https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77918
--- Comment #6 from iii at gcc dot gnu.org --- Author: iii Date: Mon Oct 7 14:59:00 2019 New Revision: 276659 URL: https://gcc.gnu.org/viewcvs?rev=276659&root=gcc&view=rev Log: Allow COND_EXPR and VEC_COND_EXPR condtions to trap Right now gimplifier does not allow VEC_COND_EXPR's condition to trap and introduces a temporary if this could happen, for example, generating _5 = _4 > { 2.0e+0, 2.0e+0, 2.0e+0, 2.0e+0 }; _6 = VEC_COND_EXPR <_5, { -1, -1, -1, -1 }, { 0, 0, 0, 0 }>; from GENERIC VEC_COND_EXPR < (*b > { 2.0e+0, 2.0e+0, 2.0e+0, 2.0e+0 }) , { -1, -1, -1, -1 } , { 0, 0, 0, 0 } > This is not necessary and makes the resulting GIMPLE harder to analyze. Change the gimplifier so as to allow COND_EXPR and VEC_COND_EXPR conditions to trap. This patch takes special care to avoid introducing trapping comparisons in GIMPLE_COND. They are not allowed, because they would require 3 outgoing edges (then, else and EH), which is awkward to say the least. Therefore, computations of such conditions should live in their own basic blocks. gcc/ChangeLog: 2019-10-07 Ilya Leoshkevich <i...@linux.ibm.com> PR target/77918 * gimple-expr.c (gimple_cond_get_ops_from_tree): Assert that the caller passes a non-trapping condition. (is_gimple_condexpr): Allow trapping conditions. (is_gimple_condexpr_1): New helper function. (is_gimple_condexpr_for_cond): New function, acts like old is_gimple_condexpr. * gimple-expr.h (is_gimple_condexpr_for_cond): New function. * gimple.c (gimple_could_trap_p_1): Handle COND_EXPR and VEC_COND_EXPR. Fix an issue with statements like i = (fp < 1.). * gimplify.c (gimplify_cond_expr): Use is_gimple_condexpr_for_cond. (gimplify_expr): Allow is_gimple_condexpr_for_cond. * tree-eh.c (operation_could_trap_p): Assert on COND_EXPR and VEC_COND_EXPR. (tree_could_trap_p): Handle COND_EXPR and VEC_COND_EXPR. * tree-ssa-forwprop.c (forward_propagate_into_gimple_cond): Use is_gimple_condexpr_for_cond, remove pointless tmp check (forward_propagate_into_cond): Remove pointless tmp check. Modified: trunk/gcc/ChangeLog trunk/gcc/gimple-expr.c trunk/gcc/gimple-expr.h trunk/gcc/gimple.c trunk/gcc/gimplify.c trunk/gcc/tree-eh.c trunk/gcc/tree-ssa-forwprop.c
