mirror of https://git.videolan.org/git/ffmpeg.git
90540c2d5a
To access data at multiple fixed offsets from a base address, this code uses a single "m" operand and code of the form "32%0", relying on the memory operand instantiation having no displacement, giving a final result of the form "32(%rax)". If the compiler uses a register and displacement, e.g. "64(%rax)", the end result becomes "3264(%rax)", which obviously does not work. Replacing the "m" operands with "r" operands allows safe addition of a displacement. In theory, multiple memory operands could use a shared base register with different index registers, "(%rax,%rbx)", potentially making more efficient use of registers. In the cases at hand, no such sharing is possible since the addresses involved are entirely unrelated. After this change, the code somewhat rudely accesses memory without using a corresponding memory operand, which in some cases can lead to unwanted "optimisations" of surrounding code. However, the original code also accesses memory not covered by a memory operand, so this is not adding any defect not already present. It is also hightly unlikely that any such optimisations could be performed here since the memory locations in questions are not accessed elsewhere in the same functions. This fixes crashes with suncc. Signed-off-by: Mans Rullgard <mans@mansr.com> |
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| compat | ||
| doc | ||
| libavcodec | ||
| libavdevice | ||
| libavfilter | ||
| libavformat | ||
| libavresample | ||
| libavutil | ||
| libswscale | ||
| presets | ||
| tests | ||
| tools | ||
| .gitignore | ||
| COPYING.GPLv2 | ||
| COPYING.GPLv3 | ||
| COPYING.LGPLv2.1 | ||
| COPYING.LGPLv3 | ||
| CREDITS | ||
| Changelog | ||
| Doxyfile | ||
| INSTALL | ||
| LICENSE | ||
| Makefile | ||
| README | ||
| RELEASE | ||
| arch.mak | ||
| avconv.c | ||
| avconv.h | ||
| avconv_filter.c | ||
| avconv_opt.c | ||
| avplay.c | ||
| avprobe.c | ||
| avserver.c | ||
| cmdutils.c | ||
| cmdutils.h | ||
| cmdutils_common_opts.h | ||
| common.mak | ||
| configure | ||
| library.mak | ||
| version.sh | ||
README
Libav README ------------ 1) Documentation ---------------- * Read the documentation in the doc/ directory. 2) Licensing ------------ * See the LICENSE file.