The prefixed instructions do not support the update form of the memory
instruction (i.e. internally this is addresses using PRE_INC, PRE_DEC, or
PRE_MODIFY).
Can I check this into the FSF trunk?
2019-11-14 Michael Meissner <meiss...@linux.ibm.com>
* gcc.target/powerpc/prefix-premodify.c: New test to make sure we
do not generate PRE_INC, PRE_DEC, or PRE_MODIFY on prefixed loads
or stores.
--- /tmp/LMc94y_prefix-premodify.c 2019-11-13 17:41:36.037020850 -0500
+++ gcc/testsuite/gcc.target/powerpc/prefix-premodify.c 2019-11-13
17:41:35.807018779 -0500
@@ -0,0 +1,47 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target powerpc_prefixed_addr_ok } */
+/* { dg-options "-O2 -mdejagnu-cpu=future" } */
+
+/* Make sure that we don't try to generate a prefixed form of the load and
+ store with update instructions. */
+
+#ifndef SIZE
+#define SIZE 50000
+#endif
+
+struct foo {
+ unsigned int field;
+ char pad[SIZE];
+};
+
+struct foo *inc_load (struct foo *p, unsigned int *q)
+{
+ *q = (++p)->field;
+ return p;
+}
+
+struct foo *dec_load (struct foo *p, unsigned int *q)
+{
+ *q = (--p)->field;
+ return p;
+}
+
+struct foo *inc_store (struct foo *p, unsigned int *q)
+{
+ (++p)->field = *q;
+ return p;
+}
+
+struct foo *dec_store (struct foo *p, unsigned int *q)
+{
+ (--p)->field = *q;
+ return p;
+}
+
+/* { dg-final { scan-assembler-times {\mpli\M|\mpla\M|\mpaddi\M} 4 } } */
+/* { dg-final { scan-assembler-times {\mplwz\M} 2 } } */
+/* { dg-final { scan-assembler-times {\mpstw\M} 2 } } */
+/* { dg-final { scan-assembler-not {\mp?lwzu\M} } } */
+/* { dg-final { scan-assembler-not {\mp?stwzu\M} } } */
+/* { dg-final { scan-assembler-not {\maddis\M} } } */
+/* { dg-final { scan-assembler-not {\maddi\M} } } */
--
Michael Meissner, IBM
IBM, M/S 2506R, 550 King Street, Littleton, MA 01460-6245, USA
email: meiss...@linux.ibm.com, phone: +1 (978) 899-4797
