137304 2014-10-01 10:29:54 -0700 [Win] 32-bit JavaScriptCore should limit itself to the C loop 2014-10-06 09:49:36 -0700 1 1 1 Unclassified WebKit JavaScriptCore 528+ (Nightly build) PC All RESOLVED FIXED InRadar P2 Normal --- 1 bfulgham bfulgham benjamin bfulgham cmarcelo commit-queue mark.lam msaboff peavo webkit-bug-importer oldest_to_newest 1038585 0 bfulgham 2014-10-01 10:29:54 -0700 The awesome LLInt interpreter layer in JSC uses SSE2 instructions that are not available in pre-Pentium 4. We need to continue supporting this old hardware as long as we are supporting Windows XP for WebKit. Consequently, we need to turn off LLInt on 32-bit Windows builds. 1038589 1 bfulgham 2014-10-01 10:40:51 -0700 <rdar://problem/18375370> 1038590 2 239034 bfulgham 2014-10-01 10:41:42 -0700 Created attachment 239034 Patch 1038591 3 239034 msaboff 2014-10-01 10:42:49 -0700 Comment on attachment 239034 Patch r=me 1038597 4 bfulgham 2014-10-01 11:22:35 -0700 Committed r174162: <http://trac.webkit.org/changeset/174162> 1038601 5 bfulgham 2014-10-01 11:29:30 -0700 Confirmed no regressions in JSC test runs with this change. 1039740 6 peavo 2014-10-06 09:17:32 -0700 Do we know which SSE2 instructions are used? Maybe we could rewrite the usage of those? 1039746 7 bfulgham 2014-10-06 09:41:48 -0700 (In reply to comment #6) > Do we know which SSE2 instructions are used? Maybe we could rewrite the usage of those? I believe the issue was the need to support IEEE floating point behavior. At one time, the Qt project had some code to use x86+math hacks to deliver similar support on non-SSE hardware, but that code probably got excised when they removed their port. Pragmatically, limiting JIT support to 64-bit is probably not the end of the world. Most people who care about performance are probably running 64-bit CPUs anyway. It would be great to re-enable the JIT for 32-bit in general, but people with specific performance needs can always build WebKit with the 32-bit JIT enabled for their own deployments. 1039749 8 peavo 2014-10-06 09:49:36 -0700 (In reply to comment #7) > (In reply to comment #6) > > Do we know which SSE2 instructions are used? Maybe we could rewrite the usage of those? > > I believe the issue was the need to support IEEE floating point behavior. At one time, the Qt project had some code to use x86+math hacks to deliver similar support on non-SSE hardware, but that code probably got excised