compiler/rustc_codegen_cranelift/src/common.rs

   1 use rustc_index::vec::IndexVec;
   2 use rustc_target::abi::{Integer, Primitive};
   3 use rustc_target::spec::{HasTargetSpec, Target};
   4
   5 use cranelift_codegen::ir::{InstructionData, Opcode, ValueDef};
   6
   7 use crate::prelude::*;
   8
   9 pub(crate) fn pointer_ty(tcx: TyCtxt<'_>) -> types::Type {
  10     match tcx.data_layout.pointer_size.bits() {
  11         16 => types::I16,
  12         32 => types::I32,
  13         64 => types::I64,
  14         bits => bug!("ptr_sized_integer: unknown pointer bit size {}", bits),
  15     }
  16 }
  17
  18 pub(crate) fn scalar_to_clif_type(tcx: TyCtxt<'_>, scalar: Scalar) -> Type {
  19     match scalar.value {
  20         Primitive::Int(int, _sign) => match int {
  21             Integer::I8 => types::I8,
  22             Integer::I16 => types::I16,
  23             Integer::I32 => types::I32,
  24             Integer::I64 => types::I64,
  25             Integer::I128 => types::I128,
  26         },
  27         Primitive::F32 => types::F32,
  28         Primitive::F64 => types::F64,
  29         Primitive::Pointer => pointer_ty(tcx),
  30     }
  31 }
  32
  33 fn clif_type_from_ty<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> Option<types::Type> {
  34     Some(match ty.kind() {
  35         ty::Bool => types::I8,
  36         ty::Uint(size) => match size {
  37             UintTy::U8 => types::I8,
  38             UintTy::U16 => types::I16,
  39             UintTy::U32 => types::I32,
  40             UintTy::U64 => types::I64,
  41             UintTy::U128 => types::I128,
  42             UintTy::Usize => pointer_ty(tcx),
  43         },
  44         ty::Int(size) => match size {
  45             IntTy::I8 => types::I8,
  46             IntTy::I16 => types::I16,
  47             IntTy::I32 => types::I32,
  48             IntTy::I64 => types::I64,
  49             IntTy::I128 => types::I128,
  50             IntTy::Isize => pointer_ty(tcx),
  51         },
  52         ty::Char => types::I32,
  53         ty::Float(size) => match size {
  54             FloatTy::F32 => types::F32,
  55             FloatTy::F64 => types::F64,
  56         },
  57         ty::FnPtr(_) => pointer_ty(tcx),
  58         ty::RawPtr(TypeAndMut {
  59             ty: pointee_ty,
  60             mutbl: _,
  61         })
  62         | ty::Ref(_, pointee_ty, _) => {
  63             if has_ptr_meta(tcx, pointee_ty) {
  64                 return None;
  65             } else {
  66                 pointer_ty(tcx)
  67             }
  68         }
  69         ty::Adt(adt_def, _) if adt_def.repr.simd() => {
  70             let (element, count) = match &tcx.layout_of(ParamEnv::reveal_all().and(ty)).unwrap().abi
  71             {
  72                 Abi::Vector { element, count } => (element.clone(), *count),
  73                 _ => unreachable!(),
  74             };
  75
  76             match scalar_to_clif_type(tcx, element).by(u16::try_from(count).unwrap()) {
  77                 // Cranelift currently only implements icmp for 128bit vectors.
