Add an alignment test to check that aligned alloca's really do get
correctly aligned. Some targets may not ensure SP is always a multiple
of STACK_BOUNDARY (particularly with outgoing arguments), which means
aligned alloca does not get correctly aligned. This can be fixed either
by aligning the outgoing arguments or setting STACK_BOUNDARY correctly.
Committed as obvious.
ChangeLog:
2017-09-06 Wilco Dijkstra <wdijk...@arm.com>
PR middle-end/78468
* gcc.dg/pr78468.c: Add alignment test.
--
diff --git a/gcc/testsuite/gcc.dg/pr78468.c b/gcc/testsuite/gcc.dg/pr78468.c
new file mode 100644
index
0000000000000000000000000000000000000000..68eb83a0868c16327e36055aae4eea34fc2ba35e
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr78468.c
@@ -0,0 +1,102 @@
+/* { dg-do run } */
+/* { dg-require-effective-target alloca } */
+/* { dg-options "-O2 -fno-inline" } */
+
+/* Test that targets correctly round the size of the outgoing arguments
+ to a multiple of STACK_BOUNDARY. There is a serious alignment bug if
+ aligned alloca does not get aligned! */
+
+__extension__ typedef __UINTPTR_TYPE__ uintptr_t;
+extern void abort (void);
+
+volatile int xx;
+volatile int x = 16;
+
+void
+t1 (int x0, int x1, int x2, int x3, int x4, int x5, int x6, int x7,
+ void *p, int align)
+{
+ xx = x0 + x1 + x2 + x3 + x4 + x4 + x6 + x7;
+ if ((int)(uintptr_t)p & (align-1))
+ abort ();
+}
+
+void
+t2 (int x0, int x1, int x2, int x3, int x4, int x5, int x6, int x7,
+ void *p, int align, int dummy)
+{
+ xx = x0 + x1 + x2 + x3 + x4 + x4 + x6 + x7;
+ if ((int)(uintptr_t)p & (align-1))
+ abort ();
+}
+
+void
+t1_a4 (int size)
+{
+ void *p = __builtin_alloca_with_align (size, 32);
+ t1 (0, 0, 0, 0, 0, 0, 0, 0, p, 4);
+}
+
+void
+t2_a4 (int size)
+{
+ void *p = __builtin_alloca_with_align (size, 32);
+ t2 (0, 0, 0, 0, 0, 0, 0, 0, p, 4, 0);
+}
+
+void
+t1_a8 (int size)
+{
+ void *p = __builtin_alloca_with_align (size, 64);
+ t1 (0, 0, 0, 0, 0, 0, 0, 0, p, 8);
+}
+
+void
+t2_a8 (int size)
+{
+ void *p = __builtin_alloca_with_align (size, 64);
+ t2 (0, 0, 0, 0, 0, 0, 0, 0, p, 8, 0);
+}
+
+void
+t1_a16 (int size)
+{
+ void *p = __builtin_alloca_with_align (size, 128);
+ t1 (0, 0, 0, 0, 0, 0, 0, 0, p, 16);
+}
+
+void
+t2_a16 (int size)
+{
+ void *p = __builtin_alloca_with_align (size, 128);
+ t2 (0, 0, 0, 0, 0, 0, 0, 0, p, 16, 0);
+}
+
+void
+t1_a32 (int size)
+{
+ void *p = __builtin_alloca_with_align (size, 256);
+ t1 (0, 0, 0, 0, 0, 0, 0, 0, p, 32);
+}
+
+void
+t2_a32 (int size)
+{
+ void *p = __builtin_alloca_with_align (size, 256);
+ t2 (0, 0, 0, 0, 0, 0, 0, 0, p, 32, 0);
+}
+
+
+int
+main ()
+{
+ t1_a4 (x);
+ t2_a4 (x);
+ t1_a8 (x);
+ t2_a8 (x);
+ t1_a16 (x);
+ t2_a16 (x);
+ t1_a32 (x);
+ t2_a32 (x);
+ return 0;
+}
