From: Richard Biener <rguenther@suse.de>
Date: Mon, 3 Jun 2019 10:17:16 +0000 (+0000)
Subject: re PR tree-optimization/90716 (gcc generates wrong debug information at -O2)
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=efb34006e9c3f9592edd77bda2e57ce14c65579b;p=gcc.git

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 f887329e929..7aabe88b4d8 100644
--- 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 93b1f09b9de..75e38b8cf6a 100644
--- 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
index 00000000000..b2f5c9d146e
--- /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 b2f2fd225a4..88f8e7a09d1 100644
--- 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);