rust/compiler/rustc_codegen_cranelift/src/common.rs

511 lines
18 KiB
Rust

use cranelift_codegen::isa::TargetFrontendConfig;
use cranelift_frontend::{FunctionBuilder, FunctionBuilderContext};
use rustc_index::IndexVec;
use rustc_middle::ty::TypeFoldable;
use rustc_middle::ty::layout::{
self, FnAbiError, FnAbiOfHelpers, FnAbiRequest, LayoutError, LayoutOfHelpers,
};
use rustc_span::source_map::Spanned;
use rustc_target::abi::call::FnAbi;
use rustc_target::abi::{Float, Integer, Primitive};
use rustc_target::spec::{HasTargetSpec, Target};
use crate::constant::ConstantCx;
use crate::debuginfo::FunctionDebugContext;
use crate::prelude::*;
pub(crate) fn pointer_ty(tcx: TyCtxt<'_>) -> types::Type {
match tcx.data_layout.pointer_size.bits() {
16 => types::I16,
32 => types::I32,
64 => types::I64,
bits => bug!("ptr_sized_integer: unknown pointer bit size {}", bits),
}
}
pub(crate) fn scalar_to_clif_type(tcx: TyCtxt<'_>, scalar: Scalar) -> Type {
match scalar.primitive() {
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(float) => match float {
Float::F16 => unimplemented!("f16_f128"),
Float::F32 => types::F32,
Float::F64 => types::F64,
Float::F128 => unimplemented!("f16_f128"),
},
// FIXME(erikdesjardins): handle non-default addrspace ptr sizes
Primitive::Pointer(_) => pointer_ty(tcx),
}
}
fn clif_type_from_ty<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> Option<types::Type> {
Some(match ty.kind() {
ty::Bool => types::I8,
ty::Uint(size) => match size {
UintTy::U8 => types::I8,
UintTy::U16 => types::I16,
UintTy::U32 => types::I32,
UintTy::U64 => types::I64,
UintTy::U128 => types::I128,
UintTy::Usize => pointer_ty(tcx),
},
ty::Int(size) => match size {
IntTy::I8 => types::I8,
IntTy::I16 => types::I16,
IntTy::I32 => types::I32,
IntTy::I64 => types::I64,
IntTy::I128 => types::I128,
IntTy::Isize => pointer_ty(tcx),
},
ty::Char => types::I32,
ty::Float(size) => match size {
FloatTy::F16 => unimplemented!("f16_f128"),
FloatTy::F32 => types::F32,
FloatTy::F64 => types::F64,
FloatTy::F128 => unimplemented!("f16_f128"),
},
ty::FnPtr(..) => pointer_ty(tcx),
ty::RawPtr(pointee_ty, _) | ty::Ref(_, pointee_ty, _) => {
if has_ptr_meta(tcx, *pointee_ty) {
return None;
} else {
pointer_ty(tcx)
}
}
ty::Param(_) => bug!("ty param {:?}", ty),
_ => return None,
})
}
fn clif_pair_type_from_ty<'tcx>(
tcx: TyCtxt<'tcx>,
ty: Ty<'tcx>,
) -> Option<(types::Type, types::Type)> {
Some(match ty.kind() {
ty::Tuple(types) if types.len() == 2 => {
(clif_type_from_ty(tcx, types[0])?, clif_type_from_ty(tcx, types[1])?)
}
ty::RawPtr(pointee_ty, _) | ty::Ref(_, pointee_ty, _) => {
if has_ptr_meta(tcx, *pointee_ty) {
(pointer_ty(tcx), pointer_ty(tcx))
} else {
return None;
}
}
_ => return None,
})
}
/// Is a pointer to this type a wide ptr?
