> In August, I wrote the following about vectorized / not vectorized loops > in HIRLAM > (see http://hirlam.org): > > > $ grep 'LOOP VECTORIZED' HL_Prepare_00.html | wc -l > > 3273 > > $ grep 'not vectorized' HL_Prepare_00.html | wc -l > > 7845 > > Yesterday, I performed a test with gcc-trunk-129472 (which is a week > old, by now): > > $ grep 'LOOP VECTORIZED' HL_Prepare_00.html | wc -l > 5316 > $ grep 'not vectorized' HL_Prepare_00.html | wc -l > 6060 >
I wonder if it's versioning-for-aliasing (run-time dependence testing) that was responsible for a lot of the new vectorizable loops > This was simply using -O3 -ffast-math on the code. Apparently a lot of > progress has been made (and perhaps the combination of loop > optimizations enabled by -O3 over -O2 play a role, too): > by the way, some of these optimizations, like predictive-commoning, can also prevent vectorization. we were going to move predcom to after vectorization - yet to be done > $ gcc -c -Q -O3 --help=optimizers > /tmp/O3-opts > $ gcc -c -Q -O2 --help=optimizers > /tmp/O2-opts > $ diff /tmp/O2-opts /tmp/O3-opts | grep enabled > > -fgcse-after-reload [enabled] > > -finline-functions [enabled] > > -fpredictive-commoning [enabled] > > -ftree-vectorize [enabled] > > -funswitch-loops [enabled] > > The timing difference is as follows: > much thanks for the update! dorit > -O3 -ffast-math: > > $ grep 'FORECAST TOOK' HL_Cycle* > HL_Cycle_2006120100.html: FORECAST TOOK 6.2284 SECONDS > HL_Cycle_2006120100.html: FORECAST TOOK 2430.0159 SECONDS > HL_Cycle_2006120106.html: FORECAST TOOK 258.1721 SECONDS > HL_Cycle_2006120106.html: FORECAST TOOK 6.1164 SECONDS > HL_Cycle_2006120106.html: FORECAST TOOK 304.9590 SECONDS > HL_Cycle_2006120112.html: FORECAST TOOK 259.7802 SECONDS > HL_Cycle_2006120112.html: FORECAST TOOK 6.1524 SECONDS > HL_Cycle_2006120112.html: FORECAST TOOK 2303.5320 SECONDS > HL_Cycle_2006120112r.html: FORECAST TOOK 417.3861 SECONDS > HL_Cycle_2006120118.html: FORECAST TOOK 259.9763 SECONDS > HL_Cycle_2006120118.html: FORECAST TOOK 6.0764 SECONDS > HL_Cycle_2006120118.html: FORECAST TOOK 306.5071 SECONDS > HL_Cycle_2006120200.html: FORECAST TOOK 259.9482 SECONDS > HL_Cycle_2006120200.html: FORECAST TOOK 6.1564 SECONDS > HL_Cycle_2006120200.html: FORECAST TOOK 2300.3560 SECONDS > HL_Cycle_2006120200r.html: FORECAST TOOK 414.8299 SECONDS > > -O2 -ffast-math: > > $ grep 'FORECAST TOOK' HL_Cycle* > HL_Cycle_2006120100.html: FORECAST TOOK 6.3244 SECONDS > HL_Cycle_2006120100.html: FORECAST TOOK 2510.3809 SECONDS > HL_Cycle_2006120106.html: FORECAST TOOK 268.3368 SECONDS > HL_Cycle_2006120106.html: FORECAST TOOK 6.2484 SECONDS > HL_Cycle_2006120106.html: FORECAST TOOK 316.4918 SECONDS > HL_Cycle_2006120112.html: FORECAST TOOK 268.1648 SECONDS > HL_Cycle_2006120112.html: FORECAST TOOK 6.2724 SECONDS > HL_Cycle_2006120112.html: FORECAST TOOK 2377.2166 SECONDS > HL_Cycle_2006120112r.html: FORECAST TOOK 432.7510 SECONDS > HL_Cycle_2006120118.html: FORECAST TOOK 270.2049 SECONDS > HL_Cycle_2006120118.html: FORECAST TOOK 6.2244 SECONDS > HL_Cycle_2006120118.html: FORECAST TOOK 316.9878 SECONDS > HL_Cycle_2006120200.html: FORECAST TOOK 268.7688 SECONDS > HL_Cycle_2006120200.html: FORECAST TOOK 6.2924 SECONDS > HL_Cycle_2006120200.html: FORECAST TOOK 2371.8962 SECONDS > HL_Cycle_2006120200r.html: FORECAST TOOK 432.6790 SECONDS > > Roughly 3.3 %. > > Kind regards, > > -- > Toon Moene - e-mail: [EMAIL PROTECTED] - phone: +31 346 214290 > Saturnushof 14, 3738 XG Maartensdijk, The Netherlands > At home: http://moene.indiv.nluug.nl/~toon/ > GNU Fortran's path to Fortran 2003: http://gcc.gnu.org/wiki/Fortran2003
