[PATCH][x86] Fix PR91814

[Richard Biener]

Boostrapped and tested on x86_64-unknown-linux-gnu.

OK?

Thanks,
Richard.

2019-09-19  Richard Biener  <rguent...@suse.de>

        PR target/91814
        * config/i386/i386-features.c (gen_gpr_to_xmm_move_src):
        Force operand to a register if it isn't nonimmediate_operand.

Index: gcc/config/i386/i386-features.c
===================================================================
--- gcc/config/i386/i386-features.c     (revision 275959)
+++ gcc/config/i386/i386-features.c     (working copy)
@@ -668,10 +668,13 @@ scalar_chain::emit_conversion_insns (rtx
 static rtx
 gen_gpr_to_xmm_move_src (enum machine_mode vmode, rtx gpr)
 {
+  if (!nonimmediate_operand (gpr, GET_MODE_INNER (vmode)))
+    gpr = force_reg (GET_MODE_INNER (vmode), gpr);
   switch (GET_MODE_NUNITS (vmode))
     {
     case 1:
-      return gen_rtx_SUBREG (vmode, gpr, 0);
+      /* We are not using this case currently.  */
+      gcc_unreachable ();
     case 2:
       return gen_rtx_VEC_CONCAT (vmode, gpr,
                                 CONST0_RTX (GET_MODE_INNER (vmode)));