pub(crate) fn has_ptr_meta<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> bool {
if ty.is_sized(tcx, ParamEnv::reveal_all()) {
return false;
}
let tail = tcx.struct_tail_for_codegen(ty, ParamEnv::reveal_all());
match tail.kind() {
ty::Foreign(..) => false,
ty::Str | ty::Slice(..) | ty::Dynamic(..) => true,
_ => bug!("unexpected unsized tail: {:?}", tail),
}
}
pub(crate) fn codegen_icmp_imm(
fx: &mut FunctionCx<'_, '_, '_>,
intcc: IntCC,
lhs: Value,
rhs: i128,
) -> Value {
let lhs_ty = fx.bcx.func.dfg.value_type(lhs);
if lhs_ty == types::I128 {
// FIXME legalize `icmp_imm.i128` in Cranelift
let (lhs_lsb, lhs_msb) = fx.bcx.ins().isplit(lhs);
let (rhs_lsb, rhs_msb) = (rhs as u128 as u64 as i64, (rhs as u128 >> 64) as u64 as i64);
match intcc {
IntCC::Equal => {
let lsb_eq = fx.bcx.ins().icmp_imm(IntCC::Equal, lhs_lsb, rhs_lsb);
let msb_eq = fx.bcx.ins().icmp_imm(IntCC::Equal, lhs_msb, rhs_msb);
fx.bcx.ins().band(lsb_eq, msb_eq)
}
IntCC::NotEqual => {
let lsb_ne = fx.bcx.ins().icmp_imm(IntCC::NotEqual, lhs_lsb, rhs_lsb);
let msb_ne = fx.bcx.ins().icmp_imm(IntCC::NotEqual, lhs_msb, rhs_msb);
fx.bcx.ins().bor(lsb_ne, msb_ne)
}
_ => {
// if msb_eq {
// lsb_cc
// } else {
// msb_cc
// }
let msb_eq = fx.bcx.ins().icmp_imm(IntCC::Equal, lhs_msb, rhs_msb);
let lsb_cc = fx.bcx.ins().icmp_imm(intcc, lhs_lsb, rhs_lsb);
let msb_cc = fx.bcx.ins().icmp_imm(intcc, lhs_msb, rhs_msb);
fx.bcx.ins().select(msb_eq, lsb_cc, msb_cc)
}
}
} else {
let rhs = rhs as i64; // Truncates on purpose in case rhs is actually an unsigned value
fx.bcx.ins().icmp_imm(intcc, lhs, rhs)
}
}
pub(crate) fn codegen_bitcast(fx: &mut FunctionCx<'_, '_, '_>, dst_ty: Type, val: Value) -> Value {
let mut flags = MemFlags::new();
flags.set_endianness(match fx.tcx.data_layout.endian {
rustc_target::abi::Endian::Big => cranelift_codegen::ir::Endianness::Big,
rustc_target::abi::Endian::Little => cranelift_codegen::ir::Endianness::Little,
});
fx.bcx.ins().bitcast(dst_ty, flags, val)
}
pub(crate) fn type_zero_value(bcx: &mut FunctionBuilder<'_>, ty: Type) -> Value {
if ty == types::I128 {
let zero = bcx.ins().iconst(types::I64, 0);
bcx.ins().iconcat(zero, zero)
} else {
bcx.ins().iconst(ty, 0)
}
}
pub(crate) fn type_min_max_value(
bcx: &mut FunctionBuilder<'_>,
ty: Type,
signed: bool,
) -> (Value, Value) {
assert!(ty.is_int());
if ty == types::I128 {
if signed {
let min = i128::MIN as u128;
let min_lsb = bcx.ins().iconst(types::I64, min as u64 as i64);
let min_msb = bcx.ins().iconst(types::I64, (min >> 64) as u64 as i64);
let min = bcx.ins().iconcat(min_lsb, min_msb);
let max = i128::MAX as u128;
let max_lsb = bcx.ins().iconst(types::I64, max as u64 as i64);
let max_msb = bcx.ins().iconst(types::I64, (max >> 64) as u64 as i64);
let max = bcx.ins().iconcat(max_lsb, max_msb);
return (min, max);
} else {
let min_half = bcx.ins().iconst(types::I64, 0);
let min = bcx.ins().iconcat(min_half, min_half);
let max_half = bcx.ins().iconst(types::I64, u64::MAX as i64);
let max = bcx.ins().iconcat(max_half, max_half);
return (min, max);
}
}
let min = match (ty, signed) {
