From 698f8c2f01ea549d77d7dc3338a12e04c11057b9 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 17 Apr 2024 14:02:58 +0200 Subject: Adding upstream version 1.64.0+dfsg1. Signed-off-by: Daniel Baumann --- compiler/rustc_codegen_ssa/src/mir/rvalue.rs | 729 +++++++++++++++++++++++++++ 1 file changed, 729 insertions(+) create mode 100644 compiler/rustc_codegen_ssa/src/mir/rvalue.rs (limited to 'compiler/rustc_codegen_ssa/src/mir/rvalue.rs') diff --git a/compiler/rustc_codegen_ssa/src/mir/rvalue.rs b/compiler/rustc_codegen_ssa/src/mir/rvalue.rs new file mode 100644 index 000000000..26b9fbf44 --- /dev/null +++ b/compiler/rustc_codegen_ssa/src/mir/rvalue.rs @@ -0,0 +1,729 @@ +use super::operand::{OperandRef, OperandValue}; +use super::place::PlaceRef; +use super::{FunctionCx, LocalRef}; + +use crate::base; +use crate::common::{self, IntPredicate}; +use crate::traits::*; +use crate::MemFlags; + +use rustc_middle::mir; +use rustc_middle::mir::Operand; +use rustc_middle::ty::cast::{CastTy, IntTy}; +use rustc_middle::ty::layout::{HasTyCtxt, LayoutOf}; +use rustc_middle::ty::{self, adjustment::PointerCast, Instance, Ty, TyCtxt}; +use rustc_span::source_map::{Span, DUMMY_SP}; + +impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { + #[instrument(level = "trace", skip(self, bx))] + pub fn codegen_rvalue( + &mut self, + mut bx: Bx, + dest: PlaceRef<'tcx, Bx::Value>, + rvalue: &mir::Rvalue<'tcx>, + ) -> Bx { + match *rvalue { + mir::Rvalue::Use(ref operand) => { + let cg_operand = self.codegen_operand(&mut bx, operand); + // FIXME: consider not copying constants through stack. (Fixable by codegen'ing + // constants into `OperandValue::Ref`; why don’t we do that yet if we don’t?) + cg_operand.val.store(&mut bx, dest); + bx + } + + mir::Rvalue::Cast(mir::CastKind::Pointer(PointerCast::Unsize), ref source, _) => { + // The destination necessarily contains a fat pointer, so if + // it's a scalar pair, it's a fat pointer or newtype thereof. + if bx.cx().is_backend_scalar_pair(dest.layout) { + // Into-coerce of a thin pointer to a fat pointer -- just + // use the operand path. + let (mut bx, temp) = self.codegen_rvalue_operand(bx, rvalue); + temp.val.store(&mut bx, dest); + return bx; + } + + // Unsize of a nontrivial struct. I would prefer for + // this to be eliminated by MIR building, but + // `CoerceUnsized` can be passed by a where-clause, + // so the (generic) MIR may not be able to expand it. + let operand = self.codegen_operand(&mut bx, source); + match operand.val { + OperandValue::Pair(..) | OperandValue::Immediate(_) => { + // Unsize from an immediate structure. We don't + // really need a temporary alloca here, but + // avoiding it would require us to have + // `coerce_unsized_into` use `extractvalue` to + // index into the struct, and this case isn't + // important enough for it. + debug!("codegen_rvalue: creating ugly alloca"); + let scratch = PlaceRef::alloca(&mut bx, operand.layout); + scratch.storage_live(&mut bx); + operand.val.store(&mut bx, scratch); + base::coerce_unsized_into(&mut bx, scratch, dest); + scratch.storage_dead(&mut bx); + } + OperandValue::Ref(llref, None, align) => { + let source = PlaceRef::new_sized_aligned(llref, operand.layout, align); + base::coerce_unsized_into(&mut bx, source, dest); + } + OperandValue::Ref(_, Some(_), _) => { + bug!