  78                 Some(vector_ty) if vector_ty.bits() == 128 => vector_ty,
  79                 _ => return None,
  80             }
  81         }
  82         ty::Param(_) => bug!("ty param {:?}", ty),
  83         _ => return None,
  84     })
  85 }
  86
  87 fn clif_pair_type_from_ty<'tcx>(
  88     tcx: TyCtxt<'tcx>,
  89     ty: Ty<'tcx>,
  90 ) -> Option<(types::Type, types::Type)> {
  91     Some(match ty.kind() {
  92         ty::Tuple(substs) if substs.len() == 2 => {
  93             let mut types = substs.types();
  94             let a = clif_type_from_ty(tcx, types.next().unwrap())?;
  95             let b = clif_type_from_ty(tcx, types.next().unwrap())?;
  96             if a.is_vector() || b.is_vector() {
  97                 return None;
  98             }
  99             (a, b)
 100         }
 101         ty::RawPtr(TypeAndMut {
 102             ty: pointee_ty,
 103             mutbl: _,
 104         })
 105         | ty::Ref(_, pointee_ty, _) => {
 106             if has_ptr_meta(tcx, pointee_ty) {
 107                 (pointer_ty(tcx), pointer_ty(tcx))
 108             } else {
 109                 return None;
 110             }
 111         }
 112         _ => return None,
 113     })
 114 }
 115
 116 /// Is a pointer to this type a fat ptr?
 117 pub(crate) fn has_ptr_meta<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> bool {
 118     let ptr_ty = tcx.mk_ptr(TypeAndMut {
 119         ty,
 120         mutbl: rustc_hir::Mutability::Not,
 121     });
 122     match &tcx
 123         .layout_of(ParamEnv::reveal_all().and(ptr_ty))
 124         .unwrap()
 125         .abi
 126     {
 127         Abi::Scalar(_) => false,
 128         Abi::ScalarPair(_, _) => true,
 129         abi => unreachable!("Abi of ptr to {:?} is {:?}???", ty, abi),
 130     }
 131 }
 132
 133 pub(crate) fn codegen_icmp_imm(
 134     fx: &mut FunctionCx<'_, '_, impl Module>,
 135     intcc: IntCC,
 136     lhs: Value,
 137     rhs: i128,
 138 ) -> Value {
 139     let lhs_ty = fx.bcx.func.dfg.value_type(lhs);
 140     if lhs_ty == types::I128 {
 141         // FIXME legalize `icmp_imm.i128` in Cranelift
 142
 143         let (lhs_lsb, lhs_msb) = fx.bcx.ins().isplit(lhs);
 144         let (rhs_lsb, rhs_msb) = (rhs as u128 as u64 as i64, (rhs as u128 >> 64) as u64 as i64);
 145
 146         match intcc {
 147             IntCC::Equal => {
 148                 let lsb_eq = fx.bcx.ins().icmp_imm(IntCC::Equal, lhs_lsb, rhs_lsb);
 149                 let msb_eq = fx.bcx.ins().icmp_imm(IntCC::Equal, lhs_msb, rhs_msb);
 150                 fx.bcx.ins().band(lsb_eq, msb_eq)
 151             }
 152             IntCC::NotEqual => {
 153                 let lsb_ne = fx.bcx.ins().icmp_imm(IntCC::NotEqual, lhs_lsb, rhs_lsb);
 154                 let msb_ne = fx.bcx.ins().icmp_imm(IntCC::NotEqual, lhs_msb, rhs_msb);
 155                 fx.bcx.ins().bor(lsb_ne, msb_ne)
 156             }
 157             _ => {
 158                 // if msb_eq {
 159                 //     lsb_cc
 160                 // } else {
 161                 //     msb_cc
 162                 // }
 163
 164                 let msb_eq = fx.bcx.ins().icmp_imm(IntCC::Equal, lhs_msb, rhs_msb);
 165                 let lsb_cc = fx.bcx.ins().icmp_imm(intcc, lhs_lsb, rhs_lsb);
 166                 let msb_cc = fx.bcx.ins().icmp_imm(intcc, lhs_msb, rhs_msb);
 167
 168                 fx.bcx.ins().select(msb_eq, lsb_cc, msb_cc)
