Re: [HACKERS] Patch: make behavior of all versions of the "isinf" function be similar

2016-02-02 Thread Tom Lane
Vitaly Burovoy  writes:
> On 1/31/16, Tom Lane  wrote:
>> 2. POSIX:2008 only requires that "The isinf() macro shall return a
>> non-zero value if and only if its argument has an infinite value."

> Ok, then I'll use "is_infinite" from "float.c".

Yeah, that's good.

> But why functions' (in "src/port/isinf.c") behavior are different? It
> is a bit confusing…

Probably the authors of those different implementations were making it
match the behavior of whatever isinf() they had locally.  I don't feel
a need to change isinf.c --- it should be zero-maintenance at this
point, especially if we suspect it is no longer used anywhere.

regards, tom lane


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Re: [HACKERS] Patch: make behavior of all versions of the "isinf" function be similar

2016-02-01 Thread Vitaly Burovoy
On 1/31/16, Tom Lane  wrote:
> 2. POSIX:2008 only requires that "The isinf() macro shall return a
> non-zero value if and only if its argument has an infinite value."
> Therefore, any assumption about the sign of the result is wrong anyway,
> and any patch that depends on it will be rejected, regardless of what
> isinf.c does.  Or else, if you can convince us that such an assumption
> is really valuable, we'd need isinf.c more not less so that we can
> replace isinf() on platforms where it doesn't meet the stronger spec.
>
>   regards, tom lane

Ok, then I'll use "is_infinite" from "float.c".
But why functions' (in "src/port/isinf.c") behavior are different? It
is a bit confusing…
-- 
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Vitaly Burovoy


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[HACKERS] Patch: make behavior of all versions of the "isinf" function be similar

2016-01-31 Thread Vitaly Burovoy
Hello, hackers!

While I was searching for a function which checks doubles for
infinity, I discovered a function "isinf" in a file src/port/isinf.c
where one of three versions returns different value for "-inf" ("1"
instead of "-1") comparing to the other two.

It seems concrete values (not just "if isinf(...)") are checked only
in float.c in float4out and float8out, but I am going to check for
concrete values in my another patch.

For systems with HAVE_FPCLASS the function returns the same result for
both "+inf" and "-inf". I can't test it on my WS, but I found only one
man page[1] where system header file "ieeefp.h" must be included for
ability to use "fpclass" function.

I guess nothing will be broken if that version of the function returns
the same results for input values as the other two.

Proposed patch makes that behavior.

P.S.: Should the patch be added to the next CF?

[1]https://docs.oracle.com/cd/E36784_01/html/E36874/fpclass-3c.html
-- 
Best regards,
Vitaly Burovoy


isinf_v1.patch
Description: Binary data

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Re: [HACKERS] Patch: make behavior of all versions of the "isinf" function be similar

2016-01-31 Thread Michael Paquier
On Mon, Feb 1, 2016 at 2:38 PM, Michael Paquier
 wrote:
> Actually, is there actually a reason to keep this file in the code
> tree? Are there platforms that do not have isinf()? Even for Windows
> environments using MSVC < 1800 this is emulated using _fpclass.

Looking at what is in the buildfarm, I noticed that isinf is provided
everywhere. Attached is a patch. Thoughts?
-- 
Michael
diff --git a/configure b/configure
index 3dd1b15..c9dd5b8 100755
--- a/configure
+++ b/configure
@@ -12633,63 +12633,6 @@ cat >>confdefs.h <<_ACEOF
 _ACEOF
 