("unsized coercion on an unsized rvalue"); + } + } + bx + } + + mir::Rvalue::Repeat(ref elem, count) => { + let cg_elem = self.codegen_operand(&mut bx, elem); + + // Do not generate the loop for zero-sized elements or empty arrays. + if dest.layout.is_zst() { + return bx; + } + + if let OperandValue::Immediate(v) = cg_elem.val { + let zero = bx.const_usize(0); + let start = dest.project_index(&mut bx, zero).llval; + let size = bx.const_usize(dest.layout.size.bytes()); + + // Use llvm.memset.p0i8.* to initialize all zero arrays + if bx.cx().const_to_opt_uint(v) == Some(0) { + let fill = bx.cx().const_u8(0); + bx.memset(start, fill, size, dest.align, MemFlags::empty()); + return bx; + } + + // Use llvm.memset.p0i8.* to initialize byte arrays + let v = bx.from_immediate(v); + if bx.cx().val_ty(v) == bx.cx().type_i8() { + bx.memset(start, v, size, dest.align, MemFlags::empty()); + return bx; + } + } + + let count = + self.monomorphize(count).eval_usize(bx.cx().tcx(), ty::ParamEnv::reveal_all()); + + bx.write_operand_repeatedly(cg_elem, count, dest) + } + + mir::Rvalue::Aggregate(ref kind, ref operands) => { + let (dest, active_field_index) = match **kind { + mir::AggregateKind::Adt(adt_did, variant_index, _, _, active_field_index) => { + dest.codegen_set_discr(&mut bx, variant_index); + if bx.tcx().adt_def(adt_did).is_enum() { + (dest.project_downcast(&mut bx, variant_index), active_field_index) + } else { + (dest, active_field_index) + } + } + _ => (dest, None), + }; + for (i, operand) in operands.iter().enumerate() { + let op = self.codegen_operand(&mut bx, operand); + // Do not generate stores and GEPis for zero-sized fields. + if !op.layout.is_zst() { + let field_index = active_field_index.unwrap_or(i); + let field = if let mir::AggregateKind::Array(_) = **kind { + let llindex = bx.cx().const_usize(field_index as u64); + dest.project_index(&mut bx, llindex) + } else { + dest.project_field(&mut bx, field_index) + }; + op.val.store(&mut bx, field); + } + } + bx + } + + _ => { + assert!(self.rvalue_creates_operand(rvalue, DUMMY_SP)); + let (mut bx, temp) = self.codegen_rvalue_operand(bx, rvalue); + temp.val.store(&mut bx, dest); + bx + } + } + } + + pub fn codegen_rvalue_unsized( + &mut self, + mut bx: Bx, + indirect_dest: PlaceRef<'tcx, Bx::Value>, + rvalue: &mir::Rvalue<'tcx>, + ) -> Bx { + debug!( + "codegen_rvalue_unsized(indirect_dest.llval={:?}, rvalue={:?})", + indirect_dest.llval, rvalue + ); + + match *rvalue { + mir::Rvalue::Use(ref operand) => { + let cg_operand = self.codegen_operand(&mut bx, operand); + cg_operand.val.store_unsized(&mut bx, indirect_dest); + bx + } + + _ => bug!("unsized assignment other than `Rvalue::Use`"), + } + } + + pub fn codegen_rvalue_operand( + &mut self, + mut bx: Bx, + rvalue: &mir::Rvalue<'tcx>, + ) -> (Bx, OperandRef<'tcx, Bx::Value>) { + assert!( + self.rvalue_creates_operand(rvalue, DUMMY_SP), + "cannot codegen {:?} to operand", + rvalue, + ); + + match *rvalue { + mir::Rvalue::Cast(ref kind, ref source, mir_cast_ty) => { + let operand = self.codegen_operand(&mut bx, source); + debug!("cast operand is {:?