Rename __LONG_DOUBLE_USES_FLOAT128 to __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI

Improve the commentary to aid future developers who will stumble
upon this novel, yet not always perfect, mechanism to support
alternative formats for long double.

Likewise, rename __LONG_DOUBLE_USES_FLOAT128 to
__LDOUBLE_REDIRECTS_TO_FLOAT128_ABI now that development work
has settled down.  The command used was

git grep -l __LONG_DOUBLE_USES_FLOAT128 ':!./ChangeLog*' | \
  xargs sed -i 's/__LONG_DOUBLE_USES_FLOAT128/__LDOUBLE_REDIRECTS_TO_FLOAT128_ABI/g'

Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>

8 files changed, 11 insertions, 14 deletions

diff --git a/sysdeps/ieee754/ldbl-128/bits/long-double.h b/sysdeps/ieee754/ldbl-128/bits/long-double.h
index 941e60505f..dd64a06db6 100644
--- a/sysdeps/ieee754/ldbl-128/bits/long-double.h
+++ b/sysdeps/ieee754/ldbl-128/bits/long-double.h
@@ -18,4 +18,4 @@
 
 /* long double is distinct from double, so there is nothing to
    define here.  */
-#define __LONG_DOUBLE_USES_FLOAT128 0
+#define __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI 0
diff --git a/sysdeps/ieee754/ldbl-128ibm-compat/bits/long-double.h b/sysdeps/ieee754/ldbl-128ibm-compat/bits/long-double.h
index 91dddbdc8b..ef834c7748 100644
--- a/sysdeps/ieee754/ldbl-128ibm-compat/bits/long-double.h
+++ b/sysdeps/ieee754/ldbl-128ibm-compat/bits/long-double.h
@@ -22,8 +22,5 @@
 #  define __NO_LONG_DOUBLE_MATH		1
 # endif
 #endif
-/* On platforms that reuse the _Float128 implementation for IEEE long
-   double, access to the correct long double functions is selected based
-   on the long double mode being used during the compilation.  On
-   powerpc64le, this is true when -mabi=ieeelongdouble is in use.  */
-#define __LONG_DOUBLE_USES_FLOAT128 (__LDBL_MANT_DIG__ == 113)
+
+#define __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI (__LDBL_MANT_DIG__ == 113)
diff --git a/sysdeps/ieee754/ldbl-128ibm-compat/math_ldbl.h b/sysdeps/ieee754/ldbl-128ibm-compat/math_ldbl.h
index 352617e178..5490b400dd 100644
--- a/sysdeps/ieee754/ldbl-128ibm-compat/math_ldbl.h
+++ b/sysdeps/ieee754/ldbl-128ibm-compat/math_ldbl.h
@@ -23,7 +23,7 @@
 
 /* Trampoline in the ldbl-128ibm headers if building against the
    old abi.  Otherwise, we have nothing to add. */
-#if __LONG_DOUBLE_USES_FLOAT128 == 0
+#if __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 0
 #include_next <math_ldbl.h>
 #endif
 
diff --git a/sysdeps/ieee754/ldbl-128ibm/bits/iscanonical.h b/sysdeps/ieee754/ldbl-128ibm/bits/iscanonical.h
index b2021b5d64..e60b3017eb 100644
--- a/sysdeps/ieee754/ldbl-128ibm/bits/iscanonical.h
+++ b/sysdeps/ieee754/ldbl-128ibm/bits/iscanonical.h
@@ -20,7 +20,7 @@
 # error "Never use <bits/iscanonical.h> directly; include <math.h> instead."
 #endif
 
-#if defined (__NO_LONG_DOUBLE_MATH) || __LONG_DOUBLE_USES_FLOAT128 == 1
+#if defined (__NO_LONG_DOUBLE_MATH) || __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 1
 # define iscanonical(x) ((void) (__typeof (x)) (x), 1)
 #else
 extern int __iscanonicall (long double __x)
diff --git a/sysdeps/ieee754/ldbl-128ibm/ieee754.h b/sysdeps/ieee754/ldbl-128ibm/ieee754.h
index fe4892d84f..b66e3b9869 100644
--- a/sysdeps/ieee754/ldbl-128ibm/ieee754.h
+++ b/sysdeps/ieee754/ldbl-128ibm/ieee754.h
@@ -112,7 +112,7 @@ union ieee754_double
 #define IEEE754_DOUBLE_BIAS	0x3ff /* Added to exponent.  */
 
 
-#if __LONG_DOUBLE_USES_FLOAT128 == 1
+#if __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 1
 /* long double is IEEE 128 bit */
 union ieee854_long_double
   {
@@ -170,7 +170,7 @@ union ieee854_long_double
 #endif
 
 
-#if __LONG_DOUBLE_USES_FLOAT128 == 0 || __GNUC_PREREQ (7, 0)
+#if __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 0 || __GNUC_PREREQ (7, 0)
 /* IBM extended format for long double.
 
    Each long double is made up of two IEEE doubles.  The value of the
@@ -183,7 +183,7 @@ union ieee854_long_double
    NaN is don't-care.  */
 union ibm_extended_long_double
   {
-# if __LONG_DOUBLE_USES_FLOAT128 == 1 && __GNUC_PREREQ (7, 0)
+# if __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 1 && __GNUC_PREREQ (7, 0)
    __ibm128 ld;
 # else
    long double ld;
diff --git a/sysdeps/ieee754/ldbl-128ibm/include/bits/iscanonical.h b/sysdeps/ieee754/ldbl-128ibm/include/bits/iscanonical.h
index 8cbd6f74bf..60d5417089 100644
--- a/sysdeps/ieee754/ldbl-128ibm/include/bits/iscanonical.h
+++ b/sysdeps/ieee754/ldbl-128ibm/include/bits/iscanonical.h
@@ -1,5 +1,5 @@
 #include_next <bits/iscanonical.h>
 
-#if !defined _ISOMAC && (__LONG_DOUBLE_USES_FLOAT128 == 0)
+#if !defined _ISOMAC && (__LDOUBLE_REDIRECTS_TO_FLOAT128_ABI == 0)
 libm_hidden_proto (__iscanonicall)
 #endif
diff --git a/sysdeps/ieee754/ldbl-96/bits/long-double.h b/sysdeps/ieee754/ldbl-96/bits/long-double.h
index b77124f842..9a2cd0dfe4 100644
--- a/sysdeps/ieee754/ldbl-96/bits/long-double.h
+++ b/sysdeps/ieee754/ldbl-96/bits/long-double.h
@@ -18,4 +18,4 @@
 
 /* long double is distinct from double, so there is nothing to
    define here.  */
-#define __LONG_DOUBLE_USES_FLOAT128 0
+#define __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI 0
diff --git a/sysdeps/ieee754/ldbl-opt/bits/long-double.h b/sysdeps/ieee754/ldbl-opt/bits/long-double.h
index 242e58410d..48688ad7e1 100644
--- a/sysdeps/ieee754/ldbl-opt/bits/long-double.h
+++ b/sysdeps/ieee754/ldbl-opt/bits/long-double.h
@@ -22,4 +22,4 @@
 #  define __NO_LONG_DOUBLE_MATH		1
 # endif
 #endif
-#define __LONG_DOUBLE_USES_FLOAT128 0
+#define __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI 0