diff options
| author | Martin Storsjö <martin@martin.st> | 2012-02-20 11:24:35 +0200 |
|---|---|---|
| committer | Martin Storsjö <martin@martin.st> | 2014-06-10 16:31:48 +0300 |
| commit | 570d4b21863b6254d6bbca9c528bede471bb4478 (patch) | |
| tree | 1a6bb2680e594b4ff09c665702393dbdc6d6afdb | |
| parent | 0776e0ef6ba4160281ef3fabea43e670f3792b4a (diff) | |
| download | ffmpeg-570d4b21863b6254d6bbca9c528bede471bb4478.tar.gz | |
x86: h264: Don't keep data in the redzone across function calls on 64 bit unix
We know that the called function (ff_chroma_inter_body_mmxext)
doesn't touch the redzone, and thus will be kept intact - thus,
this doesn't fix any bug per se.
However, valgrind's memcheck tool intentionally assumes that the
redzone is clobbered on every function call and function return
(see a long comment in valgrind/memcheck/mc_main.c). This avoids
false positives in that tool, at the cost of an extra stack pointer
adjustment.
The other alternative would be a valgrind suppression for this issue,
but that's an extra burden for everybody that wants to run libavcodec
within valgrind.
Signed-off-by: Martin Storsjö <martin@martin.st>
| -rw-r--r-- | libavcodec/x86/h264_deblock.asm | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/libavcodec/x86/h264_deblock.asm b/libavcodec/x86/h264_deblock.asm index 8a9fdf6c35..61642a0f47 100644 --- a/libavcodec/x86/h264_deblock.asm +++ b/libavcodec/x86/h264_deblock.asm @@ -821,10 +821,10 @@ cglobal deblock_v_chroma_8, 5,6 ; int8_t *tc0) ;----------------------------------------------------------------------------- cglobal deblock_h_chroma_8, 5,7 -%if UNIX64 - %define buf0 [rsp-24] - %define buf1 [rsp-16] -%elif WIN64 +%if ARCH_X86_64 + ; This could use the red zone on 64 bit unix to avoid the stack pointer + ; readjustment, but valgrind assumes the red zone is clobbered on + ; function calls and returns. sub rsp, 16 %define buf0 [rsp] %define buf1 [rsp+8] @@ -840,7 +840,7 @@ cglobal deblock_h_chroma_8, 5,7 movq m0, buf0 movq m3, buf1 TRANSPOSE8x4B_STORE PASS8ROWS(t5, r0, r1, t6) -%if WIN64 +%if ARCH_X86_64 add rsp, 16 %endif RET |