Commit Graph

196 Commits

Author SHA1 Message Date
Tom Lane 02a6a54ecd Make use of compiler builtins and/or assembly for CLZ, CTZ, POPCNT.
Test for the compiler builtins __builtin_clz, __builtin_ctz, and
__builtin_popcount, and make use of these in preference to
handwritten C code if they're available.  Create src/port
infrastructure for "leftmost one", "rightmost one", and "popcount"
so as to centralize these decisions.

On x86_64, __builtin_popcount generally won't make use of the POPCNT
opcode because that's not universally supported yet.  Provide code
that checks CPUID and then calls POPCNT via asm() if available.
This requires indirecting through a function pointer, which is
an annoying amount of overhead for a one-instruction operation,
but it's probably not worth working harder than this for our
current use-cases.

I'm not sure we've found all the existing places that could profit
from this new infrastructure; but we at least touched all the
ones that used copied-and-pasted versions of the bitmapset.c code,
and got rid of multiple copies of the associated constant arrays.

While at it, replace c-compiler.m4's one-per-builtin-function
macros with a single one that can handle all the cases we need
to worry about so far.  Also, because I'm paranoid, make those
checks into AC_LINK checks rather than just AC_COMPILE; the
former coding failed to verify that libgcc has support for the
builtin, in cases where it's not inline code.

David Rowley, Thomas Munro, Alvaro Herrera, Tom Lane

Discussion: https://postgr.es/m/CAKJS1f9WTAGG1tPeJnD18hiQW5gAk59fQ6WK-vfdAKEHyRg2RA@mail.gmail.com
2019-02-15 23:22:33 -05:00
Alvaro Herrera 457aef0f1f Revert attempts to use POPCNT etc instructions
This reverts commits fc6c72747a, 109de05cbb, d0b4663c23 and
711bab1e4d.

Somebody will have to try harder before submitting this patch again.
I've spent entirely too much time on it already, and the #ifdef maze yet
to be written in order for it to build at all got on my nerves.  The
amount of work needed to get a platform-specific performance improvement
that's barely above the noise level is not worth it.
2019-02-15 16:32:30 -03:00
Alvaro Herrera 109de05cbb Fix portability issues in pg_bitutils
We were using uint64 function arguments as "long int" arguments to
compiler builtins, which fails on machines where long ints are 32 bits:
the upper half of the uint64 was being ignored.  Fix by using the "ll"
builtin variants instead, which on those machines take 64 bit arguments.

Also, remove configure tests for __builtin_popcountl() (as well as
"long" variants for ctz and clz): the theory here is that any compiler
version will provide all widths or none, so one test suffices.  Were
this theory to be wrong, we'd have to add tests for
__builtin_popcountll() and friends, which would be tedious.

Per failures in buildfarm member lapwing and ensuing discussion.
2019-02-13 20:09:48 -03:00
Alvaro Herrera 711bab1e4d Add basic support for using the POPCNT and SSE4.2s LZCNT opcodes
These opcodes have been around in the AMD world since 2007, and 2008 in
the case of intel.  They're supported in GCC and Clang via some __builtin
macros.  The opcodes may be unavailable during runtime, in which case we
fall back on a C-based implementation of the code.  In order to get the
POPCNT instruction we must pass the -mpopcnt option to the compiler.  We
do this only for the pg_bitutils.c file.

David Rowley (with fragments taken from a patch by Thomas Munro)

Discussion: https://postgr.es/m/CAKJS1f9WTAGG1tPeJnD18hiQW5gAk59fQ6WK-vfdAKEHyRg2RA@mail.gmail.com
2019-02-13 16:10:06 -03:00
Andrew Gierth f397e08599 Use strtof() and not strtod() for float4 input.
Using strtod() creates a double-rounding problem; the input decimal
value is first rounded to the nearest double; rounding that to the
nearest float may then give an incorrect result.

An example is that 7.038531e-26 when input via strtod and then rounded
to float4 gives 0xAE43FEp-107 instead of the correct 0xAE43FDp-107.

Values output by earlier PG versions with extra_float_digits=3 should
all be read in with the same values as previously. However, values
supplied by other software using shortest representations could be
mis-read.

On platforms that lack a strtof() entirely, we fall back to the old
incorrect rounding behavior. (As strtof() is required by C99, such
platforms are considered of primarily historical interest.) On VS2013,
some workarounds are used to get correct error handling.

The regression tests now test for the correct input values, so
platforms that lack strtof() will need resultmap entries. An entry for
HP-UX 10 is included (more may be needed).

