re PR rtl-optimization/79386 (ICE: segmentation fault in cprop w/ -O2 on 32-bit BE powerpc)

	PR rtl-optimization/79386
	* cprop.c (bypass_conditional_jumps): Initialize
	bypass_last_basic_block already before splitting bbs after
	unconditional traps...
	(bypass_conditional_jumps): ... rather than here.

	* gcc.c-torture/compile/pr79386.c: New test.

From-SVN: r245251

gcc/ChangeLog

 2017-02-07  Jakub Jelinek  <jakub@redhat.com>
 
+	PR rtl-optimization/79386
+	* cprop.c (bypass_conditional_jumps): Initialize
+	bypass_last_basic_block already before splitting bbs after
+	unconditional traps...
+	(bypass_conditional_jumps): ... rather than here.
+
 	PR target/79299
 	* config/i386/sse.md (xtg_mode, gatherq_mode): New mode attrs.
 	(*avx512f_gathersi<mode>, *avx512f_gathersi<mode>_2,

gcc/cprop.c

@@ -1697,7 +1697,6 @@ bypass_conditional_jumps (void)
   if (ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb == EXIT_BLOCK_PTR_FOR_FN (cfun))
     return 0;
 
-  bypass_last_basic_block = last_basic_block_for_fn (cfun);
   mark_dfs_back_edges ();
 
   changed = 0;
@@ -1863,6 +1862,11 @@ one_cprop_pass (void)
 	      }
 	}
 
+      /* Make sure bypass_conditional_jumps will ignore not just its new
+	 basic blocks, but also the ones after unconditional traps (those are
+	 unreachable and will be eventually removed as such).  */
+      bypass_last_basic_block = last_basic_block_for_fn (cfun);
+
       while (!uncond_traps.is_empty ())
 	{
 	  rtx_insn *insn = uncond_traps.pop ();

gcc/testsuite/ChangeLog

+2017-02-07  Jakub Jelinek  <jakub@redhat.com>
+
+	PR rtl-optimization/79386
+	* gcc.c-torture/compile/pr79386.c: New test.
+
 2017-02-07  Dominik Vogt  <vogt@linux.vnet.ibm.com>
 	    Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>
 

gcc/testsuite/gcc.c-torture/compile/pr79386.c

+/* PR rtl-optimization/79386 */
+
+int a, b;
+
+int
+foo (int x)
+{
+  int c;
+  int *d, *e;
+
+  if (b == 0)
+    {
+      c = 0;
+      e = &b;
+      d = &b;
+    }
+  else
+    {
+      int f;
+
+      c = 1;
+      for (f = 0; f < 9; ++f)
+	c *= 3;
+      e = (int *) (__UINTPTR_TYPE__) c;
+      d = &x;
+    }
+  *e = c < 3;
+  if (*e != 0)
+    {
+      int g;
+
+      b += (a != 0) ? a : 1;
+      if (g != 0 || x != 0)
+	*d = 0;
+      if (b >= 0)
+	{
+	  if (g != 0)
+	    g = x;
+	  if (*d / g != 0)
+	    for (;;)
+	      ;
+	}
+    }
+
+  return b * (a != 0 && *d != 0);
+}