\ get some data on potential (partial) inlining \ Copyright (C) 2004 Free Software Foundation, Inc. \ This file is part of Gforth. \ Gforth is free software; you can redistribute it and/or \ modify it under the terms of the GNU General Public License \ as published by the Free Software Foundation; either version 2 \ of the License, or (at your option) any later version. \ This program is distributed in the hope that it will be useful, \ but WITHOUT ANY WARRANTY; without even the implied warranty of \ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the \ GNU General Public License for more details. \ You should have received a copy of the GNU General Public License \ along with this program; if not, write to the Free Software \ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA. \ relies on some Gforth internals \ !! assumption: each file is included only once; otherwise you get \ the counts for just one of the instances of the file. This can be \ fixed by making sure that every source position occurs only once as \ a profile point. true constant count-calls? \ do some profiling of colon definitions etc. \ for true COUNT-CALLS?: \ What data do I need for evaluating the effectiveness of (partial) inlining? \ static and dynamic counts of everything: \ original BB length (histogram and average) \ BB length with partial inlining (histogram and average) \ since we cannot partially inline library calls, we use a parameter \ that represents the amount of partial inlining we can expect there. \ number of tail calls (original and after partial inlining) \ number of calls (original and after partial inlining) \ reason for BB end: call, return, execute, branch \ how many static calls are there to a word? How many of the dynamic \ calls call just a single word? \ how much does inlining called-once words help? \ how much does inlining words without control flow help? \ how much does partial inlining help? \ what's the overlap? \ optimizing return-to-returns (tail calls), return-to-calls, call-to-calls struct cell% list-next end-struct list% list% cell% 2* field profile-count cell% 2* field profile-sourcepos cell% field profile-char \ character position in line count-calls? [if] cell% field profile-colondef? \ is this a colon definition start cell% field profile-calls \ static calls to the colon def (calls%) cell% field profile-straight-line \ may contain calls, but no other CF cell% field profile-calls-from \ static calls in the colon def [endif] end-struct profile% \ profile point list% cell% field calls%-call \ ptr to profile point of bb containing the call end-struct calls% variable profile-points \ linked list of profile% 0 profile-points ! variable next-profile-point-p \ the address where the next pp will be stored profile-points next-profile-point-p ! count-calls? [if] variable last-colondef-profile \ pointer to the pp of last colon definition [endif] \ list stuff \ profile-point stuff : new-profile-point ( -- addr ) profile% %alloc >r 0. r@ profile-count 2! current-sourcepos r@ profile-sourcepos 2! >in @ r@ profile-char ! [ count-calls? ] [if] r@ profile-colondef? off 0 r@ profile-calls ! r@ profile-straight-line on 0 r@ profile-calls-from ! [endif] 0 r@ list-next ! r@ next-profile-point-p @ ! r@ list-next next-profile-point-p ! r> ; : print-profile ( -- ) profile-points @ begin dup while dup >r r@ profile-sourcepos 2@ .sourcepos ." :" r@ profile-char @ 0 .r ." : " r@ profile-count 2@ 0 d.r cr r> list-next @ repeat drop ; : print-profile-coldef ( -- ) profile-points @ begin dup while dup >r r@ profile-colondef? @ if r@ profile-sourcepos 2@ .sourcepos ." :" r@ profile-char @ 3 .r ." : " r@ profile-count 2@ 10 d.r r@ profile-straight-line @ space 2 .r r@ profile-calls @ 4 .r cr endif r> list-next @ repeat drop ; : dinc ( profilep -- ) \ increment double pointed to by d-addr profile-count dup 2@ 1. d+ rot 2! ; : profile-this ( -- ) new-profile-point POSTPONE literal POSTPONE dinc ; \ Various words trigger PROFILE-THIS. In order to avoid getting \ several calls to PROFILE-THIS from a compiling word (like ?EXIT), we \ just wait until the next word is parsed by the text interpreter (in \ compile state) and call PROFILE-THIS only once then. The whole \ BEFORE-WORD hooking etc. is there for this. \ The reason that we do this is because we use the source position for \ the profiling information, and there's only one source position for \ ?EXIT. If we used the threaded code position instead, we would see \ that ?EXIT compiles to several threaded-code words, and could use \ different profile points for them. However, usually dealing with \ the source is more practical. \ Another benefit is that we can ask for profiling anywhere in a \ control-flow word (even before it compiles its own stuff). \ Potential problem: Consider "COMPILING ] [" where COMPILING compiles \ a whole colon definition (and triggers our profiler), but during the \ compilation of the colon definition there is no parsing. Afterwards \ you get interpret state at first (no profiling, either), but after \ the "]" you get parsing in compile state, and PROFILE-THIS gets \ called (and compiles code that is never executed). It would be \ better if we had a way of knowing whether we are in a colon def or \ not (and used that knowledge instead of STATE). Defer before-word-profile ( -- ) ' noop IS before-word-profile : before-word1 ( -- ) before-word-profile defers before-word ; ' before-word1 IS before-word : profile-this-compiling ( -- ) state @ if profile-this ['] noop IS before-word-profile endif ; : cock-profiler ( -- ) \ as in cock the gun - pull the trigger ['] profile-this-compiling IS before-word-profile [ count-calls? ] [if] \ we are at a non-colondef profile point last-colondef-profile @ profile-straight-line off [endif] ; : hook-profiling-into ( "name" -- ) \ make (deferred word) "name" call cock-profiler, too ' >body >r :noname POSTPONE cock-profiler r@ @ compile, \ old hook behaviour POSTPONE ; r> ! ; \ change hook behaviour : note-execute ( -- ) \ end of BB due to execute ; : note-call ( addr -- ) \ addr is the body address of a called colon def or does handler dup 3 cells + @ ['] dinc >body = if 1 over cell+ @ profile-calls +! endif drop ; : prof-compile, ( xt -- ) dup >does-code if dup >does-code note-call then dup >code-address CASE docol: OF dup >body note-call ENDOF dodefer: OF note-execute ENDOF dofield: OF >body @ ['] lit+ peephole-compile, , EXIT ENDOF \ dofield: OF >body @ POSTPONE literal ['] + peephole-compile, EXIT ENDOF \ code words and ;code-defined words (code words could be optimized): dup in-dictionary? IF drop POSTPONE literal ['] execute peephole-compile, EXIT THEN ENDCASE DEFERS compile, ; \ hook-profiling-into then-like \ \ hook-profiling-into if-like \ subsumed by other-control-flow \ \ hook-profiling-into ahead-like \ subsumed by other-control-flow \ hook-profiling-into other-control-flow \ hook-profiling-into begin-like \ hook-profiling-into again-like \ hook-profiling-into until-like : :-hook-profile ( -- ) defers :-hook next-profile-point-p @ profile-this @ dup last-colondef-profile ! profile-colondef? on ; ' :-hook-profile IS :-hook ' prof-compile, IS compile,