[FFmpeg-devel] [PATCH 09/10] avcodec/x86/vc1: guard usage of undefined functions with preprocessor

[Kacper Michajłow]

The asumption is that DCE will remove references to those functions.
However some compilers with certain instrumentation enabled doesn't DCE
those at all, resulting in linking failure. Tested with cl.exe -RTCu -RTCs.

Signed-off-by: Kacper Michajłow <kasper93 at gmail.com>
---
 libavcodec/x86/vc1dsp.h      | 4 ++++
 libavcodec/x86/vc1dsp_init.c | 2 ++
 2 files changed, 6 insertions(+)

diff --git a/libavcodec/x86/vc1dsp.h b/libavcodec/x86/vc1dsp.h
index fdd4de1813..6185407b18 100644
--- a/libavcodec/x86/vc1dsp.h
+++ b/libavcodec/x86/vc1dsp.h
@@ -23,7 +23,11 @@
 
 #include "libavcodec/vc1dsp.h"
 
+#if HAVE_6REGS && HAVE_INLINE_ASM && HAVE_MMX_EXTERNAL
+
 void ff_vc1dsp_init_mmx(VC1DSPContext *dsp);
 void ff_vc1dsp_init_mmxext(VC1DSPContext *dsp);
 
+#endif /* HAVE_6REGS && HAVE_INLINE_ASM && HAVE_MMX_EXTERNAL */
+
 #endif /* AVCODEC_X86_VC1DSP_H */
diff --git a/libavcodec/x86/vc1dsp_init.c b/libavcodec/x86/vc1dsp_init.c
index 90b2f3624e..e8163f2886 100644
--- a/libavcodec/x86/vc1dsp_init.c
+++ b/libavcodec/x86/vc1dsp_init.c
@@ -102,6 +102,7 @@ av_cold void ff_vc1dsp_init_x86(VC1DSPContext *dsp)
 {
     int cpu_flags = av_get_cpu_flags();
 
+#if HAVE_6REGS && HAVE_INLINE_ASM && HAVE_MMX_EXTERNAL
     if (HAVE_6REGS && INLINE_MMX(cpu_flags))
         if (EXTERNAL_MMX(cpu_flags))
         ff_vc1dsp_init_mmx(dsp);
@@ -109,6 +110,7 @@ av_cold void ff_vc1dsp_init_x86(VC1DSPContext *dsp)
     if (HAVE_6REGS && INLINE_MMXEXT(cpu_flags))
         if (EXTERNAL_MMXEXT(cpu_flags))
         ff_vc1dsp_init_mmxext(dsp);
+#endif /* HAVE_6REGS && HAVE_INLINE_ASM && HAVE_MMX_EXTERNAL */
 
 #define ASSIGN_LF4(EXT) \
         dsp->vc1_v_loop_filter4  = ff_vc1_v_loop_filter4_ ## EXT; \
-- 
2.50.1