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;
     }



Reply via email to