Steve Ellcey <sell...@imgtec.com> writes: > On Sat, 2013-03-23 at 14:50 +0000, Richard Sandiford wrote: >> This is similar in spirit to -mbranch-likely. It'd be good for consistency >> if they were defined in a similar style. I think that means removing >> !TARGET_MIPS16 from ISA_HAS_MADD_MSUB and instead having: >> >> #define GENERATE_MADD_MSUB (TARGET_IMADD && !TARGET_MIPS16) >> >> There would also be: >> >> #define PTF_AVOID_IMADD 0x2 >> >> which should be included in the 74k description, and a block similar to >> the MASK_BRANCHLIKELY one in mips_option_override. There needs to be >> documentation in invoke.texi. > > I can do it this way if you want, I was using -mllsc as my template for > how to implement this. Do you think the -mllsc flag should be > implemented in the same way as -mbranch-likely?
-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