[libav-devel] [PATCH 1/8] x86inc: warn if XOP integer FMA instruction emulation is impossible

Henrik Gramner henrik at gramner.com
Sat Aug 1 17:27:31 CEST 2015


From: Anton Mitrofanov <BugMaster at narod.ru>

Emulation requires a temporary register if arguments 1 and 4 are the same; this
doesn't obey the semantics of the original instruction, so we can't emulate
that in x86inc.

Also add pmacsdql emulation.

Signed-off-by: Henrik Gramner <henrik at gramner.com>
---
 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 a6e1f33..4c0a4bd 100644
--- a/libavutil/x86/x86inc.asm
+++ b/libavutil/x86/x86inc.asm
@@ -1410,15 +1410,18 @@ AVX_INSTR pfmul, 1, 0, 1
     %macro %1 4-7 %1, %2, %3
         %if cpuflag(xop)
             v%5 %1, %2, %3, %4
-        %else
+        %elifnidn %1, %4
             %6 %1, %2, %3
             %7 %1, %4
+        %else
+            %error non-xop emulation of ``%5 %1, %2, %3, %4'' is not supported
         %endif
     %endmacro
 %endmacro
 
-FMA_INSTR  pmacsdd,  pmulld, paddd
 FMA_INSTR  pmacsww,  pmullw, paddw
+FMA_INSTR  pmacsdd,  pmulld, paddd ; sse4 emulation
+FMA_INSTR pmacsdql,  pmuldq, paddq ; sse4 emulation
 FMA_INSTR pmadcswd, pmaddwd, paddd
 
 ; tzcnt is equivalent to "rep bsf" and is backwards-compatible with bsf.
-- 
1.8.3.2



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