Steve Ellcey <sell...@imgtec.com> writes: > On Mon, 2013-03-25 at 16:45 +0000, Richard Sandiford wrote: > >> -mllsc is a little different in that it can be used even when the >> ISA doesn't support it (thanks to kernel emulation). -mimadd isn't >> like that though: we only want to use MADD/MSUB if the ISA has it. >> So I think it makes sense to leave -mllsc as it is but do -mimadd >> in the same way as -mbranch-likely. >> >> Thanks, >> Richard > > OK, Here is a patch that implements -mimadd in the same manner as > -mbranch-likely.
It still needs the invoke.texi documentation. :-) Looks good otherwise, just a very small nit: > -/* Masks that affect tuning. > - > - PTF_AVOID_BRANCHLIKELY > - Set if it is usually not profitable to use branch-likely instructions > - for this target, typically because the branches are always predicted > - taken and so incur a large overhead when not taken. */ > -#define PTF_AVOID_BRANCHLIKELY 0x1 > +/* Masks that affect tuning. */ > + > +/* Set PTF_AVOID_BRANCHLIKELY if is usually not profitable to use > + branch-likely instructions for this target, typically because > + the branches are always predicted taken and so incur a large > + overhead when not taken. */ > +#define PTF_AVOID_BRANCHLIKELY 0x1 > +/* Set PTF_AVOID_IMADD if it is usually not profitable to use the > + integer madd or msub instructions because of the overhead of > + getting the result out of the HI/LO registers. */ > +#define PTF_AVOID_IMADD 0x2 It wasn't obvious with just one PTK_*, but the idea was to lay this out in the same way as the mips-protos.h enums. I.e.: /* Masks that affect tuning. PTF_AVOID_BRANCHLIKELY Set if it is usually not profitable to use branch-likely instructions for this target, typically because the branches are always predicted taken and so incur a large overhead when not taken. PTF_AVOID_IMADD Set if it is usually not profitable to use the integer MADD or MSUB instructions because of the overhead of getting the result out of the HI/LO registers. */ #define PTF_AVOID_BRANCHLIKELY 0x1 #define PTF_AVOID_IMADD 0x2 That's trivial enough not to need a retest, but please post the invoke.texi patch. Thanks, Richard