1 use crate::mir::operand::OperandRef;
4 use rustc_middle::mir::interpret::{ConstValue, ErrorHandled};
5 use rustc_middle::ty::layout::HasTyCtxt;
6 use rustc_middle::ty::{self, Ty};
7 use rustc_span::source_map::Span;
8 use rustc_target::abi::Abi;
10 use super::FunctionCx;
12 impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
13 pub fn eval_mir_constant_to_operand(
16 constant: &mir::Constant<'tcx>,
17 ) -> Result<OperandRef<'tcx, Bx::Value>, ErrorHandled> {
18 let val = self.eval_mir_constant(constant)?;
19 let ty = self.monomorphize(constant.ty());
20 Ok(OperandRef::from_const(bx, val, ty))
23 pub fn eval_mir_constant(
25 constant: &mir::Constant<'tcx>,
26 ) -> Result<ConstValue<'tcx>, ErrorHandled> {
27 let ct = self.monomorphize(constant.literal);
29 mir::ConstantKind::Ty(ct) => match ct.kind() {
30 ty::ConstKind::Unevaluated(uv) => uv.expand(),
31 ty::ConstKind::Value(val) => {
32 return Ok(self.cx.tcx().valtree_to_const_val((ct.ty(), val)));
36 "encountered bad ConstKind after monomorphizing: {:?}",
40 mir::ConstantKind::Unevaluated(uv, _) => uv,
41 mir::ConstantKind::Val(val, _) => return Ok(val),
44 self.cx.tcx().const_eval_resolve(ty::ParamEnv::reveal_all(), uv, None).map_err(|err| {
46 ErrorHandled::Reported(_) => {
47 self.cx.tcx().sess.span_err(constant.span, "erroneous constant encountered");
49 ErrorHandled::TooGeneric => {
50 span_bug!(constant.span, "codegen encountered polymorphic constant: {:?}", err);
57 /// process constant containing SIMD shuffle indices
58 pub fn simd_shuffle_indices(
63 constant: Result<ConstValue<'tcx>, ErrorHandled>,
64 ) -> (Bx::Value, Ty<'tcx>) {
67 let field_ty = ty.builtin_index().unwrap();
68 let c = mir::ConstantKind::from_value(val, ty);
69 let values: Vec<_> = bx
71 .destructure_mir_constant(ty::ParamEnv::reveal_all(), c)
75 if let Some(prim) = field.try_to_scalar() {
76 let layout = bx.layout_of(field_ty);
77 let Abi::Scalar(scalar) = layout.abi else {
78 bug!("from_const: invalid ByVal layout: {:#?}", layout);
80 bx.scalar_to_backend(prim, scalar, bx.immediate_backend_type(layout))
82 bug!("simd shuffle field {:?}", field)
86 let llval = bx.const_struct(&values, false);
90 bx.tcx().sess.span_err(span, "could not evaluate shuffle_indices at compile time");
91 // We've errored, so we don't have to produce working code.
92 let ty = self.monomorphize(ty);
93 let llty = bx.backend_type(bx.layout_of(ty));
94 (bx.const_undef(llty), ty)