[Ada] small performance improvements
Arnaud Charlet
charlet@adacore.com
Mon Apr 9 08:20:00 GMT 2007
Tested on i686-linux, committed on trunk
Improve performance and make some routines in namet.adb more fool-proof.
Add some routines to ease debugging.
2007-04-06 Robert Dewar <dewar@adacore.com>
* namet.ads, namet.adb (wn): Improve this debugging routine. Calling
it no longer destroys the contents of Name_Buffer or Name_Len and
non-standard and invalid names are handled better.
(Get_Decoded_Name_String): Improve performance by using
Name_Has_No_Encodings flag in the name table.
(Is_Valid_Name): New function to determine whether a Name_Id is valid.
Used for debugging printouts.
-------------- next part --------------
Index: namet.ads
===================================================================
--- namet.ads (revision 123291)
+++ namet.ads (working copy)
@@ -6,7 +6,7 @@
-- --
-- S p e c --
-- --
--- Copyright (C) 1992-2005 Free Software Foundation, Inc. --
+-- Copyright (C) 1992-2006, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
@@ -291,6 +291,10 @@ package Namet is
-- passed in Name_Buffer and Name_Len (which are not affected by the call).
-- Name_Buffer (it loads these as for Get_Name_String).
+ function Is_Valid_Name (Id : Name_Id) return Boolean;
+ -- True if Id is a valid name -- points to a valid entry in the
+ -- Name_Entries table.
+
procedure Reset_Name_Table;
-- This procedure is used when there are multiple source files to reset
-- the name table info entries associated with current entries in the
@@ -358,16 +362,22 @@ package Namet is
-- in encoded form (i.e. including Uhh, Whhh, Qx, _op as they appear in
-- the name table). If Id is Error_Name, or No_Name, no text is output.
- procedure wn (Id : Name_Id);
- pragma Export (Ada, wn);
- -- Like Write_Name, but includes new line at end. Intended for use
- -- from the debugger only.
-
procedure Write_Name_Decoded (Id : Name_Id);
-- Like Write_Name, except that the name written is the decoded name, as
-- described for Get_Decoded_Name_String, and the resulting value stored
-- in Name_Len and Name_Buffer is the decoded name.
+ procedure wn (Id : Name_Id);
+ pragma Export (Ada, wn);
+ -- This routine is intended for debugging use only (i.e. it is intended to
+ -- be called from the debugger). It writes the characters of the specified
+ -- name using the standard output procedures in package Output, followed by
+ -- a new line. The name is written in encoded form (i.e. including Uhh,
+ -- Whhh, Qx, _op as they appear in the name table). If Id is Error_Name,
+ -- No_Name, or invalid an appropriate string is written (<Error_Name>,
+ -- <No_Name>, <invalid name>). Unlike Write_Name, this call does not affect
+ -- the contents of Name_Buffer or Name_Len.
+
---------------------------
-- Table Data Structures --
---------------------------
@@ -404,6 +414,12 @@ private
Byte_Info : Byte;
-- Byte value associated with this name
+ Name_Has_No_Encodings : Boolean;
+ -- This flag is set True if the name entry is known not to contain any
+ -- special character encodings. This is used to speed up repeated calls
+ -- to Get_Decoded_Name_String. A value of False means that it is not
+ -- known whether the name contains any such encodings.
+
Hash_Link : Name_Id;
-- Link to next entry in names table for same hash code
Index: namet.adb
===================================================================
--- namet.adb (revision 123291)
+++ namet.adb (working copy)
@@ -6,7 +6,7 @@
-- --
-- B o d y --
-- --
--- Copyright (C) 1992-2005 Free Software Foundation, Inc. --
+-- Copyright (C) 1992-2006, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
@@ -244,11 +244,18 @@ package body Namet is
begin
Get_Name_String (Id);
+ -- Skip scan if we already know there are no encodings
+
+ if Name_Entries.Table (Id).Name_Has_No_Encodings then
+ return;
+ end if;
+
-- Quick loop to see if there is anything special to do
P := 1;
loop
if P = Name_Len then
+ Name_Entries.Table (Id).Name_Has_No_Encodings := True;
return;
else