}", operand); + let cast = bx.cx().layout_of(self.monomorphize(mir_cast_ty)); + + let val = match *kind { + mir::CastKind::PointerExposeAddress => { + assert!(bx.cx().is_backend_immediate(cast)); + let llptr = operand.immediate(); + let llcast_ty = bx.cx().immediate_backend_type(cast); + let lladdr = bx.ptrtoint(llptr, llcast_ty); + OperandValue::Immediate(lladdr) + } + mir::CastKind::Pointer(PointerCast::ReifyFnPointer) => { + match *operand.layout.ty.kind() { + ty::FnDef(def_id, substs) => { + let instance = ty::Instance::resolve_for_fn_ptr( + bx.tcx(), + ty::ParamEnv::reveal_all(), + def_id, + substs, + ) + .unwrap() + .polymorphize(bx.cx().tcx()); + OperandValue::Immediate(bx.get_fn_addr(instance)) + } + _ => bug!("{} cannot be reified to a fn ptr", operand.layout.ty), + } + } + mir::CastKind::Pointer(PointerCast::ClosureFnPointer(_)) => { + match *operand.layout.ty.kind() { + ty::Closure(def_id, substs) => { + let instance = Instance::resolve_closure( + bx.cx().tcx(), + def_id, + substs, + ty::ClosureKind::FnOnce, + ) + .expect("failed to normalize and resolve closure during codegen") + .polymorphize(bx.cx().tcx()); + OperandValue::Immediate(bx.cx().get_fn_addr(instance)) + } + _ => bug!("{} cannot be cast to a fn ptr", operand.layout.ty), + } + } + mir::CastKind::Pointer(PointerCast::UnsafeFnPointer) => { + // This is a no-op at the LLVM level. + operand.val + } + mir::CastKind::Pointer(PointerCast::Unsize) => { + assert!(bx.cx().is_backend_scalar_pair(cast)); + let (lldata, llextra) = match operand.val { + OperandValue::Pair(lldata, llextra) => { + // unsize from a fat pointer -- this is a + // "trait-object-to-supertrait" coercion. + (lldata, Some(llextra)) + } + OperandValue::Immediate(lldata) => { + // "standard" unsize + (lldata, None) + } + OperandValue::Ref(..) => { + bug!("by-ref operand {:?} in `codegen_rvalue_operand`", operand); + } + }; + let (lldata, llextra) = + base::unsize_ptr(&mut bx, lldata, operand.layout.ty, cast.ty, llextra); + OperandValue::Pair(lldata, llextra) + } + mir::CastKind::Pointer(PointerCast::MutToConstPointer) + | mir::CastKind::Misc + if bx.cx().is_backend_scalar_pair(operand.layout) => + { + if let OperandValue::Pair(data_ptr, meta) = operand.val { + if bx.cx().is_backend_scalar_pair(cast) { + let data_cast = bx.pointercast( + data_ptr, + bx.cx().scalar_pair_element_backend_type(cast, 0, true), + ); + OperandValue::Pair(data_cast, meta) + } else { + // cast to thin-ptr + // Cast of fat-ptr to thin-ptr is an extraction of data-ptr and + // pointer-cast of that pointer to desired pointer type. + let llcast_ty = bx.cx().immediate_backend_type(cast); + let llval = bx.pointercast(data_ptr, llcast_ty); + OperandValue::Immediate(llval) + } + } else { + bug!("unexpected non-pair operand"); + } + } + mir::CastKind::Pointer( + PointerCast::MutToConstPointer | PointerCast::ArrayToPointer, + ) + | mir::CastKind::Misc + // Since int2ptr can have arbitrary integer types as input (so we have to do + // sign extension and all that), it is currently best handled in the same code + // path as the other integer-to-X casts. + | mir::CastKind::PointerFromExposedAddress => { + assert!