when they removed their port. > > Pragmatically, limiting JIT support to 64-bit is probably not the end of the world. Most people who care about performance are probably running 64-bit CPUs anyway. It would be great to re-enable the JIT for 32-bit in general, but people with specific performance needs can always build WebKit with the 32-bit JIT enabled for their own deployments. Ok :) I also see that there are a number of ASSERT(isSSE2Present()) statements in MacroAssemblerX86Common.h which indicates where SSE2 is required. 239034 2014-10-01 10:41:42 -0700 2014-10-01 10:42:49 -0700 Patch bug-137304-20141001104358.patch text/plain 3094 bfulgham SW5kZXg6IFNvdXJjZS9KYXZhU2NyaXB0Q29yZS9DaGFuZ2VMb2cKPT09PT09PT09PT09PT09PT09 PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PQotLS0gU291 cmNlL0phdmFTY3JpcHRDb3JlL0NoYW5nZUxvZwkocmV2aXNpb24gMTc0MTYwKQorKysgU291cmNl L0phdmFTY3JpcHRDb3JlL0NoYW5nZUxvZwkod29ya2luZyBjb3B5KQpAQCAtMSwzICsxLDE0IEBA CisyMDE0LTEwLTAxICBCcmVudCBGdWxnaGFtICA8YmZ1bGdoYW1AYXBwbGUuY29tPgorCisgICAg ICAgIFtXaW5dIDMyLWJpdCBKYXZhU2NyaXB0Q29yZSBzaG91bGQgbGltaXQgaXRzZWxmIHRvIHRo ZSBDIGxvb3AKKyAgICAgICAgaHR0cHM6Ly9idWdzLndlYmtpdC5vcmcvc2hvd19idWcuY2dpP2lk PTEzNzMwNAorICAgICAgICA8cmRhcjovL3Byb2JsZW0vMTgzNzUzNzA+CisKKyAgICAgICAgUmV2 aWV3ZWQgYnkgTk9CT0RZIChPT1BTISkuCisKKyAgICAgICAgKiBKYXZhU2NyaXB0Q29yZS52Y3hw cm9qL0xMSW50L0xMSW50QXNzZW1ibHkvYnVpbGQtTExJbnRBc3NlbWJseS5wbDoKKyAgICAgICAg VXNlIHRoZSBDIGxvb3AgZm9yIDMyLWJpdCBidWlsZHMuCisKIDIwMTQtMDktMzAgIEJyaWFuIEou IEJ1cmcgIDxidXJnQGNzLndhc2hpbmd0b24uZWR1PgogCiAgICAgICAgIFdlYiBJbnNwZWN0b3I6 IEVycm9yU3RyaW5nIHNob3VsZCBiZSBwYXNzZWQgYnkgcmVmZXJlbmNlCkluZGV4OiBTb3VyY2Uv SmF2YVNjcmlwdENvcmUvSmF2YVNjcmlwdENvcmUudmN4cHJvai9MTEludC9MTEludEFzc2VtYmx5 L2J1aWxkLUxMSW50QXNzZW1ibHkucGwKPT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09 PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PQotLS0gU291cmNlL0phdmFTY3JpcHRD b3JlL0phdmFTY3JpcHRDb3JlLnZjeHByb2ovTExJbnQvTExJbnRBc3NlbWJseS9idWlsZC1MTElu dEFzc2VtYmx5LnBsCShyZXZpc2lvbiAxNzQxMzkpCisrKyBTb3VyY2UvSmF2YVNjcmlwdENvcmUv SmF2YVNjcmlwdENvcmUudmN4cHJvai9MTEludC9MTEludEFzc2VtYmx5L2J1aWxkLUxMSW50QXNz ZW1ibHkucGwJKHdvcmtpbmcgY29weSkKQEAgLTYyLDcgKzYyLDEzIEBAIHByaW50IE9VVFBVVEZJ TEVOQU1FICJFTkRcbiI7CiBjbG9zZShPVVRQVVRGSUxFTkFNRSk7CiAKICMgSWYgeW91IHdhbnQg dG8gZW5hYmxlIHRoZSBMTElOVCBDIGxvb3AsIHNldCBPVVRQVVRGSUxFTkFNRSB0byAiTExJbnRB c3NlbWJseS5oIgotbXkgJE9VVFBVVEZJTEVOQU1FID0gRmlsZTo6U3BlYy0+Y2F0ZmlsZSgkREVS