[PATCH 0/3] genmatch: Speed up recompilation after changes to match.pd

[PATCH 0/3] genmatch: Speed up recompilation after changes to match.pd

[Andrzej Turko]

The following reduces the number of object files that need to be rebuilt
after match.pd has been modified. Right now a change to match.pd which
adds/removes a line almost always forces recompilation of all files that
genmatch generates from it. This is because of unnecessary changes to
the generated .cc files:

1. Function names and ordering change as does the way the functions are
        distributed across multiple source files.
2. Code locations from match.pd are quoted directly (including line
        numbers) by logging fprintf calls.

This patch addresses the those issues without changing the behaviour
of the generated code. The first one is solved by making sure that minor
changes to match.pd do not influence the order in which functions are
generated. The second one by using a lookup table with line numbers.

Now a change to a single function will trigger a rebuild of 4 object
files (one with the function  and the one with the lookup table both for
gimple and generic) instead all of them (20 by default).
For reference, this decreased the rebuild time with 48 threads from 3.5
minutes to 1.5 minutes on my machine.


Note for reviewers: I do not have write access.

Andrzej Turko (3):
  Support get_or_insert in ordered_hash_map
  genmatch: Reduce variability of generated code
  genmatch: Log line numbers indirectly

 gcc/Makefile.in               |  4 +-
 gcc/genmatch.cc               | 76 ++++++++++++++++++++++++++++++-----
 gcc/ordered-hash-map-tests.cc | 19 +++++++--
 gcc/ordered-hash-map.h        | 26 ++++++++++++
 4 files changed, 110 insertions(+), 15 deletions(-)

-- 
2.34.1

[PATCH 1/3] Support get_or_insert in ordered_hash_map

[Andrzej Turko]

Get_or_insert method is already supported by the unordered hash map.
Adding it to the ordered map enables us to replace the unordered map
with the ordered one in cases where ordering may be useful.

Signed-off-by: Andrzej Turko <andrzej.turko@gmail.com>

gcc/ChangeLog:

	* ordered-hash-map.h: Add get_or_insert.
	* Makefile.in: Require the ordered map header for genmatch.o.
	* ordered-hash-map-tests.cc: Use get_or_insert in tests.

Signed-off-by: Andrzej Turko <andrzej.turko@gmail.com>
---
 gcc/Makefile.in               |  4 ++--
 gcc/ordered-hash-map-tests.cc | 19 +++++++++++++++----
 gcc/ordered-hash-map.h        | 26 ++++++++++++++++++++++++++
 3 files changed, 43 insertions(+), 6 deletions(-)

diff --git a/gcc/Makefile.in b/gcc/Makefile.in
index e99628cec07..2429128cbf2 100644
--- a/gcc/Makefile.in
+++ b/gcc/Makefile.in
@@ -3004,8 +3004,8 @@ build/genhooks.o : genhooks.cc $(TARGET_DEF) $(C_TARGET_DEF)		\
   $(COMMON_TARGET_DEF) $(D_TARGET_DEF) $(BCONFIG_H) $(SYSTEM_H) errors.h
 build/genmddump.o : genmddump.cc $(RTL_BASE_H) $(BCONFIG_H) $(SYSTEM_H)	\
   $(CORETYPES_H) $(GTM_H) errors.h $(READ_MD_H) $(GENSUPPORT_H)
-build/genmatch.o : genmatch.cc $(BCONFIG_H) $(SYSTEM_H) \
-  $(CORETYPES_H) errors.h $(HASH_TABLE_H) hash-map.h $(GGC_H) is-a.h \
+build/genmatch.o : genmatch.cc $(BCONFIG_H) $(SYSTEM_H) $(CORETYPES_H) \
+  errors.h $(HASH_TABLE_H) hash-map.h $(GGC_H) is-a.h ordered-hash-map.h \
   tree.def builtins.def internal-fn.def case-cfn-macros.h $(CPPLIB_H)
 build/gencfn-macros.o : gencfn-macros.cc $(BCONFIG_H) $(SYSTEM_H)	\
   $(CORETYPES_H) errors.h $(HASH_TABLE_H) hash-set.h builtins.def	\
diff --git a/gcc/ordered-hash-map-tests.cc b/gcc/ordered-hash-map-tests.cc
index 1c26bbfa979..55894c25fa0 100644
--- a/gcc/ordered-hash-map-tests.cc
+++ b/gcc/ordered-hash-map-tests.cc
@@ -58,6 +58,7 @@ static void
 test_map_of_strings_to_int ()
 {
   ordered_hash_map <const char *, int> m;
+  bool existed;
 
   const char *ostrich = "ostrich";
   const char *elephant = "elephant";
@@ -74,17 +75,23 @@ test_map_of_strings_to_int ()
   ASSERT_EQ (false, m.put (ostrich, 2));
   ASSERT_EQ (false, m.put (elephant, 4));
   ASSERT_EQ (false, m.put (ant, 6));
-  ASSERT_EQ (false, m.put (spider, 8));
+  existed = true;
+  int &value = m.get_or_insert (spider, &existed);
+  value = 8;
+  ASSERT_EQ (false, existed);
   ASSERT_EQ (false, m.put (millipede, 750));
   ASSERT_EQ (false, m.put (eric, 3));
 
+
   /* Verify that we can recover the stored values.  */
   ASSERT_EQ (6, m.elements ());
   ASSERT_EQ (2, *m.get (ostrich));
   ASSERT_EQ (4, *m.get (elephant));
   ASSERT_EQ (6, *m.get (ant));
   ASSERT_EQ (8, *m.get (spider));
-  ASSERT_EQ (750, *m.get (millipede));
+  existed = false;
+  ASSERT_EQ (750, m.get_or_insert (millipede, &existed));
+  ASSERT_EQ (true, existed);
   ASSERT_EQ (3, *m.get (eric));
 
