[FFmpeg-devel] [PATCH] Fix AVX-512-VNNI_hevc_qpel_filters_avx512icl

* [FFmpeg-devel] [PATCH] Fix AVX-512-VNNI_hevc_qpel_filters_avx512icl
@ 2022-04-28 17:17 Felix LeClair
  2022-04-29  5:08 ` Wu Jianhua
  0 siblings, 1 reply; 3+ messages in thread
From: Felix LeClair @ 2022-04-28 17:17 UTC (permalink / raw)
  To: ffmpeg-devel

Issue: On extremely new hardware using either IceLake or super sets of 
Intel IceLakes avx512 instructions, commit 
d4cd8830bdac3e26c8e75cd92e574c159fecc4f7 causes build issues. 
Specifically a NASM macro expansion of qpel_filter_v is never properly 
defined/initialized.

The issue is the definition was erroneously placed inside a conditional 
which will not trigger unless the original definition failed (has to do 
with if PIC is defined, becomes a bit of a catch 22)
Specifically the error is

X86ASM    libavcodec/x86/hevc_mc.o
libavcodec/x86/hevc_mc.asm:1854: error: symbol `..@88472.table' not defined
libavcodec/x86/hevc_mc.asm:1806: ... from macro 
`HEVC_PUT_HEVC_QPEL_HV_AVX512ICL' defined here
libavcodec/x86/hevc_mc.asm:1730: ... from macro `QPEL_FILTER_V' defined here
...
repeats a few times...
...
make: *** [ffbuild/common.mak:100: libavcodec/x86/hevc_mc.o] Error 1
```
Specific error was discussed by kurosu and myself (fclc) on the 
ffmpeg-devel irc.

This commit fixes the above by swapping lines 1796 and 1795, moving the 
define out of the conditional

Side note: It seems fate didn't pick up on this, may merit looking into 
(as mentioned by nevcairiel).

Signed-off-by: Felix LeClair (FCLC) <felix.leclair123@hotmail.com>
---
  libavcodec/x86/hevc_mc.asm | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/x86/hevc_mc.asm b/libavcodec/x86/hevc_mc.asm
index c07948dd9b..e159adccc7 100644
--- a/libavcodec/x86/hevc_mc.asm
+++ b/libavcodec/x86/hevc_mc.asm
@@ -1792,8 +1792,8 @@ cglobal hevc_put_hevc_qpel_hv%1_%2, 6, 7, 27, dst, 
src, srcstride, height, mx, m
      sub            srcq, tmpq
      sub             myq, 1
      shl             myq, 5
-%ifdef PIC
  %define %%table hevc_qpel_filters_avx512icl_v_%1
+%ifdef PIC
      lea tmpq, [%%table]
      %define FILTER tmpq
  %else
-- 
2.32.0

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^ permalink raw reply	[flat|nested] 3+ messages in thread