Reviewed-By: Tom Lane
Discussion: https://postgr.es/m/871s5emitx.fsf@news-spur.riddles.org.uk
Discussion: https://postgr.es/m/87d0owlqpv.fsf@news-spur.riddles.org.uk
2019-02-13 15:19:44 +00:00
Tom Lane ee27584c4a Second try at fixing ecpglib thread-safety problem.
While Windows (allegedly) has _configthreadlocale() pretty far back,
it seems MinGW didn't acquire support for that till more recently.
Fortunately, we can use an autoconf probe on that toolchain,
instead of guessing whether it's there.  (Hm, I wonder whether Cygwin
will need this also.)

Per buildfarm.

Discussion: https://postgr.es/m/20190121193512.tdmcnic2yjxlufaw@alap3.anarazel.de
2019-01-21 16:17:10 -05:00
Tom Lane 8eb4a9312c Avoid thread-safety problem in ecpglib.
ecpglib attempts to force the LC_NUMERIC locale to "C" while reading
server output, to avoid problems with strtod() and related functions.
Historically it's just issued setlocale() calls to do that, but that
has major problems if we're in a threaded application.  setlocale()
itself is not required by POSIX to be thread-safe (and indeed is not,
on recent OpenBSD).  Moreover, its effects are process-wide, so that
we could cause unexpected results in other threads, or another thread
could change our setting.

On platforms having uselocale(), which is required by POSIX:2008,
we can avoid these problems by using uselocale() instead.  Windows
goes its own way as usual, but we can make it safe by using
_configthreadlocale().  Platforms having neither continue to use the
old code, but that should be pretty much nobody among current systems.

This should get back-patched, but let's see what the buildfarm
thinks of it first.

Michael Meskes and Tom Lane; thanks also to Takayuki Tsunakawa.

Discussion: https://postgr.es/m/31420.1547783697@sss.pgh.pa.us
2019-01-21 12:07:02 -05:00
Magnus Hagander 0301db623d Replace @postgresql.org with @lists.postgresql.org for mailinglists
Commit c0d0e54084 replaced the ones in the documentation, but missed out
on the ones in the code. Replace those as well, but unlike c0d0e54084,
don't backpatch the code changes to avoid breaking translations.
2019-01-19 19:06:35 +01:00
Michael Paquier 1707a0d2aa Remove configure switch --disable-strong-random
This removes a portion of infrastructure introduced by fe0a0b5 to allow
compilation of Postgres in environments where no strong random source is
available, meaning that there is no linking to OpenSSL and no
/dev/urandom (Windows having its own CryptoAPI).  No systems shipped
this century lack /dev/urandom, and the buildfarm is actually not
testing this switch at all, so just remove it.  This simplifies
particularly some backend code which included a fallback implementation
using shared memory, and removes a set of alternate regression output
files from pgcrypto.

Author: Michael Paquier
Reviewed-by: Tom Lane
Discussion: https://postgr.es/m/20181230063219.GG608@paquier.xyz
2019-01-01 20:05:51 +09:00
Tom Lane a73d083195 Modernize our code for looking up descriptive strings for Unix signals.
At least as far back as the 2008 spec, POSIX has defined strsignal(3)
for looking up descriptive strings for signal numbers.  We hadn't gotten
the word though, and were still using the crufty old sys_siglist array,
which is in no standard even though most Unixen provide it.

Aside from not being formally standards-compliant, this was just plain
ugly because it involved #ifdef's at every place using the code.

To eliminate the #ifdef's, create a portability function pg_strsignal,
which wraps strsignal(3) if available and otherwise falls back to
sys_siglist[] if available.  The set of Unixen with neither API is
probably empty these days, but on any platform with neither, you'll
just get "unrecognized signal".  All extant callers print the numeric
signal number too, so no need to work harder than that.

Along the way, upgrade pg_basebackup's child-error-exit reporting
to match the rest of the system.

Discussion: https://postgr.es/m/25758.1544983503@sss.pgh.pa.us
2018-12-16 19:38:57 -05:00
Thomas Munro 3fd2a7932e Provide pg_pread() and pg_pwrite() for random I/O.
Forward to POSIX pread() and pwrite(), or emulate them if unavailable.
The emulation is not perfect as the file position is changed, so
we'll put pg_ prefixes on the names to minimize the risk of confusion
in future patches that might inadvertently try to mix pread() and read()
on the same file descriptor.

Author: Thomas Munro
Reviewed-by: Tom Lane, Jesper Pedersen
Discussion: https://postgr.es/m/CAEepm=02rapCpPR3ZGF2vW=SBHSdFYO_bz_f-wwWJonmA3APgw@mail.gmail.com
2018-11-07 09:50:01 +13:00
Tom Lane abd9ca377d Make assorted performance improvements in snprintf.c.
In combination, these changes make our version of snprintf as fast
or faster than most platforms' native snprintf, except for cases
involving floating-point conversion (which we still delegate to
the native sprintf).  The speed penalty for a float conversion
is down to around 10% though, much better than before.

