This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
Re: IA32: printing FP register variables
- To: bcombee at metrowerks dot com, jimb at cygnus dot com
- Subject: Re: IA32: printing FP register variables
- From: Michael Meissner <meissner at cygnus dot com>
- Date: Fri, 9 Jul 1999 17:00:47 -0400
- Cc: egcs at egcs dot cygnus dot com, gdb at sourceware dot cygnus dot com
| I'm sorry, Ben, but I'm still confused about how you find the FP
| register containing a variable. I think there's a fundamental,
| difficult problem here which you don't seem to be mentioning at all.
| Perhaps you have solved it already, and assume we have too.
|
| In code generated by your compiler, is the value of TOP (the three-bit
| FPU stack pointer) at function entry known at compile time? Or does
| its value depend on the caller, and the caller's caller, etc.?
Yes, IIRC the IA32 abi explicitly requires the FP stack to be empty at the time
of a call. Otherwise, you couldn't write any code using it all, since the
stack might be full and any value pushed would result in an exception.