re PR bootstrap/80838 (PGO/LTO bootstrapped compiler 5% slower than pure PGO bootstra...

	PR lto/80838
	* lto-wrapper.c (remove_option): New function.
	(merge_and_complain): Merge PIC/PIE options more realistically.

From-SVN: r250094

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 73cb4fef085ccb0417688ee9dcf7dd51a4504859..aa82521884eba27bf9dcc4afab5b91c8a7725e95 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2017-07-07  Jan Hubicka  <hubicka@ucw.cz>
+
+       PR lto/80838
+       * lto-wrapper.c (remove_option): New function.
+       (merge_and_complain): Merge PIC/PIE options more realistically.
+
 2017-07-10  Georg-Johann Lay  <avr@gjlay.de>
 
        Better ISR prologues by supporting GASes __gcc_isr pseudo insn.

diff --git a/gcc/lto-wrapper.c b/gcc/lto-wrapper.c
index 2545a317fb61accee713ce7521933b239d2d89ad..5e75a4fa48cef999fd34c8bdcdcd42bf807d62af 100644 (file)
--- a/gcc/lto-wrapper.c
+++ b/gcc/lto-wrapper.c
@@ -192,6 +192,20 @@ append_option (struct cl_decoded_option **decoded_options,
          sizeof (struct cl_decoded_option));
 }
 
+/* Remove option number INDEX from DECODED_OPTIONS, update
+   DECODED_OPTIONS_COUNT.  */
+
+static void
+remove_option (struct cl_decoded_option **decoded_options,
+              int index, unsigned int *decoded_options_count)
+{
+  --*decoded_options_count;
+  memmove (&(*decoded_options)[index + 1],
+          &(*decoded_options)[index],
+          sizeof (struct cl_decoded_option)
+          * (*decoded_options_count - index));
+}
+
 /* Try to merge and complain about options FDECODED_OPTIONS when applied
    ontop of DECODED_OPTIONS.  */
 
@@ -202,6 +216,8 @@ merge_and_complain (struct cl_decoded_option **decoded_options,
                    unsigned int fdecoded_options_count)
 {
   unsigned int i, j;
+  struct cl_decoded_option *pic_option = NULL;
+  struct cl_decoded_option *pie_option = NULL;
 
   /* ???  Merge options from files.  Most cases can be
      handled by either unioning or intersecting
@@ -238,10 +254,6 @@ merge_and_complain (struct cl_decoded_option **decoded_options,
        case OPT_fdiagnostics_show_option:
        case OPT_fdiagnostics_show_location_:
        case OPT_fshow_column:
-       case OPT_fPIC:
-       case OPT_fpic:
-       case OPT_fPIE:
-       case OPT_fpie:
        case OPT_fcommon:
        case OPT_fgnu_tm:
          /* Do what the old LTO code did - collect exactly one option
@@ -255,6 +267,16 @@ merge_and_complain (struct cl_decoded_option **decoded_options,
            append_option (decoded_options, decoded_options_count, foption);
          break;
 
+       /* Figure out what PIC/PIE level wins and merge the results.  */
+       case OPT_fPIC:
+       case OPT_fpic:
+         pic_option = foption;
+         break;
+       case OPT_fPIE:
+       case OPT_fpie:
+         pie_option = foption;
+         break;
+
        case OPT_fopenmp:
        case OPT_fopenacc:
        case OPT_fcilkplus:
@@ -286,18 +308,6 @@ merge_and_complain (struct cl_decoded_option **decoded_options,
                         foption->orig_option_with_args_text);
          break;
 
-       case OPT_foffload_abi_:
-         for (j = 0; j < *decoded_options_count; ++j)
-           if ((*decoded_options)[j].opt_index == foption->opt_index)
-             break;
-         if (j == *decoded_options_count)
-           append_option (decoded_options, decoded_options_count, foption);
-         else if (foption->value != (*decoded_options)[j].value)
-           fatal_error (input_location,
-                        "Option %s not used consistently in all LTO input"
-                        " files", foption->orig_option_with_args_text);
-         break;
-
        case OPT_O:
        case OPT_Ofast:
        case OPT_Og:
@@ -368,12 +378,70 @@ merge_and_complain (struct cl_decoded_option **decoded_options,
              (*decoded_options)[j].value = 1;
            }
          break;
+ 
+
+       case OPT_foffload_abi_:
+         for (j = 0; j < *decoded_options_count; ++j)
+           if ((*decoded_options)[j].opt_index == foption->opt_index)
+             break;
+         if (j == *decoded_options_count)
+           append_option (decoded_options, decoded_options_count, foption);
+         else if (foption->value != (*decoded_options)[j].value)
+           fatal_error (input_location,
+                        "Option %s not used consistently in all LTO input"
+                        " files", foption->orig_option_with_args_text);
+         break;
+
 
        case OPT_foffload_:
          append_option (decoded_options, decoded_options_count, foption);
          break;
        }
     }
+
+  /* Merge PIC options:
+      -fPIC + -fpic = -fpic
+      -fPIC + -fno-pic = -fno-pic
+      -fpic/-fPIC + nothin = nothing.  
+     It is a common mistake to mix few -fPIC compiled objects into otherwise
+     non-PIC code.  We do not want to build everything with PIC then.
+
+     It would be good to warn on mismatches, but it is bit hard to do as
+     we do not know what nothing translates to.  */
+    
+  for (unsigned int j = 0; j < *decoded_options_count;)
+    if ((*decoded_options)[j].opt_index == OPT_fPIC
+        || (*decoded_options)[j].opt_index == OPT_fpic)
+      {
+       if (!pic_option
+           || (pic_option->value > 0) != ((*decoded_options)[j].value > 0))
+         remove_option (decoded_options, j, decoded_options_count);
+       else if (pic_option->opt_index == OPT_fPIC
+                && (*decoded_options)[j].opt_index == OPT_fpic)
+         {
+           (*decoded_options)[j] = *pic_option;
+           j++;
+         }
+       else
+         j++;
+      }
+   else if ((*decoded_options)[j].opt_index == OPT_fPIE
+            || (*decoded_options)[j].opt_index == OPT_fpie)
+      {
+       if (!pie_option
+           || pie_option->value != (*decoded_options)[j].value)
+         remove_option (decoded_options, j, decoded_options_count);
+       else if (pie_option->opt_index == OPT_fPIE
+                && (*decoded_options)[j].opt_index == OPT_fpie)
+         {
+           (*decoded_options)[j] = *pie_option;
+           j++;
+         }
+       else
+         j++;
+      }
+   else
+     j++;
 }
 
 /* Auxiliary function that frees elements of PTR and PTR itself.