Hi Mike,

Thanks for this clean-up!

On 8/25/21 5:09 PM, Michael Meissner wrote:
 From 327273dfeec5c000f3c33ca7b88ee0097fd33586 Mon Sep 17 00:00:00 2001
From: Michael Meissner <meiss...@linux.ibm.com>
Date: Wed, 25 Aug 2021 00:31:35 -0400
Subject: [PATCH] Fix float128-call.c test for power8 IEEE 128 and power10.

I built a compiler on a little endian power8 system where the default long
double was IEEE 128-bit instead of IBM 128-bit.  I discovered that on
power8, we would generate a lxvd2x and xxpermdi to deal with the endianess
instead of the Altivec lxv.

In addition, I noticed the constant that was being loaded (1.0q) could be
loaded by the lxvkq instruction.

I rewrote the test to handle all forms of vector load and store that can
be generated.  And I changed the constant to be one that lxvkq does not
support.

I did bootstrap tests on the following systems, and the the test ran in all
environments (each of the systems were configured for the cpu mentioned):

    1)  Little endian power9  with IBM  128-bit long double
    2)  Little endian power9  with IEEE 128-bit long double
    3)  Little endian power8  with IBM  128-bit long double
    4)  Little endian power8  with IEEE 128-bit long double
    5)  Little endian power10 with IBM  128-bit long double
    6)  Little endian power10 with IEEE 128-bit long double
    7)  Big endian    power8  with IBM  128-bit long double

Can I check this patch into the master branch and later backport it to GCC-11?

2021-08-25  Michael Meissner  <meiss...@linux.ibm.com>

gcc/testsuite/
        * gcc.target/powerpc/float128-call.c: Fix test for IEEE 128-bit
        long double and power10.
---
  .../gcc.target/powerpc/float128-call.c        | 27 +++++++++++++------
  1 file changed, 19 insertions(+), 8 deletions(-)

diff --git a/gcc/testsuite/gcc.target/powerpc/float128-call.c 
b/gcc/testsuite/gcc.target/powerpc/float128-call.c
index b64ffc68bfa..d1cf47e4298 100644
--- a/gcc/testsuite/gcc.target/powerpc/float128-call.c
+++ b/gcc/testsuite/gcc.target/powerpc/float128-call.c
@@ -6,22 +6,33 @@
  #error "-mfloat128 is not supported."
  #endif
+/* Pick a constant to load that cannot be generated by the power10 lxvkq
+   instruction.  */
  #ifdef __LONG_DOUBLE_IEEE128__
  #define TYPE long double
-#define ONE  1.0L
+#define TEN  10.0L
#else
  #define TYPE __float128
-#define ONE  1.0Q
+#define TEN  10.0Q
  #endif
/* Test to make sure vector registers are used for passing IEEE 128-bit
     floating point values and returning them. Also make sure the 'q' suffix is
-   handled.  */
-TYPE one (void) { return ONE; }
+   handled for __float128.  */
+TYPE one (void) { return TEN; }

This amuses me, and I want to keep it this way. :-)
  void store (TYPE a, TYPE *p) { *p = a; }
-/* { dg-final { scan-assembler {\mlxvd2x 34\M} {target be} } } */
-/* { dg-final { scan-assembler {\mstxvd2x 34\M} {target be} } } */
-/* { dg-final { scan-assembler {\mlvx 2\M} {target le} } }  */
-/* { dg-final { scan-assembler {\mstvx 2\M} {target le} } } */
+/* This regexp captures the different vector load/stores that can be generated:
+
+       lxvd2x  -- big endian power7/power8, little endian power8
+       lvx     -- Altivec
+       lxv     -- power9
+       plxv    -- power10
+       lxvx    -- X-form variant.
+       stxvd2x -- big endian power7/power8, little endian power8
+       stvx    -- Altivec

For symmetry, also mention stxvx as an X-form variant?

Looks fine to me, recommend approval.

Thanks,
Bill

+       lxvx    -- power9/power10.  */
+
+/* { dg-final { scan-assembler {\mlxvd2x 34\M|\mlvx 2\M|\mp?lxvx? 34\M} } } */
+/* { dg-final { scan-assembler {\mstxvd2x 34\M|\mstvx 2\M|\mstxvx 34\M} } } */

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