   /* Verify that the order of insertion is preserved.  */
@@ -113,6 +120,7 @@ test_map_of_int_to_strings ()
 {
   const int EMPTY = -1;
   const int DELETED = -2;
+  bool existed;
   typedef int_hash <int, EMPTY, DELETED> int_hash_t;
   ordered_hash_map <int_hash_t, const char *> m;
 
@@ -131,7 +139,9 @@ test_map_of_int_to_strings ()
   ASSERT_EQ (false, m.put (2, ostrich));
   ASSERT_EQ (false, m.put (4, elephant));
   ASSERT_EQ (false, m.put (6, ant));
-  ASSERT_EQ (false, m.put (8, spider));
+  const char* &value = m.get_or_insert (8, &existed);
+  value = spider;
+  ASSERT_EQ (false, existed);
   ASSERT_EQ (false, m.put (750, millipede));
   ASSERT_EQ (false, m.put (3, eric));
 
@@ -141,7 +151,8 @@ test_map_of_int_to_strings ()
   ASSERT_EQ (*m.get (4), elephant);
   ASSERT_EQ (*m.get (6), ant);
   ASSERT_EQ (*m.get (8), spider);
-  ASSERT_EQ (*m.get (750), millipede);
+  ASSERT_EQ (m.get_or_insert (750, &existed), millipede);
+  ASSERT_EQ (existed, TRUE);
   ASSERT_EQ (*m.get (3), eric);
 
   /* Verify that the order of insertion is preserved.  */
diff --git a/gcc/ordered-hash-map.h b/gcc/ordered-hash-map.h
index 6b68cc96305..9fc875182e1 100644
--- a/gcc/ordered-hash-map.h
+++ b/gcc/ordered-hash-map.h
@@ -76,6 +76,32 @@ public:
     return m_map.get (k);
   }
 
+  /* Return a reference to the value for the passed in key, creating the entry
+    if it doesn't already exist.  If existed is not NULL then it is set to
+    false if the key was not previously in the map, and true otherwise.  */
+
+  Value &get_or_insert (const Key &k, bool *existed = NULL)
+  {
+    bool _existed;
+    Value &ret = m_map.get_or_insert (k, &_existed);
+
+    if (!_existed)
+      {
+	bool key_present;
+	int &slot = m_key_index.get_or_insert (k, &key_present);
+	if (!key_present)
+	  {
+	    slot = m_keys.length ();
+	    m_keys.safe_push (k);
+	  }
+      }
+
+    if (existed)
+      *existed = _existed;
+
+    return ret;
+  }
+
   /* Removing a key removes it from the map, but retains the insertion
      order.  */
 
-- 
2.34.1

[PATCH 2/3] genmatch: Reduce variability of generated code

[Andrzej Turko]

So far genmatch has been using an unordered map to store information about
functions to be generated. Since corresponding locations from match.pd were
used as keys in the map, even small changes to match.pd which caused
line number changes would change the order in which the functions are
generated. This would reshuffle the functions between the generated .cc files.
This way even a minimal modification to match.pd forces recompilation of all
object files originating from match.pd on rebuild.

This commit makes sure that functions are generated in the order of their
processing (in contrast to the random order based on hashes of their
locations in match.pd). This is done by replacing the unordered map with an
ordered one. This way small changes to match.pd does not cause function
renaming and reshuffling among generated source files.
Together with the subsequent change to logging fprintf calls, this
removes unnecessary changes to the files generated by genmatch allowing
for reuse of already built object files during rebuild. The aim is to
make editing of match.pd and subsequent testing easier.

Signed-off-by: Andrzej Turko <andrzej.turko@gmail.com>

gcc/ChangeLog:

	* genmatch.cc: Make sinfo map ordered.

Signed-off-by: Andrzej Turko <andrzej.turko@gmail.com>
---
 gcc/genmatch.cc | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/gcc/genmatch.cc b/gcc/genmatch.cc
index 2302f2a7ff0..1deca505603 100644
--- a/gcc/genmatch.cc
+++ b/gcc/genmatch.cc
@@ -29,6 +29,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "hash-table.h"
 #include "hash-set.h"
 #include "is-a.h"
+#include "ordered-hash-map.h"
 
 
 /* Stubs for GGC referenced through instantiations triggered by hash-map.  */
@@ -1684,7 +1685,7 @@ struct sinfo_hashmap_traits : simple_hashmap_traits<pointer_hash<dt_simplify>,
   template <typename T> static inline void remove (T &) {}
 };
 
-typedef hash_map<void * /* unused */, sinfo *, sinfo_hashmap_traits>
+typedef ordered_hash_map<void * /* unused */, sinfo *, sinfo_hashmap_traits>
   sinfo_map_t;
 
 /* Current simplifier ID we are processing during insertion into the
-- 
2.34.1

[PATCH 3/3] genmatch: Log line numbers indirectly

[Andrzej Turko]

Currently fprintf calls logging to a dump file take line numbers
in the match.pd file directly as arguments.
When match.pd is edited, referenced code changes line numbers,
which causes changes to many fprintf calls and, thus, to many
(usually all) .cc files generated by genmatch. This forces make
to (unnecessarily) rebuild many .o files.

With this change those logging fprintf calls reference an array
of line numbers, which is defined in one of the produced files.
Thanks to this, when match.pd changes, it is enough to rebuild
that single file and, of course, those actually affected by the
change.

Signed-off-by: Andrzej Turko <andrzej.turko@gmail.com>

gcc/ChangeLog:

	* genmatch.cc: Keep line numbers from match.pd in an array.

