::comments::add_arg_comment(
fx,
"ret",
RETURN_PLACE,
None,
ret_param,
output_pass_mode,
ret_layout.ty,
);
}
pub fn codegen_with_call_return_arg<'tcx, B: Backend, T>(
fx: &mut FunctionCx<'_, 'tcx, B>,
fn_sig: FnSig<'tcx>,
ret_place: Option<CPlace<'tcx>>,
f: impl FnOnce(&mut FunctionCx<'_, 'tcx, B>, Option<Value>) -> (Inst, T),
) -> (Inst, T) {
let ret_layout = fx.layout_of(fn_sig.output());
let output_pass_mode = get_pass_mode(fx.tcx, ret_layout);
let return_ptr = match output_pass_mode {
PassMode::NoPass => None,
PassMode::ByRef => match ret_place {
Some(ret_place) => Some(ret_place.to_addr(fx)),
None => Some(fx.bcx.ins().iconst(fx.pointer_type, 43)),
},
PassMode::ByVal(_) | PassMode::ByValPair(_, _) => None,
};
let (call_inst, meta) = f(fx, return_ptr);
match output_pass_mode {
PassMode::NoPass => {}
PassMode::ByVal(_) => {
if let Some(ret_place) = ret_place {
let ret_val = fx.bcx.inst_results(call_inst)[0];
ret_place.write_cvalue(fx, CValue::by_val(ret_val, ret_layout));
}
}
PassMode::ByValPair(_, _) => {
if let Some(ret_place) = ret_place {
let ret_val_a = fx.bcx.inst_results(call_inst)[0];
let ret_val_b = fx.bcx.inst_results(call_inst)[1];
ret_place.write_cvalue(fx, CValue::by_val_pair(ret_val_a, ret_val_b, ret_layout));
}
}
PassMode::ByRef => {}
}
(call_inst, meta)
}
pub fn codegen_return(fx: &mut FunctionCx<impl Backend>) {
match get_pass_mode(fx.tcx, fx.return_layout()) {
PassMode::NoPass | PassMode::ByRef => {
fx.bcx.ins().return_(&[]);
}
PassMode::ByVal(_) => {
let place = fx.get_local_place(RETURN_PLACE);
let ret_val = place.to_cvalue(fx).load_scalar(fx);
fx.bcx.ins().return_(&[ret_val]);
}
PassMode::ByValPair(_, _) => {
let place = fx.get_local_place(RETURN_PLACE);
let (ret_val_a, ret_val_b) = place.to_cvalue(fx).load_scalar_pair(fx);
fx.bcx.ins().return_(&[ret_val_a, ret_val_b]);
}
}
}

18
src/common.rs
View File

@ -1,3 +1,4 @@
use rustc::ty::layout::{FloatTy, Integer, Primitive};
use rustc_target::spec::{HasTargetSpec, Target};
use cranelift::codegen::ir::{Opcode, InstructionData, ValueDef};
@ -17,6 +18,23 @@ pub fn pointer_ty(tcx: TyCtxt) -> types::Type {
}
}
pub fn scalar_to_clif_type(tcx: TyCtxt, scalar: Scalar) -> Type {
match scalar.value {
Primitive::Int(int, _sign) => match int {
Integer::I8 => types::I8,
Integer::I16 => types::I16,
Integer::I32 => types::I32,
Integer::I64 => types::I64,
Integer::I128 => types::I128,
},
Primitive::Float(flt) => match flt {
FloatTy::F32 => types::F32,
FloatTy::F64 => types::F64,
},
Primitive::Pointer => pointer_ty(tcx),
}
}
pub fn clif_type_from_ty<'tcx>(
tcx: TyCtxt<'tcx>,
ty: Ty<'tcx>,

7
src/value_and_place.rs
View File

@ -63,6 +63,13 @@ pub fn force_stack<'a>(self, fx: &mut FunctionCx<'_, 'tcx, impl Backend>) -> Val
}
}
pub fn try_to_addr(self) -> Option<Value> {
match self.0 {
CValueInner::ByRef(addr) => Some(addr),
CValueInner::ByVal(_) | CValueInner::ByValPair(_, _) => None,
}
}
/// Load a value with layout.abi of scalar
pub fn load_scalar<'a>(self, fx: &mut FunctionCx<'_, 'tcx, impl Backend>) -> Value {
let layout = self.1;