Annotation of gforth/profile.fs, revision 1.2

1.1       anton       1: \ count execution of control-flow edges
                      2: 
                      3: \ Copyright (C) 2004 Free Software Foundation, Inc.
                      4: 
                      5: \ This file is part of Gforth.
                      6: 
                      7: \ Gforth is free software; you can redistribute it and/or
                      8: \ modify it under the terms of the GNU General Public License
                      9: \ as published by the Free Software Foundation; either version 2
                     10: \ of the License, or (at your option) any later version.
                     11: 
                     12: \ This program is distributed in the hope that it will be useful,
                     13: \ but WITHOUT ANY WARRANTY; without even the implied warranty of
                     14: \ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
                     15: \ GNU General Public License for more details.
                     16: 
                     17: \ You should have received a copy of the GNU General Public License
                     18: \ along with this program; if not, write to the Free Software
                     19: \ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
                     20: 
                     21: 
                     22: \ relies on some Gforth internals
                     23: 
                     24: \ !! assumption: each file is included only once; otherwise you get
                     25: \ the counts for just one of the instances of the file.  This can be
                     26: \ fixed by making sure that every source position occurs only once as
                     27: \ a profile point.
                     28: 
1.2     ! anton      29: true constant count-calls? \ do some profiling of colon definitions etc.
        !            30: 
1.1       anton      31: struct
                     32:     cell%    field profile-next
                     33:     cell% 2* field profile-count
                     34:     cell% 2* field profile-sourcepos
                     35:     cell%    field profile-char \ character position in line
1.2     ! anton      36:     count-calls? [if]
        !            37:        cell% field profile-colondef? \ is this a colon definition
        !            38:        cell% field profile-calls \ static calls to the colon def
        !            39:        cell% field profile-straight-line \ may contain calls, but no other CF
        !            40:        cell% field profile-calls-from \ static calls in the colon def
        !            41:     [endif]
1.1       anton      42: end-struct profile% \ profile point
                     43: 
                     44: variable profile-points \ linked list of profile%
                     45: 0 profile-points !
1.2     ! anton      46: variable next-profile-point-p \ the address where the next pp will be stored
        !            47: profile-points next-profile-point-p !
        !            48: count-calls? [if]
        !            49:     variable last-colondef-profile \ pointer to the pp of last colon definition
        !            50: [endif]
        !            51:     
1.1       anton      52: : new-profile-point ( -- addr )
                     53:     profile% %alloc >r
                     54:     0. r@ profile-count 2!
                     55:     current-sourcepos r@ profile-sourcepos 2!
                     56:     >in @ r@ profile-char !
1.2     ! anton      57:     [ count-calls? ] [if]
        !            58:        r@ profile-colondef? off
        !            59:        0 r@ profile-calls !
        !            60:        r@ profile-straight-line on
        !            61:        0 r@ profile-calls-from !
        !            62:     [endif]
        !            63:     0 r@ profile-next !
        !            64:     r@ next-profile-point-p @ !
        !            65:     r@ profile-next next-profile-point-p !
1.1       anton      66:     r> ;
                     67: 
                     68: : print-profile ( -- )
                     69:     profile-points @ begin
                     70:        dup while
                     71:            dup >r
                     72:            r@ profile-sourcepos 2@ .sourcepos ." :"
                     73:            r@ profile-char @ 0 .r ." : "
                     74:            r@ profile-count 2@ 0 d.r cr
                     75:            r> profile-next @
                     76:     repeat
                     77:     drop ;
                     78: 
1.2     ! anton      79: : print-profile-coldef ( -- )
        !            80:     profile-points @ begin
        !            81:        dup while
        !            82:            dup >r
        !            83:            r@ profile-colondef? @ if
        !            84:                r@ profile-sourcepos 2@ .sourcepos ." :"
        !            85:                r@ profile-char @ 0 .r ." : "
        !            86:                r@ profile-count 2@ 0 d.r
        !            87:                r@ profile-straight-line @ space .