Signed-off-by: Andrzej Turko <andrzej.turko@gmail.com>
---
 gcc/genmatch.cc | 73 +++++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 65 insertions(+), 8 deletions(-)

diff --git a/gcc/genmatch.cc b/gcc/genmatch.cc
index 1deca505603..0a480a140c9 100644
--- a/gcc/genmatch.cc
+++ b/gcc/genmatch.cc
@@ -217,9 +217,48 @@ fp_decl_done (FILE *f, const char *trailer)
     fprintf (header_file, "%s;", trailer);
 }
 
+/* Line numbers for use by indirect line directives.  */
+static vec<int> dbg_line_numbers;
+
+static void
+write_header_declarations (bool gimple, FILE *f)
+{
+  if (gimple)
+    fprintf (f, "\nextern int __gimple_dbg_line_numbers[];\n");
+  else
+    fprintf (f, "\nextern int __generic_dbg_line_numbers[];\n");
+}
+
+static void
+define_dbg_line_numbers (bool gimple, FILE *f)
+{
+  if (gimple)
+    fprintf (f, "\nint __gimple_dbg_line_numbers[%d] = {",
+	    dbg_line_numbers.length ());
+  else
+    fprintf (f, "\nint __generic_dbg_line_numbers[%d] = {",
+	    dbg_line_numbers.length ());
+
+   if (dbg_line_numbers.is_empty ())
+    {
+      fprintf (f, "};\n\n");
+      return;
+    }
+
+  for (int i = 0; i < (int)dbg_line_numbers.length () - 1; i++)
+    {
+      if (i % 20 == 0)
+	fprintf (f, "\n\t");
+
+      fprintf (f, "%d, ", dbg_line_numbers[i]);
+    }
+  fprintf (f, "%d\n};\n\n", dbg_line_numbers.last ());
+}
+
 static void
 output_line_directive (FILE *f, location_t location,
-		       bool dumpfile = false, bool fnargs = false)
+		      bool dumpfile = false, bool fnargs = false,
+		      bool indirect_line_numbers = false, bool gimple = false)
 {
   const line_map_ordinary *map;
   linemap_resolve_location (line_table, location, LRK_SPELLING_LOCATION, &map);
@@ -239,7 +278,20 @@ output_line_directive (FILE *f, location_t location,
 	++file;
 
       if (fnargs)
-	fprintf (f, "\"%s\", %d", file, loc.line);
+  {
+  if (indirect_line_numbers)
+    {
+      if (gimple)
+  fprintf (f, "\"%s\", __gimple_dbg_line_numbers[%d]",
+	  file, dbg_line_numbers.length ());
+      else
+  fprintf (f, "\"%s\", __generic_dbg_line_numbers[%d]",
+	  file, dbg_line_numbers.length ());
+      dbg_line_numbers.safe_push (loc.line);
+    }
+  else
+    fprintf (f, "\"%s\", %d", file, loc.line);
+  }
       else
 	fprintf (f, "%s:%d", file, loc.line);
     }
@@ -3378,7 +3430,8 @@ dt_operand::gen (FILE *f, int indent, bool gimple, int depth)
 /* Emit a fprintf to the debug file to the file F, with the INDENT from
    either the RESULT location or the S's match location if RESULT is null. */
 static void
-emit_debug_printf (FILE *f, int indent, class simplify *s, operand *result)
+emit_debug_printf (FILE *f, int indent, class simplify *s, operand *result,
+				  bool gimple)
 {
   fprintf_indent (f, indent, "if (UNLIKELY (debug_dump)) "
 	   "fprintf (dump_file, \"%s ",
@@ -3387,7 +3440,7 @@ emit_debug_printf (FILE *f, int indent, class simplify *s, operand *result)
   fprintf (f, "%%s:%%d, %%s:%%d\\n\", ");
   output_line_directive (f,
 			 result ? result->location : s->match->location, true,
-			 true);
+			 true, true, gimple);
   fprintf (f, ", __FILE__, __LINE__);\n");
 }
 
@@ -3524,7 +3577,7 @@ dt_simplify::gen_1 (FILE *f, int indent, bool gimple, operand *result)
   if (!result)
     {
       /* If there is no result then this is a predicate implementation.  */
-      emit_debug_printf (f, indent, s, result);
+      emit_debug_printf (f, indent, s, result, gimple);
       fprintf_indent (f, indent, "return true;\n");
     }
   else if (gimple)
@@ -3615,7 +3668,7 @@ dt_simplify::gen_1 (FILE *f, int indent, bool gimple, operand *result)
 	}
       else
 	gcc_unreachable ();
-      emit_debug_printf (f, indent, s, result);
+      emit_debug_printf (f, indent, s, result, gimple);
       fprintf_indent (f, indent, "return true;\n");
     }
   else /* GENERIC */
@@ -3670,7 +3723,7 @@ dt_simplify::gen_1 (FILE *f, int indent, bool gimple, operand *result)
 	    }
 	  if (is_predicate)
 	    {
-	      emit_debug_printf (f, indent, s, result);
+	      emit_debug_printf (f, indent, s, result, gimple);
 	      fprintf_indent (f, indent, "return true;\n");
 	    }
 	  else
@@ -3738,7 +3791,7 @@ dt_simplify::gen_1 (FILE *f, int indent, bool gimple, operand *result)
 				  i);
 		}
 	    }
-	  emit_debug_printf (f, indent, s, result);
+	  emit_debug_printf (f, indent, s, result, gimple);
 	  fprintf_indent (f, indent, "return _r;\n");
 	}
     }
@@ -5447,6 +5500,7 @@ main (int argc, char **argv)
       parts.quick_push (stdout);
       write_header (stdout, s_include_file);
       write_header_includes (gimple, stdout);
+      write_header_declarations (gimple, stdout);
     }
   else
     {
@@ -5460,6 +5514,7 @@ main (int argc, char **argv)
       fprintf (header_file, "#ifndef GCC_GIMPLE_MATCH_AUTO_H\n"
 			    "#define GCC_GIMPLE_MATCH_AUTO_H\n");
       write_header_includes (gimple, header_file);
+      write_header_declarations (gimple, header_file);
     }
 
