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authorPaul E. Murphy <murphyp@linux.vnet.ibm.com>2020-02-14 16:41:11 -0600
committerPaul E. Murphy <murphyp@linux.vnet.ibm.com>2020-04-30 08:52:08 -0500
commite2239af353b053b9c645e396b13bce8688f9d615 (patch)
treeb4bcb6aa914181703a211dcf3cf6a7aa52107670 /bits/long-double.h
parent86005fdbf40d6fc84d84c824d75c656e7c1398e3 (diff)
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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>
Diffstat (limited to 'bits/long-double.h')
-rw-r--r--bits/long-double.h15
1 files changed, 14 insertions, 1 deletions
diff --git a/bits/long-double.h b/bits/long-double.h
index 6e16447e65..bdde78f49a 100644
--- a/bits/long-double.h
+++ b/bits/long-double.h
@@ -37,4 +37,17 @@
 #ifndef __NO_LONG_DOUBLE_MATH
 # define __NO_LONG_DOUBLE_MATH	1
 #endif
-#define __LONG_DOUBLE_USES_FLOAT128 0
+
+/* The macro __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI is used to determine the
+   choice of the underlying ABI of long double.  It will always assume
+   a constant value for each translation unit.
+
+   If the value is non-zero, any API which is parameterized by the long
+   double type (i.e the scanf/printf family of functions or the explicitly
+   parameterized math.h functions) will be redirected to a compatible
+   implementation using _Float128 ABI via symbols suffixed with ieee128.
+
+   The mechanism this macro uses to acquire may be a function
+   of architecture, or target specific options used to invoke the
+   compiler.  */
+#define __LDOUBLE_REDIRECTS_TO_FLOAT128_ABI 0