Use correct names for __ibm128 if long double is IEEE 128-bit.

If you are on a PowerPC system where the default long double is IEEE
128-bit (either through the compiler option -mabi=ieeelongdouble or via
the configure option --with-long-double-format=ieee), GCC used the wrong
names for some of the conversion functions for the __ibm128 type.

Internally, GCC uses IFmode for __ibm128 if long double is IEEE 128-bit,
instead of TFmode when long double is IBM 128-bit.  This patch adds the
missing conversions to prevent the 'if' name from being used.

In particular, before the patch, the conversions used were:

    IFmode to DImode signed:	__fixifdi	instead of __fixtfdi
    IFmode to DImode unsigned	__fixunsifti	instead of __fixunstfti
    DImode to IFmode signed:	__floatdiif	instead of __floatditf
    DImode to IFmode unsigned:	__floatundiif	instead of __floatunditf

2022-02-14  Michael Meissner  <meissner@the-meissners.org>

gcc/
	PR target/104253
	* config/rs6000/rs6000.cc (init_float128_ibm): Update the
	conversion functions used to convert IFmode types.

gcc/testsuite/
	PR target/104253
	* gcc.target/powerpc/pr104253.c: New test.

2 files changed, 162 insertions, 0 deletions

diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc
index bc3ef072..e76c017 100644
--- a/gcc/config/rs6000/rs6000.cc
+++ b/gcc/config/rs6000/rs6000.cc
@@ -11018,6 +11018,12 @@ init_float128_ibm (machine_mode mode)
       set_conv_libfunc (trunc_optab, DDmode, mode, "__dpd_trunctfdd");
       set_conv_libfunc (sext_optab, TDmode, mode, "__dpd_extendtftd");
 
+      set_conv_libfunc (sfix_optab, DImode, mode, "__fixtfdi");
+      set_conv_libfunc (ufix_optab, DImode, mode, "__fixunstfdi");
+
+      set_conv_libfunc (sfloat_optab, mode, DImode, "__floatditf");
+      set_conv_libfunc (ufloat_optab, mode, DImode, "__floatunditf");
+
       if (TARGET_POWERPC64)
 	{
 	  set_conv_libfunc (sfix_optab, TImode, mode, "__fixtfti");
diff --git a/gcc/testsuite/gcc.target/powerpc/pr104253.c b/gcc/testsuite/gcc.target/powerpc/pr104253.c
new file mode 100644
index 0000000..02049cc
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/pr104253.c
@@ -0,0 +1,156 @@
+/*
+ * Require float128 support because __ibm128 currently is not enabled unless we
+ * also have __float128 support.  We require software IEEE 128-bit support,
+ * which will work on power8.  If we have hardware IEEE 128-bit support (power9
+ * or power10), ppc_float128_sw will still enable running the test.
+ */
+
+/* { dg-do run } */
+/* { require-effective-target ppc_float128_sw } */
+/* { dg-options "-O2 -mvsx -mfloat128" } */
+
+/*
+ * PR target/104253
+ *
+ * Verify that the various conversions to and from __ibm128 work.  When the
+ *  default for long double is changed to IEEE 128-bit, originally GCC would
+ *  call the functions using an 'if' name instead of 'tf' name.
+ */
+
+#include <stdlib.h>
+
+extern float              ibm128_to_sf  (__ibm128) __attribute__((noinline));
+extern double             ibm128_to_df  (__ibm128) __attribute__((noinline));
+extern int                ibm128_to_si  (__ibm128) __attribute__((noinline));
+extern long long          ibm128_to_di  (__ibm128) __attribute__((noinline));
+extern unsigned int       ibm128_to_usi (__ibm128) __attribute__((noinline));
+extern unsigned long long ibm128_to_udi (__ibm128) __attribute__((noinline));
+
+extern __ibm128 sf_to_ibm128  (float)              __attribute__((noinline));
+extern __ibm128 df_to_ibm128  (double)             __attribute__((noinline));
+extern __ibm128 si_to_ibm128  (int)                __attribute__((noinline));
+extern __ibm128 di_to_ibm128  (long long)          __attribute__((noinline));
+extern __ibm128 usi_to_ibm128 (unsigned int)       __attribute__((noinline));
+extern __ibm128 udi_to_ibm128 (unsigned long long) __attribute__((noinline));
+
+float
+ibm128_to_sf  (__ibm128 x)
+{
+  return x;
+}
+
+double
+ibm128_to_df  (__ibm128 x)
+{
+  return x;
+}
+
+int
+ibm128_to_si  (__ibm128 x)
+{
+  return x;
+}
+
+long long
+ibm128_to_di  (__ibm128 x)
+{
+  return x;
+}
+
+unsigned int
+ibm128_to_usi (__ibm128 x)
+{
+  return x;
+}
+
+unsigned long long
+ibm128_to_udi (__ibm128 x)
+{
+  return x;
+}
+
+__ibm128
+sf_to_ibm128  (float x)
+{
+  return x;
+}
+
+__ibm128
+df_to_ibm128  (double x)
+{
+  return x;
+}
+
+__ibm128
+si_to_ibm128  (int x)
+{
+  return x;
+}
+
+__ibm128
+di_to_ibm128  (long long x)
+{
+  return x;
+}
+
+__ibm128
+usi_to_ibm128 (unsigned int x)
+{
+  return x;
+}
+
+__ibm128
+udi_to_ibm128 (unsigned long long x)
+{
+  return x;
+}
+
+volatile float			seven_sf	= 7.0f;
+volatile double			seven_df	= 7.0;
+volatile int			seven_si	= 7;
+volatile long long		seven_di	= 7LL;
+volatile unsigned int		seven_usi	= 7U;
+volatile unsigned long long	seven_udi	= 7ULL;
+volatile __ibm128		seven_ibm128	= 7.0;
+
+int
+main (void)
+{
+  if (seven_ibm128 != sf_to_ibm128 (seven_sf))
+    abort ();
+
+  if (seven_ibm128 != df_to_ibm128 (seven_df))
+    abort ();
+
+  if (seven_ibm128 != si_to_ibm128 (seven_si))
+    abort ();
+
+  if (seven_ibm128 != di_to_ibm128 (seven_di))
+    abort ();
+
+  if (seven_ibm128 != usi_to_ibm128 (seven_usi))
+    abort ();
+
+  if (seven_ibm128 != udi_to_ibm128 (seven_udi))
+    abort ();
+
+  if (seven_sf != ibm128_to_sf (seven_ibm128))
+    abort ();
+
+  if (seven_df != ibm128_to_df (seven_ibm128))
+    abort ();
+
+  if (seven_si != ibm128_to_si (seven_ibm128))
+    abort ();
+
+  if (seven_di != ibm128_to_di (seven_ibm128))
+    abort ();
+
+  if (seven_usi != ibm128_to_usi (seven_ibm128))
+    abort ();
+
+  if (seven_udi != ibm128_to_udi (seven_ibm128))
+    abort ();
+
+  return 0;
+}