   /* Go over all predicates defined with patterns and perform
@@ -5502,6 +5557,8 @@ main (int argc, char **argv)
 
   dt.gen (parts, gimple);
 
+  define_dbg_line_numbers (gimple, choose_output (parts));
+
   for (FILE *f : parts)
     {
       fprintf (f, "#pragma GCC diagnostic pop\n");
-- 
2.34.1

Re: [PATCH 1/3] Support get_or_insert in ordered_hash_map

[Richard Biener]

On Mon, Jul 31, 2023 at 1:06 PM Andrzej Turko via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> Get_or_insert method is already supported by the unordered hash map.
> Adding it to the ordered map enables us to replace the unordered map
> with the ordered one in cases where ordering may be useful.

OK.  Note the Makefile.in change really belongs to another patch in
the series, without this
it could be pushed independently.

Thanks,
Richard.

> Signed-off-by: Andrzej Turko <andrzej.turko@gmail.com>
>
> gcc/ChangeLog:
>
>         * ordered-hash-map.h: Add get_or_insert.
>         * Makefile.in: Require the ordered map header for genmatch.o.
>         * ordered-hash-map-tests.cc: Use get_or_insert in tests.
>
> Signed-off-by: Andrzej Turko <andrzej.turko@gmail.com>
> ---
>  gcc/Makefile.in               |  4 ++--
>  gcc/ordered-hash-map-tests.cc | 19 +++++++++++++++----
>  gcc/ordered-hash-map.h        | 26 ++++++++++++++++++++++++++
>  3 files changed, 43 insertions(+), 6 deletions(-)
>
> diff --git a/gcc/Makefile.in b/gcc/Makefile.in
> index e99628cec07..2429128cbf2 100644
> --- a/gcc/Makefile.in
> +++ b/gcc/Makefile.in
> @@ -3004,8 +3004,8 @@ build/genhooks.o : genhooks.cc $(TARGET_DEF) $(C_TARGET_DEF)              \
>    $(COMMON_TARGET_DEF) $(D_TARGET_DEF) $(BCONFIG_H) $(SYSTEM_H) errors.h
>  build/genmddump.o : genmddump.cc $(RTL_BASE_H) $(BCONFIG_H) $(SYSTEM_H)        \
>    $(CORETYPES_H) $(GTM_H) errors.h $(READ_MD_H) $(GENSUPPORT_H)
> -build/genmatch.o : genmatch.cc $(BCONFIG_H) $(SYSTEM_H) \
> -  $(CORETYPES_H) errors.h $(HASH_TABLE_H) hash-map.h $(GGC_H) is-a.h \
> +build/genmatch.o : genmatch.cc $(BCONFIG_H) $(SYSTEM_H) $(CORETYPES_H) \
> +  errors.h $(HASH_TABLE_H) hash-map.h $(GGC_H) is-a.h ordered-hash-map.h \
>    tree.def builtins.def internal-fn.def case-cfn-macros.h $(CPPLIB_H)
>  build/gencfn-macros.o : gencfn-macros.cc $(BCONFIG_H) $(SYSTEM_H)      \
>    $(CORETYPES_H) errors.h $(HASH_TABLE_H) hash-set.h builtins.def      \
> diff --git a/gcc/ordered-hash-map-tests.cc b/gcc/ordered-hash-map-tests.cc
> index 1c26bbfa979..55894c25fa0 100644
> --- a/gcc/ordered-hash-map-tests.cc
> +++ b/gcc/ordered-hash-map-tests.cc
> @@ -58,6 +58,7 @@ static void
>  test_map_of_strings_to_int ()
>  {
>    ordered_hash_map <const char *, int> m;
> +  bool existed;
>
>    const char *ostrich = "ostrich";
>    const char *elephant = "elephant";
> @@ -74,17 +75,23 @@ test_map_of_strings_to_int ()
>    ASSERT_EQ (false, m.put (ostrich, 2));
>    ASSERT_EQ (false, m.put (elephant, 4));
>    ASSERT_EQ (false, m.put (ant, 6));
> -  ASSERT_EQ (false, m.put (spider, 8));
> +  existed = true;
> +  int &value = m.get_or_insert (spider, &existed);
> +  value = 8;
> +  ASSERT_EQ (false, existed);
>    ASSERT_EQ (false, m.put (millipede, 750));
>    ASSERT_EQ (false, m.put (eric, 3));
>
> +
>    /* Verify that we can recover the stored values.  */
>    ASSERT_EQ (6, m.elements ());
>    ASSERT_EQ (2, *m.get (ostrich));
>    ASSERT_EQ (4, *m.get (elephant));
>    ASSERT_EQ (6, *m.get (ant));
>    ASSERT_EQ (8, *m.get (spider));
> -  ASSERT_EQ (750, *m.get (millipede));
> +  existed = false;
> +  ASSERT_EQ (750, m.get_or_insert (millipede, &existed));
> +  ASSERT_EQ (true, existed);
>    ASSERT_EQ (3, *m.get (eric));
>
>    /* Verify that the order of insertion is preserved.  */
> @@ -113,6 +120,7 @@ test_map_of_int_to_strings ()
>  {
>    const int EMPTY = -1;
>    const int DELETED = -2;
> +  bool existed;
>    typedef int_hash <int, EMPTY, DELETED> int_hash_t;
>    ordered_hash_map <int_hash_t, const char *> m;
>
> @@ -131,7 +139,9 @@ test_map_of_int_to_strings ()
>    ASSERT_EQ (false, m.put (2, ostrich));
>    ASSERT_EQ (false, m.put (4, elephant));
>    ASSERT_EQ (false, m.put (6, ant));
> -  ASSERT_EQ (false, m.put (8, spider));
> +  const char* &value = m.get_or_insert (8, &existed);
> +  value = spider;
> +  ASSERT_EQ (false, existed);
>    ASSERT_EQ (false, m.put (750, millipede));
>    ASSERT_EQ (false, m.put (3, eric));
>
> @@ -141,7 +151,8 @@ test_map_of_int_to_strings ()
>    ASSERT_EQ (*m.get (4), elephant);
>    ASSERT_EQ (*m.get (6), ant);
>    ASSERT_EQ (*m.get (8), spider);
> -  ASSERT_EQ (*m.get (750), millipede);
> +  ASSERT_EQ (m.get_or_insert (750, &existed), millipede);
> +  ASSERT_EQ (existed, TRUE);
>    ASSERT_EQ (*m.get (3), eric);
>
>    /* Verify that the order of insertion is preserved.  */
> diff --git a/gcc/ordered-hash-map.h b/gcc/ordered-hash-map.h
> index 6b68cc96305..9fc875182e1 100644
> --- a/gcc/ordered-hash-map.h
> +++ b/gcc/ordered-hash-map.h
> @@ -76,6 +76,32 @@ public:
>      return m_map.get (k);
>    }
>
> +  /* Return a reference to the value for the passed in key, creating the entry
> +    if it doesn't already exist.  If existed is not NULL then it is set to
> +    false if the key was not previously in the map, and true otherwise.  */
> +
> +  Value &get_or_insert (const Key &k, bool *existed = NULL)
> +  {
> +    bool _existed;
> +    Value &ret = m_map.get_or_insert (k, &_existed);
> +
> +    if (!_existed)
> +      {
> +       bool key_present;
> +       int &slot = m_key_index.get_or_insert (k, &key_present);
> +       if (!key_present)
> +         {
> +           slot = m_keys.length ();
> +           m_keys.safe_push (k);
> +         }
> +      }
> +
> +    if (existed)
> +      *existed = _existed;
> +
> +    return ret;
> +  }
> +
>    /* Removing a key removes it from the map, but retains the insertion
>       order.  */
>
> --
> 2.34.1
>

