2009/11/24 Vitaly Repeshko <[email protected]>: > > On Tue, Nov 24, 2009 at 11:40 AM, slowpoison <[email protected]> wrote: >> >> On Nov 22, 2:50 am, Erik Corry <[email protected]> wrote: >>> You need to build with the -fno-strict-aliasing option. I don't know >>> a good way to get scons to autodetect gcc-4.4.x and switch it on by >>> default. There's something in the SConstruct file to detect gcc-4.4 >>> but either it doesn't work or it doesn't trigger for gcc-4.4.1. I'm >>> not good enough with scons to understand this. Prepending it to your >>> scons command line like so >> >> I did build with that option but still see the same problem. Actually, >> the v8.gyp file already has that and to turn that on I just defined >> the variable gcc_version=44. Let me show you the g++ command that >> ensued: >> >> g++ -Werror -pthread -fno-exceptions -fno-asynchronous-unwind-tables - >> fvisibility=hidden -Wall -D_FILE_OFFSET_BITS=64 -m32 -march=pentium4 - >> msse2 -mfpmath=sse -fno-ident -fdata-sections -ffunction-sections - >> fomit-frame-pointer -O3 -fno-strict-aliasing -fno-tree-vrp -fno-rtti - >> fno-threadsafe-statics -fvisibility-inlines-hidden - >> DENABLE_LOGGING_AND_PROFILING -DENABLE_DEBUGGER_SUPPORT - >> D__STDC_FORMAT_MACROS -DV8_TARGET_ARCH_IA32 -DV8_NATIVE_REGEXP - >> DCHROMIUM_BUILD -DNDEBUG -DNVALGRIND -Iv8/src -MMD -MF out/Release/ >> obj.target/mksnapshot/v8/src/mksnapshot.o.d.tmp -c -o out/Release/ >> obj.target/mksnapshot/v8/src/mksnapshot.o v8/src/mksnapshot.cc >> >> So, clearly, that option is in there. But to no avail. > > Doesn't -march=pentium4 -msse2 -mfpmath=sse exceed the abilities of Pentium > III?
Yes it does. Looks like the Chromium build scripts are assuming SSE2. It used to be that if you built the Chrome branded browser it would assume SSE2, but if you built it Chromium branded then it built without SSE2. That was pretty sucky and may have been changed. There was also an issue where there were some webkit tests that broke without SSE2 because of tiny variations in floating point precision... -- Erik Corry --~--~---------~--~----~------------~-------~--~----~ v8-dev mailing list [email protected] http://groups.google.com/group/v8-dev -~----------~----~----~----~------~----~------~--~---
