Hi All, Attaching a pragma to a loop which has a complex condition often gets the pragma dropped. e.g.
#pragma GCC novector while (i < N && parse_tables_n--) before lowering this is represented as: if (ANNOTATE_EXPR <i <= 305 && parse_tables_n-- != 0, no-vector>) ... But after lowering the condition is broken appart and attached to the final component of the expression: if (parse_tables_n.2_2 != 0) goto <D.4456>; else goto <D.4453>; <D.4456>: iftmp.1D.4452 = 1; goto <D.4454>; <D.4453>: iftmp.1D.4452 = 0; <D.4454>: D.4451 = .ANNOTATE (iftmp.1D.4452, 2, 0); if (D.4451 != 0) goto <D.4442>; else goto <D.4440>; <D.4440>: and it's never heard from again because during replace_loop_annotate we only inspect the loop header and latch for annotations. Since annotations were supposed to apply to the loop as a whole this fixes it by also checking the loop exit src blocks for annotations. 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..a29681bffb902d2d05e3f18764ab519aacb3c5bc 100644 --- a/gcc/tree-cfg.cc +++ b/gcc/tree-cfg.cc @@ -327,6 +327,10 @@ replace_loop_annotate (void) if (loop->latch) replace_loop_annotate_in_block (loop->latch, loop); + /* Then also check all other exits. */ + 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; } --
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..a29681bffb902d2d05e3f18764ab519aacb3c5bc 100644 --- a/gcc/tree-cfg.cc +++ b/gcc/tree-cfg.cc @@ -327,6 +327,10 @@ replace_loop_annotate (void) if (loop->latch) replace_loop_annotate_in_block (loop->latch, loop); + /* Then also check all other exits. */ + 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; }