1 files changed, 34 insertions, 19 deletions
diff --git a/compiler/rustc_codegen_llvm/src/intrinsic.rs b/compiler/rustc_codegen_llvm/src/intrinsic.rs
index 23e6f054a7c..1eac2157cac 100644
--- a/compiler/rustc_codegen_llvm/src/intrinsic.rs
+++ b/compiler/rustc_codegen_llvm/src/intrinsic.rs
@@ -1079,7 +1079,7 @@ fn generic_simd_intrinsic<'ll, 'tcx>(
             .map(|(arg_idx, val)| {
                 let idx = val.unwrap_leaf().try_to_i32().unwrap();
                 if idx >= i32::try_from(total_len).unwrap() {
-                    bx.sess().dcx().emit_err(InvalidMonomorphization::ShuffleIndexOutOfBounds {
+                    bx.sess().dcx().emit_err(InvalidMonomorphization::SimdIndexOutOfBounds {
                         span,
                         name,
                         arg_idx: arg_idx as u64,
@@ -1138,24 +1138,15 @@ fn generic_simd_intrinsic<'ll, 'tcx>(
                 let val = bx.const_get_elt(vector, i as u64);
                 match bx.const_to_opt_u128(val, true) {
                     None => {
-                        bx.sess().dcx().emit_err(
-                            InvalidMonomorphization::ShuffleIndexNotConstant {
-                                span,
-                                name,
-                                arg_idx,
-                            },
-                        );
-                        None
+                        bug!("typeck should have already ensured that these are const")
                     }
                     Some(idx) if idx >= total_len => {
-                        bx.sess().dcx().emit_err(
-                            InvalidMonomorphization::ShuffleIndexOutOfBounds {
-                                span,
-                                name,
-                                arg_idx,
-                                total_len,
-                            },
-                        );
+                        bx.sess().dcx().emit_err(InvalidMonomorphization::SimdIndexOutOfBounds {
+                            span,
+                            name,
+                            arg_idx,
+                            total_len,
+                        });
                         None
                     }
                     Some(idx) => Some(bx.const_i32(idx as i32)),
@@ -1184,10 +1175,22 @@ fn generic_simd_intrinsic<'ll, 'tcx>(
                 out_ty: arg_tys[2]
             }
         );
+        let idx = bx
+            .const_to_opt_u128(args[1].immediate(), false)
+            .expect("typeck should have ensure that this is a const");
+        if idx >= in_len.into() {
+            bx.sess().dcx().emit_err(InvalidMonomorphization::SimdIndexOutOfBounds {
+                span,
+                name,
+                arg_idx: 1,
+                total_len: in_len.into(),
+            });
+            return Ok(bx.const_null(llret_ty));
+        }
         return Ok(bx.insert_element(
             args[0].immediate(),
             args[2].immediate(),
-            args[1].immediate(),
+            bx.const_i32(idx as i32),
         ));
     }
     if name == sym::simd_extract {
@@ -1195,7 +1198,19 @@ fn generic_simd_intrinsic<'ll, 'tcx>(
             ret_ty == in_elem,
             InvalidMonomorphization::ReturnType { span, name, in_elem, in_ty, ret_ty }
         );
-        return Ok(bx.extract_element(args[0].immediate(), args[1].immediate()));
+        let idx = bx
+            .const_to_opt_u128(args[1].immediate(), false)
+            .expect("typeck should have ensure that this is a const");
+        if idx >= in_len.into() {
+            bx.sess().dcx().emit_err(InvalidMonomorphization::SimdIndexOutOfBounds {
+                span,
+                name,
+                arg_idx: 1,
+                total_len: in_len.into(),
+            });
+            return Ok(bx.const_null(llret_ty));
+        }
+        return Ok(bx.extract_element(args[0].immediate(), bx.const_i32(idx as i32)));
     }
 
     if name == sym::simd_select {