re PR tree-optimization/90716 (gcc generates wrong debug information at -O2)

2019-06-03  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/90716
	* tree-loop-distribution.c (destroy_loop): Process blocks in
	correct order.

	* gcc.dg/guality/pr90716.c: New testcase.

From-SVN: r271858

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index f887329e929630ac95c871674b9cd6c0637c37b8..7aabe88b4d8d38014d0ddc7ce7b558c3db0142cf 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2019-06-03  Richard Biener  <rguenther@suse.de>
+
+       PR tree-optimization/90716
+       * tree-loop-distribution.c (destroy_loop): Process blocks in
+       correct order.
+
 2019-06-03  Prathamesh Kulkarni  <prathamesh.kulkarni@linaro.org>
 
        PR target/88837

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 93b1f09b9de9827fa822c72400f5ca30cab7871f..75e38b8cf6a13cd225b699458a4f66c4c9700aa4 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2019-06-03  Richard Biener  <rguenther@suse.de>
+
+       PR tree-optimization/90716
+       * gcc.dg/guality/pr90716.c: New testcase.
+
 2019-06-03  Prathamesh Kulkarni  <prathamesh.kulkarni@linaro.org>
 
        PR target/88837

diff --git a/gcc/testsuite/gcc.dg/guality/pr90716.c b/gcc/testsuite/gcc.dg/guality/pr90716.c
new file mode 100644 (file)
index 0000000..b2f5c9d
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/guality/pr90716.c
@@ -0,0 +1,25 @@
+/* { dg-do run } */
+/* { dg-options "-g" } */
+
+void __attribute__((noinline))
+optimize_me_not ()
+{
+  __asm__ volatile ("" : : : "memory");
+}
+int a[7][8];
+int main()
+{
+  int b, j;
+  b = 0;
+  for (; b < 7; b++) {
+      j = 0;
+      for (; j < 8; j++)
+       a[b][j] = 0;
+  }
+  /* j may very well be optimized out, so we cannot test for j == 8.
+     Instead test j + 1 which will make the test UNSUPPORTED if i
+     is optimized out.  Since the test previously had wrong debug
+     with j == 0 this is acceptable.  */
+  optimize_me_not(); /* { dg-final { gdb-test . "j + 1" "9" } } */
+  return 0;
+}

diff --git a/gcc/tree-loop-distribution.c b/gcc/tree-loop-distribution.c
index b2f2fd225a47bab6483e2102cd2d449c4dc9aa73..88f8e7a09d1571fed16ba841ceb91edfe21e83a5 100644 (file)
--- a/gcc/tree-loop-distribution.c
+++ b/gcc/tree-loop-distribution.c
@@ -1104,15 +1104,13 @@ destroy_loop (struct loop *loop)
 
   gimple_stmt_iterator dst_gsi = gsi_after_labels (exit->dest);
   bool safe_p = single_pred_p (exit->dest);
-  i = nbbs;
-  do
+  for (unsigned i = 0; i < nbbs; ++i)
     {
       /* We have made sure to not leave any dangling uses of SSA
          names defined in the loop.  With the exception of virtuals.
         Make sure we replace all uses of virtual defs that will remain
         outside of the loop with the bare symbol as delete_basic_block
         will release them.  */
-      --i;
       for (gphi_iterator gsi = gsi_start_phis (bbs[i]); !gsi_end_p (gsi);
           gsi_next (&gsi))
        {
@@ -1147,7 +1145,6 @@ destroy_loop (struct loop *loop)
            gsi_next (&gsi);
        }
     }
-  while (i != 0);
 
   redirect_edge_pred (exit, src);
   exit->flags &= ~(EDGE_TRUE_VALUE|EDGE_FALSE_VALUE);