When I use -O2 -mtune=pentium4 -ffast-math on SPEC CPU 2K on Linux/x86 with gcc 4.2, I get
*** Miscompare of 200.s, see /export/spec/src/2000/spec/benchspec/CINT2000/176.gcc/run/00000004/200.s.mis *** Miscompare of scilab.s, see /export/spec/src/2000/spec/benchspec/CINT2000/176.gcc/run/00000004/scilab.s.mis Is that a known issue? H.J.