http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44578
kl4yfd at gmail dot com changed:
What |Removed |Added
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CC| |kl4yfd at gmail dot com
--- Comment #3 from kl4yfd at gmail dot com 2012-11-15 06:36:17 UTC ---
Additional way to cause this bug discovered.
By using global mmX register variables, reads & writes to/from these locations
incur mmX operands automatically.
Even when compiled _without_ -mmmx flag, these MMX operands are generated by
gcc!
As the bug name states, no emms opcode is generated to leave MMX state/mode and
return the FPU to working order.
1) why does gcc _not_ place the emms opcode at the end of all binaries
compiled with -mmmx for safety-sake?
2) Why does gcc generate MMX opcodes even without the -mmmx compile flag?
-------------------
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.6/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro
4.6.3-1ubuntu5' --with-bugurl=file:///usr/share/doc/gcc-4.6/README.Bugs
--enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr
--program-suffix=-4.6 --enable-shared --enable-linker-build-id
--with-system-zlib --libexecdir=/usr/lib --without-included-gettext
--enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.6
--libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu
--enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-gnu-unique-object
--enable-plugin --enable-objc-gc --disable-werror --with-arch-32=i686
--with-tune=generic --enable-checking=release --build=x86_64-linux-gnu
--host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 4.6.3 (Ubuntu/Linaro 4.6.3-1ubuntu5)
