FFmpeg

109212 Commits

37 Branches

400 Tags

492 MiB

Tag: Branch: Tree: 87bae6b018

Commit Graph

Author	SHA1	Message	Date
James Cowgill	50a4dff69f	avcodec/arm/sbcenc: avoid callee preserved vfp registers When compiling FFmpeg with GCC-9, some very random segfaults were observed in code which had previously called down into the SBC encoder NEON assembly routines. This was caused by these functions clobbering some of the vfp callee saved registers (d8 - d15 aka q4 - q7). GCC was using these registers to save local variables, but after these functions returned, they would contain garbage. Fix by reallocating the registers in the two affected functions in the following way: ff_sbc_analyze_4_neon: q2-q5 => q8-q11, then q1-q4 => q8-q11 ff_sbc_analyze_8_neon: q2-q9 => q8-q15 The reason for using these replacements is to keep closely related sets of registers consecutively numbered which hopefully makes the code more easy to follow. Since this commit only reallocates registers, it should have no performance impact. Signed-off-by: James Cowgill <jcowgill@debian.org> Signed-off-by: Martin Storsjö <martin@martin.st>	3 years ago
Aurelien Jacobs	f677718bc8	sbcenc: add armv6 and neon asm optimizations This was originally based on libsbc, and was fully integrated into ffmpeg.	7 years ago

Author

SHA1

Message

Date

James Cowgill

50a4dff69f

avcodec/arm/sbcenc: avoid callee preserved vfp registers

When compiling FFmpeg with GCC-9, some very random segfaults were
observed in code which had previously called down into the SBC encoder
NEON assembly routines. This was caused by these functions clobbering
some of the vfp callee saved registers (d8 - d15 aka q4 - q7). GCC was
using these registers to save local variables, but after these
functions returned, they would contain garbage.

Fix by reallocating the registers in the two affected functions in
the following way:
 ff_sbc_analyze_4_neon: q2-q5 => q8-q11, then q1-q4 => q8-q11
 ff_sbc_analyze_8_neon: q2-q9 => q8-q15

The reason for using these replacements is to keep closely related
sets of registers consecutively numbered which hopefully makes the
code more easy to follow. Since this commit only reallocates
registers, it should have no performance impact.

Signed-off-by: James Cowgill <jcowgill@debian.org>
Signed-off-by: Martin Storsjö <martin@martin.st>

3 years ago

Aurelien Jacobs

f677718bc8

sbcenc: add armv6 and neon asm optimizations

This was originally based on libsbc, and was fully integrated into ffmpeg.

7 years ago

2 Commits (87bae6b0189d5cb71b836890078f96a4d1abd277)