Re: [Qemu-devel] [PATCH] fix fdiv instruction

[Richard Henderson]

On 06/23/2018 01:17 PM, Programmingkid wrote:
>>> https://www.pdfdrive.net/powerpc-microprocessor-family-the-programming-environments-for-32-e3087633.html
>>> This document has the information on the fdiv. Page 133 has the information 
>>> on what action is executed when a division by zero situation takes place. 

Even in your referenced PDF, table 3-13, it says that frD is unmodified.

>>  struct sigaction a = { .sa_sigaction = handle, .sa_flags = SA_SIGINFO };
>>  sigaction(SIGFPE, &a, NULL);
>>  feenableexcept(FE_ALL_EXCEPT);
> 
> This is C99 code. There are a lot of floating point bugs with this 
> implementation. I suggest all future testing be done using PowerPC assembly 
> language only.

Um.. have you really ever seen an implementation that won't set ZE?

> What compiler did you use to compile this program?

gcc 7.2.

> What operating system did you run this program on?

CentOS 7, so kernel 3.10, glibc 2.17.

> What are the specs of the system you used to test this program on?

CHRP IBM,8231-E2B (Power7).


r~