(types::I8, false) | (types::I16, false) | (types::I32, false) | (types::I64, false) => {
0i64
}
(types::I8, true) => i64::from(i8::MIN as u8),
(types::I16, true) => i64::from(i16::MIN as u16),
(types::I32, true) => i64::from(i32::MIN as u32),
(types::I64, true) => i64::MIN,
_ => unreachable!(),
};
let max = match (ty, signed) {
(types::I8, false) => i64::from(u8::MAX),
(types::I16, false) => i64::from(u16::MAX),
(types::I32, false) => i64::from(u32::MAX),
(types::I64, false) => u64::MAX as i64,
(types::I8, true) => i64::from(i8::MAX as u8),
(types::I16, true) => i64::from(i16::MAX as u16),
(types::I32, true) => i64::from(i32::MAX as u32),
(types::I64, true) => i64::MAX,
_ => unreachable!(),
};
let (min, max) = (bcx.ins().iconst(ty, min), bcx.ins().iconst(ty, max));
(min, max)
}
pub(crate) fn type_sign(ty: Ty<'_>) -> bool {
match ty.kind() {
ty::Ref(..) | ty::RawPtr(..) | ty::FnPtr(..) | ty::Char | ty::Uint(..) | ty::Bool => false,
ty::Int(..) => true,
ty::Float(..) => false, // `signed` is unused for floats
_ => panic!("{}", ty),
}
}
pub(crate) fn create_wrapper_function(
module: &mut dyn Module,
sig: Signature,
wrapper_name: &str,
callee_name: &str,
) {
let wrapper_func_id = module.declare_function(wrapper_name, Linkage::Export, &sig).unwrap();
let callee_func_id = module.declare_function(callee_name, Linkage::Import, &sig).unwrap();
let mut ctx = Context::new();
ctx.func.signature = sig;
{
let mut func_ctx = FunctionBuilderContext::new();
let mut bcx = FunctionBuilder::new(&mut ctx.func, &mut func_ctx);
let block = bcx.create_block();
bcx.switch_to_block(block);
let func = &mut bcx.func.stencil;
let args = func
.signature
.params
.iter()
.map(|param| func.dfg.append_block_param(block, param.value_type))
.collect::<Vec<Value>>();
let callee_func_ref = module.declare_func_in_func(callee_func_id, &mut bcx.func);
let call_inst = bcx.ins().call(callee_func_ref, &args);
let results = bcx.inst_results(call_inst).to_vec(); // Clone to prevent borrow error
bcx.ins().return_(&results);
bcx.seal_all_blocks();
bcx.finalize();
}
module.define_function(wrapper_func_id, &mut ctx).unwrap();
}
pub(crate) struct FunctionCx<'m, 'clif, 'tcx: 'm> {
pub(crate) cx: &'clif mut crate::CodegenCx,
pub(crate) module: &'m mut dyn Module,
pub(crate) tcx: TyCtxt<'tcx>,
pub(crate) target_config: TargetFrontendConfig, // Cached from module
pub(crate) pointer_type: Type, // Cached from module
pub(crate) constants_cx: ConstantCx,
pub(crate) func_debug_cx: Option<FunctionDebugContext>,
pub(crate) instance: Instance<'tcx>,
pub(crate) symbol_name: String,
pub(crate) mir: &'tcx Body<'tcx>,
pub(crate) fn_abi: &'tcx FnAbi<'tcx, Ty<'tcx>>,
pub(crate) bcx: FunctionBuilder<'clif>,
pub(crate) block_map: IndexVec<BasicBlock, Block>,
pub(crate) local_map: IndexVec<Local, CPlace<'tcx>>,
/// When `#[track_caller]` is used, the implicit caller location is stored in this variable.
pub(crate) caller_location: Option<CValue<'tcx>>,
pub(crate) clif_comments: crate::pretty_clif::CommentWriter,
/// This should only be accessed by `CPlace::new_var`.
