ffmpeg | branch: master | Henrik Gramner <hen...@gramner.com> | Thu Jan 21 00:05:15 2016 +0100| [91ed050f426ba9747ea42b14e762ed412a28da76] | committer: Anton Khirnov
x86inc: Preserve arguments when allocating stack space When allocating stack space with a larger alignment than the known stack alignment a temporary register is used for storing the stack pointer. Ensure that this isn't one of the registers used for passing arguments. Signed-off-by: Anton Khirnov <an...@khirnov.net> > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=91ed050f426ba9747ea42b14e762ed412a28da76 --- libavutil/x86/x86inc.asm | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/libavutil/x86/x86inc.asm b/libavutil/x86/x86inc.asm index fc58b74..7d6c171 100644 --- a/libavutil/x86/x86inc.asm +++ b/libavutil/x86/x86inc.asm @@ -386,8 +386,11 @@ DECLARE_REG_TMP_SIZE 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14 %if %1 != 0 && required_stack_alignment > STACK_ALIGNMENT %if %1 > 0 %assign regs_used (regs_used + 1) - %elif ARCH_X86_64 && regs_used == num_args && num_args <= 4 + UNIX64 * 2 - %warning "Stack pointer will overwrite register argument" + %endif + %if ARCH_X86_64 && regs_used < 5 + UNIX64 * 3 + ; Ensure that we don't clobber any registers containing arguments. For UNIX64 we also preserve r6 (rax) + ; since it's used as a hidden argument in vararg functions to specify the number of vector registers used. + %assign regs_used 5 + UNIX64 * 3 %endif %endif %endif _______________________________________________ ffmpeg-cvslog mailing list ffmpeg-cvslog@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-cvslog
