simd/jfdctfst-sse2-64.asm


Log

Author Commit Date CI Message
DRC bd49803f 2016-02-19T08:53:33 Use consistent/modern code formatting for pointers The convention used by libjpeg: type * variable; is not very common anymore, because it looks too much like multiplication. Some (particularly C++ programmers) prefer to tuck the pointer symbol against the type: type* variable; to emphasize that a pointer to a type is effectively a new type. However, this can also be confusing, since defining multiple variables on the same line would not work properly: type* variable1, variable2; /* Only variable1 is actually a pointer. */ This commit reformats the entirety of the libjpeg-turbo code base so that it uses the same code formatting convention for pointers that the TurboJPEG API code uses: type *variable1, *variable2; This seems to be the most common convention among C programmers, and it is the convention used by other codec libraries, such as libpng and libtiff.
DRC 55e328ec 2014-08-22T18:30:44 Revert r1335 and r1336. It was a valiant effort, but on Windows, xmm8-xmm15 are non-volatile, and the overhead of pushing them onto the stack at the beginning of each function and popping them at the end was causing worse performance (in the neighborhood of 3-5%) than just using the work areas and limiting the register usage to xmm0-xmm7. Best to leave the SSE2 code alone. We can optimize the register usage for AVX2, once that port takes place. git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@1382 632fc199-4ca6-4c93-a231-07263d6284db
DRC 8a74848a 2014-08-09T22:58:18 Oops. The Windows version of collect_args/uncollect_args uses rsp, so we still need the rsp prologue/epilogue, despite the fact that we aren't using the stack as a work area. This fixes a segfault on Windows caused by r1335. git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@1336 632fc199-4ca6-4c93-a231-07263d6284db
DRC a8ab3424 2014-08-09T14:30:28 Attempt to improve performance by refactoring the compression-side color conversion and DCT algorithms so that they take full advantage of the additional registers available with 64-bit SSE2. This produces a somewhat yawn-worthy speedup of 2-3%, but at least the code is a lot more readable now. git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@1335 632fc199-4ca6-4c93-a231-07263d6284db
DRC 24e92e9f 2014-05-10T09:53:34 Using subdirectories unfortunately opened up a can of worms. In order to prevent object name conflicts, it is necessary to use the subdir-objects automake directive, but it simply doesn't work right on some of the versions of automake we still have to support. Another option would be to add a separate Makefile.am file to each subdirectory, but that requires maintaining a completely different set of build rules for each one. Fortunately, however, we're in the 21st century now, so we can use filenames longer than 8.3. git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@1282 632fc199-4ca6-4c93-a231-07263d6284db