I can't reproduce it (otherwise I wouldn't have committed it), it bootstrapped/regtested just fine for me.
Can one of those who can reproduce it give me preprocessed mf-runtime.i and exact gcc options that triggered it?
I have attached the stripped down testcase. The bug is triggered with: ./cc1 mf-runtime-i.c -march=i686
extern unsigned char __mf_lc_shift; float __mf_adapt_cache () { return __mf_lc_shift; }