re PR rtl-optimization/52714 (ICE in fixup_reorder_chain, at cfglayout.c:880)

	PR rtl-optimization/52714
	* combine.c (try_combine): Allow combining two insns into two
	new insns if at least one of those is a noop.

gcc/testsuite/
	* gcc.target/m68k/pr52714.c: New testcase.

From-SVN: r218302

1 files changed, 33 insertions, 0 deletions

diff --git a/gcc/testsuite/gcc.target/m68k/pr52714.c b/gcc/testsuite/gcc.target/m68k/pr52714.c
new file mode 100644
index 00000000000..0a52a1d4d3a
--- /dev/null
+++ b/gcc/testsuite/gcc.target/m68k/pr52714.c
@@ -0,0 +1,33 @@
+/* PR rtl-optimization/52714
+
+   Check that combine manages to remove the "stack == 0" test.
+   Without ICEing.  */
+
+/* { dg-do compile } */
+/* { dg-options "-O1" } */
+
+int __re_compile_fastmap(unsigned char *p)
+{
+    unsigned char **stack;
+    unsigned size;
+    unsigned avail;
+
+    stack = __builtin_alloca(5 * sizeof(unsigned char*));
+    if (stack == 0)
+	return -2;
+    size = 5;
+    avail = 0;
+
+    for (;;) {
+	switch (*p++) {
+	case 0:
+	    if (avail == size)
+		return -2;
+	    stack[avail++] = p;
+	}
+    }
+
+    return 0;
+}
+
+/* { dg-final { scan-assembler-not {\mtst\.l %sp\M} } } */