This patch is the same as:
https://gcc.gnu.org/ml/gcc-patches/2019-12/msg01499.html
It adds a new test to make sure if we are using a prefixed load or store
instruction, the compiler does not try to use a load with update or store with
update version of the isntruction, since there are no prefixed version of those
instructions. Can I check this into the trunk?
2020-01-09 Michael Meissner <meiss...@linux.ibm.com>
* gcc.target/powerpc/prefix-no-premodify.c: Make sure we do not
generate the non-existent PLWZU instruction if -mcpu=future.
Index: gcc/testsuite/gcc.target/powerpc/prefix-no-premodify.c
===================================================================
--- gcc/testsuite/gcc.target/powerpc/prefix-no-premodify.c (revision
280082)
+++ gcc/testsuite/gcc.target/powerpc/prefix-no-premodify.c (working copy)
@@ -0,0 +1,50 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target powerpc_prefixed_addr } */
+/* { dg-options "-O2 -mdejagnu-cpu=future" } */
+
+/* Make sure that we don't generate a prefixed form of the load and store with
+ update instructions (i.e. instead of generating LWZU we have to generate
+ PLWZ plus a PADDI). */
+
+#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; /* PLWZ, PADDI, STW. */
+ return p;
+}
+
+struct foo *dec_load (struct foo *p, unsigned int *q)
+{
+ *q = (--p)->field; /* PLWZ, PADDI, STW. */
+ return p;
+}
+
+struct foo *inc_store (struct foo *p, unsigned int *q)
+{
+ (++p)->field = *q; /* LWZ, PADDI, PSTW. */
+ return p;
+}
+
+struct foo *dec_store (struct foo *p, unsigned int *q)
+{
+ (--p)->field = *q; /* LWZ, PADDI, PSTW. */
+ return p;
+}
+
+/* { dg-final { scan-assembler-times {\mlwz\M} 2 } } */
+/* { dg-final { scan-assembler-times {\mstw\M} 2 } } */
+/* { dg-final { scan-assembler-times {\mpaddi\M} 4 } } */
+/* { dg-final { scan-assembler-times {\mplwz\M} 2 } } */
+/* { dg-final { scan-assembler-times {\mpstw\M} 2 } } */
+/* { dg-final { scan-assembler-not {\mplwzu\M} } } */
+/* { dg-final { scan-assembler-not {\mpstwu\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
