> > I think this isn't entirely good. For simple cases for > do {} while the condition ends up in the latch while for while () {} > loops it ends up in the header. In your case the latch isn't empty > so it doesn't end up with the conditional. > > I think your patch is OK to the point of looking at all loop exit > sources but you should elide the special-casing of header and > latch since it's really only exit conditionals that matter. > That makes sense, since in both cases the edges are in the respective blocks. Should have thought about it more. So how about this one. Bootstrapped Regtested on aarch64-none-linux-gnu and no issues. Ok for master? Thanks, Tamar gcc/ChangeLog: * tree-cfg.cc (replace_loop_annotate): Inspect loop edges for annotations. gcc/testsuite/ChangeLog: * gcc.dg/vect/vect-novect_gcond.c: New test. --- inline copy of patch --- diff --git a/gcc/testsuite/gcc.dg/vect/vect-novect_gcond.c b/gcc/testsuite/gcc.dg/vect/vect-novect_gcond.c new file mode 100644 index 0000000000000000000000000000000000000000..01e69cbef9d51b234c08a400c78dc078d53252f1 --- /dev/null +++ b/gcc/testsuite/gcc.dg/vect/vect-novect_gcond.c @@ -0,0 +1,39 @@ +/* { dg-add-options vect_early_break } */ +/* { dg-require-effective-target vect_early_break_hw } */ +/* { dg-require-effective-target vect_int } */ +/* { dg-additional-options "-O3" } */ + +/* { dg-final { scan-tree-dump-not "LOOP VECTORIZED" "vect" } } */ + +#include "tree-vect.h" + +#define N 306 +#define NEEDLE 136 + +int table[N]; + +__attribute__ ((noipa)) +int foo (int i, unsigned short parse_tables_n) +{ + parse_tables_n >>= 9; + parse_tables_n += 11; +#pragma GCC novector + while (i < N && parse_tables_n--) + table[i++] = 0; + + return table[NEEDLE]; +} + +int main () +{ + check_vect (); + +#pragma GCC novector + for (int j = 0; j < N; j++) + table[j] = -1; + + if (foo (0, 0xFFFF) != 0) + __builtin_abort (); + + return 0; +} diff --git a/gcc/tree-cfg.cc b/gcc/tree-cfg.cc index cdd439fe7506e7bc33654ffa027b493f23d278ac..bdffc3b4ed277724e81b7dd67fe7966e8ece0c13 100644 --- a/gcc/tree-cfg.cc +++ b/gcc/tree-cfg.cc @@ -320,12 +320,9 @@ replace_loop_annotate (void) for (auto loop : loops_list (cfun, 0)) { - /* First look into the header. */ - replace_loop_annotate_in_block (loop->header, loop); - - /* Then look into the latch, if any. */ - if (loop->latch) - replace_loop_annotate_in_block (loop->latch, loop); + /* Check all exit source blocks for annotations. */ + for (auto e : get_loop_exit_edges (loop)) + replace_loop_annotate_in_block (e->src, loop); /* Push the global flag_finite_loops state down to individual loops. */ loop->finite_p = flag_finite_loops;