(bx.cx().is_backend_immediate(cast)); + let ll_t_out = bx.cx().immediate_backend_type(cast); + if operand.layout.abi.is_uninhabited() { + let val = OperandValue::Immediate(bx.cx().const_undef(ll_t_out)); + return (bx, OperandRef { val, layout: cast }); + } + let r_t_in = + CastTy::from_ty(operand.layout.ty).expect("bad input type for cast"); + let r_t_out = CastTy::from_ty(cast.ty).expect("bad output type for cast"); + let ll_t_in = bx.cx().immediate_backend_type(operand.layout); + let llval = operand.immediate(); + + let newval = match (r_t_in, r_t_out) { + (CastTy::Int(i), CastTy::Int(_)) => { + bx.intcast(llval, ll_t_out, i.is_signed()) + } + (CastTy::Float, CastTy::Float) => { + let srcsz = bx.cx().float_width(ll_t_in); + let dstsz = bx.cx().float_width(ll_t_out); + if dstsz > srcsz { + bx.fpext(llval, ll_t_out) + } else if srcsz > dstsz { + bx.fptrunc(llval, ll_t_out) + } else { + llval + } + } + (CastTy::Int(i), CastTy::Float) => { + if i.is_signed() { + bx.sitofp(llval, ll_t_out) + } else { + bx.uitofp(llval, ll_t_out) + } + } + (CastTy::Ptr(_) | CastTy::FnPtr, CastTy::Ptr(_)) => { + bx.pointercast(llval, ll_t_out) + } + (CastTy::Int(i), CastTy::Ptr(_)) => { + let usize_llval = + bx.intcast(llval, bx.cx().type_isize(), i.is_signed()); + bx.inttoptr(usize_llval, ll_t_out) + } + (CastTy::Float, CastTy::Int(IntTy::I)) => { + bx.cast_float_to_int(true, llval, ll_t_out) + } + (CastTy::Float, CastTy::Int(_)) => { + bx.cast_float_to_int(false, llval, ll_t_out) + } + _ => bug!("unsupported cast: {:?} to {:?}", operand.layout.ty, cast.ty), + }; + OperandValue::Immediate(newval) + } + }; + (bx, OperandRef { val, layout: cast }) + } + + mir::Rvalue::Ref(_, bk, place) => { + let mk_ref = move |tcx: TyCtxt<'tcx>, ty: Ty<'tcx>| { + tcx.mk_ref( + tcx.lifetimes.re_erased, + ty::TypeAndMut { ty, mutbl: bk.to_mutbl_lossy() }, + ) + }; + self.codegen_place_to_pointer(bx, place, mk_ref) + } + + mir::Rvalue::CopyForDeref(place) => { + let operand = self.codegen_operand(&mut bx, &Operand::Copy(place)); + (bx, operand) + } + mir::Rvalue::AddressOf(mutability, place) => { + let mk_ptr = move |tcx: TyCtxt<'tcx>, ty: Ty<'tcx>| { + tcx.mk_ptr(ty::TypeAndMut { ty, mutbl: mutability }) + }; + self.codegen_place_to_pointer(bx, place, mk_ptr) + } + + mir::Rvalue::Len(place) => { + let size = self.evaluate_array_len(&mut bx, place); + let operand = OperandRef { + val: OperandValue::Immediate(size), + layout: bx.cx().layout_of(bx.tcx().types.usize), + }; + (bx, operand) + } + + mir::Rvalue::BinaryOp(op, box (ref lhs, ref rhs)) => { + let lhs = self.codegen_operand(&mut bx, lhs); + let rhs = self.codegen_operand(&mut bx, rhs); + let llresult = match (lhs.val, rhs.val) { + ( + OperandValue::Pair(lhs_addr, lhs_extra), + OperandValue::Pair(rhs_addr, rhs_extra), + ) => self.codegen_fat_ptr_binop( + &mut bx, + op, + lhs_addr, + lhs_extra, + rhs_addr, + rhs_extra, + lhs.layout.ty, + ), + + (OperandValue::Immediate(lhs_val), OperandValue::Immediate(rhs_val)) => { + self.codegen_scalar_binop(&mut bx, op, lhs_val, rhs_val, lhs.layout.ty) + } + + _ => bug!