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[glibc] Prepare vfprintf to use __printf_fp/__printf_fphex with float128 arg
- From: Gabriel F.T.Gomes <gftg at sourceware dot org>
- To: glibc-cvs at sourceware dot org
- Date: 27 Jun 2019 21:04:30 -0000
- Subject: [glibc] Prepare vfprintf to use __printf_fp/__printf_fphex with float128 arg
https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=1626f499d159f17d5d99dc41497b52074f3850df
commit 1626f499d159f17d5d99dc41497b52074f3850df
Author: Gabriel F. T. Gomes <gabrielftg@linux.ibm.com>
Date: Thu Jun 27 17:43:44 2019 -0300
Prepare vfprintf to use __printf_fp/__printf_fphex with float128 arg
On powerpc64le, long double can currently take two formats: the same as
double (-mlong-double-64) or IBM Extended Precision (default with
-mlong-double-128 or explicitly with -mabi=ibmlongdouble). The internal
implementation of printf-like functions is aware of these possibilities
and properly parses floating-point values from the variable arguments,
before making calls to __printf_fp and __printf_fphex. These functions
are also aware of the format possibilities and know how to convert both
formats to string.
When library support for TS 18661-3 was added to glibc, __printf_fp and
__printf_fphex were extended with support for an additional type
(__float128/_Float128) with a different format (binary128). Now that
powerpc64le is getting support for its third long double format, and
taking into account that this format is the same as the format of
__float128/_Float128, this patch extends __vfprintf_internal to properly
call __printf_fp and __printf_fphex with this new format.
Tested for powerpc64le (with additional patches to actually enable the
use of these preparations) and for x86_64.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Diff:
---
ChangeLog | 16 +++++++++
libio/libioP.h | 20 ++++++++---
stdio-common/printf-parse.h | 3 ++
stdio-common/vfprintf-internal.c | 73 +++++++++++++++++++++++++++++++++-------
4 files changed, 95 insertions(+), 17 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index 306c942..2405703 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,19 @@
+2019-06-27 Gabriel F. T. Gomes <gabrielftg@linux.ibm.com>
+
+ * libio/libioP.h (PRINTF_LDBL_USES_FLOAT128): New macro to be
+ used as a mask for the mode argument of __vfprintf_internal.
+ * stdio-common/printf-parse.h (printf_arg): New union member:
+ pa_float128.
+ * stdio-common/vfprintf-internal.c
+ (PARSE_FLOAT_VA_ARG_EXTENDED): New macro.
+ (PARSE_FLOAT_VA_ARG): Likewise.
+ (SETUP_FLOAT128_INFO): Likewise.
+ (process_arg): Use PARSE_FLOAT_VA_ARG_EXTENDED and
+ SETUP_FLOAT128_INFO.
+ [__HAVE_FLOAT128_UNLIKE_LDBL] (printf_positional): Write
+ floating-point value to the new union member, pa_float128.
+ (printf_positional): Zero-initialize args_value[cnt] with memset.
+
2019-06-27 Florian Weimer <fweimer@redhat.com>
[BZ #24740]
diff --git a/libio/libioP.h b/libio/libioP.h
index afa46cc..8db24e1 100644
--- a/libio/libioP.h
+++ b/libio/libioP.h
@@ -712,10 +712,22 @@ extern int __vswprintf_internal (wchar_t *string, size_t maxlen,
defined to 1 or 2. Otherwise, such checks are ignored.
PRINTF_CHK indicates, to the internal function being called, that the
- call is originated from one of the __*printf_chk functions. */
-#define PRINTF_LDBL_IS_DBL 0x0001
-#define PRINTF_FORTIFY 0x0002
-#define PRINTF_CHK 0x0004
+ call is originated from one of the __*printf_chk functions.
