我使用Xcode6.4和libvpx-1.4.0，运行'./configure --target = x86-iphonesimulator-gcc'或'./configure --target = x86_64-iphonesimulator-gcc'，错误是报道：
Configuring selected codecs
enabling vp8_encoder
enabling vp8_decoder
enabling vp9_encoder
enabling vp9_decoder
Configuring for target 'x86-iphonesimulator-gcc'
enabling x86
enabling runtime_cpu_detect
enabling mmx
enabling sse
enabling sse2
enabling sse3
enabling ssse3
enabling sse4_1
enabling avx
enabling avx2
Unsupported version of nasm: NASM version 0.98.40 (Apple Computer, Inc. build 11) compiled on Jun 17 2015
Neither yasm nor nasm have been found
Configuration failed. This could reflect a misconfiguration of your
toolchains, improper options selected, or another problem. If you
don't see any useful error messages above, the next step is to look
at the configure error log file (config.log) to determine what
configure was trying to do when it died.
并在config.log中：
# ../configure --target=x86-iphonesimulator-gcc --prefix=./installed_path
Configuring selected codecs
enabling vp8_encoder
enabling vp8_decoder
enabling vp9_encoder
enabling vp9_decoder
Configuring for target 'x86-iphonesimulator-gcc'
enabling x86
check_cpp
BEGIN /var/folders/nc/zrk3k0nj79x3wxvs314rwrsw0000gp/T//vpx-conf-11165-3411.c
1 #if !defined(__ILP32__) || !defined(__x86_64__)
2 #error "not x32"
3 #endif
END /var/folders/nc/zrk3k0nj79x3wxvs314rwrsw0000gp/T//vpx-conf-11165-3411.c
gcc -miphoneos-version-min=6.0 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator8.4.sdk -E -o /var/folders/nc/zrk3k0nj79x3wxvs314rwrsw0000gp/T//vpx-conf-11165-3411.o /var/folders/nc/zrk3k0nj79x3wxvs314rwrsw0000gp/T//vpx-conf-11165-3411.c
/var/folders/nc/zrk3k0nj79x3wxvs314rwrsw0000gp/T//vpx-conf-11165-3411.c:2:2: error: "not x32"
#error "not x32"
^
1 error generated.
enabling runtime_cpu_detect
check_cflags -mmmx
check_cc -Werror -mmmx
BEGIN /var/folders/nc/zrk3k0nj79x3wxvs314rwrsw0000gp/T//vpx-conf-11165-3411.c
1 int x;
END /var/folders/nc/zrk3k0nj79x3wxvs314rwrsw0000gp/T//vpx-conf-11165-3411.c
gcc -miphoneos-version-min=6.0 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator8.4.sdk -m32 -Werror -mmmx -c -o /var/folders/nc/zrk3k0nj79x3wxvs314rwrsw0000gp/T//vpx-conf-11165-3411.o /var/folders/nc/zrk3k0nj79x3wxvs314rwrsw0000gp/T//vpx-conf-11165-3411.c
enabling mmx
check_cflags -msse
check_cc -Werror -msse
BEGIN /var/folders/nc/zrk3k0nj79x3wxvs314rwrsw0000gp/T//vpx-conf-11165-3411.c
1 int x;
END /var/folders/nc/zrk3k0nj79x3wxvs314rwrsw0000gp/T//vpx-conf-11165-3411.c
gcc -miphoneos-version-min=6.0 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator8.4.sdk -m32 -Werror -msse -c -o /var/folders/nc/zrk3k0nj79x3wxvs314rwrsw0000gp/T//vpx-conf-11165-3411.o /var/folders/nc/zrk3k0nj79x3wxvs314rwrsw0000gp/T//vpx-conf-11165-3411.c
enabling sse
check_cflags -msse2
check_cc -Werror -msse2
BEGIN /var/folders/nc/zrk3k0nj79x3wxvs314rwrsw0000gp/T//vpx-conf-11165-3411.c