Re: [PATCH 2/3] genmatch: Reduce variability of generated code

[Richard Biener]

On Mon, Jul 31, 2023 at 1:06 PM Andrzej Turko via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> So far genmatch has been using an unordered map to store information about
> functions to be generated. Since corresponding locations from match.pd were
> used as keys in the map, even small changes to match.pd which caused
> line number changes would change the order in which the functions are
> generated. This would reshuffle the functions between the generated .cc files.
> This way even a minimal modification to match.pd forces recompilation of all
> object files originating from match.pd on rebuild.
>
> This commit makes sure that functions are generated in the order of their
> processing (in contrast to the random order based on hashes of their
> locations in match.pd). This is done by replacing the unordered map with an
> ordered one. This way small changes to match.pd does not cause function
> renaming and reshuffling among generated source files.
> Together with the subsequent change to logging fprintf calls, this
> removes unnecessary changes to the files generated by genmatch allowing
> for reuse of already built object files during rebuild. The aim is to
> make editing of match.pd and subsequent testing easier.
>
> Signed-off-by: Andrzej Turko <andrzej.turko@gmail.com>

OK.

Thanks,
Richard.

> gcc/ChangeLog:
>
>         * genmatch.cc: Make sinfo map ordered.
>
> Signed-off-by: Andrzej Turko <andrzej.turko@gmail.com>
> ---
>  gcc/genmatch.cc | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/gcc/genmatch.cc b/gcc/genmatch.cc
> index 2302f2a7ff0..1deca505603 100644
> --- a/gcc/genmatch.cc
> +++ b/gcc/genmatch.cc
> @@ -29,6 +29,7 @@ along with GCC; see the file COPYING3.  If not see
>  #include "hash-table.h"
>  #include "hash-set.h"
>  #include "is-a.h"
> +#include "ordered-hash-map.h"
>
>
>  /* Stubs for GGC referenced through instantiations triggered by hash-map.  */
> @@ -1684,7 +1685,7 @@ struct sinfo_hashmap_traits : simple_hashmap_traits<pointer_hash<dt_simplify>,
>    template <typename T> static inline void remove (T &) {}
>  };
>
> -typedef hash_map<void * /* unused */, sinfo *, sinfo_hashmap_traits>
> +typedef ordered_hash_map<void * /* unused */, sinfo *, sinfo_hashmap_traits>
>    sinfo_map_t;
>
>  /* Current simplifier ID we are processing during insertion into the
> --
> 2.34.1
>

Re: [PATCH 3/3] genmatch: Log line numbers indirectly

[Richard Biener]

On Mon, Jul 31, 2023 at 1:07 PM Andrzej Turko via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> Currently fprintf calls logging to a dump file take line numbers
> in the match.pd file directly as arguments.
> When match.pd is edited, referenced code changes line numbers,
> which causes changes to many fprintf calls and, thus, to many
> (usually all) .cc files generated by genmatch. This forces make
> to (unnecessarily) rebuild many .o files.
>
> With this change those logging fprintf calls reference an array
> of line numbers, which is defined in one of the produced files.
> Thanks to this, when match.pd changes, it is enough to rebuild
> that single file and, of course, those actually affected by the
> change.
>
> Signed-off-by: Andrzej Turko <andrzej.turko@gmail.com>

How does this affect the size of the executable?  We are replacing
pushing a small immediate to the stack with an indexed load plus push.