 169             }
 170         }
 171     } else {
 172         let rhs = i64::try_from(rhs).expect("codegen_icmp_imm rhs out of range for <128bit int");
 173         fx.bcx.ins().icmp_imm(intcc, lhs, rhs)
 174     }
 175 }
 176
 177 fn resolve_normal_value_imm(func: &Function, val: Value) -> Option<i64> {
 178     if let ValueDef::Result(inst, 0 /*param*/) = func.dfg.value_def(val) {
 179         if let InstructionData::UnaryImm {
 180             opcode: Opcode::Iconst,
 181             imm,
 182         } = func.dfg[inst]
 183         {
 184             Some(imm.into())
 185         } else {
 186             None
 187         }
 188     } else {
 189         None
 190     }
 191 }
 192
 193 fn resolve_128bit_value_imm(func: &Function, val: Value) -> Option<u128> {
 194     let (lsb, msb) = if let ValueDef::Result(inst, 0 /*param*/) = func.dfg.value_def(val) {
 195         if let InstructionData::Binary {
 196             opcode: Opcode::Iconcat,
 197             args: [lsb, msb],
 198         } = func.dfg[inst]
 199         {
 200             (lsb, msb)
 201         } else {
 202             return None;
 203         }
 204     } else {
 205         return None;
 206     };
 207
 208     let lsb = u128::from(resolve_normal_value_imm(func, lsb)? as u64);
 209     let msb = u128::from(resolve_normal_value_imm(func, msb)? as u64);
 210
 211     Some(msb << 64 | lsb)
 212 }
 213
 214 pub(crate) fn resolve_value_imm(func: &Function, val: Value) -> Option<u128> {
 215     if func.dfg.value_type(val) == types::I128 {
 216         resolve_128bit_value_imm(func, val)
 217     } else {
 218         resolve_normal_value_imm(func, val).map(|imm| u128::from(imm as u64))
 219     }
 220 }
 221
 222 pub(crate) fn type_min_max_value(
 223     bcx: &mut FunctionBuilder<'_>,
 224     ty: Type,
 225     signed: bool,
 226 ) -> (Value, Value) {
 227     assert!(ty.is_int());
 228
 229     if ty == types::I128 {
 230         if signed {
 231             let min = i128::MIN as u128;
 232             let min_lsb = bcx.ins().iconst(types::I64, min as u64 as i64);
 233             let min_msb = bcx.ins().iconst(types::I64, (min >> 64) as u64 as i64);
 234             let min = bcx.ins().iconcat(min_lsb, min_msb);
 235
 236             let max = i128::MAX as u128;
 237             let max_lsb = bcx.ins().iconst(types::I64, max as u64 as i64);
 238             let max_msb = bcx.ins().iconst(types::I64, (max >> 64) as u64 as i64);
 239             let max = bcx.ins().iconcat(max_lsb, max_msb);
 240
 241             return (min, max);
 242         } else {
 243             let min_half = bcx.ins().iconst(types::I64, 0);
 244             let min = bcx.ins().iconcat(min_half, min_half);
 245
 246             let max_half = bcx.ins().iconst(types::I64, u64::MAX as i64);
 247             let max = bcx.ins().iconcat(max_half, max_half);
 248
 249             return (min, max);
 250         }
 251     }
 252
 253     let min = match (ty, signed) {
 254         (types::I8, false) | (types::I16, false) | (types::I32, false) | (types::I64, false) => {
 255             0i64
 256         }
 257         (types::I8, true) => i64::from(i8::MIN),
 258         (types::I16, true) => i64::from(i16::MIN),
 259         (types::I32, true) => i64::from(i32::MIN),
 260         (types::I64, true) => i64::MIN,
 261         _ => unreachable!(),
 262     };
 263
 264     let max = match (ty, signed) {
 265         (types::I8, false) => i64::from(u8::MAX),