+
+ PRINTF_LDBL_USES_FLOAT128 is used on platforms where the long double
+ format used to be different from the IEC 60559 double format *and*
+ also different from the Quadruple 128-bits IEC 60559 format (such as
+ the IBM Extended Precision format on powerpc or the 80-bits IEC 60559
+ format on x86), but was later converted to the Quadruple 128-bits IEC
+ 60559 format, which is the same format that the _Float128 always has
+ (hence the `USES_FLOAT128' suffix in the name of the flag). When set
+ to one, this macro indicates that long double values are to be
+ handled as having this new format. Otherwise, they should be handled
+ as the previous format on that platform. */
+#define PRINTF_LDBL_IS_DBL 0x0001
+#define PRINTF_FORTIFY 0x0002
+#define PRINTF_CHK 0x0004
+#define PRINTF_LDBL_USES_FLOAT128 0x0008
extern size_t _IO_getline (FILE *,char *, size_t, int, int);
libc_hidden_proto (_IO_getline)
diff --git a/stdio-common/printf-parse.h b/stdio-common/printf-parse.h
index 3975086..00f3280 100644
--- a/stdio-common/printf-parse.h
+++ b/stdio-common/printf-parse.h
@@ -57,6 +57,9 @@ union printf_arg
unsigned long long int pa_u_long_long_int;
double pa_double;
long double pa_long_double;
+#if __HAVE_FLOAT128_UNLIKE_LDBL
+ _Float128 pa_float128;
+#endif
const char *pa_string;
const wchar_t *pa_wstring;
void *pa_pointer;
diff --git a/stdio-common/vfprintf-internal.c b/stdio-common/vfprintf-internal.c
index ead2b04..d9dca78 100644
--- a/stdio-common/vfprintf-internal.c
+++ b/stdio-common/vfprintf-internal.c
@@ -68,6 +68,57 @@
} while (0)
#define UNBUFFERED_P(S) ((S)->_flags & _IO_UNBUFFERED)
+#if __HAVE_FLOAT128_UNLIKE_LDBL
+# define PARSE_FLOAT_VA_ARG_EXTENDED(INFO) \
+ do \
+ { \
+ if (is_long_double \
+ && (mode_flags & PRINTF_LDBL_USES_FLOAT128) != 0) \
+ { \
+ INFO.is_binary128 = 1; \
+ the_arg.pa_float128 = va_arg (ap, _Float128); \
+ } \
+ else \
+ { \
+ PARSE_FLOAT_VA_ARG (INFO); \
+ } \
+ } \
+ while (0)
+#else
+# define PARSE_FLOAT_VA_ARG_EXTENDED(INFO) \
+ PARSE_FLOAT_VA_ARG (INFO);
+#endif
+
+#define PARSE_FLOAT_VA_ARG(INFO) \
+ do \
+ { \
+ INFO.is_binary128 = 0; \
+ if (is_long_double) \
+ the_arg.pa_long_double = va_arg (ap, long double); \
+ else \
+ the_arg.pa_double = va_arg (ap, double); \
+ } \
+ while (0)
+
+#if __HAVE_FLOAT128_UNLIKE_LDBL
+# define SETUP_FLOAT128_INFO(INFO) \
+ do \
+ { \
+ if ((mode_flags & PRINTF_LDBL_USES_FLOAT128) != 0) \
+ INFO.is_binary128 = is_long_double; \
+ else \
+ INFO.is_binary128 = 0; \
+ } \
+ while (0)
+#else
+# define SETUP_FLOAT128_INFO(INFO) \
+ do \
+ { \
+ INFO.is_binary128 = 0; \
+ } \
+ while (0)
+#endif
+
#define done_add(val) \
do { \
unsigned int _val = val; \
@@ -771,10 +822,7 @@ static const uint8_t jump_table[] =
.wide = sizeof (CHAR_T) != 1, \
.is_binary128 = 0}; \
\
- if (is_long_double) \
- the_arg.pa_long_double = va_arg (ap, long double); \
- else \
- the_arg.pa_double = va_arg (ap, double); \
+ PARSE_FLOAT_VA_ARG_EXTENDED (info); \
ptr = (const void *) &the_arg; \
\
function_done = __printf_fp (s, &info, &ptr); \
@@ -787,8 +835,7 @@ static const uint8_t jump_table[] =
fspec->data_arg_type = PA_DOUBLE; \
fspec->info.is_long_double = 0; \
} \
- /* Not supported by *printf functions. */ \
- fspec->info.is_binary128 = 0; \
+ SETUP_FLOAT128_INFO (fspec->info); \
\
function_done = __printf_fp (s, &fspec->info, &ptr); \
} \
@@ -831,10 +878,7 @@ static const uint8_t jump_table[] =
.wide = sizeof (CHAR_T) != 1, \
.is_binary128 = 0}; \
\
- if (is_long_double) \
- the_arg.pa_long_double = va_arg (ap, long double); \
- else \
- the_arg.pa_double = va_arg (ap, double); \
+ PARSE_FLOAT_VA_ARG_EXTENDED (info); \
ptr = (const void *) &the_arg; \
\
function_done = __printf_fphex (s, &info, &ptr); \
@@ -844,8 +888,7 @@ static const uint8_t jump_table[] =
ptr = (const void *) &args_value[fspec->data_arg]; \
if (__glibc_unlikely ((mode_flags & PRINTF_LDBL_IS_DBL) != 0)) \
fspec->info.is_long_double = 0; \
- /* Not supported by *printf functions. */ \
- fspec->info.is_binary128 = 0; \
+ SETUP_FLOAT128_INFO (fspec->info); \
\
function_done = __printf_fphex (s, &fspec->info, &ptr); \
} \
@@ -1869,6 +1912,10 @@ printf_positional (FILE *s, const CHAR_T *format, int readonly_format,
args_value[cnt].pa_double = va_arg (*ap_savep, double);
args_type[cnt] &= ~PA_FLAG_LONG_DOUBLE;
}
+#if __HAVE_FLOAT128_UNLIKE_LDBL
+ else if ((mode_flags & PRINTF_LDBL_USES_FLOAT128) != 0)
+ args_value[cnt].pa_float128 = va_arg (*ap_savep, _Float128);
+#endif
else
args_value[cnt].pa_long_double = va_arg (*ap_savep, long double);
break;
@@ -1887,7 +1934,7 @@ printf_positional (FILE *s, const CHAR_T *format, int readonly_format,
(args_value[cnt].pa_user, ap_savep);
}
else
- args_value[cnt].pa_long_double = 0.0;
+ memset (&args_value[cnt], 0, sizeof (args_value[cnt]));
break;
case -1:
/* Error case. Not all parameters appear in N$ format