search for: paren_expr

...that. I think this is a misunderstanding of where I'm going, see above. > Other languages are more interesting in this regard. Fortran, for instance, allows reassociation within parentheses. (Can that even be represented with instruction metadata?) I'm aware of Fortran parentheses (PAREN_EXPR in gcc). If it can't be expressed well then too bad: reassociation can just be turned off and we won't optimize Fortran as well as we could. (As mentioned above I have no intention of turning on reassociation based on the current flag since it can introduce an unbounded number of ULPs of...

Duncan, I have some issues with representing this as a single "fast" mode flag, which mostly boil down to the fact that this is a very C-centric view of the world. And, since C compilers are not generally known for their awesomeness on issues of numerics, I'm not sure that's a good idea. Having something called a "fast" or "relaxed" mode implies that it is

The attached patch is a first attempt at representing "-ffast-math" at the IR level, in fact on individual floating point instructions (fadd, fsub etc). It is done using metadata. We already have a "fpmath" metadata type which can be used to signal that reduced precision is OK for a floating point operation, eg %z = fmul float %x, %y, !fpmath !0 ... !0 = metadata