Notable changes:

* Rather than always parsing the format twice to see if it contains
instances of %n$, do the extra scan only if we actually find a $.
This obviously wins for non-localized formats, and even when there
is use of %n$, we can avoid scanning text before the first % twice.

* Use strchrnul() if available to find the next %, and emit the
literal text between % escapes as strings rather than char-by-char.

* Create a bespoke function (dopr_outchmulti) for the common case
of emitting N copies of the same character, in place of writing
loops around dopr_outch.

* Simplify construction of the format string for invocations of sprintf
for floats.

* Const-ify some internal functions, and avoid unnecessary use of
pass-by-reference arguments.

Patch by me, reviewed by Andres Freund

Discussion: https://postgr.es/m/11787.1534530779@sss.pgh.pa.us
2018-10-03 10:18:15 -04:00
Tom Lane 751f532b97 Try another way to detect the result type of strerror_r().
The method we've traditionally used, of redeclaring strerror_r() to
see if the compiler complains of inconsistent declarations, turns out
not to work reliably because some compilers only report a warning,
not an error.  Amazingly, this has gone undetected for years, even
though it certainly breaks our detection of whether strerror_r
succeeded.

Let's instead test whether the compiler will take the result of
strerror_r() as a switch() argument.  It's possible this won't
work universally either, but it's the best idea I could come up with
on the spur of the moment.

We should probably back-patch this once the dust settles, but
first let's see what the buildfarm thinks of it.

Discussion: https://postgr.es/m/10877.1537993279@sss.pgh.pa.us
2018-09-26 18:23:13 -04:00
Tom Lane 96bf88d527 Always use our own versions of *printf().
We've spent an awful lot of effort over the years in coping with
platform-specific vagaries of the *printf family of functions.  Let's just
forget all that mess and standardize on always using src/port/snprintf.c.
This gets rid of a lot of configure logic, and it will allow a saner
approach to dealing with %m (though actually changing that is left for
a follow-on patch).

Preliminary performance testing suggests that as it stands, snprintf.c is
faster than the native printf functions for some tasks on some platforms,
and slower for other cases.  A pending patch will improve that, though
cases with floating-point conversions will doubtless remain slower unless
we want to put a *lot* of effort into that.  Still, we've not observed
that *printf is really a performance bottleneck for most workloads, so
I doubt this matters much.

Patch by me, reviewed by Michael Paquier

Discussion: https://postgr.es/m/2975.1526862605@sss.pgh.pa.us
2018-09-26 13:13:57 -04:00
Tom Lane 26e9d4d4ef Convert elog.c's useful_strerror() into a globally-used strerror wrapper.
elog.c has long had a private strerror wrapper that handles assorted
possible failures or deficiencies of the platform's strerror.  On Windows,
it also knows how to translate Winsock error codes, which the native
strerror does not.  Move all this code into src/port/strerror.c and
define strerror() as a macro that invokes it, so that both our frontend
and backend code will have all of this behavior.

I believe this constitutes an actual bug fix on Windows, since AFAICS
our frontend code did not report Winsock error codes properly before this.
However, the main point is to lay the groundwork for implementing %m
in src/port/snprintf.c: the behavior we want %m to have is this one,
not the native strerror's.

Note that this throws away the prior use of src/port/strerror.c,
which was to implement strerror() on platforms lacking it.  That's
been dead code for nigh twenty years now, since strerror() was
already required by C89.

We should likewise cause strerror_r to use this behavior, but
I'll tackle that separately.

Patch by me, reviewed by Michael Paquier

Discussion: https://postgr.es/m/2975.1526862605@sss.pgh.pa.us
2018-09-26 11:06:42 -04:00
Tom Lane 60e612b602 Use ppoll(2), if available, to wait for input in pgbench.
Previously, pgbench always used select(2) for this purpose, but that's
problematic for very high client counts, because select() can't deal
with file descriptor numbers larger than FD_SETSIZE.  It's pretty common
for that to be only 1024 or so, whereas modern OSes can allow many more
open files than that.  Using poll(2) would surmount that problem, but it
creates another one: poll()'s timeout resolution is only 1ms, which is
poor enough to cause problems with --rate specifications approaching or
exceeding 1K TPS.

On platforms that have ppoll(2), which includes Linux and recent
FreeBSD, we can use that to avoid the FD_SETSIZE problem without any
loss of timeout resolution.  Hence, add configure logic to test for
ppoll(), and use it if available.

