Handle conditional compilation of CPU-specific FFT code in the Makefile.

Also replace one coarse MMX condition with more fine-grained
3DNow!/3DNowExt!/SSE conditions.

Originally committed as revision 17409 to svn://svn.ffmpeg.org/ffmpeg/trunk

configure

@@ -908,7 +908,6 @@ HAVE_LIST="
 
 # options emitted with CONFIG_ prefix but not available on command line
 CONFIG_EXTRA="
-    fft_mmx
     oldscaler
 "
 
@@ -976,8 +975,6 @@ ssse3_deps="sse"
 vis_deps="sparc"
 
 # common features
-fft_suggest="fft_mmx"
-fft_mmx_deps="mmx yasm"
 oldscaler_deps="!swscale"
 
 # decoders / encoders

libavcodec/Makefile

@@ -402,6 +402,12 @@ OBJS-$(HAVE_PTHREADS)                  += pthread.o
 OBJS-$(HAVE_W32THREADS)                += w32thread.o
 
 # processor-specific code
+FFT-OBJS-$(HAVE_AMD3DNOW)              += x86/fft_3dn.o
+FFT-OBJS-$(HAVE_AMD3DNOWEXT)           += x86/fft_3dn2.o
+FFT-OBJS-$(HAVE_SSE)                   += x86/fft_sse.o
+OBJS-$(CONFIG_FFT)                     += $(FFT-OBJS-yes)
+
+YASM-OBJS-$(CONFIG_FFT)                += x86/fft_mmx.o
 YASM-OBJS-$(CONFIG_GPL)                += x86/h264_deblock_sse2.o       \
                                           x86/h264_idct_sse2.o          \
 
@@ -435,11 +441,6 @@ OBJS-$(HAVE_MMX)                       += x86/cpuid.o                   \
                                           x86/simple_idct_mmx.o         \
                                           $(MMX-OBJS-yes)
 
-OBJS-$(CONFIG_FFT_MMX)                 += x86/fft_3dn.o                 \
-                                          x86/fft_3dn2.o                \
-                                          x86/fft_mmx.o                 \
-                                          x86/fft_sse.o                 \
-
 OBJS-$(ARCH_ALPHA)                     += alpha/dsputil_alpha.o         \
                                           alpha/dsputil_alpha_asm.o     \
                                           alpha/motion_est_alpha.o      \