(), + }; + let operand = OperandRef { + val: OperandValue::Immediate(llresult), + layout: bx.cx().layout_of(op.ty(bx.tcx(), lhs.layout.ty, rhs.layout.ty)), + }; + (bx, operand) + } + mir::Rvalue::CheckedBinaryOp(op, box (ref lhs, ref rhs)) => { + let lhs = self.codegen_operand(&mut bx, lhs); + let rhs = self.codegen_operand(&mut bx, rhs); + let result = self.codegen_scalar_checked_binop( + &mut bx, + op, + lhs.immediate(), + rhs.immediate(), + lhs.layout.ty, + ); + let val_ty = op.ty(bx.tcx(), lhs.layout.ty, rhs.layout.ty); + let operand_ty = bx.tcx().intern_tup(&[val_ty, bx.tcx().types.bool]); + let operand = OperandRef { val: result, layout: bx.cx().layout_of(operand_ty) }; + + (bx, operand) + } + + mir::Rvalue::UnaryOp(op, ref operand) => { + let operand = self.codegen_operand(&mut bx, operand); + let lloperand = operand.immediate(); + let is_float = operand.layout.ty.is_floating_point(); + let llval = match op { + mir::UnOp::Not => bx.not(lloperand), + mir::UnOp::Neg => { + if is_float { + bx.fneg(lloperand) + } else { + bx.neg(lloperand) + } + } + }; + (bx, OperandRef { val: OperandValue::Immediate(llval), layout: operand.layout }) + } + + mir::Rvalue::Discriminant(ref place) => { + let discr_ty = rvalue.ty(self.mir, bx.tcx()); + let discr_ty = self.monomorphize(discr_ty); + let discr = self + .codegen_place(&mut bx, place.as_ref()) + .codegen_get_discr(&mut bx, discr_ty); + ( + bx, + OperandRef { + val: OperandValue::Immediate(discr), + layout: self.cx.layout_of(discr_ty), + }, + ) + } + + mir::Rvalue::NullaryOp(null_op, ty) => { + let ty = self.monomorphize(ty); + assert!(bx.cx().type_is_sized(ty)); + let layout = bx.cx().layout_of(ty); + let val = match null_op { + mir::NullOp::SizeOf => layout.size.bytes(), + mir::NullOp::AlignOf => layout.align.abi.bytes(), + }; + let val = bx.cx().const_usize(val); + let tcx = self.cx.tcx(); + ( + bx, + OperandRef { + val: OperandValue::Immediate(val), + layout: self.cx.layout_of(tcx.types.usize), + }, + ) + } + + mir::Rvalue::ThreadLocalRef(def_id) => { + assert!(bx.cx().tcx().is_static(def_id)); + let static_ = bx.get_static(def_id); + let layout = bx.layout_of(bx.cx().tcx().static_ptr_ty(def_id)); + let operand = OperandRef::from_immediate_or_packed_pair(&mut bx, static_, layout); + (bx, operand) + } + mir::Rvalue::Use(ref operand) => { + let operand = self.codegen_operand(&mut bx, operand); + (bx, operand) + } + mir::Rvalue::Repeat(..) | mir::Rvalue::Aggregate(..) => { + // According to `rvalue_creates_operand`, only ZST + // aggregate rvalues are allowed to be operands. + let ty = rvalue.ty(self.mir, self.cx.tcx()); + let operand = + OperandRef::new_zst(&mut bx, self.cx.layout_of(self.monomorphize(ty))); + (bx, operand) + } + mir::Rvalue::ShallowInitBox(ref operand, content_ty) => { + let operand = self.codegen_operand(&mut bx, operand); + let lloperand = operand.immediate(); + + let content_ty = self.monomorphize(content_ty); + let box_layout = bx.cx().layout_of(bx.tcx().mk_box(content_ty)); + let llty_ptr = bx.cx().backend_type(box_layout); + + let val = bx.pointercast(lloperand, llty_ptr); + let operand = OperandRef { val: OperandValue::Immediate(val), layout: box_layout }; + (bx, operand) + } + } + } + + fn evaluate_array_len(&mut self, bx: &mut Bx, place: mir::Place<'tcx>) -> Bx::Value { + // ZST are passed as operands and require special handling + // because codegen_place() panics