Re: [PATCH], PowerPC long double transition patches, v2, Patch #4 (fix bug in clone/target attributes on long double == IEEE 128-bit systems)

[Michael Meissner]

This patch prevents the special overriding of the complex float128
multiply/divide functions from being run twice if there are clone or target
attributes.  I wasn't aware that the hook used to initialize the built-in
functions is run each time you change the target options.  The built-in
function handling aborts if the name had already been set.

I have tested this on a little endian power8 sysytem using two builds with long
double set to IEEE and IBM 128-bit.  This patch fixes testsuite errors from
using the clone or target attributes.  Can I install it in the trunk and GCC
8.x branches?

[gcc]
2018-06-20  Michael Meissner  <meiss...@linux.ibm.com>

        * config/rs6000/rs6000.c (init_float128_ieee): Prevent complex
        multiply and divide external functions from being created more
        than once.

-- 
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

Index: gcc/config/rs6000/rs6000.c
===================================================================
--- gcc/config/rs6000/rs6000.c  (revision 261574)
+++ gcc/config/rs6000/rs6000.c  (working copy)
@@ -17892,9 +17892,14 @@ init_float128_ieee (machine_mode mode)
 {
   if (FLOAT128_VECTOR_P (mode))
     {
-      /* Set up to call __mulkc3 and __divkc3 under -mabi=ieeelongdouble.  */
-     if (mode == TFmode && TARGET_IEEEQUAD)
+      static bool complex_muldiv_init_p = false;
+
+      /* Set up to call __mulkc3 and __divkc3 under -mabi=ieeelongdouble.  If
+        we have clone or target attributes, this will be called a second
+        time.  We want to create the built-in function only once.  */
+     if (mode == TFmode && TARGET_IEEEQUAD && !complex_muldiv_init_p)
        {
+        complex_muldiv_init_p = true;
         built_in_function fncode_mul =
           (built_in_function) (BUILT_IN_COMPLEX_MUL_MIN + TCmode
                                - MIN_MODE_COMPLEX_FLOAT);