https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94743
--- Comment #10 from Richard Earnshaw <rearnsha at gcc dot gnu.org> --- (In reply to Christophe Lyon from comment #9) > > My initial thoughts are along the lines of... > > Only try to save FP registers that this function directly clobbers. > What's the point of saving these if a callee clobbers other registers? > They need to be done early enough to ensure that any code in *this* function does not clobber them. Any additional registers would have to be saved by a library call that does that. > Shouldn't that be something like save-nothing vs save-all-FP-regs if there > is a callee? > > Do you mean save direct clobbers only when the handler is a leaf function? Well, obviously if it's a leaf function, saving only the registers that are clobbered is enough, and the compiler can do the analysis to ensure that. > > > Provide libgcc routines to save/restore the FP context. > Do you mean such routines should push all FP regs+status regs? All registers that are are call clobbered. There's no need to do the call-saved registers as the compiler can do that on an as-needed case already.
