On Sun, Jan 31, 2016 at 10:18 PM, James Almer <jamr...@gmail.com> wrote: > On 1/31/2016 4:48 PM, Timothy Gu wrote: >> +; ff_vc1_inv_trans_?x?_dc_mmxext(uint8_t *dest, int linesize, int16_t >> *block) >> +INIT_MMX mmxext >> +cglobal vc1_inv_trans_4x4_dc, 3,4,0, dest, linesize, block >> + movsx r3d, WORD [blockq] > > Can this value be negative? Because you're using it as an argument > for lea using native size after movsx sign extended the value to 32 > bits, which means that on x86_64 the upper bits of the register will > be zeroed. > > If it can you'll have to use blockq/r3q everywhere, and if it can't > then use movzx and shr.
The destination of those lea instructions are 32-bit, so the upper half is discarded anyway. Fun fact: you _can_ use the 32-bit register form inside the lea brackets, but doing so would just require a REX prefix without affecting the output, so you don't really want to do that. _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
