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Re: [PATCH, rs6000] Fix PR85755: PowerPC Gcc's -mupdate produces inefficient code
On 6/8/18 11:21 AM, Segher Boessenkool wrote:
> On Fri, Jun 08, 2018 at 10:35:22AM -0500, Peter Bergner wrote:
>> +/* { dg-final { scan-assembler-times {\mstdu\M} 2 } } */
>> +/* { dg-final { scan-assembler-not {\mstfdu\M} } } */
>
> Does this need p8 at all? Would it be better to just test without -mcpu=,
> on just whatever default cpu is thrown at it? p8 is default for powerpc64le
> so it will get plenty coverage.
>
> You do need an lp64 target btw.
I guess I was just following what was reported in the bugzilla, but you
are correct, we don't need -mcpu=power8. How about the following?
Peter
Index: pr85755.c
===================================================================
--- pr85755.c (nonexistent)
+++ pr85755.c (working copy)
@@ -0,0 +1,22 @@
+/* { dg-do compile { target { powerpc*-*-* } } } */
+/* { dg-options "-O1" } */
+
+void
+preinc (long *q, long n)
+{
+ long i;
+ for (i = 0; i < n; i++)
+ q[i] = i;
+}
+
+void
+predec (long *q, long n)
+{
+ long i;
+ for (i = n; i >= 0; i--)
+ q[i] = i;
+}
+
+/* { dg-final { scan-assembler-times {\mstwu\M} 2 { target ilp32 } } } */
+/* { dg-final { scan-assembler-times {\mstdu\M} 2 { target lp64 } } } */
+/* { dg-final { scan-assembler-not {\mstfdu\M} } } */