 
-
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for isinf" >&5
-$as_echo_n "checking for isinf... " >&6; }
-if ${ac_cv_func_isinf+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-#include 
-double glob_double;
-
-int
-main ()
-{
-return isinf(glob_double) ? 0 : 1;
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_link "$LINENO"; then :
-  ac_cv_func_isinf=yes
-else
-  ac_cv_func_isinf=no
-fi
-rm -f core conftest.err conftest.$ac_objext \
-conftest$ac_exeext conftest.$ac_ext
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_func_isinf" >&5
-$as_echo "$ac_cv_func_isinf" >&6; }
-
-if test $ac_cv_func_isinf = yes ; then
-
-$as_echo "#define HAVE_ISINF 1" >>confdefs.h
-
-else
-  case " $LIBOBJS " in
-  *" isinf.$ac_objext "* ) ;;
-  *) LIBOBJS="$LIBOBJS isinf.$ac_objext"
- ;;
-esac
-
-  # Look for a way to implement a substitute for isinf()
-  for ac_func in fpclass fp_class fp_class_d class
-do :
-  as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
-ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
-if eval test \"x\$"$as_ac_var"\" = x"yes"; then :
-  cat >>confdefs.h <<_ACEOF
-#define `$as_echo "HAVE_$ac_func" | $as_tr_cpp` 1
-_ACEOF
- break
-fi
-done
-
-fi
-
 ac_fn_c_check_func "$LINENO" "crypt" "ac_cv_func_crypt"
 if test "x$ac_cv_func_crypt" = xyes; then :
   $as_echo "#define HAVE_CRYPT 1" >>confdefs.h
diff --git a/configure.in b/configure.in
index 9398482..5c75fea 100644
--- a/configure.in
+++ b/configure.in
@@ -1502,25 +1502,6 @@ fi
 
 AC_CHECK_DECLS([snprintf, vsnprintf])
 
-
-dnl Cannot use AC_CHECK_FUNC because isinf may be a macro
-AC_CACHE_CHECK([for isinf], ac_cv_func_isinf,
-[AC_LINK_IFELSE([AC_LANG_PROGRAM([
-#include 
-double glob_double;
-],
-[return isinf(glob_double) ? 0 : 1;])],
-[ac_cv_func_isinf=yes],
-[ac_cv_func_isinf=no])])
-
-if test $ac_cv_func_isinf = yes ; then
-  AC_DEFINE(HAVE_ISINF, 1, [Define to 1 if you have isinf().])
-else
-  AC_LIBOBJ(isinf)
-  # Look for a way to implement a substitute for isinf()
-  AC_CHECK_FUNCS([fpclass fp_class fp_class_d class], [break])
-fi
-
 AC_REPLACE_FUNCS([crypt fls getopt getrusage inet_aton mkdtemp random rint srandom strerror strlcat strlcpy])
 
 case $host_os in
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 16a272e..deac60e 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -276,9 +276,6 @@
 /* Define to 1 if you have support for IPv6. */
 #undef HAVE_IPV6
 
-/* Define to 1 if you have isinf(). */
-#undef HAVE_ISINF
-
 /* Define to 1 if you have the  header file. */
 #undef HAVE_LANGINFO_H
 
diff --git a/src/include/pg_config.h.win32 b/src/include/pg_config.h.win32
index 8566065..52cfbce 100644
--- a/src/include/pg_config.h.win32
+++ b/src/include/pg_config.h.win32
@@ -187,9 +187,6 @@
 /* Define to 1 if you have support for IPv6. */
 #define HAVE_IPV6 1
 
-/* Define to 1 if you have isinf(). */
-#define HAVE_ISINF 1
-
 /* Define to 1 if you have the  header file. */
 /* #undef HAVE_LANGINFO_H */
 
diff --git a/src/include/port.h b/src/include/port.h
index 9fc79f4..e908340 100644
--- a/src/include/port.h
+++ b/src/include/port.h
@@ -374,10 +374,6 @@ extern int	fls(int mask);
 extern int	getpeereid(int sock, uid_t *uid, gid_t *gid);
 #endif
 
-#ifndef HAVE_ISINF
-extern int	isinf(double x);
-#endif
-
 #ifndef HAVE_MKDTEMP
 extern char *mkdtemp(char *path);
 #endif
diff --git a/src/interfaces/ecpg/ecpglib/.gitignore b/src/interfaces/ecpg/ecpglib/.gitignore
index 8ef6401..e23e8f0 100644
--- a/src/interfaces/ecpg/ecpglib/.gitignore
+++ b/src/interfaces/ecpg/ecpglib/.gitignore
@@ -7,4 +7,3 @@
 /strlcpy.c
 /thread.c
 /win32setlocale.c
-/isinf.c
diff --git a/src/interfaces/ecpg/ecpglib/Makefile b/src/interfaces/ecpg/ecpglib/Makefile
index 39c4232..a27db67 100644
--- a/src/interfaces/ecpg/ecpglib/Makefile
+++ b/src/interfaces/ecpg/ecpglib/Makefile
@@ -27,7 +27,7 @@ LIBS := $(filter-out -lpgport, $(LIBS))
 
