32 bit platforms don't have 64 bit pointers

Author: oli-obk

compiler/rustc_mir/src/const_eval/eval_queries.rs

@@ -14,7 +14,7 @@ use rustc_middle::ty::print::with_no_trimmed_paths;
 use rustc_middle::ty::{self, subst::Subst, TyCtxt};
 use rustc_span::source_map::Span;
 use rustc_target::abi::{Abi, LayoutOf};
-use std::convert::{TryFrom, TryInto};
+use std::convert::TryInto;
 
 pub fn note_on_undefined_behavior_error() -> &'static str {
     "The rules on what exactly is undefined behavior aren't clear, \
@@ -140,7 +140,8 @@ pub(super) fn op_to_const<'tcx>(
         Scalar::Raw(int) => {
             assert!(mplace.layout.is_zst());
             assert_eq!(
-                u64::try_from(int).unwrap() % mplace.layout.align.abi.bytes(),
+                int.assert_bits(ecx.tcx.data_layout.pointer_size)
+                    % u128::from(mplace.layout.align.abi.bytes()),
                 0,
                 "this MPlaceTy must come from a validated constant, thus we can assume the \
                 alignment is correct",