https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90329
--- Comment #14 from rguenther at suse dot de <rguenther at suse dot de> --- On Mon, 6 May 2019, tomas.kalibera at gmail dot com wrote: > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90329 > > --- Comment #13 from Tomas Kalibera <tomas.kalibera at gmail dot com> --- > I understand the compiler may not know and typically does not whether the > called function accepts "character(len=1)" or "character(len=*)", so it may > have to pass the 1. But the situation where I suggest not writing the 1 is > more > subtle (see my original post - > https://gcc.gnu.org/ml/fortran/2019-05/msg00021.html). > > There DPOSV is tail-calling (jumping) into DPOTRS). DPOSV wants to pass on the > length of UPLO (1) to DPOTRS. DPOSV knows it was called with this hidden > length > argument of 1, and indeed at the same location on the stack as it is needed > for > DPOTRS, as the length of the same variable UPLO, but it still writes a > compile-time constant 1 to that location on the stack that already has (should > have) 1. I think that's called sibling-calling, not tailcalling (tail-call with same arguments).