 OBJS= execute.o typename.o descriptor.o sqlda.o data.o error.o prepare.o memory.o \
 	connect.o misc.o path.o pgstrcasecmp.o \
-	$(filter snprintf.o strlcpy.o win32setlocale.o isinf.o, $(LIBOBJS)) $(WIN32RES)
+	$(filter snprintf.o strlcpy.o win32setlocale.o, $(LIBOBJS)) $(WIN32RES)
 
 # thread.c is needed only for non-WIN32 implementation of path.c
 ifneq ($(PORTNAME), win32)
@@ -55,7 +55,7 @@ include 

Re: [HACKERS] Patch: make behavior of all versions of the "isinf" function be similar

2016-01-31 Thread Michael Paquier
On Mon, Feb 1, 2016 at 4:04 PM, Tom Lane  wrote:

> 1. I don't think the buildfarm is sufficient evidence to conclude that
> isinf.c is required nowhere.  It was in use as late as 2004, judging
> by the git history, and I don't know of good reason to assume we do not
> need it now.
>

This was 12 years ago... Btw, after a bit of digging, I found out that even
SunOS 5.1 includes it:
http://www.unix.com/man-page/sunos/3m/isinf/
-- 
Michael


Re: [HACKERS] Patch: make behavior of all versions of the "isinf" function be similar

2016-01-31 Thread Tom Lane
Michael Paquier  writes:
> On Mon, Feb 1, 2016 at 2:38 PM, Michael Paquier
>  wrote:
>> Actually, is there actually a reason to keep this file in the code
>> tree? Are there platforms that do not have isinf()? Even for Windows
>> environments using MSVC < 1800 this is emulated using _fpclass.

> Looking at what is in the buildfarm, I noticed that isinf is provided
> everywhere. Attached is a patch. Thoughts?

Two comments:

1. I don't think the buildfarm is sufficient evidence to conclude that
isinf.c is required nowhere.  It was in use as late as 2004, judging
by the git history, and I don't know of good reason to assume we do not
need it now.

2. POSIX:2008 only requires that "The isinf() macro shall return a
non-zero value if and only if its argument has an infinite value."
Therefore, any assumption about the sign of the result is wrong anyway,
and any patch that depends on it will be rejected, regardless of what
isinf.c does.  Or else, if you can convince us that such an assumption
is really valuable, we'd need isinf.c more not less so that we can
replace isinf() on platforms where it doesn't meet the stronger spec.

regards, tom lane


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Re: [HACKERS] Patch: make behavior of all versions of the "isinf" function be similar

2016-01-31 Thread Michael Paquier
On Mon, Feb 1, 2016 at 8:13 AM, Vitaly Burovoy  wrote:
> While I was searching for a function which checks doubles for
> infinity, I discovered a function "isinf" in a file src/port/isinf.c
> where one of three versions returns different value for "-inf" ("1"
> instead of "-1") comparing to the other two.
>
> For systems with HAVE_FPCLASS the function returns the same result for
> both "+inf" and "-inf". I can't test it on my WS, but I found only one
> man page[1] where system header file "ieeefp.h" must be included for
> ability to use "fpclass" function.

That's the case on OSX, but on Linux -1 is returned for -Inf, and 1 for +Inf.

> I guess nothing will be broken if that version of the function returns
> the same results for input values as the other two.
> Proposed patch makes that behavior.

Actually, is there actually a reason to keep this file in the code
tree? Are there platforms that do not have isinf()? Even for Windows
environments using MSVC < 1800 this is emulated using _fpclass.
-- 
Michael


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