Auto merge of #103917 - oli-obk:layout_math, r=RalfJung,lcnr

Various cleanups around scalar layout restrictions

Pulled out of https://github.com/rust-lang/rust/pull/103724

1 files changed, 4 insertions, 12 deletions

diff --git a/compiler/rustc_const_eval/src/interpret/validity.rs b/compiler/rustc_const_eval/src/interpret/validity.rs
index cd7a472c0f0..0e85c7d11bc 100644
--- a/compiler/rustc_const_eval/src/interpret/validity.rs
+++ b/compiler/rustc_const_eval/src/interpret/validity.rs
@@ -785,18 +785,10 @@ impl<'rt, 'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> ValueVisitor<'mir, 'tcx, M>
                 }
             }
             Abi::ScalarPair(a_layout, b_layout) => {
-                // There is no `rustc_layout_scalar_valid_range_start` for pairs, so
-                // we would validate these things as we descend into the fields,
-                // but that can miss bugs in layout computation. Layout computation
-                // is subtle due to enums having ScalarPair layout, where one field
-                // is the discriminant.
-                if cfg!(debug_assertions)
-                    && !a_layout.is_uninit_valid()
-                    && !b_layout.is_uninit_valid()
-                {
-                    // We can only proceed if *both* scalars need to be initialized.
-                    // FIXME: find a way to also check ScalarPair when one side can be uninit but
-                    // the other must be init.
+                // We can only proceed if *both* scalars need to be initialized.
+                // FIXME: find a way to also check ScalarPair when one side can be uninit but
+                // the other must be init.
+                if !a_layout.is_uninit_valid() && !b_layout.is_uninit_valid() {
                     let (a, b) =
                         self.read_immediate(op, "initiailized scalar value")?.to_scalar_pair();
                     self.visit_scalar(a, a_layout)?;