confusion about fma description in section 16.9 of gccint doc.

[Kenneth Zadeck]

Section 16.9 of the current gcc doc is as follows.   It implies that the 
fma pattern should/could be used on a machine that double rounds the 
multiply add.

`fmam4'
    Multiply operand 2 and operand 1, then add operand 3, storing the
    result in operand 0. All operands must have mode m. This pattern is
    used to implement the |fma|, |fmaf|, and |fmal| builtin functions
    from the ISO C99 standard. The |fma| operation may produce different
    results than doing the multiply followed by the add if the machine
    does not perform a rounding step between the operations.

However, this gccint doc says that this pattern is to be used to 
implement the fma* builtin functions of ISO C99.

The iso c99 standard states:

7.12.13 Floating multiply-add
7.12.13.1 Thefmafunctions
Synopsis
1	#include<math.h>  double fma(double x, double y, double z); float fmaf(float x, float y, float z); long double fmal(long double x, long double y,
long double z);
Description
2	The fma functions compute (x × y) + z, rounded as one ternary operation: they compute the value (as if) to infinite precision and round once to the result format, according to the rounding mode characterized by the value of FLT_ROUNDS.
Returns
3	The fma functions return (x × y) + z, rounded as one ternary operation.


Point 2 of the standard above states that those functions only do single 
rounding.  My guess is that the gccint doc is wrong.    (I should point 
out that the gccint doc for the new rtl operator in section 10.9 does 
require only single rounding.   But that is not the question here.)

Should i change the section 16.9 doc to indicate that this pattern is 
only to be used if the machine can do this with a single rounding?

kenny