rs6000.c (rs6000_option_override_internal): Enable -fvariable-expansion-in-unroller...

2019-06-27  Bill Schmidt  <wschmidt@linux.ibm.com>

	* config/rs6000/rs6000.c (rs6000_option_override_internal): Enable
	-fvariable-expansion-in-unroller by default.
	* doc/invoke.texi (-fvariable-expansion-in-unroller): Document new
	default for Power.

From-SVN: r272754

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index b94e7b2e1e8827e27917167a6e6bdb61eed34438..93dbd4f160430ae58eab331bcd5b04b87b7f959d 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2019-06-27  Bill Schmidt  <wschmidt@linux.ibm.com>
+
+       * config/rs6000/rs6000.c (rs6000_option_override_internal): Enable
+       -fvariable-expansion-in-unroller by default.
+       * doc/invoke.texi (-fvariable-expansion-in-unroller): Document new
+       default for Power.
+
 2019-06-27  David Edelsohn  <dje.gcc@gmail.com>
 
        Revert

diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index 1837b312f55b4b69f5a6a01b2a1b9b203f3598b8..3b59db5cf2cd0f9b1ab8a17776f68afb4bf239d1 100644 (file)
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -3616,6 +3616,12 @@ rs6000_option_override_internal (bool global_init_p)
       && !global_options_set.x_flag_asynchronous_unwind_tables)
     flag_asynchronous_unwind_tables = 1;
 
+  /* -fvariable-expansion-in-unroller is a win for POWER whenever the
+     loop unroller is active.  It is only checked during unrolling, so
+     we can just set it on by default.  */
+  if (!global_options_set.x_flag_variable_expansion_in_unroller)
+    flag_variable_expansion_in_unroller = 1;
+
   /* Set the pointer size.  */
   if (TARGET_64BIT)
     {

diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 03d2895c9d7e56df0cd3c14e9914160d42ab4010..04fd504496e5af25ab0fc0f346b2efbbb9cf1b66 100644 (file)
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -9849,6 +9849,9 @@ This optimization is enabled by default.
 With this option, the compiler creates multiple copies of some
 local variables when unrolling a loop, which can result in superior code.
 
+This optimization is enabled by default for PowerPC targets, but disabled
+by default otherwise.
+
 @item -fpartial-inlining
 @opindex fpartial-inlining
 Inline parts of functions.  This option has any effect only