 266         (types::I16, false) => i64::from(u16::MAX),
 267         (types::I32, false) => i64::from(u32::MAX),
 268         (types::I64, false) => u64::MAX as i64,
 269         (types::I8, true) => i64::from(i8::MAX),
 270         (types::I16, true) => i64::from(i16::MAX),
 271         (types::I32, true) => i64::from(i32::MAX),
 272         (types::I64, true) => i64::MAX,
 273         _ => unreachable!(),
 274     };
 275
 276     let (min, max) = (bcx.ins().iconst(ty, min), bcx.ins().iconst(ty, max));
 277
 278     (min, max)
 279 }
 280
 281 pub(crate) fn type_sign(ty: Ty<'_>) -> bool {
 282     match ty.kind() {
 283         ty::Ref(..) | ty::RawPtr(..) | ty::FnPtr(..) | ty::Char | ty::Uint(..) | ty::Bool => false,
 284         ty::Int(..) => true,
 285         ty::Float(..) => false, // `signed` is unused for floats
 286         _ => panic!("{}", ty),
 287     }
 288 }
 289
 290 pub(crate) struct FunctionCx<'clif, 'tcx, M: Module> {
 291     pub(crate) cx: &'clif mut crate::CodegenCx<'tcx, M>,
 292     pub(crate) tcx: TyCtxt<'tcx>,
 293     pub(crate) pointer_type: Type, // Cached from module
 294
 295     pub(crate) instance: Instance<'tcx>,
 296     pub(crate) mir: &'tcx Body<'tcx>,
 297
 298     pub(crate) bcx: FunctionBuilder<'clif>,
 299     pub(crate) block_map: IndexVec<BasicBlock, Block>,
 300     pub(crate) local_map: IndexVec<Local, CPlace<'tcx>>,
 301
 302     /// When `#[track_caller]` is used, the implicit caller location is stored in this variable.
 303     pub(crate) caller_location: Option<CValue<'tcx>>,
 304
 305     /// See [`crate::optimize::code_layout`] for more information.
 306     pub(crate) cold_blocks: EntitySet<Block>,
 307
 308     pub(crate) clif_comments: crate::pretty_clif::CommentWriter,
 309     pub(crate) source_info_set: indexmap::IndexSet<SourceInfo>,
 310
 311     /// This should only be accessed by `CPlace::new_var`.
 312     pub(crate) next_ssa_var: u32,
 313
 314     pub(crate) inline_asm_index: u32,
 315 }
 316
 317 impl<'tcx, M: Module> LayoutOf for FunctionCx<'_, 'tcx, M> {
 318     type Ty = Ty<'tcx>;
 319     type TyAndLayout = TyAndLayout<'tcx>;
 320
 321     fn layout_of(&self, ty: Ty<'tcx>) -> TyAndLayout<'tcx> {
 322         assert!(!ty.still_further_specializable());
 323         self.tcx
 324             .layout_of(ParamEnv::reveal_all().and(&ty))
 325             .unwrap_or_else(|e| {
 326                 if let layout::LayoutError::SizeOverflow(_) = e {
 327                     self.tcx.sess.fatal(&e.to_string())
 328                 } else {
 329                     bug!("failed to get layout for `{}`: {}", ty, e)
 330                 }
 331             })
 332     }
 333 }
 334
 335 impl<'tcx, M: Module> layout::HasTyCtxt<'tcx> for FunctionCx<'_, 'tcx, M> {
 336     fn tcx<'b>(&'b self) -> TyCtxt<'tcx> {
 337         self.tcx
 338     }
 339 }
 340
 341 impl<'tcx, M: Module> rustc_target::abi::HasDataLayout for FunctionCx<'_, 'tcx, M> {
 342     fn data_layout(&self) -> &rustc_target::abi::TargetDataLayout {
 343         &self.tcx.data_layout
 344     }
 345 }
 346
 347 impl<'tcx, M: Module> layout::HasParamEnv<'tcx> for FunctionCx<'_, 'tcx, M> {
 348     fn param_env(&self) -> ParamEnv<'tcx> {
 349         ParamEnv::reveal_all()
 350     }
 351 }
 352
 353 impl<'tcx, M: Module> HasTargetSpec for FunctionCx<'_, 'tcx, M> {
 354     fn target_spec(&self) -> &Target {
 355         &self.tcx.sess.target
 356     }
