I used -O2. Is there some standard floating point test that would be a better gauge?
Kevin Kirspel Electrical Engineer - Sr. Staff Opti Medical 235 Hembree Park Drive Roswell GA 30076 Tel: (770)-510-4444 ext. 81642 Direct: (770)-688-1642 Fax: (770)-510-4445 -----Original Message----- From: Sebastian Huber [mailto:sebastian.hu...@embedded-brains.de] Sent: Monday, August 22, 2016 1:41 AM To: Kirspel, Kevin <kevin-kirs...@idexx.com>; devel@rtems.org Subject: Re: [PATCH 1/2] RTEMS Source Builder changes for lpc32xx VFP support On 19/08/16 17:18, Kirspel, Kevin wrote: > I built GCC with the hard abi. The software ran fine but I see a performance > hit with the hard abi. > > ABI: Test Execution Time (ms) > soft 1358 > softfp 96 > hard 109 > > I don't know why the hard is slower than the softfp. Here was my test code. Which compiler options did you use for this test? I am pretty sure that the compiler will reduce your test code to constants with -O2, since you only use constant expressions. > > int ii; > uint32_t end_time, start_time; > double dvalue[8], dresult[20]; > > start_time = rtems_clock_get_ticks_since_boot(); > for( ii = 0; ii < 20; ii++ ) > { > dresult[ii] = 0.0; > } > dvalue[0] = 12.12; > dvalue[1] = 23.23; > dvalue[2] = 34.34; > dvalue[3] = 45.45; > dvalue[4] = 56.56; > dvalue[5] = 67.67; > dvalue[6] = 78.78; > dvalue[7] = 89.89; > for( ii = 0; ii < 10000; ii++ ) > { > dresult[0] += (( dvalue[0] * dvalue[0] ) + ( dvalue[1] * dvalue[1] > ) + ( dvalue[2] * dvalue[2] ) + ( dvalue[3] * dvalue[3] ) + > ( dvalue[4] * dvalue[4] ) + ( dvalue[5] * dvalue[5] ) + ( > dvalue[6] * dvalue[6] ) + ( dvalue[7] * dvalue[7] )) / > (( dvalue[0] / dvalue[1] ) - ( dvalue[1] / dvalue[2] ) - ( > dvalue[2] / dvalue[3] ) - ( dvalue[3] / dvalue[4] ) - > ( dvalue[4] / dvalue[5] ) - ( dvalue[5] / dvalue[6] ) - ( > dvalue[6] / dvalue[7] )); > dresult[1] += cos( dvalue[0] * PI / 180.0 ); > dresult[2] += sin( dvalue[1] * PI / 180.0 ); > dresult[3] += tan( dvalue[2] * PI / 180.0 ); > dresult[4] += acos( 1 / dvalue[3] ) * 180.0 / PI; > dresult[5] += asin( 1 / dvalue[4] ) * 180.0 / PI; > dresult[6] += atan( dvalue[5] ) * 180.0 / PI; > dresult[7] += atan2( dvalue[6], dvalue[7] ) * 180.0 / PI; > dresult[8] += cosh( 1 / dvalue[7] ); > dresult[9] += sinh( dvalue[0] ); > dresult[10] += tanh( dvalue[1] ); > dresult[11] += acosh( dvalue[2] ); > dresult[12] += asinh( dvalue[3] ); > dresult[13] += atanh( 1 / dvalue[4] ); > dresult[14] += exp( 1 / dvalue[5] ); > dresult[15] += pow( dvalue[6], 1 / dvalue[7] ); > dresult[16] += sqrt( dvalue[7] ); > dresult[17] += log( dvalue[0] ); > dresult[18] += log10( dvalue[1] ); > dresult[19] += log2( dvalue[2] ); > } > end_time = rtems_clock_get_ticks_since_boot(); > for( ii = 0; ii < 20; ii++ ) > { > printf( "dresult[%d] = %f\n", ii, dresult[ii] ); > } > printf( "VFP Execution Time: %lu\n", end_time - start_time ); > > Kevin Kirspel > Electrical Engineer - Sr. Staff > Opti Medical > 235 Hembree Park Drive > Roswell GA 30076 > Tel: (770)-510-4444 ext. 81642 > Direct: (770)-688-1642 > Fax: (770)-510-4445 > > -----Original Message----- > From: Sebastian Huber [mailto:sebastian.hu...@embedded-brains.de] > Sent: Friday, August 19, 2016 8:56 AM > To: Kirspel, Kevin <kevin-kirs...@idexx.com>; devel@rtems.org > Subject: Re: [PATCH 1/2] RTEMS Source Builder changes for lpc32xx VFP support > > On 19/08/16 14:39, Kirspel, Kevin wrote: >> This goes back 5 or more years ago so my recollection might be off but I had >> issues with GCC 4.5.2 using -mfloat-abi=hard. NXP recommends >> -mfloat-abi=softfp. I can't find the article or forum now but I think it >> had to do with the fact that the LPC3250 VFP didn't support all the required >> instructions for -mfloat-abi=hard (something about needing a Undefined >> Instruction exception handler to process unsupported VFP instructions). >> Using -mfloat-abi=softfp eliminates the need for the Undefined Instruction >> exception handler to handle unsupported VFP instructions. > The used VFP instructions should not depend on hard vs. softfp ABI since this > should only affect the calling conventions. In addition we use now GCC 6. > Could you please test with -mfloat-abi=hard. This is what all the other VFP > multilibs use. > > -- > Sebastian Huber, embedded brains GmbH > > Address : Dornierstr. 4, D-82178 Puchheim, Germany > Phone : +49 89 189 47 41-16 > Fax : +49 89 189 47 41-09 > E-Mail : sebastian.hu...@embedded-brains.de > PGP : Public key available on request. > > Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG. > > _______________________________________________ > devel mailing list > devel@rtems.org > http://lists.rtems.org/mailman/listinfo/devel -- Sebastian Huber, embedded brains GmbH Address : Dornierstr. 4, D-82178 Puchheim, Germany Phone : +49 89 189 47 41-16 Fax : +49 89 189 47 41-09 E-Mail : sebastian.hu...@embedded-brains.de PGP : Public key available on request. Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG. _______________________________________________ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