Maybe further indirecting the whole dumping, passing an index of the
match and __FILE__/__LINE__ would help here, so instead of

                          if (UNLIKELY (debug_dump)) fprintf
(dump_file, "Matching expression %s:%d, %s:%d\n", "match.pd", 2522,
__FILE__, __LINE__);

we emit sth like

                          if (UNLIKELY (debug_dump)) dump_match (2522,
__FILE__, __LINE__);

with 2522 replaced by the ID?  That would also get rid of the inline
varargs invocation which might help code size as well (on some targets).

Richard.

> gcc/ChangeLog:
>
>         * genmatch.cc: Keep line numbers from match.pd in an array.
>
> Signed-off-by: Andrzej Turko <andrzej.turko@gmail.com>
> ---
>  gcc/genmatch.cc | 73 +++++++++++++++++++++++++++++++++++++++++++------
>  1 file changed, 65 insertions(+), 8 deletions(-)
>
> diff --git a/gcc/genmatch.cc b/gcc/genmatch.cc
> index 1deca505603..0a480a140c9 100644
> --- a/gcc/genmatch.cc
> +++ b/gcc/genmatch.cc
> @@ -217,9 +217,48 @@ fp_decl_done (FILE *f, const char *trailer)
>      fprintf (header_file, "%s;", trailer);
>  }
>
> +/* Line numbers for use by indirect line directives.  */
> +static vec<int> dbg_line_numbers;
> +
> +static void
> +write_header_declarations (bool gimple, FILE *f)
> +{
> +  if (gimple)
> +    fprintf (f, "\nextern int __gimple_dbg_line_numbers[];\n");
> +  else
> +    fprintf (f, "\nextern int __generic_dbg_line_numbers[];\n");
> +}
> +
> +static void
> +define_dbg_line_numbers (bool gimple, FILE *f)
> +{
> +  if (gimple)
> +    fprintf (f, "\nint __gimple_dbg_line_numbers[%d] = {",
> +           dbg_line_numbers.length ());
> +  else
> +    fprintf (f, "\nint __generic_dbg_line_numbers[%d] = {",
> +           dbg_line_numbers.length ());
> +
> +   if (dbg_line_numbers.is_empty ())
> +    {
> +      fprintf (f, "};\n\n");
> +      return;
> +    }
> +
> +  for (int i = 0; i < (int)dbg_line_numbers.length () - 1; i++)
> +    {
> +      if (i % 20 == 0)
> +       fprintf (f, "\n\t");
> +
> +      fprintf (f, "%d, ", dbg_line_numbers[i]);
> +    }
> +  fprintf (f, "%d\n};\n\n", dbg_line_numbers.last ());
> +}
> +
>  static void
>  output_line_directive (FILE *f, location_t location,
> -                      bool dumpfile = false, bool fnargs = false)
> +                     bool dumpfile = false, bool fnargs = false,
> +                     bool indirect_line_numbers = false, bool gimple = false)
>  {
>    const line_map_ordinary *map;
>    linemap_resolve_location (line_table, location, LRK_SPELLING_LOCATION, &map);
> @@ -239,7 +278,20 @@ output_line_directive (FILE *f, location_t location,
>         ++file;
>
>        if (fnargs)
> -       fprintf (f, "\"%s\", %d", file, loc.line);
> +  {
> +  if (indirect_line_numbers)
> +    {
> +      if (gimple)
> +  fprintf (f, "\"%s\", __gimple_dbg_line_numbers[%d]",
> +         file, dbg_line_numbers.length ());
> +      else
> +  fprintf (f, "\"%s\", __generic_dbg_line_numbers[%d]",
> +         file, dbg_line_numbers.length ());
> +      dbg_line_numbers.safe_push (loc.line);
> +    }
> +  else
> +    fprintf (f, "\"%s\", %d", file, loc.line);
> +  }
>        else
>         fprintf (f, "%s:%d", file, loc.line);
>      }
> @@ -3378,7 +3430,8 @@ dt_operand::gen (FILE *f, int indent, bool gimple, int depth)
>  /* Emit a fprintf to the debug file to the file F, with the INDENT from
>     either the RESULT location or the S's match location if RESULT is null. */
>  static void
> -emit_debug_printf (FILE *f, int indent, class simplify *s, operand *result)
> +emit_debug_printf (FILE *f, int indent, class simplify *s, operand *result,
> +                                 bool gimple)
>  {
>    fprintf_indent (f, indent, "if (UNLIKELY (debug_dump)) "
>            "fprintf (dump_file, \"%s ",
> @@ -3387,7 +3440,7 @@ emit_debug_printf (FILE *f, int indent, class simplify *s, operand *result)
>    fprintf (f, "%%s:%%d, %%s:%%d\\n\", ");
>    output_line_directive (f,
>                          result ? result->location : s->match->location, true,
> -                        true);
> +                        true, true, gimple);
>    fprintf (f, ", __FILE__, __LINE__);\n");
>  }
>
> @@ -3524,7 +3577,7 @@ dt_simplify::gen_1 (FILE *f, int indent, bool gimple, operand *result)
>    if (!result)
>      {
>        /* If there is no result then this is a predicate implementation.  */
> -      emit_debug_printf (f, indent, s, result);
> +      emit_debug_printf (f, indent, s, result, gimple);
>        fprintf_indent (f, indent, "return true;\n");
>      }
>    else if (gimple)
> @@ -3615,7 +3668,7 @@ dt_simplify::gen_1 (FILE *f, int indent, bool gimple, operand *result)
>         }
>        else
>         gcc_unreachable ();
> -      emit_debug_printf (f, indent, s, result);
> +      emit_debug_printf (f, indent, s, result, gimple);
>        fprintf_indent (f, indent, "return true;\n");
>      }
>    else /* GENERIC */
> @@ -3670,7 +3723,7 @@ dt_simplify::gen_1 (FILE *f, int indent, bool gimple, operand *result)
>             }
>           if (is_predicate)
>             {
> -             emit_debug_printf (f, indent, s, result);
> +             emit_debug_printf (f, indent, s, result, gimple);
>               fprintf_indent (f, indent, "return true;\n");
>             }
>           else
> @@ -3738,7 +3791,7 @@ dt_simplify::gen_1 (FILE *f, int indent, bool gimple, operand *result)
>                                   i);
>                 }
>             }
> -         emit_debug_printf (f, indent, s, result);
> +         emit_debug_printf (f, indent, s, result, gimple);
>           fprintf_indent (f, indent, "return _r;\n");
>         }
>      }
> @@ -5447,6 +5500,7 @@ main (int argc, char **argv)
>        parts.quick_push (stdout);
>        write_header (stdout, s_include_file);
>        write_header_includes (gimple, stdout);
> +      write_header_declarations (gimple, stdout);
>      }
>    else
>      {
> @@ -5460,6 +5514,7 @@ main (int argc, char **argv)
>        fprintf (header_file, "#ifndef GCC_GIMPLE_MATCH_AUTO_H\n"
>                             "#define GCC_GIMPLE_MATCH_AUTO_H\n");
>        write_header_includes (gimple, header_file);
> +      write_header_declarations (gimple, header_file);
>      }
>
>    /* Go over all predicates defined with patterns and perform
> @@ -5502,6 +5557,8 @@ main (int argc, char **argv)
>
>    dt.gen (parts, gimple);
>
> +  define_dbg_line_numbers (gimple, choose_output (parts));
> +
>    for (FILE *f : parts)
>      {
>        fprintf (f, "#pragma GCC diagnostic pop\n");
> --
> 2.34.1
>

