Mark Geisert wrote: > Is there something I need to do to "condition" the Cygwin environment to > generate FP exceptions? I saw the code in winsup/something/or/other to map > x86 > FP exceptions to SIGFPE but it seems somehow the exceptions aren't being > generated in the first place.
Very possibly not. There's probably a bit in the FPUCW you need to set or something. Ah, yes: see winsup/cygwin/crt0.c: > /* In the following ifdef'd i386 code, the FPU precision is set to 80 bits > and all FPU exceptions are masked. The former is needed to make long > doubles work correctly. The latter causes the FPU to generate NaNs and > Infinities instead of signals for certain operations. > */ > #define FPU_RESERVED 0xF0C0 > #define FPU_DEFAULT 0x033f > { > volatile unsigned short cw; > > /* Get Control Word */ > __asm__ volatile ("fnstcw %0" : "=m" (cw) : ); > > /* mask in */ > cw &= FPU_RESERVED; > cw |= FPU_DEFAULT; > > /* set cw */ > __asm__ volatile ("fldcw %0" :: "m" (cw)); > } You can copy and paste that hunk into your own main() and change the constants to anything you like. cheers, DaveK -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple