Evaluate constants in SIMD vec lengths before rejecting them

Author: oli-obk

compiler/rustc_hir_analysis/src/check/intrinsicck.rs

@@ -83,6 +83,7 @@ impl<'a, 'tcx> InlineAsmCtxt<'a, 'tcx> {
 
                 let (size, ty) = match elem_ty.kind() {
                     ty::Array(ty, len) => {
+                        let len = self.tcx.normalize_erasing_regions(self.typing_env, *len);
                         if let Some(len) = len.try_to_target_usize(self.tcx) {
                             (len, *ty)
                         } else {

tests/ui/asm/named_const_simd_vec_len.rs

@@ -1,6 +1,8 @@
 //! This is a regression test to ensure that we evaluate
 //! SIMD vector length constants instead of assuming they are literals.
 
+//@check-pass
+
 #![feature(repr_simd)]
 
 const C: usize = 16;
@@ -13,7 +15,6 @@ pub unsafe fn foo(a: Foo) {
     std::arch::asm!(
         "movaps {src}, {src}",
         src = in(xmm_reg) a,
-        //~^ ERROR: cannot use value of type `Foo` for inline assembly
     );
 }