RFC: powerpc64le: Enable support for IEEE long double gabriel/powerpc-ieee128-printscan

Not for glibc-2.31 - Do not commit!

No changes since v3.

Changes since v2:

  - Added definition of LDBL_IBM128_COMPAT_VERSION and
    LDBL_IBM128_VERSION (moved from a previous commit).

Changes since v1:

  - Use __LONG_DOUBLE_USES_FLOAT128 directly.

-- 8< --
On platforms where long double may have two different formats, i.e.: the
same format as double (64-bits) or something else (128-bits), building
with -mlong-double-128 is the default and function calls in the user
program match the name of the function in Glibc.  When building with
-mlong-double-64, Glibc installed headers redirect such calls to the
appropriate function.

This patch adds similar redirections to be used by user code builds in
IEEE long double mode (-mabi=ieeelongdouble).  It also skips some uses
of libc_hidden_proto in internal headers, because they also produce
redirections, causing a redirection conflict.

PS: Missing NEWS entry.

1 files changed, 11 insertions, 5 deletions

diff --git a/libio/stdio.h b/libio/stdio.h
index 1abce9b3f1..819d0a6402 100644
--- a/libio/stdio.h
+++ b/libio/stdio.h
@@ -400,9 +400,12 @@ extern int sscanf (const char *__restrict __s,
 		   const char *__restrict __format, ...) __THROW;
 
 /* For historical reasons, the C99-compliant versions of the scanf
-   functions are at alternative names.  When __LDBL_COMPAT is in
-   effect, this is handled in bits/stdio-ldbl.h.  */
-#if !__GLIBC_USE (DEPRECATED_SCANF) && !defined __LDBL_COMPAT
+   functions are at alternative names.  When __LDBL_COMPAT or
+   __LONG_DOUBLE_USES_FLOAT128 are in effect, this is handled in
+   bits/stdio-ldbl.h.  */
+#include <bits/floatn.h>
+#if !__GLIBC_USE (DEPRECATED_SCANF) && !defined __LDBL_COMPAT \
+    && __LONG_DOUBLE_USES_FLOAT128 == 0
 # ifdef __REDIRECT
 extern int __REDIRECT (fscanf, (FILE *__restrict __stream,
 				const char *__restrict __format, ...),
@@ -447,7 +450,8 @@ extern int vsscanf (const char *__restrict __s,
 
 /* Same redirection as above for the v*scanf family.  */
 # if !__GLIBC_USE (DEPRECATED_SCANF)
-#  if defined __REDIRECT && !defined __LDBL_COMPAT
+#  if defined __REDIRECT && !defined __LDBL_COMPAT \
+      && __LONG_DOUBLE_USES_FLOAT128 == 0
 extern int __REDIRECT (vfscanf,
 		       (FILE *__restrict __s,
 			const char *__restrict __format, __gnuc_va_list __arg),
@@ -866,7 +870,9 @@ extern int __overflow (FILE *, int);
 #if __USE_FORTIFY_LEVEL > 0 && defined __fortify_function
 # include <bits/stdio2.h>
 #endif
-#ifdef __LDBL_COMPAT
+
+#include <bits/floatn.h>
+#if defined __LDBL_COMPAT || __LONG_DOUBLE_USES_FLOAT128 == 1
 # include <bits/stdio-ldbl.h>
 #endif