[Gambas-bugtracker] Bug #3221: using fast unsafe, when var is used in a loop and then printed after it is not optimized, can it be fixed

[<bugtracker@xxxxxxxxxxxxxx>]

http://gambaswiki.org/bugtracker/edit?object=BUG.3221&from=L21haW4-

Brian G reported a new bug.

Summary
-------

using fast unsafe, when var is used in a loop and then printed after it is not optimized, can it be fixed

Type             : Request
Priority         : High
Gambas version   : Master
Product          : JIT compiler


Description
-----------

When a variable is used in a loop and then is not used after the loop, the loop is extremely fast. but if the variable is referenced after the loop then the loop is extremely slow.

It looks like the variables are moved to registers for the loop. but if referenced later after the loop then they are stored each time or doing actual work on the variables.
It becomes an order of magnitude slower.
I have attached a project as an example.

Would it be possible to store the registers into the variables as the loop exits instead of updating them within the loop? the jit would have to know when the loop does an exit. wherever it happens.

see attached program


System information
------------------

[System]
Gambas=3.22.99 1341824 (master)
OperatingSystem=Linux
Distribution=Linux Mint 22.3 (Zena)
Kernel=7.2.0-070200-generic
Architecture=x86_64
Cores=8
Memory=13923M
Language=en_US.UTF-8
Platform=x11
Desktop=MATE
DesktopResolution=96
DesktopScale=7
WidgetTheme=proxy
Font=Ubuntu Mono,10
DarkTheme=False
[Programs]
appimage-builder=appimage-builder: 1.1.0
dpkg=Debian 'dpkg' package management program version 1.22.6 (amd64).
gcc=gcc (Ubuntu 13.3.0-6ubuntu2~24.04.1) 13.3.0
git=git version 2.43.0
msgmerge=msgmerge (GNU gettext-tools) 0.21
rpmbuild=RPM version 4.18.2
[Libraries]
Cairo=libcairo.so.2.11800.0
Curl=libcurl.so.4.8.0
DBus=libdbus-1.so.3.32.4
GDK2=libgdk-x11-2.0.so.0.2400.33
GDK3=libgdk-3.so.0.2409.32
GStreamer=libgstreamer-1.0.so.0.2402.0
GTK+2=libgtk-x11-2.0.so.0.2400.33
GTK+3=libgtk-3.so.0.2409.32
OpenGL=libGL.so.1.7.0
Poppler=libpoppler.so.134.0.0
QT5=libQt5Core.so.5.15.13
QT6=libQt6Core.so.6.4.2
RSvg=librsvg-2.so.2.50.0
SDL=libSDL2-2.0.so.0.3000.0
SQLite3=libsqlite3.so.0.8.6
[Environment]
CLUTTER_BACKEND=x11
COMPIZ_CONFIG_PROFILE=mint
DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/1000/bus
DESKTOP_SESSION=mate
DISPLAY=:0
GB_GUI=gb.qt6
GDMSESSION=mate
GDM_LANG=en_US
GIO_LAUNCHED_DESKTOP_FILE_PID=545212
GPG_AGENT_INFO=/run/user/1000/gnupg/S.gpg-agent:0:1
GTK3_MODULES=xapp-gtk3-module
GTK_MODULES=gail:atk-bridge
GTK_OVERLAY_SCROLLING=0
HOME=<home>
LANG=en_US.UTF-8
LANGUAGE=en_US.UTF-8
LC_ADDRESS=en_US.UTF-8
LC_IDENTIFICATION=en_US.UTF-8
LC_MEASUREMENT=en_US.UTF-8
LC_MONETARY=en_US.UTF-8
LC_NAME=en_US.UTF-8
LC_NUMERIC=en_US.UTF-8
LC_PAPER=en_US.UTF-8
LC_TELEPHONE=en_US.UTF-8
LC_TIME=en_US.UTF-8
LIBVIRT_DEFAULT_URI=qemu:///system
LOGNAME=<user>
MATE_DESKTOP_SESSION_ID=this-is-deprecated
NVM_BIN=<home>/.nvm/versions/node/v24.11.0/bin
NVM_CD_FLAGS=
NVM_DIR=<home>/.nvm
NVM_INC=<home>/.nvm/versions/node/v24.11.0/include/node
PAPERSIZE=a4
PATH=<home>/.nvm/versions/node/v24.11.0/bin:<home>/.config/emacs/bin:<home>/.local/bin:<home>/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin:/usr/local/go/bin
PICO_SDK_PATH=<home>/Projects/picomite/pico/pico-sdk
PWD=<home>
QT_ACCESSIBILITY=1
QT_FONT_DPI=96
QT_LOGGING_RULES=*.debug=false
QT_SCALE_FACTOR=1
SESSION_MANAGER=local/<hostname>:@/tmp/.ICE-unix/28376,unix/<hostname>:/tmp/.ICE-unix/28376
SHELL=/usr/bin/gsh
SHLVL=0
SSH_AUTH_SOCK=/run/user/1000/keyring/ssh
TZ=:/etc/localtime
USER=<user>
XAUTHORITY=<home>/.Xauthority
XDG_ACTIVATION_TOKEN=mate-panel-28878-<hostname>-gambas3-19_TIME77818771
XDG_CONFIG_DIRS=/etc/xdg/xdg-mate:/etc/xdg
XDG_CURRENT_DESKTOP=MATE
XDG_DATA_DIRS=/usr/share/mate:<home>/.local/share/flatpak/exports/share:/var/lib/flatpak/exports/share:/usr/local/share:/usr/share
XDG_GREETER_DATA_DIR=/var/lib/lightdm-data/<user>
XDG_RUNTIME_DIR=/run/user/1000
XDG_SEAT=seat0
XDG_SEAT_PATH=/org/freedesktop/DisplayManager/Seat0
XDG_SESSION_CLASS=user
XDG_SESSION_DESKTOP=mate
XDG_SESSION_ID=c4
XDG_SESSION_PATH=/org/freedesktop/DisplayManager/Session1
XDG_SESSION_TYPE=x11
XDG_VTNR=7
gshlibrary=<home>/Projects/gshlibrary
gshproject=<home>/Projects/gsh



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