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Re: Defect in XBD math.h

To: "yyyyyyyyyyyyyyy@xxxxxxxxxxxxx" <yyyyyyyyyyyyyyy@xxxxxxxxxxxxx>
Subject: Re: Defect in XBD math.h
From: "Fred J. Tydeman" <yyyyyyy@xxxxxxxxx>
Date: Tue, 15 Apr 03 19:45:57 -0700
Priority: Normal
On Tue, 15 Apr 2003 18:48:32 +0100 (BST), yyyyyyy@xxxxxxx wrote:

>The Base Specifications Issue 6 language when taken with the C99
>specification language does not imply the test
>
>         ELSE
>            VERIFY that the fma() operations used time more than the CPU time
>            that the direct operations used
>
>The test should not test for anything if any of the FP_FAST_* macros are
>not defined. The language "indicate whether the fma() family of
>functions are fast compared with direct code", has been used to imply
>that the macro is a switch on two types of behaviour which is not the
>C99 intent.

My personal opinion is it was C99's intent that the FP_FAST_* macros
not being defined means that the fma() functions are slow as compared
to x*y+z.  And, hence, the VSX test is correct.
---
Fred J. Tydeman        Tydeman Consulting
yyyyyyy@xxxxxxxxx      Programming, testing, numerics
+1 (775) 287-5904      Vice-chair of J11 (ANSI "C")
Sample C99+FPCE tests: ftp://jump.net/pub/tybor/
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