diff options
Diffstat (limited to 'compiler/rustc_codegen_ssa/src/base.rs')
| -rw-r--r-- | compiler/rustc_codegen_ssa/src/base.rs | 22 |
1 files changed, 13 insertions, 9 deletions
diff --git a/compiler/rustc_codegen_ssa/src/base.rs b/compiler/rustc_codegen_ssa/src/base.rs index 198e56963..1d5205ac6 100644 --- a/compiler/rustc_codegen_ssa/src/base.rs +++ b/compiler/rustc_codegen_ssa/src/base.rs @@ -148,10 +148,9 @@ pub fn unsized_info<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>( (&ty::Array(_, len), &ty::Slice(_)) => { cx.const_usize(len.eval_target_usize(cx.tcx(), ty::ParamEnv::reveal_all())) } - ( - &ty::Dynamic(ref data_a, _, src_dyn_kind), - &ty::Dynamic(ref data_b, _, target_dyn_kind), - ) if src_dyn_kind == target_dyn_kind => { + (&ty::Dynamic(data_a, _, src_dyn_kind), &ty::Dynamic(data_b, _, target_dyn_kind)) + if src_dyn_kind == target_dyn_kind => + { let old_info = old_info.expect("unsized_info: missing old info for trait upcasting coercion"); if data_a.principal_def_id() == data_b.principal_def_id() { @@ -322,8 +321,13 @@ pub fn cast_shift_expr_rhs<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>( if lhs_sz < rhs_sz { bx.trunc(rhs, lhs_llty) } else if lhs_sz > rhs_sz { - // FIXME (#1877: If in the future shifting by negative - // values is no longer undefined then this is wrong. + // We zero-extend even if the RHS is signed. So e.g. `(x: i32) << -1i8` will zero-extend the + // RHS to `255i32`. But then we mask the shift amount to be within the size of the LHS + // anyway so the result is `31` as it should be. All the extra bits introduced by zext + // are masked off so their value does not matter. + // FIXME: if we ever support 512bit integers, this will be wrong! For such large integers, + // the extra bits introduced by zext are *not* all masked away any more. + assert!(lhs_sz <= 256); bx.zext(rhs, lhs_llty) } else { rhs @@ -453,8 +457,8 @@ pub fn maybe_create_entry_wrapper<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>( cx.set_frame_pointer_type(llfn); cx.apply_target_cpu_attr(llfn); - let llbb = Bx::append_block(&cx, llfn, "top"); - let mut bx = Bx::build(&cx, llbb); + let llbb = Bx::append_block(cx, llfn, "top"); + let mut bx = Bx::build(cx, llbb); bx.insert_reference_to_gdb_debug_scripts_section_global(); @@ -680,7 +684,7 @@ pub fn codegen_crate<B: ExtraBackendMethods>( // Calculate the CGU reuse let cgu_reuse = tcx.sess.time("find_cgu_reuse", || { - codegen_units.iter().map(|cgu| determine_cgu_reuse(tcx, &cgu)).collect::<Vec<_>>() + codegen_units.iter().map(|cgu| determine_cgu_reuse(tcx, cgu)).collect::<Vec<_>>() }); crate::assert_module_sources::assert_module_sources(tcx, &|cgu_reuse_tracker| { |