Re: [PATCH 3/3] genmatch: Log line numbers indirectly

[Andrzej Turko]

[-- Attachment #1: Type: text/plain, Size: 8593 bytes --]

Thank you for the review.

Yes, this increases the binary size.
I have implemented this in the third version of this patch series, is that
what you had in mind?

Originally, this change increased the sizes of binaries 8-12 kB, but after
updating the master branch, this change would actually decrease the
executable size. I described in more detail in the new cover letter.

Andrzej

On Mon, Jul 31, 2023, 15:49 Richard Biener <richard.guenther@gmail.com>
wrote:

> On Mon, Jul 31, 2023 at 1:07 PM Andrzej Turko via Gcc-patches
> <gcc-patches@gcc.gnu.org> wrote:
> >
> > Currently fprintf calls logging to a dump file take line numbers
> > in the match.pd file directly as arguments.
> > When match.pd is edited, referenced code changes line numbers,
> > which causes changes to many fprintf calls and, thus, to many
> > (usually all) .cc files generated by genmatch. This forces make
> > to (unnecessarily) rebuild many .o files.
> >
> > With this change those logging fprintf calls reference an array
> > of line numbers, which is defined in one of the produced files.
> > Thanks to this, when match.pd changes, it is enough to rebuild
> > that single file and, of course, those actually affected by the
> > change.
> >
> > Signed-off-by: Andrzej Turko <andrzej.turko@gmail.com>
>
> How does this affect the size of the executable?  We are replacing
> pushing a small immediate to the stack with an indexed load plus push.
>
> Maybe further indirecting the whole dumping, passing an index of the
> match and __FILE__/__LINE__ would help here, so instead of
>
>                           if (UNLIKELY (debug_dump)) fprintf
> (dump_file, "Matching expression %s:%d, %s:%d\n", "match.pd", 2522,
> __FILE__, __LINE__);
>
> we emit sth like
>
>                           if (UNLIKELY (debug_dump)) dump_match (2522,
> __FILE__, __LINE__);
>
> with 2522 replaced by the ID?  That would also get rid of the inline
> varargs invocation which might help code size as well (on some targets).
>
> Richard.
>
> > gcc/ChangeLog:
> >
> >         * genmatch.cc: Keep line numbers from match.pd in an array.
> >
> > Signed-off-by: Andrzej Turko <andrzej.turko@gmail.com>
> > ---
> >  gcc/genmatch.cc | 73 +++++++++++++++++++++++++++++++++++++++++++------
> >  1 file changed, 65 insertions(+), 8 deletions(-)
> >
> > diff --git a/gcc/genmatch.cc b/gcc/genmatch.cc
> > index 1deca505603..0a480a140c9 100644
> > --- a/gcc/genmatch.cc
> > +++ b/gcc/genmatch.cc
> > @@ -217,9 +217,48 @@ fp_decl_done (FILE *f, const char *trailer)
> >      fprintf (header_file, "%s;", trailer);
> >  }
> >
> > +/* Line numbers for use by indirect line directives.  */
> > +static vec<int> dbg_line_numbers;
> > +
> > +static void
> > +write_header_declarations (bool gimple, FILE *f)
> > +{
> > +  if (gimple)
> > +    fprintf (f, "\nextern int __gimple_dbg_line_numbers[];\n");
> > +  else
> > +    fprintf (f, "\nextern int __generic_dbg_line_numbers[];\n");
> > +}
> > +
> > +static void
> > +define_dbg_line_numbers (bool gimple, FILE *f)
> > +{
> > +  if (gimple)
> > +    fprintf (f, "\nint __gimple_dbg_line_numbers[%d] = {",
> > +           dbg_line_numbers.length ());
> > +  else
> > +    fprintf (f, "\nint __generic_dbg_line_numbers[%d] = {",
> > +           dbg_line_numbers.length ());
> > +
> > +   if (dbg_line_numbers.is_empty ())
> > +    {
> > +      fprintf (f, "};\n\n");
> > +      return;
> > +    }
> > +
> > +  for (int i = 0; i < (int)dbg_line_numbers.length () - 1; i++)
> > +    {
> > +      if (i % 20 == 0)
> > +       fprintf (f, "\n\t");
> > +
> > +      fprintf (f, "%d, ", dbg_line_numbers[i]);
> > +    }
> > +  fprintf (f, "%d\n};\n\n", dbg_line_numbers.last ());
> > +}
> > +
> >  static void
> >  output_line_directive (FILE *f, location_t location,
> > -                      bool dumpfile = false, bool fnargs = false)
> > +                     bool dumpfile = false, bool fnargs = false,
> > +                     bool indirect_line_numbers = false, bool gimple =
> false)
> >  {
> >    const line_map_ordinary *map;
> >    linemap_resolve_location (line_table, location,
> LRK_SPELLING_LOCATION, &map);
