https://gcc.gnu.org/bugzilla/show_bug.cgi?id=52544
mobi at mobiphil dot com changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |mobi at mobiphil dot com --- Comment #7 from mobi at mobiphil dot com --- Hi, I run into the same issue. Strange enough few days ago some similar construct was working, that is I could use -finstrument-functions. (Do not remember, if I did some package update on the ubuntu workstation I work). Now for a simple program: #include <emmintrin.h> void setbytes(char *p, int c) { __m128i i = _mm_set_epi8(c, c, c, c, c, c, c, c, c, c, c, c, c, c, c, c); _mm_stream_si128((__m128i *)&p[0], i); _mm_stream_si128((__m128i *)&p[16], i); _mm_stream_si128((__m128i *)&p[32], i); _mm_stream_si128((__m128i *)&p[48], i); } char cucu[1000]; int main() { setbytes(cucu, 3); } ->gcc t.c -finstrument-functions /tmp/ccDMgc7s.o:t.c:function setbytes: error: undefined reference to '_mm_set_epi8' /tmp/ccDMgc7s.o:t.c:function setbytes: error: undefined reference to '_mm_set_epi8' /tmp/ccDMgc7s.o:t.c:function setbytes: error: undefined reference to '_mm_stream_si128' /tmp/ccDMgc7s.o:t.c:function setbytes: error: undefined reference to '_mm_stream_si128' /tmp/ccDMgc7s.o:t.c:function setbytes: error: undefined reference to '_mm_stream_si128' /tmp/ccDMgc7s.o:t.c:function setbytes: error: undefined reference to '_mm_stream_si128' collect2: error: ld returned 1 exit status