SVZFRF9TT1VSQ0VTX0RJUiwgJ0xvd0xldmVsSW50ZXJwcmV0ZXJXaW4uYXNtJyk7CisjIFdlIG9u bHkgd2FudCB0aGUgQyBsb29wIGZvciAzMi1iaXQgV2luZG93cyBzbyB3ZSBjYW4gY29udGludWUg dG8gc3VwcG9ydCBvbGQgQ1BVcy4KK215ICRPVVRQVVRGSUxFTkFNRTsKK2lmICgiJEFSR1ZbM10i IGVxICIzMiIpIHsKKyAgICAkT1VUUFVURklMRU5BTUUgPSBGaWxlOjpTcGVjLT5jYXRmaWxlKCRE RVJJVkVEX1NPVVJDRVNfRElSLCAnTExJbnRBc3NlbWJseS5oJyk7Cit9IGVsc2UgeworICAgICRP VVRQVVRGSUxFTkFNRSA9IEZpbGU6OlNwZWMtPmNhdGZpbGUoJERFUklWRURfU09VUkNFU19ESVIs ICdMb3dMZXZlbEludGVycHJldGVyV2luLmFzbScpOworfQogCiBteSAkb2ZmbGluZUFzbSA9IEZp bGU6OlNwZWMtPmNhdGZpbGUoJFhTUkNST09ULCAnb2ZmbGluZWFzbScsICdhc20ucmInKTsKIG15 ICRsb3dMZXZlbEludGVycHJldGVyID0gRmlsZTo6U3BlYy0+Y2F0ZmlsZSgkWFNSQ1JPT1QsICds bGludCcsICdMb3dMZXZlbEludGVycHJldGVyLmFzbScpOwpJbmRleDogU291cmNlL1dURi9DaGFu Z2VMb2cKPT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09 PT09PT09PT09PT09PT09PQotLS0gU291cmNlL1dURi9DaGFuZ2VMb2cJKHJldmlzaW9uIDE3NDE2 MCkKKysrIFNvdXJjZS9XVEYvQ2hhbmdlTG9nCSh3b3JraW5nIGNvcHkpCkBAIC0xLDMgKzEsMTMg QEAKKzIwMTQtMTAtMDEgIEJyZW50IEZ1bGdoYW0gIDxiZnVsZ2hhbUBhcHBsZS5jb20+CisKKyAg ICAgICAgW1dpbl0gMzItYml0IEphdmFTY3JpcHRDb3JlIHNob3VsZCBsaW1pdCBpdHNlbGYgdG8g dGhlIEMgbG9vcAorICAgICAgICBodHRwczovL2J1Z3Mud2Via2l0Lm9yZy9zaG93X2J1Zy5jZ2k/ aWQ9MTM3MzA0CisgICAgICAgIDxyZGFyOi8vcHJvYmxlbS8xODM3NTM3MD4KKworICAgICAgICBS ZXZpZXdlZCBieSBOT0JPRFkgKE9PUFMhKS4KKworICAgICAgICAqIHd0Zi9QbGF0Zm9ybS5oOiBG b3JjZSB0aGUgQyBsb29wIHdoZW4gYnVpbGRpbmcgZm9yIDMyLWJpdCBXaW5kb3dzLgorCiAyMDE0 LTA5LTMwICBDaHJpc3RvcGhlIER1bWV6ICA8Y2R1bWV6QGFwcGxlLmNvbT4KIAogICAgICAgICBH ZW5lcmFsaXplIGlzPD4oKSAvIGRvd25jYXN0PD4oKSBzdXBwb3J0IHRvIGFsbCB0eXBlcwpJbmRl eDogU291cmNlL1dURi93dGYvUGxhdGZvcm0uaAo9PT09PT09PT09PT09PT09PT09PT09PT09PT09 PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09Ci0tLSBTb3VyY2UvV1RGL3d0 Zi9QbGF0Zm9ybS5oCShyZXZpc2lvbiAxNzQxMzkpCisrKyBTb3VyY2UvV1RGL3d0Zi9QbGF0Zm9y bS5oCSh3b3JraW5nIGNvcHkpCkBAIC03MjgsNiArNzI4LDEyIEBACiAjZGVmaW5lIEVOQUJMRV9D T05DVVJSRU5UX0pJVCAxCiAjZW5kaWYKIAorLyogV2UgZG8gbm90IHdhbnQgdG8gYWxsb3cgTExJ bnQgb24gMzItYml0IFdpbmRvd3Mgc28gdGhhdCB3ZSBjYW4gc3VwcG9ydCBzb21lIGFuY2llbnQK KyAgIENQVXMgdGhhdCBkbyBub3QgaGF2ZSBTU0UyIHN1cHBvcnQgKi8KKyNpZiBPUyhXSU5ET1dT KSAmJiAhQ1BVKFg4Nl82NCkKKyNkZWZpbmUgRU5BQkxFX0xMSU5UX0NfTE9PUCAxCisjZW5kaWYK KwogLyogRGlzYWJsZSB0aGUgSklUIGlmIHdlIGZvcmNlIHRoZSBMTEludCBDIExvb3AgKi8KICNp ZiBkZWZpbmVkKEVOQUJMRV9MTElOVF9DX0xPT1ApICYmIEVOQUJMRV9MTElOVF9DX0xPT1AKICN1 bmRlZiBFTkFCTEVfSklUCg==