115553 2013-05-03 09:57:25 -0700 SunSpider 1.0: 3d-morph: use epsilon to check result 2013-05-04 01:28:22 -0700 1 1 1 Unclassified WebKit Tools / Tests 528+ (Nightly build) Unspecified Unspecified RESOLVED DUPLICATE 115580 P2 Normal --- 0 ctruta webkit-unassigned commit-queue fpizlo ggaren rniwa oldest_to_newest 884189 0 ctruta 2013-05-03 09:57:25 -0700 3d-morph.js fails on QNX. The testOutput is expected to be a number that starts with a 6, but the actual output is approx. -4.97e-14. I reimplemented 3d-morph in C, and I executed it both with double and long double on x86_64 Linux. By using double calculations and sin(), the result was 6.75e-14. By using long double calculations and sinl(), the result was -6.279e-14. Is the theoretical result supposed to be zero, and the actual one closed to zero, due to error accumulations? Running the same program on ARM QNX, the result (using double and sin()) was -4.97e-14, i.e. same as inside JSC. Then I looked at all intermediate results returned by sin(). Out of 240 distinct calls to sin(), about ~65 of them are different by exactly 1ULP. In my understanding, that error should be acceptable. 884194 1 200429 ctruta 2013-05-03 10:03:04 -0700 Created attachment 200429 Patch 884226 2 200429 fpizlo 2013-05-03 10:53:43 -0700 Comment on attachment 200429 Patch We should test this on other platforms as well. Note that sin() is not defined to have *any* precision guarantee in ECMAScript. So even if our engine can achieve this level of erro it might not be fair to require others to. 884227 3 200429 fpizlo 2013-05-03 10:56:04 -0700 Comment on attachment 200429 Patch Oh. Sorry. You're making the test even more lax. I'll have to think about it. 884506 4 200429 ctruta 2013-05-04 01:21:26 -0700 Comment on attachment 200429 Patch Removing r? and cq? flags. I resubmitted this patch accidentally in bug 115580, and it landed over there. 884507 5 ctruta 2013-05-04 01:21:56 -0700 *** This bug has been marked as a duplicate of bug 115580 *** 884509 6 ctruta 2013-05-04 01:28:22 -0700 At the WebKit meeting, Filip Pizlo required additional data to back my precision claims regarding 1ULP roundoff errors. I will provide the test program and the intermediate output values, for comparison, in the other bug. 200429 2013-05-03 10:03:04 -0700 2013-05-04 01:21:26 -0700 Patch patch.diff text/plain 