Re: [ft-devel] FT_MulFix assembly

[Miles Bader]

On Tue, Sep 7, 2010 at 4:28 AM, James Cloos <address@hidden> wrote:
>>>>>> "MB" == Miles Bader <address@hidden> writes:
>
> MB> The compiler generates the following assembly:
>
> MB>     mov     %esi, %eax
> MB>     mov     %edi, %edi
> MB>     imulq   %rdi, %rax
> MB>     addq    $32768, %rax
> MB>     shrq    $16, %rax
>
> That does not match the C code though; it rounds negative values wrong.
>
> The C version does away-from-zero rounding.

Do you have test cases that show this?  I tried using random inputs,
but even up to billions of iterations, I can't seem to find a set of
inputs where my function yields different results from yours.

Thanks,

-Miles


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