pub(crate) next_ssa_var: u32,
}
impl<'tcx> LayoutOfHelpers<'tcx> for FunctionCx<'_, '_, 'tcx> {
#[inline]
fn handle_layout_err(&self, err: LayoutError<'tcx>, span: Span, ty: Ty<'tcx>) -> ! {
RevealAllLayoutCx(self.tcx).handle_layout_err(err, span, ty)
}
}
impl<'tcx> FnAbiOfHelpers<'tcx> for FunctionCx<'_, '_, 'tcx> {
#[inline]
fn handle_fn_abi_err(
&self,
err: FnAbiError<'tcx>,
span: Span,
fn_abi_request: FnAbiRequest<'tcx>,
) -> ! {
RevealAllLayoutCx(self.tcx).handle_fn_abi_err(err, span, fn_abi_request)
}
}
impl<'tcx> layout::HasTyCtxt<'tcx> for FunctionCx<'_, '_, 'tcx> {
fn tcx<'b>(&'b self) -> TyCtxt<'tcx> {
self.tcx
}
}
impl<'tcx> rustc_target::abi::HasDataLayout for FunctionCx<'_, '_, 'tcx> {
fn data_layout(&self) -> &rustc_target::abi::TargetDataLayout {
&self.tcx.data_layout
}
}
impl<'tcx> layout::HasParamEnv<'tcx> for FunctionCx<'_, '_, 'tcx> {
fn param_env(&self) -> ParamEnv<'tcx> {
ParamEnv::reveal_all()
}
}
impl<'tcx> HasTargetSpec for FunctionCx<'_, '_, 'tcx> {
fn target_spec(&self) -> &Target {
&self.tcx.sess.target
}
}
impl<'tcx> FunctionCx<'_, '_, 'tcx> {
pub(crate) fn monomorphize<T>(&self, value: T) -> T
where
T: TypeFoldable<TyCtxt<'tcx>> + Copy,
{
self.instance.instantiate_mir_and_normalize_erasing_regions(
self.tcx,
ty::ParamEnv::reveal_all(),
ty::EarlyBinder::bind(value),
)
}
pub(crate) fn clif_type(&self, ty: Ty<'tcx>) -> Option<Type> {
clif_type_from_ty(self.tcx, ty)
}
pub(crate) fn clif_pair_type(&self, ty: Ty<'tcx>) -> Option<(Type, Type)> {
clif_pair_type_from_ty(self.tcx, ty)
}
pub(crate) fn get_block(&self, bb: BasicBlock) -> Block {
*self.block_map.get(bb).unwrap()
}
pub(crate) fn get_local_place(&mut self, local: Local) -> CPlace<'tcx> {
*self.local_map.get(local).unwrap_or_else(|| {
panic!("Local {:?} doesn't exist", local);
})
}
pub(crate) fn create_stack_slot(&mut self, size: u32, align: u32) -> Pointer {
let abi_align = if self.tcx.sess.target.arch == "s390x" { 8 } else { 16 };
if align <= abi_align {
let stack_slot = self.bcx.create_sized_stack_slot(StackSlotData {
kind: StackSlotKind::ExplicitSlot,
// FIXME Don't force the size to a multiple of <abi_align> bytes once Cranelift gets
// a way to specify stack slot alignment.
size: (size + abi_align - 1) / abi_align * abi_align,
align_shift: 4,
});
Pointer::stack_slot(stack_slot)
} else {
// Alignment is too big to handle using the above hack. Dynamically realign a stack slot
// instead. This wastes some space for the realignment.
let stack_slot = self.bcx.create_sized_stack_slot(StackSlotData {
kind: StackSlotKind::ExplicitSlot,
// FIXME Don't force the size to a multiple of <abi_align> bytes once Cranelift gets
// a way to specify stack slot alignment.
