[PATCH][match-and-simplify] Dump what patterns get applied

[Richard Biener <rguenther at suse dot de>]

The following adds dumping what patterns get applied with -details.
This is useful for tracking down which patterns cause a miscompile.

Applied.

Richard.

2014-09-11  Richard Biener  <rguenther@suse.de>

	* genmatch.c (output_line_directive): Add variant for dump files.
	(dt_simplify::gen): Write to dump file with TDF_DETAILS what
	patterns get applied.
	* gimple-match-head: Include dumpfile.h.
	* generic-match-head: Likewise.

Index: gcc/genmatch.c
===================================================================
--- gcc/genmatch.c	(revision 215124)
+++ gcc/genmatch.c	(working copy)
@@ -64,16 +64,28 @@ fatal_at (const cpp_token *tk, const cha
 }
 
 static void
-output_line_directive (FILE *f, source_location location)
+output_line_directive (FILE *f, source_location location,
+		       bool dumpfile = false)
 {
   const line_map *map;
   linemap_resolve_location (line_table, location, LRK_SPELLING_LOCATION, &map);
   expanded_location loc = linemap_expand_location (line_table, map, location);
-  /* Other gen programs really output line directives here, at least for
-     development it's right now more convenient to have line information
-     from the generated file.  Still keep the directives as comment for now
-     to easily back-point to the meta-description.  */
-  fprintf (f, "/* #line %d \"%s\" */\n", loc.line, loc.file);
+  if (dumpfile)
+    {
+      /* When writing to a dumpfile only dump the filename.  */
+      const char *file = strrchr (loc.file, DIR_SEPARATOR);
+      if (!file)
+	file = loc.file;
+      else
+	++file;
+      fprintf (f, "%s:%d", file, loc.line);
+    }
+  else
+    /* Other gen programs really output line directives here, at least for
+       development it's right now more convenient to have line information
+       from the generated file.  Still keep the directives as comment for now
+       to easily back-point to the meta-description.  */
+    fprintf (f, "/* #line %d \"%s\" */\n", loc.line, loc.file);
 }
 
 
@@ -1710,9 +1722,8 @@ dt_operand::gen_generic_kids (FILE *f)
 void
 dt_simplify::gen (FILE *f, bool gimple)
 {
-  output_line_directive (f, s->result_location);
-
   fprintf (f, "{\n");
+  output_line_directive (f, s->result_location);
   fprintf (f, "tree captures[%u] ATTRIBUTE_UNUSED = {};\n", dt_simplify::capture_max);
 
   for (unsigned i = 0; i < dt_simplify::capture_max; ++i)
@@ -1729,15 +1740,16 @@ dt_simplify::gen (FILE *f, bool gimple)
       for (int i = s->ifexpr_vec.length () - 1; i >= 0; --i)
 	{
 	  if_or_with &w = s->ifexpr_vec[i];
-	  output_line_directive (f, w.location);
 	  if (w.is_with)
 	    {
 	      fprintf (f, "{\n");
+	      output_line_directive (f, w.location);
 	      w.cexpr->gen_transform (f, NULL, true, 1, "type");
 	      n_braces++;
 	    }
 	  else
 	    {
+	      output_line_directive (f, w.location);
 	      fprintf (f, "if (");
 	      if (i == 0 || s->ifexpr_vec[i-1].is_with)
 		w.cexpr->gen_transform (f, NULL, true, 1, "type");
@@ -1768,6 +1780,11 @@ dt_simplify::gen (FILE *f, bool gimple)
       n_braces++;
     }
 
+  fprintf (f, "if (dump_file && (dump_flags & TDF_DETAILS)) "
+	   "fprintf (dump_file, \"Applying pattern ");
+  output_line_directive (f, s->result_location, true);
+  fprintf (f, ", %%s:%%d\\n\", __FILE__, __LINE__);\n");
+
   if (gimple)
     {
       if (s->result->type == operand::OP_EXPR)
Index: gcc/gimple-match-head.c
===================================================================
--- gcc/gimple-match-head.c	(revision 215009)
+++ gcc/gimple-match-head.c	(working copy)
@@ -38,6 +38,7 @@ along with GCC; see the file COPYING3.
 #include "expr.h"
 #include "tree-dfa.h"
 #include "builtins.h"
+#include "dumpfile.h"
 #include "gimple-match.h"
 
 #define integral_op_p(node) INTEGRAL_TYPE_P(TREE_TYPE(node))
Index: gcc/generic-match-head.c
===================================================================
--- gcc/generic-match-head.c	(revision 215009)
+++ gcc/generic-match-head.c	(working copy)
@@ -38,6 +38,7 @@ along with GCC; see the file COPYING3.
 #include "expr.h"
 #include "tree-dfa.h"
 #include "builtins.h"
+#include "dumpfile.h"
 
 #define INTEGER_CST_P(node) (TREE_CODE(node) == INTEGER_CST)
 #define integral_op_p(node) INTEGRAL_TYPE_P(TREE_TYPE(node))