[PATCH PR83789] Fix for Altivec builtin failure

[Kaushik Phatak]

Hi,
Please find below a patch to fix PR83789.
The altivec builtin '__builtin_altivec_lvx' fails for the 32-bit powerpc-linux 
target.
This is observed in gcc-7 onwards and does not affect powerpc64-linux target.

This is regression tested for powerpc-linux.
Please let me know if this patch is OK.

Regards,
Kaushik M Phatak

2018-02-01  Kaushik Phatak  <kaushik.pha...@kpit.com>

        PR target/83789
        * config/rs6000/rs6000.c (altivec_expand_builtin): Provide
           support for 32-bit target for altivec builtin.



Index: gcc/config/rs6000/rs6000.c
===================================================================
--- gcc/config/rs6000/rs6000.c  (revision 256400)
+++ gcc/config/rs6000/rs6000.c  (working copy)
@@ -15799,8 +15799,10 @@
                                        exp, target, false);
     case ALTIVEC_BUILTIN_LVX:
     case ALTIVEC_BUILTIN_LVX_V4SI:
-      return altivec_expand_lv_builtin (CODE_FOR_altivec_lvx_v4si_2op,
-                                       exp, target, false);
+      return altivec_expand_lv_builtin (((TARGET_64BIT)
+                                        ? CODE_FOR_altivec_lvx_v4si_2op
+                                        : CODE_FOR_altivec_lvx_v4si_internal),
+                                          exp, target, false);
     case ALTIVEC_BUILTIN_LVX_V8HI:
       return altivec_expand_lv_builtin (CODE_FOR_altivec_lvx_v8hi_2op,
                                        exp, target, false);