Here is the updated metrics with -fno-builtin. You are right in the sense that the generated code did not call the underlying math functions. I will generate a patch for the hard implementation.
softp - 4493 ms hard - 4263 ms 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 7:34 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 22/08/16 13:23, Kirspel, Kevin wrote: > I used -O2. Did you look at the generated code? I guess you find no calls to the standard math library functions. Which timing numbers do you get if you use "-O2 -fno-builtin" instead? > 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