1721 ctruta ZGlmZiAtLWdpdCBhL1BlcmZvcm1hbmNlVGVzdHMvU3VuU3BpZGVyL0NoYW5nZUxvZyBiL1BlcmZv cm1hbmNlVGVzdHMvU3VuU3BpZGVyL0NoYW5nZUxvZwppbmRleCBmZWVkMjAzZWE3Li4xODM0ZjY1 MzkyIDEwMDY0NAotLS0gYS9QZXJmb3JtYW5jZVRlc3RzL1N1blNwaWRlci9DaGFuZ2VMb2cKKysr IGIvUGVyZm9ybWFuY2VUZXN0cy9TdW5TcGlkZXIvQ2hhbmdlTG9nCkBAIC0xLDMgKzEsMTQgQEAK KzIwMTMtMDUtMDMgIENvc21pbiBUcnV0YSAgPGN0cnV0YUBibGFja2JlcnJ5LmNvbT4KKworICAg ICAgICBTdW5TcGlkZXIgMS4wOiAzZC1tb3JwaDogdXNlIGVwc2lsb24gdG8gY2hlY2sgcmVzdWx0 CisgICAgICAgIGh0dHBzOi8vYnVncy53ZWJraXQub3JnL3Nob3dfYnVnLmNnaT9pZD0xMTU1NTMK KworICAgICAgICBSZXZpZXdlZCBieSBOT0JPRFkgKE9PUFMhKS4KKworICAgICAgICBTdW5TcGlk ZXIvM2QtbW9ycGggc2hvdWxkIGJlIG1vcmUgbGVuaWVudCBpbiB2YWxpZGF0aW5nIGl0cyByZXN1 bHRzLCBzaW5jZSB0aGV5IGRlcGVuZCBvbiBNYXRoLnNpbiwgd2hpY2ggaXNuJ3QgZm9ybWFsbHkg c3BlY2lmaWVkLgorCisgICAgICAgICogdGVzdHMvc3Vuc3BpZGVyLTEuMC8zZC1tb3JwaC5qczoK KwogMjAxMy0wNC0xOSAgRmlsaXAgUGl6bG8gIDxmcGl6bG9AYXBwbGUuY29tPgogCiAgICAgICAg IFN1blNwaWRlci9zdHJpbmctdGFnY2xvdWQgc2hvdWxkIGJlIG1vcmUgbGVuaWVudCBpbiB2YWxp ZGF0aW5nIGl0cyByZXN1bHRzLCBzaW5jZSB0aGV5IGRlcGVuZCBvbiBNYXRoLmxvZywgd2hpY2gg aXNuJ3QgZm9ybWFsbHkgc3BlY2lmaWVkCmRpZmYgLS1naXQgYS9QZXJmb3JtYW5jZVRlc3RzL1N1 blNwaWRlci90ZXN0cy9zdW5zcGlkZXItMS4wLzNkLW1vcnBoLmpzIGIvUGVyZm9ybWFuY2VUZXN0 cy9TdW5TcGlkZXIvdGVzdHMvc3Vuc3BpZGVyLTEuMC8zZC1tb3JwaC5qcwppbmRleCBmYjlkODFk NDAwLi45NjFiOGY2ODBiIDEwMDY0NAotLS0gYS9QZXJmb3JtYW5jZVRlc3RzL1N1blNwaWRlci90 ZXN0cy9zdW5zcGlkZXItMS4wLzNkLW1vcnBoLmpzCisrKyBiL1BlcmZvcm1hbmNlVGVzdHMvU3Vu U3BpZGVyL3Rlc3RzL3N1bnNwaWRlci0xLjAvM2QtbW9ycGguanMKQEAgLTU4LDYgKzU4LDYgQEAg YSA9IG51bGw7CiAvLyBzYXlzIC0gdGhhdCBzaW4oKSBoYXMgdG8gcmV0dXJuIGEgdmFsdWUgd2l0 aGluIDEgdWxwIG9mIGV4YWN0IC0gdGhlbiB3ZSBzdGlsbAogLy8gd291bGQgbm90IGJlIGFibGUg dG8gZG8gYW4gZXhhY3QgdGVzdCBoZXJlIHNpbmNlIHRoYXQgd291bGQgYWxsb3cgZm9yIGp1c3Qg ZW5vdWdoCiAvLyBsb3ctYml0IHNsb3AgdG8gY3JlYXRlIHBvc3NpYmx5IGJpZyBlcnJvcnMgZHVl IHRvIHRlc3RPdXRwdXQgYmVpbmcgYSBzdW0uCi12YXIgZXhwZWN0ZWQgPSA2OwotaWYgKCgiIiAr IHRlc3RPdXRwdXQpWzBdICE9IGV4cGVjdGVkKQotICAgIHRocm93ICJFcnJvcjogYmFkIHRlc3Qg b3V0cHV0OiBleHBlY3RlZCBsZWFkaW5nIGRpZ2l0IHRvIGJlICIgKyBleHBlY3RlZCArICIgYnV0 IGdvdCAiICsgdGVzdE91dHB1dDsKK3ZhciBlcHNpbG9uID0gMWUtMTM7CitpZiAoTWF0aC5hYnMo dGVzdE91dHB1dCkgPj0gZXBzaWxvbikKKyAgICB0aHJvdyAiRXJyb3I6IGJhZCB0ZXN0IG91dHB1 dDogZXhwZWN0ZWQgbWFnbml0dWRlIGJlbG93ICIgKyBlcHNpbG9uICsgIiBidXQgZ290ICIgKyB0 ZXN0T3V0cHV0Owo=