What is: __builtin_ia32_vec_ext_v2df
??? It wasn't in the original emmintrin.h, so presumably isn't actually part of SSE2, but it is present in the testsuite, and it is not visible to the compiler when -mno-sse2 is set. See for instance the files sse2-vec-#.c. (Randomly selected) Example: sse2-vec-4.c: res[2] = __builtin_ia32_vec_ext_v8hi ((__v8hi)val1.x, 2); gcc -Wall -msse -mno-sse2 -I. -m32 -lm -DSOFT_SSE2 -o foo sse2-vec-4.c sse2-vec-4.c: In function 'sse2_test': sse2-vec-4.c:27: warning: implicit declaration of function '__builtin_ia32_vec_ext_v8hi' /root/tmp/ccYAq3IB.o: In function `sse2_test': sse2-vec-4.c:(.text+0x58c): undefined reference to `__builtin_ia32_vec_ext_v8hi' . . . /root/tmp/ccYAq3IB.o:sse2-vec-4.c:(.text+0x613): more undefined references to `__builtin_ia32_vec_ext_v8hi' follow collect2: ld returned 1 exit status Thanks, David Mathog mat...@caltech.edu Manager, Sequence Analysis Facility, Biology Division, Caltech
