From: Jakub Jelinek <jakub@redhat.com>
Date: Fri, 30 Aug 2019 11:12:23 +0000 (+0200)
Subject: backport: re PR tree-optimization/87895 (ICE in purge_dead_edges, at cfgrtl.c:3246)
X-Git-Tag: releases/gcc-7.5.0~291
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5ba94a17e7b5934e179dca7b408a5cd92f0bc0cd;p=thirdparty%2Fgcc.git

backport: re PR tree-optimization/87895 (ICE in purge_dead_edges, at cfgrtl.c:3246)

	Backported from mainline
	2018-11-20  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/87895
	* omp-simd-clone.c (ipa_simd_modify_function_body): When removing
	or replacing GIMPLE_RETURN, set EDGE_FALLTHRU on the edge to EXIT.
	(simd_clone_adjust): Don't set EDGE_FALLTHRU here. In a loop that
	redirects edges to EXIT to edges to incr_bb, iterate while EXIT
	has any preds and always use EDGE_PRED (, 0).

	* gcc.dg/gomp/pr87895-1.c: New test.
	* gcc.dg/gomp/pr87895-2.c: New test.
	* gcc.dg/gomp/pr87895-3.c: New test.

From-SVN: r275070
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index fab10b03da02..131276bcf50b 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,6 +1,15 @@
 2019-08-30  Jakub Jelinek  <jakub@redhat.com>
 
 	Backported from mainline
+	2018-11-20  Jakub Jelinek  <jakub@redhat.com>
+
+	PR tree-optimization/87895
+	* omp-simd-clone.c (ipa_simd_modify_function_body): When removing
+	or replacing GIMPLE_RETURN, set EDGE_FALLTHRU on the edge to EXIT.
+	(simd_clone_adjust): Don't set EDGE_FALLTHRU here. In a loop that
+	redirects edges to EXIT to edges to incr_bb, iterate while EXIT
+	has any preds and always use EDGE_PRED (, 0).
+
 	2018-10-20  Jakub Jelinek  <jakub@redhat.com>
 
 	PR middle-end/87647
diff --git a/gcc/omp-simd-clone.c b/gcc/omp-simd-clone.c
index 99589d446646..9af80a45eb8f 100644
--- a/gcc/omp-simd-clone.c
+++ b/gcc/omp-simd-clone.c
@@ -993,6 +993,8 @@ ipa_simd_modify_function_body (struct cgraph_node *node,
 	  if (greturn *return_stmt = dyn_cast <greturn *> (stmt))
 	    {
 	      tree retval = gimple_return_retval (return_stmt);
+	      edge e = find_edge (bb, EXIT_BLOCK_PTR_FOR_FN (cfun));
+	      e->flags |= EDGE_FALLTHRU;
 	      if (!retval)
 		{
 		  gsi_remove (&gsi, true);
@@ -1133,14 +1135,9 @@ simd_clone_adjust (struct cgraph_node *node)
       basic_block orig_exit = EDGE_PRED (EXIT_BLOCK_PTR_FOR_FN (cfun), 0)->src;
       incr_bb = create_empty_bb (orig_exit);
       add_bb_to_loop (incr_bb, body_bb->loop_father);
-      /* The succ of orig_exit was EXIT_BLOCK_PTR_FOR_FN (cfun), with an empty
-	 flag.  Set it now to be a FALLTHRU_EDGE.  */
-      gcc_assert (EDGE_COUNT (orig_exit->succs) == 1);
-      EDGE_SUCC (orig_exit, 0)->flags |= EDGE_FALLTHRU;
-      for (unsigned i = 0;
-	   i < EDGE_COUNT (EXIT_BLOCK_PTR_FOR_FN (cfun)->preds); ++i)
+      while (EDGE_COUNT (EXIT_BLOCK_PTR_FOR_FN (cfun)->preds))
 	{
-	  edge e = EDGE_PRED (EXIT_BLOCK_PTR_FOR_FN (cfun), i);
+	  edge e = EDGE_PRED (EXIT_BLOCK_PTR_FOR_FN (cfun), 0);
 	  redirect_edge_succ (e, incr_bb);
 	}
     }
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 6d31fbb97117..30c2257164f7 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,6 +1,13 @@
 2019-08-30  Jakub Jelinek  <jakub@redhat.com>
- 
+
 	Backported from mainline
+	2018-11-20  Jakub Jelinek  <jakub@redhat.com>
+
+	PR tree-optimization/87895
+	* gcc.dg/gomp/pr87895-1.c: New test.
+	* gcc.dg/gomp/pr87895-2.c: New test.
+	* gcc.dg/gomp/pr87895-3.c: New test.
+
 	2018-11-19  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/60994
diff --git a/gcc/testsuite/gcc.dg/gomp/pr87895-1.c b/gcc/testsuite/gcc.dg/gomp/pr87895-1.c
new file mode 100644
index 000000000000..22f5c6914164
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/gomp/pr87895-1.c
@@ -0,0 +1,19 @@
+/* PR tree-optimization/87895 */
+/* { dg-do compile } */
+/* { dg-additional-options "-O0" } */
+
+#pragma omp declare simd
+int
+foo (int x)
+{
+  if (x == 0)
+    return 0;
+}
+
+#pragma omp declare simd
+int
+bar (int *x, int y)
+{
+  if ((y == 0) ? (*x = 0) : *x)
+    return 0;
+}
diff --git a/gcc/testsuite/gcc.dg/gomp/pr87895-2.c b/gcc/testsuite/gcc.dg/gomp/pr87895-2.c
new file mode 100644
index 000000000000..3d27715428ea
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/gomp/pr87895-2.c
@@ -0,0 +1,5 @@
+/* PR tree-optimization/87895 */
+/* { dg-do compile } */
+/* { dg-additional-options "-O1" } */
+
+#include "pr87895-1.c"
diff --git a/gcc/testsuite/gcc.dg/gomp/pr87895-3.c b/gcc/testsuite/gcc.dg/gomp/pr87895-3.c
new file mode 100644
index 000000000000..382ad6d84cd3
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/gomp/pr87895-3.c
@@ -0,0 +1,18 @@
+/* PR tree-optimization/87895 */
+/* { dg-do compile } */
+/* { dg-additional-options "-O2" } */
+
+#pragma omp declare simd
+int foo (int x) __attribute__((noreturn));
+
+#pragma omp declare simd
+int
+bar (int x, int y)
+{
+  if (y == 1)
+    foo (x + 2);
+  if (y == 10)
+    foo (x + 6);
+  if (y != 25)
+    return 4;
+}