 357 }
 358
 359 impl<'tcx, M: Module> FunctionCx<'_, 'tcx, M> {
 360     pub(crate) fn monomorphize<T>(&self, value: T) -> T
 361     where
 362         T: TypeFoldable<'tcx> + Copy,
 363     {
 364         self.instance.subst_mir_and_normalize_erasing_regions(
 365             self.tcx,
 366             ty::ParamEnv::reveal_all(),
 367             value,
 368         )
 369     }
 370
 371     pub(crate) fn clif_type(&self, ty: Ty<'tcx>) -> Option<Type> {
 372         clif_type_from_ty(self.tcx, ty)
 373     }
 374
 375     pub(crate) fn clif_pair_type(&self, ty: Ty<'tcx>) -> Option<(Type, Type)> {
 376         clif_pair_type_from_ty(self.tcx, ty)
 377     }
 378
 379     pub(crate) fn get_block(&self, bb: BasicBlock) -> Block {
 380         *self.block_map.get(bb).unwrap()
 381     }
 382
 383     pub(crate) fn get_local_place(&mut self, local: Local) -> CPlace<'tcx> {
 384         *self.local_map.get(local).unwrap_or_else(|| {
 385             panic!("Local {:?} doesn't exist", local);
 386         })
 387     }
 388
 389     pub(crate) fn set_debug_loc(&mut self, source_info: mir::SourceInfo) {
 390         let (index, _) = self.source_info_set.insert_full(source_info);
 391         self.bcx.set_srcloc(SourceLoc::new(index as u32));
 392     }
 393
 394     pub(crate) fn get_caller_location(&mut self, span: Span) -> CValue<'tcx> {
 395         if let Some(loc) = self.caller_location {
 396             // `#[track_caller]` is used; return caller location instead of current location.
 397             return loc;
 398         }
 399
 400         let topmost = span.ctxt().outer_expn().expansion_cause().unwrap_or(span);
 401         let caller = self.tcx.sess.source_map().lookup_char_pos(topmost.lo());
 402         let const_loc = self.tcx.const_caller_location((
 403             rustc_span::symbol::Symbol::intern(&caller.file.name.to_string()),
 404             caller.line as u32,
 405             caller.col_display as u32 + 1,
 406         ));
 407         crate::constant::codegen_const_value(self, const_loc, self.tcx.caller_location_ty())
 408     }
 409
 410     pub(crate) fn triple(&self) -> &target_lexicon::Triple {
 411         self.cx.module.isa().triple()
 412     }
 413
 414     pub(crate) fn anonymous_str(&mut self, prefix: &str, msg: &str) -> Value {
 415         use std::collections::hash_map::DefaultHasher;
 416         use std::hash::{Hash, Hasher};
 417
 418         let mut hasher = DefaultHasher::new();
 419         msg.hash(&mut hasher);
 420         let msg_hash = hasher.finish();
 421         let mut data_ctx = DataContext::new();
 422         data_ctx.define(msg.as_bytes().to_vec().into_boxed_slice());
 423         let msg_id = self
 424             .cx
 425             .module
 426             .declare_data(
 427                 &format!("__{}_{:08x}", prefix, msg_hash),
 428                 Linkage::Local,
 429                 false,
 430                 false,
 431             )
 432             .unwrap();
 433
 434         // Ignore DuplicateDefinition error, as the data will be the same
 435         let _ = self.cx.module.define_data(msg_id, &data_ctx);
 436
 437         let local_msg_id = self.cx.module.declare_data_in_func(msg_id, self.bcx.func);
 438         #[cfg(debug_assertions)]
 439         {
 440             self.add_comment(local_msg_id, msg);
 441         }
 442         self.bcx.ins().global_value(self.pointer_type, local_msg_id)
 443     }
 444 }