rs6000: re-enable web and rnreg with -funroll-loops

Previously, limited unrolling was enabled at O2 for powerpc in r278034.  At that
time, -fweb and -frename-registers were not enabled together with -funroll-loops
even for -O3.  After that, we notice there are some performance degradations on
SPEC2006fp which caused by without web and rnreg.  This patch enable -fweb
and -frename-registers for -funroll-loops to align original behavior before
r278034.

gcc/
2019-12-23  Jiufu Guo  <guojiufu@linux.ibm.com>

	* config/rs6000/rs6000.c (rs6000_option_override_internal): Enable
	-fweb and -frename-registers with -funroll-loops

From-SVN: r279725

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 6023ccabe78c3d4c509b4c9c9bae1f9c552301a6..525a8f013d819f7847f37dd68596d5a8374ac8c5 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2019-12-24  Jiufu Guo  <guojiufu@linux.ibm.com>
+
+       * config/rs6000/rs6000.c (rs6000_option_override_internal): Enable
+       -fweb and -frename-registers with -funroll-loops
+
 2019-12-22  Gerald Pfeifer  <gerald@pfeifer.com>
 
        * doc/invoke.texi (-flto): Use "compile time" as a noun.

diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index 9dd09b95902e31317dc94d9bc96937a81d5cf9bc..5ee426cb1da271abb7cd0298b8d9d78c7fe2c468 100644 (file)
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -4538,12 +4538,19 @@ rs6000_option_override_internal (bool global_init_p)
                           param_sched_pressure_algorithm,
                           SCHED_PRESSURE_MODEL);
 
-      /* Explicit -funroll-loops turns -munroll-only-small-loops off.  */
-      if (((global_options_set.x_flag_unroll_loops && flag_unroll_loops)
+      /* Explicit -funroll-loops turns -munroll-only-small-loops off, and
+        turns -fweb and -frename-registers on.  */
+      if ((global_options_set.x_flag_unroll_loops && flag_unroll_loops)
           || (global_options_set.x_flag_unroll_all_loops
               && flag_unroll_all_loops))
-         && !global_options_set.x_unroll_only_small_loops)
-       unroll_only_small_loops = 0;
+       {
+         if (!global_options_set.x_unroll_only_small_loops)
+           unroll_only_small_loops = 0;
+         if (!global_options_set.x_flag_rename_registers)
+           flag_rename_registers = 1;
+         if (!global_options_set.x_flag_web)
+           flag_web = 1;
+       }
 
       /* If using typedef char *va_list, signal that
         __builtin_va_start (&ap, 0) can be optimized to