Investigate speed string sharing in MetaModelica

[Adrian Pop]

See if enabling string sharing for the OpenModelica compiler will bring more speed.

[Adrian Pop]

Implemented command line parameter for enabling/disabling string sharing when running omc.

-string-sharing
-no-string-sharing

This is part of the new upcoming MetaModelica (OMDev).

[Adrian Pop]

Notice that the execution was run with omcp.exe which enables the gcc profiling (see attached).

The execution of EngineV6.mos with string-sharing:

adrpo@kafka ~/dev/OpenModelica/testsuite/libraries/multibody/loops
$ time ../../../../build/bin/omc -log -string-sharing EngineV6.mos > traceEngineV6-string-sharing.txt 2>&1

[HEAP:	10628 minor collections, 24 major collections, 24870368 words currently in use]
[HEAP:	1048576 words allocated to young, 30482731 words allocated to current, 24/0 heap expansions/shrinkings performed]
[HEAP: 	1358942 words allocated into managed C heap (from mk_* functions), collected 6 times, remaining uncollected 7 words]
[HEAP: 	14245 strings totaling 52659 words where shared]
[HEAP:	5.04 seconds waisted while doing GC]
[STACK:	0 words currently in use (498578 words max, 4194304 words total)]
[ARRAY:	0 words currently in use in the array trail]
[TRAIL:	0 words currently in use]
[MOTOR:	2741046767 tailcalls performed]

201.1 MB memory used.

real    58m5.478s
user    0m0.015s
sys     0m0.045s

The execution of EngineV6.mos without string-sharing:

adrpo@kafka ~/dev/OpenModelica/testsuite/libraries/multibody/loops
$ time ../../../../build/bin/omc -log -no-string-sharing EngineV6.mos > traceEngineV6-no-string-sharing.txt 2>&1

[HEAP:  1048576 words allocated to young, 30482731 words allocated to current, 24/0 heap expansions/shrinkings performed]
[HEAP:  1411601 words allocated into managed C heap (from mk_* functions), collected 6 times, remaining uncollected 7 words]
[HEAP:  0 strings totaling 0 words where shared]
[HEAP:  5.07 seconds waisted while doing GC]
[STACK: 0 words currently in use (498578 words max, 4194304 words total)]
[ARRAY: 0 words currently in use in the array trail]
[TRAIL: 0 words currently in use]
[MOTOR: 2741046767 tailcalls performed]

201.1 MB memory used.

real    57m8.854s
user    0m0.000s
sys     0m0.061s

[Adrian Pop]

The execution traces.

[Adrian Pop]

The execution traces.

[Adrian Pop]

The gprof logs for the execution.