From: Segher Boessenkool <segher@kernel.crashing.org>
Date: Thu, 1 Dec 2016 02:04:10 +0000 (+0100)
Subject: combine: Emit a barrier after unconditional trap (PR78607)
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=0f09127808018c479214478d3f79e0ac40a3c55b;p=gcc.git

combine: Emit a barrier after unconditional trap (PR78607)

After an unconditional trap there should be a barrier.  In most cases
one is automatically inserted, but not if the trap is the final insn in
the instruction stream.  We need to emit one explicitly.


	PR rtl-optimization/78607
	* combine.c (try_combine): Emit a barrier after a unconditional trap.

gcc/testsuite/
	PR rtl-optimization/78607
	* gcc.c-torture/compile/pr78607.c: New testcase.

From-SVN: r243092
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 7a46cd22253..e2f7b25e9be 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2016-12-01  Segher Boessenkool  <segher@kernel.crashing.org>
+
+	PR rtl-optimization/78607
+	* combine.c (try_combine): Emit a barrier after a unconditional trap.
+
 2016-11-30  Michael Meissner  <meissner@linux.vnet.ibm.com>
 
 	PR target/78602
diff --git a/gcc/combine.c b/gcc/combine.c
index a8dae89d7b3..faafcb741f4 100644
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -4627,6 +4627,7 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0,
       basic_block bb = BLOCK_FOR_INSN (i3);
       gcc_assert (bb);
       remove_edge (split_block (bb, i3));
+      emit_barrier_after_bb (bb);
       *new_direct_jump_p = 1;
     }
 
@@ -4637,6 +4638,7 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0,
       basic_block bb = BLOCK_FOR_INSN (undobuf.other_insn);
       gcc_assert (bb);
       remove_edge (split_block (bb, undobuf.other_insn));
+      emit_barrier_after_bb (bb);
       *new_direct_jump_p = 1;
     }
 
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index f38b5863baa..bf4bd8ac218 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2016-12-01  Segher Boessenkool  <segher@kernel.crashing.org>
+
+	PR rtl-optimization/78607
+	* gcc.c-torture/compile/pr78607.c: New testcase.
+
 2016-11-30  Martin Sebor  <msebor@redhat.com>
 
 	PR tree-optimization/78586
diff --git a/gcc/testsuite/gcc.c-torture/compile/pr78607.c b/gcc/testsuite/gcc.c-torture/compile/pr78607.c
new file mode 100644
index 00000000000..2c5420d8e7e
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/pr78607.c
@@ -0,0 +1,12 @@
+/* PR rtl-optimization/78607 */
+
+void
+rc (int cx)
+{
+  int mq;
+
+  if (mq == 0 && (cx / 0) != 0)
+    for (;;)
+      {
+      }
+}