@@ -865,17 +872,16 @@ package body Namet is
-- Initialize entries for one character names
for C in Character loop
- Name_Entries.Increment_Last;
- Name_Entries.Table (Name_Entries.Last).Name_Chars_Index :=
- Name_Chars.Last;
- Name_Entries.Table (Name_Entries.Last).Name_Len := 1;
- Name_Entries.Table (Name_Entries.Last).Hash_Link := No_Name;
- Name_Entries.Table (Name_Entries.Last).Int_Info := 0;
- Name_Entries.Table (Name_Entries.Last).Byte_Info := 0;
- Name_Chars.Increment_Last;
- Name_Chars.Table (Name_Chars.Last) := C;
- Name_Chars.Increment_Last;
- Name_Chars.Table (Name_Chars.Last) := ASCII.NUL;
+ Name_Entries.Append
+ ((Name_Chars_Index => Name_Chars.Last,
+ Name_Len => 1,
+ Byte_Info => 0,
+ Int_Info => 0,
+ Name_Has_No_Encodings => True,
+ Hash_Link => No_Name));
+
+ Name_Chars.Append (C);
+ Name_Chars.Append (ASCII.NUL);
end loop;
-- Clear hash table
@@ -961,6 +967,15 @@ package body Namet is
return Name_Chars.Table (S + 1) = 'O';
end Is_Operator_Name;
+ -------------------
+ -- Is_Valid_Name --
+ -------------------
+
+ function Is_Valid_Name (Id : Name_Id) return Boolean is
+ begin
+ return Id in Name_Entries.First .. Name_Entries.Last;
+ end Is_Valid_Name;
+
--------------------
-- Length_Of_Name --
--------------------
@@ -999,23 +1014,21 @@ package body Namet is
function Name_Enter return Name_Id is
begin
- Name_Entries.Increment_Last;
- Name_Entries.Table (Name_Entries.Last).Name_Chars_Index :=
- Name_Chars.Last;
- Name_Entries.Table (Name_Entries.Last).Name_Len := Short (Name_Len);
- Name_Entries.Table (Name_Entries.Last).Hash_Link := No_Name;
- Name_Entries.Table (Name_Entries.Last).Int_Info := 0;
- Name_Entries.Table (Name_Entries.Last).Byte_Info := 0;
+ Name_Entries.Append
+ ((Name_Chars_Index => Name_Chars.Last,
+ Name_Len => Short (Name_Len),
+ Byte_Info => 0,
+ Int_Info => 0,
+ Name_Has_No_Encodings => False,
+ Hash_Link => No_Name));
-- Set corresponding string entry in the Name_Chars table
for J in 1 .. Name_Len loop
- Name_Chars.Increment_Last;
- Name_Chars.Table (Name_Chars.Last) := Name_Buffer (J);
+ Name_Chars.Append (Name_Buffer (J));
end loop;
- Name_Chars.Increment_Last;
- Name_Chars.Table (Name_Chars.Last) := ASCII.NUL;
+ Name_Chars.Append (ASCII.NUL);
return Name_Entries.Last;
end Name_Enter;
@@ -1095,7 +1108,6 @@ package body Namet is
Name_Entries.Last + 1;
exit Search;
end if;
-
end loop Search;
end if;
@@ -1103,23 +1115,21 @@ package body Namet is
-- hash table. We now create a new entry in the names table. The hash
-- link pointing to the new entry (Name_Entries.Last+1) has been set.
- Name_Entries.Increment_Last;
- Name_Entries.Table (Name_Entries.Last).Name_Chars_Index :=
- Name_Chars.Last;
- Name_Entries.Table (Name_Entries.Last).Name_Len := Short (Name_Len);
- Name_Entries.Table (Name_Entries.Last).Hash_Link := No_Name;
- Name_Entries.Table (Name_Entries.Last).Int_Info := 0;
- Name_Entries.Table (Name_Entries.Last).Byte_Info := 0;
+ Name_Entries.Append
+ ((Name_Chars_Index => Name_Chars.Last,
+ Name_Len => Short (Name_Len),
+ Hash_Link => No_Name,
+ Name_Has_No_Encodings => False,
+ Int_Info => 0,
+ Byte_Info => 0));
-- Set corresponding string entry in the Name_Chars table
for J in 1 .. Name_Len loop
- Name_Chars.Increment_Last;
- Name_Chars.Table (Name_Chars.Last) := Name_Buffer (J);
+ Name_Chars.Append (Name_Buffer (J));
end loop;
- Name_Chars.Increment_Last;
- Name_Chars.Table (Name_Chars.Last) := ASCII.NUL;
+ Name_Chars.Append (ASCII.NUL);
return Name_Entries.Last;
end if;
@@ -1343,8 +1353,27 @@ package body Namet is
--------
procedure wn (Id : Name_Id) is
+ S : Int;
+
begin
- Write_Name (Id);
+ if not Id'Valid then
+ Write_Str ("<invalid name_id>");
+
+ elsif Id = No_Name then
+ Write_Str ("<No_Name>");
+
+ elsif Id = Error_Name then
+ Write_Str ("<Error_Name>");
+
+ else
+ S := Name_Entries.Table (Id).Name_Chars_Index;
+ Name_Len := Natural (Name_Entries.Table (Id).Name_Len);
+
+ for J in 1 .. Name_Len loop
+ Write_Char (Name_Chars.Table (S + Int (J)));
+ end loop;
+ end if;
+
Write_Eol;
end wn;
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