Function arguments should never get promoted

src/librustc_mir/transform/qualify_consts.rs

@@ -639,15 +639,15 @@ impl<'a, 'tcx> Checker<'a, 'tcx> {
                             per_local.insert(local);
                         }
                     }
-                    cx.per_local[IsNotPromotable].insert(local);
+                    cx.per_local[IsNotConst].insert(local);
                 }
 
                 LocalKind::Var if mode == Mode::Fn => {
                     cx.per_local[IsNotConst].insert(local);
                 }
 
                 LocalKind::Temp if !temps[local].is_promotable() => {
-                    cx.per_local[IsNotPromotable].insert(local);
+                    cx.per_local[IsNotConst].insert(local);
                 }
 
                 _ => {}
@@ -817,15 +817,15 @@ impl<'a, 'tcx> Checker<'a, 'tcx> {
             }
         }
 
-        // Ensure the `IsNotPromotable` qualification is preserved.
+        // Ensure the `IsNotConst` qualification is preserved.
         // NOTE(eddyb) this is actually unnecessary right now, as
         // we never replace the local's qualif, but we might in
         // the future, and so it serves to catch changes that unset
         // important bits (in which case, asserting `contains` could
         // be replaced with calling `insert` to re-set the bit).
         if kind == LocalKind::Temp {
             if !self.temp_promotion_state[index].is_promotable() {
-                assert!(self.cx.per_local[IsNotPromotable].contains(index));
+                assert!(self.cx.per_local[IsNotConst].contains(index));
             }
         }
     }

src/test/ui/consts/const_arg_local.rs

@@ -0,0 +1,13 @@
+// only-x86_64
+
+#[cfg(target_arch = "x86")]
+use std::arch::x86::*;
+#[cfg(target_arch = "x86_64")]
+use std::arch::x86_64::*;
+
+unsafe fn pclmul(a: __m128i, b: __m128i) -> __m128i {
+    let imm8 = 3;
+    _mm_clmulepi64_si128(a, b, imm8) //~ ERROR argument 3 is required to be a constant
+}
+
+fn main() {}

src/test/ui/consts/const_arg_local.stderr

@@ -0,0 +1,8 @@
+error: argument 3 is required to be a constant
+  --> $DIR/const_arg_local.rs:10:5
+   |
+LL |     _mm_clmulepi64_si128(a, b, imm8)
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+

src/test/ui/consts/const_arg_promotable.rs

@@ -0,0 +1,12 @@
+// only-x86_64
+
+#[cfg(target_arch = "x86")]
+use std::arch::x86::*;
+#[cfg(target_arch = "x86_64")]
+use std::arch::x86_64::*;
+
+unsafe fn pclmul(a: __m128i, b: __m128i) -> __m128i {
+    _mm_clmulepi64_si128(a, b, *&mut 42) //~ ERROR argument 3 is required to be a constant
+}
+
+fn main() {}

src/test/ui/consts/const_arg_promotable.stderr

@@ -0,0 +1,8 @@
+error: argument 3 is required to be a constant
+  --> $DIR/const_arg_promotable.rs:9:5
+   |
+LL |     _mm_clmulepi64_si128(a, b, *&mut 42)
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+

src/test/ui/consts/const_arg_wrapper.rs

@@ -0,0 +1,12 @@
+// only-x86_64
+
+#[cfg(target_arch = "x86")]
+use std::arch::x86::*;
+#[cfg(target_arch = "x86_64")]
+use std::arch::x86_64::*;
+
+unsafe fn pclmul(a: __m128i, b: __m128i, imm8: i32) -> __m128i {
+    _mm_clmulepi64_si128(a, b, imm8) //~ ERROR argument 3 is required to be a constant
+}
+
+fn main() {}

src/test/ui/consts/const_arg_wrapper.stderr

@@ -0,0 +1,8 @@
+error: argument 3 is required to be a constant
+  --> $DIR/const_arg_wrapper.rs:9:5
+   |
+LL |     _mm_clmulepi64_si128(a, b, imm8)
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+