The following fixes LOOP_VECTORIZED IFNs made useless by CFG cleanup after if-conversion by re-verifying the mentioned loops still exist.
Bootstrapped on x86_64-unknown-linux-gnu, testing in progress. Richard. 2019-02-08 Richard Biener <rguent...@suse.de> PR tree-optimization/89247 * tree-if-conv.c: Include tree-cfgcleanup.h. (version_loop_for_if_conversion): Record LOOP_VECTORIZED call. (tree_if_conversion): Pass through predicate vector. (pass_if_conversion::execute): Do CFG cleanup and SSA update inline, see if any if-converted loops we refrece in LOOP_VECTORIZED calls vanished and fixup. * tree-if-conv.h (tree_if_conversion): Adjust prototype. * gcc.dg/torture/pr89247.c: New testcase. Index: gcc/tree-if-conv.c =================================================================== --- gcc/tree-if-conv.c (revision 268668) +++ gcc/tree-if-conv.c (working copy) @@ -119,6 +119,7 @@ along with GCC; see the file COPYING3. #include "internal-fn.h" #include "fold-const.h" #include "tree-ssa-sccvn.h" +#include "tree-cfgcleanup.h" /* Only handle PHIs with no more arguments unless we are asked to by simd pragma. */ @@ -2719,7 +2720,7 @@ combine_blocks (struct loop *loop) consistent after the condition is folded in the vectorizer. */ static struct loop * -version_loop_for_if_conversion (struct loop *loop) +version_loop_for_if_conversion (struct loop *loop, vec<gimple *> *preds) { basic_block cond_bb; tree cond = make_ssa_name (boolean_type_node); @@ -2759,6 +2760,7 @@ version_loop_for_if_conversion (struct l new_loop->force_vectorize = false; gsi = gsi_last_bb (cond_bb); gimple_call_set_arg (g, 1, build_int_cst (integer_type_node, new_loop->num)); + preds->safe_push (g); gsi_insert_before (&gsi, g, GSI_SAME_STMT); update_ssa (TODO_update_ssa); return new_loop; @@ -2979,7 +2981,7 @@ ifcvt_local_dce (basic_block bb) changed. */ unsigned int -tree_if_conversion (struct loop *loop) +tree_if_conversion (struct loop *loop, vec<gimple *> *preds) { unsigned int todo = 0; bool aggressive_if_conv; @@ -3027,7 +3029,7 @@ tree_if_conversion (struct loop *loop) struct loop *vloop = (versionable_outer_loop_p (loop_outer (loop)) ? loop_outer (loop) : loop); - struct loop *nloop = version_loop_for_if_conversion (vloop); + struct loop *nloop = version_loop_for_if_conversion (vloop, preds); if (nloop == NULL) goto cleanup; if (vloop != loop) @@ -3139,11 +3141,12 @@ pass_if_conversion::execute (function *f if (number_of_loops (fun) <= 1) return 0; + auto_vec<gimple *> preds; FOR_EACH_LOOP (loop, 0) if (flag_tree_loop_if_convert == 1 || ((flag_tree_loop_vectorize || loop->force_vectorize) && !loop->dont_vectorize)) - todo |= tree_if_conversion (loop); + todo |= tree_if_conversion (loop, &preds); if (todo) { @@ -3158,7 +3161,30 @@ pass_if_conversion::execute (function *f gcc_assert (!bb->aux); } - return todo; + /* Perform IL update now, it might elide some loops. */ + if (todo & TODO_cleanup_cfg) + { + cleanup_tree_cfg (); + if (need_ssa_update_p (fun)) + todo |= TODO_update_ssa; + } + if (todo & TODO_update_ssa_any) + update_ssa (todo & TODO_update_ssa_any); + + /* If if-conversion elided the loop fall back to the original one. */ + for (unsigned i = 0; i < preds.length (); ++i) + { + gimple *g = preds[i]; + unsigned ifcvt_loop = tree_to_uhwi (gimple_call_arg (g, 0)); + if (!get_loop (fun, ifcvt_loop)) + { + if (dump_file) + fprintf (dump_file, "If-converted loop vanished\n"); + fold_loop_internal_call (g, boolean_false_node); + } + } + + return 0; } } // anon namespace Index: gcc/tree-if-conv.h =================================================================== --- gcc/tree-if-conv.h (revision 268668) +++ gcc/tree-if-conv.h (working copy) @@ -19,6 +19,6 @@ along with GCC; see the file COPYING3. #ifndef GCC_TREE_IF_CONV_H #define GCC_TREE_IF_CONV_H -unsigned int tree_if_conversion (struct loop *); +unsigned int tree_if_conversion (struct loop *, vec<gimple *> * = NULL); #endif /* GCC_TREE_IF_CONV_H */ Index: gcc/testsuite/gcc.dg/torture/pr89247.c =================================================================== --- gcc/testsuite/gcc.dg/torture/pr89247.c (nonexistent) +++ gcc/testsuite/gcc.dg/torture/pr89247.c (working copy) @@ -0,0 +1,13 @@ +/* { dg-do compile } */ + +int *a; +void b() +{ + void *c = &&d; + for (;;) + d: + if (*a) + ; + else + *a = ({ 0 < b; }); +}