https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86489
--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> --- (In reply to kugan from comment #3) > (In reply to Richard Biener from comment #2) > > gimple *phi = SSA_NAME_DEF_STMT (b_11); > > if (gimple_code (phi) != GIMPLE_PHI > > || (gimple_assign_lhs (and_stmt) > > != gimple_phi_arg_def (phi, loop_latch_edge (loop)->dest_idx))) > > return false; > > > > this may fail if the PHI in question is not the correct one in which case > > it may not have the argument at the latch dest_idx. Try first verifying > > that the loop latch destination is indeed gimple_bb (phi). > > yes, thanks for spotting. I am testing the following patch: > > diff --git a/gcc/tree-ssa-loop-niter.c b/gcc/tree-ssa-loop-niter.c > index f6fa2f7..fbdf838 100644 > --- a/gcc/tree-ssa-loop-niter.c > +++ b/gcc/tree-ssa-loop-niter.c > @@ -2555,6 +2555,7 @@ number_of_iterations_popcount (loop_p loop, edge exit, > ... = PHI <b_5(2), b_6(3)>. */ > gimple *phi = SSA_NAME_DEF_STMT (b_11); > if (gimple_code (phi) != GIMPLE_PHI > + || (gimple_bb (phi) != loop_latch_edge (loop)->dest) > || (gimple_assign_lhs (and_stmt) > != gimple_phi_arg_def (phi, loop_latch_edge (loop)->dest_idx))) > return false; > > is checking that there is argument at the latch dest_idx (argument count of > PHI) is still necessary? No, the number of edges determines that. The above patch is OK if it bootstraps/tests OK. Richard.
