http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53511
--- Comment #7 from Oleg Endo <olegendo at gcc dot gnu.org> 2012-06-05 20:08:08
UTC ---
> (In reply to comment #4)
>
> Make -mfused-madd no-op instead to remove for the backward
> compatibility.
Sorry, I don't quite follow. According to my understanding we have
something like the following...
(A): New behavior (attachment 27558, using common gcc/config/fused-madd.opt)
(B): Old behavior
(C): New behavior, with -mfused-madd being a nop
| | (A) | (B) | (C)
1st option | 2nd option | fma pat. | fmac pat.| fma pat. (new)
| | (new) | (old) | (mfused-madd = nop)
=================+==================+==========+==========+==================
<no option> | -ffp-contract= | 1 | 0 | 1
| <no opt = fast> | | |
-----------------+------------------+----------+----------+------------------
<no option> | -fpp-contract=off| 0 | 0 | 0
-----------------+------------------+----------+----------+------------------
-mfused-madd | -ffp-contract= | 1 | 1 | 1
| <no opt = fast> | | |
-----------------+------------------+----------+----------+------------------
-mno-fused-madd | -ffp-contract= | 0 | 0 | 0
| <no opt = fast> | | |
-----------------+------------------+----------+----------+------------------
-mfused-madd | -fpp-contract=off| 0 | 1 | 0
-----------------+------------------+----------+----------+------------------
-mno-fused-madd | -fpp-contract=off| 0 | 0 | 0
-----------------+------------------+----------+----------+------------------
-fpp-contract=off| -mfused-madd | 1 | 1 | 0 (*)
-----------------+------------------+----------+----------+------------------
-fpp-contract=off| -mno-fused-madd | 0 | 0 | 0
-----------------+------------------+----------+----------+------------------
My intention was to avoid having any special -mfused-madd handling in the SH
target code and to re-use the existing common gcc/config/fused-madd.opt.
Making -mfused-madd a no-op with special handling will only differ in the (*)
marked case. Is this what you had in mind?
