[Bug target/84369] test case gcc.dg/sms-10.c fails on power9

[bergner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84369

Peter Bergner <bergner at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2018-04-12
                 CC|                            |bergner at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #2 from Peter Bergner <bergner at gcc dot gnu.org> ---
Confirmed.  Looking at the rtl dumps, the only difference coming into SMS, is
the following (due to combine):

-(insn 25 23 26 4 (set (reg:DI 150 [ iD.2875+-4 ])
-        (sign_extend:DI (subreg/v:SI (reg/v:DI 137 [ iD.2875+-4 ]) 4)))
"/home/bergner/gcc/gcc-fsf-mainline-mcpu-native/gcc/testsuite/gcc.dg/sms-10.c":33
38 {extendsidi2}
-     (nil))
+(note 25 23 26 4 NOTE_INSN_DELETED)
 (insn 26 25 28 4 (set (reg:DI 151)
-        (ashift:DI (reg:DI 150 [ iD.2875+-4 ])
-            (const_int 3 [0x3])))
"/home/bergner/gcc/gcc-fsf-mainline-mcpu-native/gcc/testsuite/gcc.dg/sms-10.c":33
270 {ashldi3}
-     (expr_list:REG_DEAD (reg:DI 150 [ iD.2875+-4 ])
-        (nil)))
+        (ashift:DI (sign_extend:DI (subreg:SI (reg/v:DI 137 [ iD.2880+-4 ])
4))
+            (const_int 3 [0x3])))
"/home/bergner/gcc/gcc-fsf-mainline-mcpu-native/gcc/testsuite/gcc.dg/sms-10.c":33
276 {ashdi3_extswsli}
+     (nil))

...and the ashdi3_extswsli pattern is only enabled with power9.  Not sure yet
why the above disables SMS, but will keep looking.