[PATCH] FIx up GIMPLE bb removal (PR tree-optimization/90208)

[Jakub Jelinek]

Hi!

The GIMPLE bb removal code doesn't really remove GIMPLE_LABEL
stmts referencing FORCED_LABELs (and likewise non-local labels,
except it turns them into FORCED_LABELs), but instead moves them
at the start of some other bb.

As can be seen on the testcases, that breaks
  if (prev_stmt && EH_LANDING_PAD_NR (label) != 0)
{
  error ("EH landing pad label ");
  print_generic_expr (stderr, label);
  fprintf (stderr, " is not first in a sequence of labels in bb %d",
   bb->index);
  err = 1;
}
checking and in theory could break
  if (prev_stmt && DECL_NONLOCAL (label))
{
  error ("nonlocal label ");
  print_generic_expr (stderr, label);
  fprintf (stderr, " is not first in a sequence of labels in bb %d",
   bb->index);
  err = 1;
}
too.  Fixed by moving these FORCED_LABELs after the existing labels
in the other bb, rather than before those.

Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

2019-04-24  Jakub Jelinek  

PR tree-optimization/90208
* tree-cfg.c (remove_bb): Move forced labels from removed bbs
after labels of new_bb, not before them.

* gcc.dg/tsan/pr90208-1.c: New test.
* gcc.dg/tsan/pr90208-2.c: New test.

--- gcc/tree-cfg.c.jj   2019-03-14 23:44:27.861560155 +0100
+++ gcc/tree-cfg.c  2019-04-23 14:40:05.949571172 +0200
@@ -2265,7 +2265,7 @@ remove_bb (basic_block bb)
  new_bb = single_succ (new_bb);
  gcc_assert (new_bb != bb);
}
- new_gsi = gsi_start_bb (new_bb);
+ new_gsi = gsi_after_labels (new_bb);
  gsi_remove (&i, false);
  gsi_insert_before (&new_gsi, stmt, GSI_NEW_STMT);
}
--- gcc/testsuite/gcc.dg/tsan/pr90208-1.c.jj2019-04-23 14:48:16.034625947 
+0200
+++ gcc/testsuite/gcc.dg/tsan/pr90208-1.c   2019-04-23 14:48:12.450684051 
+0200
@@ -0,0 +1,5 @@
+/* PR tree-optimization/90208 */
+/* { dg-do compile } */
+/* { dg-options "-O3 -fexceptions -fsanitize=thread" } */
+
+#include "../../gcc.c-torture/compile/pr89280.c"
--- gcc/testsuite/gcc.dg/tsan/pr90208-2.c.jj2019-04-23 14:50:23.850553809 
+0200
+++ gcc/testsuite/gcc.dg/tsan/pr90208-2.c   2019-04-23 14:51:09.819808554 
+0200
@@ -0,0 +1,20 @@
+/* PR tree-optimization/90208 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -fexceptions -fsanitize=thread" } */
+
+void *b[5];
+void foo (void);
+
+void
+bar (int d)
+{
+  while (d)
+foo ();
+}
+
+void
+baz (void)
+{
+  bar (2);
+  __builtin_setjmp (b);
+}

Jakub

Re: [PATCH] FIx up GIMPLE bb removal (PR tree-optimization/90208)

[Richard Biener]

On April 24, 2019 10:02:00 AM GMT+02:00, Jakub Jelinek  wrote:
>Hi!
>
>The GIMPLE bb removal code doesn't really remove GIMPLE_LABEL
>stmts referencing FORCED_LABELs (and likewise non-local labels,
>except it turns them into FORCED_LABELs), but instead moves them
>at the start of some other bb.
>
>As can be seen on the testcases, that breaks
>  if (prev_stmt && EH_LANDING_PAD_NR (label) != 0)
>{
>  error ("EH landing pad label ");
>  print_generic_expr (stderr, label);
> fprintf (stderr, " is not first in a sequence of labels in bb %d",
>   bb->index);
>  err = 1;
>}
>checking and in theory could break
>  if (prev_stmt && DECL_NONLOCAL (label))
>{
>  error ("nonlocal label ");
>  print_generic_expr (stderr, label);
> fprintf (stderr, " is not first in a sequence of labels in bb %d",
>   bb->index);
>  err = 1;
>}
>too.  Fixed by moving these FORCED_LABELs after the existing labels
>in the other bb, rather than before those.
>
>Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

OK. 

Richard. 

>2019-04-24  Jakub Jelinek  
>
>   PR tree-optimization/90208
>   * tree-cfg.c (remove_bb): Move forced labels from removed bbs
>   after labels of new_bb, not before them.
>
>   * gcc.dg/tsan/pr90208-1.c: New test.
>   * gcc.dg/tsan/pr90208-2.c: New test.
>
>--- gcc/tree-cfg.c.jj  2019-03-14 23:44:27.861560155 +0100
>+++ gcc/tree-cfg.c 2019-04-23 14:40:05.949571172 +0200
>@@ -2265,7 +2265,7 @@ remove_bb (basic_block bb)
> new_bb = single_succ (new_bb);
> gcc_assert (new_bb != bb);
>   }
>-new_gsi = gsi_start_bb (new_bb);
>+new_gsi = gsi_after_labels (new_bb);
> gsi_remove (&i, false);
> gsi_insert_before (&new_gsi, stmt, GSI_NEW_STMT);
>   }
>--- gcc/testsuite/gcc.dg/tsan/pr90208-1.c.jj   2019-04-23
>14:48:16.034625947 +0200
>+++ gcc/testsuite/gcc.dg/tsan/pr90208-1.c  2019-04-23 14:48:12.450684051
>+0200
>@@ -0,0 +1,5 @@
>+/* PR tree-optimization/90208 */
>+/* { dg-do compile } */
>+/* { dg-options "-O3 -fexceptions -fsanitize=thread" } */
>+
>+#include "../../gcc.c-torture/compile/pr89280.c"
>--- gcc/testsuite/gcc.dg/tsan/pr90208-2.c.jj   2019-04-23
>14:50:23.850553809 +0200
>+++ gcc/testsuite/gcc.dg/tsan/pr90208-2.c  2019-04-23 14:51:09.819808554
>+0200
>@@ -0,0 +1,20 @@
>+/* PR tree-optimization/90208 */
>+/* { dg-do compile } */
>+/* { dg-options "-O2 -fexceptions -fsanitize=thread" } */
>+
>+void *b[5];
>+void foo (void);
>+
>+void
>+bar (int d)
>+{
>+  while (d)
>+foo ();
>+}
>+
>+void
>+baz (void)
>+{
>+  bar (2);
>+  __builtin_setjmp (b);
>+}
>
>   Jakub