if Local is operand. + if let Some(index) = place.as_local() { + if let LocalRef::Operand(Some(op)) = self.locals[index] { + if let ty::Array(_, n) = op.layout.ty.kind() { + let n = n.eval_usize(bx.cx().tcx(), ty::ParamEnv::reveal_all()); + return bx.cx().const_usize(n); + } + } + } + // use common size calculation for non zero-sized types + let cg_value = self.codegen_place(bx, place.as_ref()); + cg_value.len(bx.cx()) + } + + /// Codegen an `Rvalue::AddressOf` or `Rvalue::Ref` + fn codegen_place_to_pointer( + &mut self, + mut bx: Bx, + place: mir::Place<'tcx>, + mk_ptr_ty: impl FnOnce(TyCtxt<'tcx>, Ty<'tcx>) -> Ty<'tcx>, + ) -> (Bx, OperandRef<'tcx, Bx::Value>) { + let cg_place = self.codegen_place(&mut bx, place.as_ref()); + + let ty = cg_place.layout.ty; + + // Note: places are indirect, so storing the `llval` into the + // destination effectively creates a reference. + let val = if !bx.cx().type_has_metadata(ty) { + OperandValue::Immediate(cg_place.llval) + } else { + OperandValue::Pair(cg_place.llval, cg_place.llextra.unwrap()) + }; + (bx, OperandRef { val, layout: self.cx.layout_of(mk_ptr_ty(self.cx.tcx(), ty)) }) + } + + pub fn codegen_scalar_binop( + &mut self, + bx: &mut Bx, + op: mir::BinOp, + lhs: Bx::Value, + rhs: Bx::Value, + input_ty: Ty<'tcx>, + ) -> Bx::Value { + let is_float = input_ty.is_floating_point(); + let is_signed = input_ty.is_signed(); + match op { + mir::BinOp::Add => { + if is_float { + bx.fadd(lhs, rhs) + } else { + bx.add(lhs, rhs) + } + } + mir::BinOp::Sub => { + if is_float { + bx.fsub(lhs, rhs) + } else { + bx.sub(lhs, rhs) + } + } + mir::BinOp::Mul => { + if is_float { + bx.fmul(lhs, rhs) + } else { + bx.mul(lhs, rhs) + } + } + mir::BinOp::Div => { + if is_float { + bx.fdiv(lhs, rhs) + } else if is_signed { + bx.sdiv(lhs, rhs) + } else { + bx.udiv(lhs, rhs) + } + } + mir::BinOp::Rem => { + if is_float { + bx.frem(lhs, rhs) + } else if is_signed { + bx.srem(lhs, rhs) + } else { + bx.urem(lhs, rhs) + } + } + mir::BinOp::BitOr => bx.or(lhs, rhs), + mir::BinOp::BitAnd => bx.and(lhs, rhs), + mir::BinOp::BitXor => bx.xor(lhs, rhs), + mir::BinOp::Offset => { + let pointee_type = input_ty + .builtin_deref(true) + .unwrap_or_else(|| bug!("deref of non-pointer {:?}", input_ty)) + .ty; + let llty = bx.cx().backend_type(bx.cx().layout_of(pointee_type)); + bx.inbounds_gep(llty, lhs, &[rhs]) + } + mir::BinOp::Shl => common::build_unchecked_lshift(bx, lhs, rhs), + mir::BinOp::Shr => common::build_unchecked_rshift(bx, input_ty, lhs, rhs), + mir::BinOp::Ne + | mir::BinOp::Lt + | mir::BinOp::Gt + | mir::BinOp::Eq + | mir::BinOp::Le + | mir::BinOp::Ge => { + if is_float { + bx.fcmp(base::bin_op_to_fcmp_predicate(op.to_hir_binop()), lhs, rhs) + } else { + bx.icmp(base::bin_op_to_icmp_predicate(op.to_hir_binop(), is_signed), lhs, rhs) + } + } + } + } + + pub fn codegen_fat_ptr_binop( + &mut self, + bx: &mut Bx, + op: mir::BinOp, + lhs_addr: Bx::Value, + lhs_extra: Bx::Value, + rhs_addr: Bx::Value, + rhs_extra: Bx::Value, + _input_ty: Ty<'tcx>, + ) -> Bx::Value { + match op { + mir::BinOp::Eq => { + let lhs = bx.icmp(IntPredicate::IntEQ, lhs_addr, rhs_addr); + let rhs = bx.icmp(IntPredicate::IntEQ, lhs_extra, rhs_extra); + bx.and(lhs, rhs) + } + mir::BinOp::Ne => { + let lhs = bx.icmp(IntPredicate::IntNE, lhs_addr, rhs_addr); + let rhs = bx.icmp(IntPredicate::IntNE, lhs_extra, rhs_extra); + bx.or(lhs, rhs) + } + mir::BinOp::Le | mir::BinOp::Lt | mir::BinOp::Ge | mir::BinOp::Gt => { + // a OP b ~ a.0 STRICT(OP) b.0 | (a.0 == b.0 && a.1 OP a.1) + let (op, strict_op) = match op { + mir::BinOp::Lt => (IntPredicate::IntULT, IntPredicate::IntULT), + mir::BinOp::Le => (IntPredicate::IntULE, IntPredicate::IntULT), + mir::BinOp::Gt => (IntPredicate::IntUGT, IntPredicate::IntUGT), + mir::BinOp::Ge => (IntPredicate::IntUGE, IntPredicate::IntUGT), + _ => bug!(), + }; + let lhs = bx.icmp(strict_op, lhs_addr, rhs_addr); + let and_lhs = bx.icmp(IntPredicate::IntEQ, lhs_addr, rhs_addr); + let and_rhs = bx.icmp(op, lhs_extra, rhs_extra); + let rhs = bx.and(and_lhs, and_rhs); + bx.or(lhs, rhs) + } + _ => { + bug!("unexpected fat ptr binop"); + } + } + } + + pub fn codegen_scalar_checked_binop( + &mut self, + bx: &mut Bx, + op: mir::BinOp, + lhs: Bx::Value, + rhs: Bx::Value, + input_ty: Ty<'tcx>, + ) -> OperandValue { + // This case can currently arise only from functions marked + // with #[rustc_inherit_overflow_checks] and inlined from + // another crate (mostly core::num generic/#[inline] fns), + // while the current crate doesn't use overflow checks. + if !bx.cx().check_overflow() { + let val = self.codegen_scalar_binop(bx, op, lhs, rhs, input_ty); + return OperandValue::Pair(val, bx.cx().const_bool(false)); + } + + let (val, of) = match op { + // These are checked using intrinsics + mir::BinOp::Add | mir::BinOp::Sub | mir::BinOp::Mul => { + let oop = match op { + mir::BinOp::Add => OverflowOp::Add, + mir::BinOp::Sub => OverflowOp::Sub, + mir::BinOp::Mul => OverflowOp::Mul, + _ => unreachable!(), + }; + bx.checked_binop(oop, input_ty, lhs, rhs) + } + mir::BinOp::Shl | mir::BinOp::Shr => { + let lhs_llty = bx.cx().val_ty(lhs); + let rhs_llty = bx.cx().val_ty(rhs); + let invert_mask = common::shift_mask_val(bx, lhs_llty, rhs_llty, true); + let outer_bits = bx.and(rhs, invert_mask); + + let of = bx.icmp(IntPredicate::IntNE, outer_bits, bx.cx().const_null(rhs_llty)); + let val = self.codegen_scalar_binop(bx, op, lhs, rhs, input_ty); + + (val, of) + } + _ => bug!("Operator `{:?}` is not a checkable operator", op), + }; + + OperandValue::Pair(val, of) + } +} + +impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { + pub fn rvalue_creates_operand(&self, rvalue: &mir::Rvalue<'tcx>, span: Span) -> bool { + match *rvalue { + mir::Rvalue::Ref(..) | + mir::Rvalue::CopyForDeref(..) | + mir::Rvalue::AddressOf(..) | + mir::Rvalue::Len(..) | + mir::Rvalue::Cast(..) | // (*) + mir::Rvalue::ShallowInitBox(..) | // (*) + mir::Rvalue::BinaryOp(..) | + mir::Rvalue::CheckedBinaryOp(..) | + mir::Rvalue::UnaryOp(..) | + mir::Rvalue::Discriminant(..) | + mir::Rvalue::NullaryOp(..) | + mir::Rvalue::ThreadLocalRef(_) | + mir::Rvalue::Use(..) => // (*) + true, + mir::Rvalue::Repeat(..) | + mir::Rvalue::Aggregate(..) => { + let ty = rvalue.ty(self.mir, self.cx.tcx()); + let ty = self.monomorphize(ty); + self.cx.spanned_layout_of(ty, span).is_zst() + } + } + + // (*) this is only true if the type is suitable + } +} -- cgit v1.2.3