1 int x;
END /var/folders/nc/zrk3k0nj79x3wxvs314rwrsw0000gp/T//vpx-conf-11165-3411.c
gcc -miphoneos-version-min=6.0 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator8.4.sdk -m32 -Werror -msse2 -c -o /var/folders/nc/zrk3k0nj79x3wxvs314rwrsw0000gp/T//vpx-conf-11165-3411.o /var/folders/nc/zrk3k0nj79x3wxvs314rwrsw0000gp/T//vpx-conf-11165-3411.c
enabling sse2
check_cflags -msse3
check_cc -Werror -msse3
BEGIN /var/folders/nc/zrk3k0nj79x3wxvs314rwrsw0000gp/T//vpx-conf-11165-3411.c
1 int x;
END /var/folders/nc/zrk3k0nj79x3wxvs314rwrsw0000gp/T//vpx-conf-11165-3411.c
gcc -miphoneos-version-min=6.0 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator8.4.sdk -m32 -Werror -msse3 -c -o /var/folders/nc/zrk3k0nj79x3wxvs314rwrsw0000gp/T//vpx-conf-11165-3411.o /var/folders/nc/zrk3k0nj79x3wxvs314rwrsw0000gp/T//vpx-conf-11165-3411.c
enabling sse3
check_cflags -mssse3
check_cc -Werror -mssse3
BEGIN /var/folders/nc/zrk3k0nj79x3wxvs314rwrsw0000gp/T//vpx-conf-11165-3411.c
1 int x;
END /var/folders/nc/zrk3k0nj79x3wxvs314rwrsw0000gp/T//vpx-conf-11165-3411.c
gcc -miphoneos-version-min=6.0 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator8.4.sdk -m32 -Werror -mssse3 -c -o /var/folders/nc/zrk3k0nj79x3wxvs314rwrsw0000gp/T//vpx-conf-11165-3411.o /var/folders/nc/zrk3k0nj79x3wxvs314rwrsw0000gp/T//vpx-conf-11165-3411.c
enabling ssse3
check_cflags -msse4
check_cc -Werror -msse4
BEGIN /var/folders/nc/zrk3k0nj79x3wxvs314rwrsw0000gp/T//vpx-conf-11165-3411.c
1 int x;
END /var/folders/nc/zrk3k0nj79x3wxvs314rwrsw0000gp/T//vpx-conf-11165-3411.c
gcc -miphoneos-version-min=6.0 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator8.4.sdk -m32 -Werror -msse4 -c -o /var/folders/nc/zrk3k0nj79x3wxvs314rwrsw0000gp/T//vpx-conf-11165-3411.o /var/folders/nc/zrk3k0nj79x3wxvs314rwrsw0000gp/T//vpx-conf-11165-3411.c
enabling sse4_1
check_cflags -mavx
check_cc -Werror -mavx
BEGIN /var/folders/nc/zrk3k0nj79x3wxvs314rwrsw0000gp/T//vpx-conf-11165-3411.c
1 int x;
END /var/folders/nc/zrk3k0nj79x3wxvs314rwrsw0000gp/T//vpx-conf-11165-3411.c
gcc -miphoneos-version-min=6.0 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator8.4.sdk -m32 -Werror -mavx -c -o /var/folders/nc/zrk3k0nj79x3wxvs314rwrsw0000gp/T//vpx-conf-11165-3411.o /var/folders/nc/zrk3k0nj79x3wxvs314rwrsw0000gp/T//vpx-conf-11165-3411.c
enabling avx
check_cflags -mavx2
check_cc -Werror -mavx2
BEGIN /var/folders/nc/zrk3k0nj79x3wxvs314rwrsw0000gp/T//vpx-conf-11165-3411.c
1 int x;
END /var/folders/nc/zrk3k0nj79x3wxvs314rwrsw0000gp/T//vpx-conf-11165-3411.c
gcc -miphoneos-version-min=6.0 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator8.4.sdk -m32 -Werror -mavx2 -c -o /var/folders/nc/zrk3k0nj79x3wxvs314rwrsw0000gp/T//vpx-conf-11165-3411.o /var/folders/nc/zrk3k0nj79x3wxvs314rwrsw0000gp/T//vpx-conf-11165-3411.c
enabling avx2
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