        !            88:                cr
        !            89:            endif
        !            90:            r> profile-next @
        !            91:     repeat
        !            92:     drop ;
        !            93: 
        !            94: 
        !            95: : dinc ( d-addr -- )
        !            96:     \ increment double pointed to by d-addr
        !            97:     dup 2@ 1. d+ rot 2! ;
        !            98: 
        !            99: : profile-this ( -- )
        !           100:     new-profile-point profile-count POSTPONE literal POSTPONE dinc ;
        !           101: 
        !           102: \ Various words trigger PROFILE-THIS.  In order to avoid getting
        !           103: \ several calls to PROFILE-THIS from a compiling word (like ?EXIT), we
        !           104: \ just wait until the next word is parsed by the text interpreter (in
        !           105: \ compile state) and call PROFILE-THIS only once then.  The whole
        !           106: \ BEFORE-WORD hooking etc. is there for this.
        !           107: 
        !           108: \ The reason that we do this is because we use the source position for
        !           109: \ the profiling information, and there's only one source position for
        !           110: \ ?EXIT.  If we used the threaded code position instead, we would see
        !           111: \ that ?EXIT compiles to several threaded-code words, and could use
        !           112: \ different profile points for them.  However, usually dealing with
        !           113: \ the source is more practical.
        !           114: 
        !           115: \ Another benefit is that we can ask for profiling anywhere in a
        !           116: \ control-flow word (even before it compiles its own stuff).
        !           117: 
        !           118: \ Potential problem: Consider "COMPILING ] [" where COMPILING compiles
        !           119: \ a whole colon definition (and triggers our profiler), but during the
        !           120: \ compilation of the colon definition there is no parsing.  Afterwards
        !           121: \ you get interpret state at first (no profiling, either), but after
        !           122: \ the "]" you get parsing in compile state, and PROFILE-THIS gets
        !           123: \ called (and compiles code that is never executed).  It would be
        !           124: \ better if we had a way of knowing whether we are in a colon def or
        !           125: \ not (and used that knowledge instead of STATE).
        !           126: 
        !           127: Defer before-word-profile ( -- )
        !           128: ' noop IS before-word-profile
        !           129: 
        !           130: : before-word1 ( -- )
        !           131:     before-word-profile defers before-word ;
        !           132: 
        !           133: ' before-word1 IS before-word
        !           134: 
        !           135: : profile-this-compiling ( -- )
        !           136:     state @ if
        !           137:        profile-this
        !           138:        ['] noop IS before-word-profile
        !           139:     endif ;
        !           140: 
        !           141: : cock-profiler ( -- )
        !           142:     \ as in cock the gun - pull the trigger
        !           143:     ['] profile-this-compiling IS before-word-profile
        !           144:     [ count-calls? ] [if] \ we are at a non-colondef profile point
        !           145:        last-colondef-profile @ profile-straight-line off
        !           146:     [endif]
        !           147: ;
        !           148: 
        !           149: : hook-profiling-into ( "name" -- )
        !           150:     \ make (deferred word) "name" call cock-profiler, too
        !           151:     ' >body >r :noname
        !           152:     POSTPONE cock-profiler
        !           153:     r@ @ compile, \ old hook behaviour
        !           154:     POSTPONE ;
        !           155:     r> ! ; \ change hook behaviour
        !           156: 
        !           157: hook-profiling-into then-like
        !           158: \ hook-profiling-into if-like
        !           159: \ hook-profiling-into ahead-like
        !           160: hook-profiling-into other-control-flow
        !           161: hook-profiling-into begin-like
        !           162: hook-profiling-into again-like
        !           163: hook-profiling-into until-like
        !           164: 
        !           165: count-calls? [if]
        !           166:     : :-hook-profile ( -- )
        !           167:        defers :-hook
        !           168:        next-profile-point-p @
        !           169:        profile-this
        !           170:        @ dup last-colondef-profile !
        !           171:        profile-colondef? on ;
        !           172: 
        !           173:     ' :-hook-profile IS :-hook
        !           174: [else]
        !           175:     hook-profiling-into exit-like
        !           176:     hook-profiling-into :-hook
        !           177: [endif]

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