size: (size + align) / abi_align * abi_align,
align_shift: 4,
});
let base_ptr = self.bcx.ins().stack_addr(self.pointer_type, stack_slot, 0);
let misalign_offset = self.bcx.ins().urem_imm(base_ptr, i64::from(align));
let realign_offset = self.bcx.ins().irsub_imm(misalign_offset, i64::from(align));
Pointer::new(self.bcx.ins().iadd(base_ptr, realign_offset))
}
}
pub(crate) fn set_debug_loc(&mut self, source_info: mir::SourceInfo) {
if let Some(debug_context) = &mut self.cx.debug_context {
let (file_id, line, column) =
debug_context.get_span_loc(self.tcx, self.mir.span, source_info.span);
let source_loc =
self.func_debug_cx.as_mut().unwrap().add_dbg_loc(file_id, line, column);
self.bcx.set_srcloc(source_loc);
}
}
pub(crate) fn get_caller_location(&mut self, source_info: mir::SourceInfo) -> CValue<'tcx> {
self.mir.caller_location_span(source_info, self.caller_location, self.tcx, |span| {
let const_loc = self.tcx.span_as_caller_location(span);
crate::constant::codegen_const_value(self, const_loc, self.tcx.caller_location_ty())
})
}
pub(crate) fn anonymous_str(&mut self, msg: &str) -> Value {
let mut data = DataDescription::new();
data.define(msg.as_bytes().to_vec().into_boxed_slice());
let msg_id = self.module.declare_anonymous_data(false, false).unwrap();
// Ignore DuplicateDefinition error, as the data will be the same
let _ = self.module.define_data(msg_id, &data);
let local_msg_id = self.module.declare_data_in_func(msg_id, self.bcx.func);
if self.clif_comments.enabled() {
self.add_comment(local_msg_id, msg);
}
self.bcx.ins().global_value(self.pointer_type, local_msg_id)
}
}
pub(crate) struct RevealAllLayoutCx<'tcx>(pub(crate) TyCtxt<'tcx>);
impl<'tcx> LayoutOfHelpers<'tcx> for RevealAllLayoutCx<'tcx> {
#[inline]
fn handle_layout_err(&self, err: LayoutError<'tcx>, span: Span, ty: Ty<'tcx>) -> ! {
if let LayoutError::SizeOverflow(_) | LayoutError::ReferencesError(_) = err {
self.0.sess.dcx().span_fatal(span, err.to_string())
} else {
self.0
.sess
.dcx()
.span_fatal(span, format!("failed to get layout for `{}`: {}", ty, err))
}
}
}
impl<'tcx> FnAbiOfHelpers<'tcx> for RevealAllLayoutCx<'tcx> {
#[inline]
fn handle_fn_abi_err(
&self,
err: FnAbiError<'tcx>,
span: Span,
fn_abi_request: FnAbiRequest<'tcx>,
) -> ! {
if let FnAbiError::Layout(LayoutError::SizeOverflow(_)) = err {
self.0.sess.dcx().emit_fatal(Spanned { span, node: err })
} else {
match fn_abi_request {
FnAbiRequest::OfFnPtr { sig, extra_args } => {
span_bug!(span, "`fn_abi_of_fn_ptr({sig}, {extra_args:?})` failed: {err:?}");
}
FnAbiRequest::OfInstance { instance, extra_args } => {
span_bug!(
span,
"`fn_abi_of_instance({instance}, {extra_args:?})` failed: {err:?}"
);
}
}
}
}
}
impl<'tcx> layout::HasTyCtxt<'tcx> for RevealAllLayoutCx<'tcx> {
fn tcx<'b>(&'b self) -> TyCtxt<'tcx> {
self.0
}
}
impl<'tcx> rustc_target::abi::HasDataLayout for RevealAllLayoutCx<'tcx> {
fn data_layout(&self) -> &rustc_target::abi::TargetDataLayout {
&self.0.data_layout
}
}
impl<'tcx> layout::HasParamEnv<'tcx> for RevealAllLayoutCx<'tcx> {
fn param_env(&self) -> ParamEnv<'tcx> {
ParamEnv::reveal_all()
}
}
impl<'tcx> HasTargetSpec for RevealAllLayoutCx<'tcx> {
fn target_spec(&self) -> &Target {
&self.0.sess.target
}
}