diff options
Diffstat (limited to 'gcc/doc/md.texi')
| -rw-r--r-- | gcc/doc/md.texi | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/gcc/doc/md.texi b/gcc/doc/md.texi index 6de4f3658a6..8418564d91c 100644 --- a/gcc/doc/md.texi +++ b/gcc/doc/md.texi @@ -3958,6 +3958,36 @@ pattern is used to implement the @code{fma}, @code{fmaf}, and multiply followed by the add if the machine does not perform a rounding step between the operations. +@cindex @code{fms@var{m}4} instruction pattern +@item @samp{fms@var{m}4} +Like @code{fma@var{m}4}, except operand 3 subtracted from the +product instead of added to the product. This is represented +in the rtl as + +@smallexample +(fma:@var{m} @var{op1} @var{op2} (neg:@var{m} @var{op3})) +@end smallexample + +@cindex @code{fnma@var{m}4} instruction pattern +@item @samp{fnma@var{m}4} +Like @code{fma@var{m}4} except that the intermediate product +is negated before being added to operand 3. This is represented +in the rtl as + +@smallexample +(fma:@var{m} (neg:@var{m} @var{op1}) @var{op2} @var{op3}) +@end smallexample + +@cindex @code{fnms@var{m}4} instruction pattern +@item @samp{fnms@var{m}4} +Like @code{fms@var{m}4} except that the intermediate product +is negated before subtracting operand 3. This is represented +in the rtl as + +@smallexample +(fma:@var{m} (neg:@var{m} @var{op1}) @var{op2} (neg:@var{m} @var{op3})) +@end smallexample + @cindex @code{min@var{m}3} instruction pattern @cindex @code{max@var{m}3} instruction pattern @item @samp{smin@var{m}3}, @samp{smax@var{m}3} |