https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103585
--- Comment #15 from Jan Hubicka <hubicka at gcc dot gnu.org> --- We get 47s runtime with -O2 -flto and 53s with -O2 -fno-inline-functions-called-once. The call sequence is: <bb 81> [local count: 109362591]: _1656 = (unsigned long) _45; _1655 = _1656 + ivtmp.1182_2540; _229 = (double *) _1655; _1646 = (unsigned long) _35; _1645 = _1646 + ivtmp.1182_2540; _230 = (double *) _1645; _1636 = (unsigned long) _55; _1635 = _1636 + ivtmp.1182_2540; _231 = (double *) _1635; _1628 = (unsigned long) _17; _1627 = _1628 + ivtmp.1182_2540; _232 = (double *) _1627; _1618 = (unsigned long) _64; _1617 = _1618 + ivtmp.1182_2540; _233 = (double *) _1617; _234 = (double *) ivtmp.1181_2551; _235 = (double *) ivtmp.1180_2575; _236 = (double *) ivtmp.1178_2586; _2607 = yield_stress; perdida.constprop.isra (&dt, &lambda, &mu, _2607, &r_infinity, &b, &x_infinity, &gamma, &eta, &plastic_strain_threshold, _229, _230, _231, _232, _236, _233, _235, _234, &failure_threshold, &crack_closure_parameter); It is not clear to me why lambda is not replaced. Howevever for dt it seems to be: ! Disqualifying parameter number 0 - Dereferences in callers would happen much more frequently. I think this is too early since if we SRA all the way down to the original caller we will avoid all dereferences completely. Other place for improvement is non-LTO. Here IPA-sra disables itself since it does not have cost model for cloning (that could be also improved). Situation could be improved by ipa-modref that may optimize away unused parts of the array descriptors. ipa-modref however gives up on the fact that perdida has Fortran i/o and it then gives up on tracking on the descriptors even if the descritors are never escaping to the i/o. For this I need to finish the non-escaping analysis. I.e. make difference between arguments that does not escape in a sense that once function return they are not saved in global memory and in a sense that they are never passed down to callee function. We also may annotate fortran i/o and understand what it does. So there is still a lot to do.
