[mono][jit] Disable passing SIMD args in SIMD regs on arm64. (#87540)

It has the following problems:
- the gshared versions of SIMD types like Vector<T_INT> are not marked
  as SIMD, so there is a calling convention mismatch if the callee is
  generic shared.
- the gsharedvt code doesn't support it, i.e. it asserts in get_arg_slots ().
- the dyncall code might not support it either.

Fixes https://github.com/dotnet/runtime/issues/87277.

diff --git a/src/mono/mono/mini/mini-arm64.c b/src/mono/mono/mini/mini-arm64.c
index de3a390..1a155b3 100644 (file)
--- a/src/mono/mono/mini/mini-arm64.c
+++ b/src/mono/mono/mini/mini-arm64.c
@@ -1541,6 +1541,8 @@ add_valuetype (CallInfo *cinfo, ArgInfo *ainfo, MonoType *t, gboolean is_return)
        size = mini_type_stack_size_full (t, &align, cinfo->pinvoke);
        align_size = ALIGN_TO (size, 8);
 
+       /* FIXME: gshared, gsharedvt, dyncalls */
+#if 0
        if (m_class_is_simd_type (klass) && size <= 16 && !cinfo->pinvoke && !is_return && cinfo->fr < FP_PARAM_REGS) {
                ainfo->storage = ArgInSIMDReg;
                ainfo->reg = cinfo->fr;
@@ -1549,6 +1551,7 @@ add_valuetype (CallInfo *cinfo, ArgInfo *ainfo, MonoType *t, gboolean is_return)
                cinfo->fr ++;
                return;
        }
+#endif
 
        nregs = align_size / 8;
        if (is_hfa (t, &nfields, &esize, field_offsets)) {