> > @@ -239,7 +278,20 @@ output_line_directive (FILE *f, location_t location,
> >         ++file;
> >
> >        if (fnargs)
> > -       fprintf (f, "\"%s\", %d", file, loc.line);
> > +  {
> > +  if (indirect_line_numbers)
> > +    {
> > +      if (gimple)
> > +  fprintf (f, "\"%s\", __gimple_dbg_line_numbers[%d]",
> > +         file, dbg_line_numbers.length ());
> > +      else
> > +  fprintf (f, "\"%s\", __generic_dbg_line_numbers[%d]",
> > +         file, dbg_line_numbers.length ());
> > +      dbg_line_numbers.safe_push (loc.line);
> > +    }
> > +  else
> > +    fprintf (f, "\"%s\", %d", file, loc.line);
> > +  }
> >        else
> >         fprintf (f, "%s:%d", file, loc.line);
> >      }
> > @@ -3378,7 +3430,8 @@ dt_operand::gen (FILE *f, int indent, bool gimple,
> int depth)
> >  /* Emit a fprintf to the debug file to the file F, with the INDENT from
> >     either the RESULT location or the S's match location if RESULT is
> null. */
> >  static void
> > -emit_debug_printf (FILE *f, int indent, class simplify *s, operand
> *result)
> > +emit_debug_printf (FILE *f, int indent, class simplify *s, operand
> *result,
> > +                                 bool gimple)
> >  {
> >    fprintf_indent (f, indent, "if (UNLIKELY (debug_dump)) "
> >            "fprintf (dump_file, \"%s ",
> > @@ -3387,7 +3440,7 @@ emit_debug_printf (FILE *f, int indent, class
> simplify *s, operand *result)
> >    fprintf (f, "%%s:%%d, %%s:%%d\\n\", ");
> >    output_line_directive (f,
> >                          result ? result->location : s->match->location,
> true,
> > -                        true);
> > +                        true, true, gimple);
> >    fprintf (f, ", __FILE__, __LINE__);\n");
> >  }
> >
> > @@ -3524,7 +3577,7 @@ dt_simplify::gen_1 (FILE *f, int indent, bool
> gimple, operand *result)
> >    if (!result)
> >      {
> >        /* If there is no result then this is a predicate
> implementation.  */
> > -      emit_debug_printf (f, indent, s, result);
> > +      emit_debug_printf (f, indent, s, result, gimple);
> >        fprintf_indent (f, indent, "return true;\n");
> >      }
> >    else if (gimple)
> > @@ -3615,7 +3668,7 @@ dt_simplify::gen_1 (FILE *f, int indent, bool
> gimple, operand *result)
> >         }
> >        else
> >         gcc_unreachable ();
> > -      emit_debug_printf (f, indent, s, result);
> > +      emit_debug_printf (f, indent, s, result, gimple);
> >        fprintf_indent (f, indent, "return true;\n");
> >      }
> >    else /* GENERIC */
> > @@ -3670,7 +3723,7 @@ dt_simplify::gen_1 (FILE *f, int indent, bool
> gimple, operand *result)
> >             }
> >           if (is_predicate)
> >             {
> > -             emit_debug_printf (f, indent, s, result);
> > +             emit_debug_printf (f, indent, s, result, gimple);
> >               fprintf_indent (f, indent, "return true;\n");
> >             }
> >           else
> > @@ -3738,7 +3791,7 @@ dt_simplify::gen_1 (FILE *f, int indent, bool
> gimple, operand *result)
> >                                   i);
> >                 }
> >             }
> > -         emit_debug_printf (f, indent, s, result);
> > +         emit_debug_printf (f, indent, s, result, gimple);
> >           fprintf_indent (f, indent, "return _r;\n");
> >         }
> >      }
> > @@ -5447,6 +5500,7 @@ main (int argc, char **argv)
> >        parts.quick_push (stdout);
> >        write_header (stdout, s_include_file);
> >        write_header_includes (gimple, stdout);
> > +      write_header_declarations (gimple, stdout);
> >      }
> >    else
> >      {
> > @@ -5460,6 +5514,7 @@ main (int argc, char **argv)
> >        fprintf (header_file, "#ifndef GCC_GIMPLE_MATCH_AUTO_H\n"
> >                             "#define GCC_GIMPLE_MATCH_AUTO_H\n");
> >        write_header_includes (gimple, header_file);
> > +      write_header_declarations (gimple, header_file);
> >      }
> >
> >    /* Go over all predicates defined with patterns and perform
> > @@ -5502,6 +5557,8 @@ main (int argc, char **argv)
> >
> >    dt.gen (parts, gimple);
> >
> > +  define_dbg_line_numbers (gimple, choose_output (parts));
> > +
> >    for (FILE *f : parts)
> >      {
> >        fprintf (f, "#pragma GCC diagnostic pop\n");
> > --
> > 2.34.1
> >
>