This patch introduces an abstraction layer into pgbench that could
be extended to support other kernel event-wait APIs such as kevents.
But actually adding such support is a matter for some future patch.

Doug Rady, reviewed by Robert Haas and Fabien Coelho, and whacked around
a good bit more by me

Discussion: https://postgr.es/m/23D017C9-81B7-484D-8490-FD94DEC4DF59@amazon.com
2018-09-24 14:40:58 -04:00
Peter Eisentraut 842cb9fa62 Refactor dlopen() support
Nowadays, all platforms except Windows and older HP-UX have standard
dlopen() support.  So having a separate implementation per platform
under src/backend/port/dynloader/ is a bit excessive.  Instead, treat
dlopen() like other library functions that happen to be missing
sometimes and put a replacement implementation under src/port/.

Discussion: https://www.postgresql.org/message-id/flat/e11a49cb-570a-60b7-707d-7084c8de0e61%402ndquadrant.com#54e735ae37476a121abb4e33c2549b03
2018-09-06 11:33:04 +02:00
Andres Freund 8ecdefc261 Remove test for VA_ARGS, implied by C99.
This simplifies logic / reduces duplication in a few headers.

Author: Andres Freund
Discussion: https://postgr.es/m/97d4b165-192d-3605-749c-f614a0c4e783@2ndquadrant.com
2018-08-24 10:41:45 -07:00
Andres Freund cb92520563 LLVMJIT: LLVMGetHostCPUFeatures now is upstream, use LLMV version if available.
Noticed thanks to buildfarm animal seawasp.

Author: Andres Freund
Backpatch: v11-, where LLVM based JIT compliation was introduced.
2018-08-24 10:21:38 -07:00
Peter Eisentraut 351855fc4e Remove obsolete linux dynloader code
This has been obsolete probably since the late 1990s.
2018-08-13 23:21:01 +02:00
Andres Freund e9a9843e13 LLVMJIT: Adapt to API changes in gdb and perf support.
During the work of upstreaming my previous patches for gdb and perf
support the API changed. Adapt.  Normally this wouldn't necessarily be
something to backpatch, but the previous API wasn't upstream, and at
least the gdb support is quite useful for debugging.

Author: Andres Freund
Backpatch: 11, where LLVM based JIT support was added.
2018-07-22 21:13:34 -07:00
Thomas Munro 9f09529952 Use signals for postmaster death on Linux.
Linux provides a way to ask for a signal when your parent process dies.
Use that to make PostmasterIsAlive() very cheap.

Based on a suggestion from Andres Freund.

Author: Thomas Munro, Heikki Linnakangas
Reviewed-By: Michael Paquier
Discussion: https://postgr.es/m/7261eb39-0369-f2f4-1bb5-62f3b6083b5e%40iki.fi
Discussion: https://postgr.es/m/20180411002643.6buofht4ranhei7k%40alap3.anarazel.de
2018-07-11 12:47:06 +12:00
Andrew Dunstan feced1387f Stamp HEAD as 12devel
Let the hacking begin ...
2018-06-30 12:47:59 -04:00
Alvaro Herrera 1d4e5edc1d Stamp 11beta2. 2018-06-25 11:09:49 -04:00
Michael Paquier bde64eb610 Track new configure flags introduced for version 11 in pg_config.h.win32
The following set of flags mainly matter when building Postgres code
with MSVC and those have been forgotten with latest developments:
- HAVE_LDAP_INITIALIZE, added by 35c0754f, and marked as disabled.
ldap_initialize() is a non-standard extension that provides a way to use
"ldaps" with OpenLDAP, but it is not supported on Windows, and instead
the non-standard ldap_sslinit() is used if WIN32 is defined.  Per input
from Thomas Munro.
- HAVE_X509_GET_SIGNATURE_NID, added by 054e8c6c, which is used by
SCRAM's channel binding tls-server-end-point.  Having this flag disabled
would cause this channel binding type to be unsupported for Windows
builds.
- HAVE_SSL_CLEAR_OPTIONS, added recently as of a364dfa4 to disable SSL
compression.
- HAVE_ASN1_STRING_GET0_DATA, added by 5c6df67, which is used to track
a new compatibility with OpenSSL 1.1.0.  This was missing from
pg_config.win32.h and is not enabled by default.  HAVE_BIO_GET_DATA,
HAVE_OPENSSL_INIT_SSL and HAVE_BIO_METH_NEW gain the same treatment.

The second and third flags are enabled with this commit, which raises
the bar of OpenSSL support to 1.0.2 on Windows as a minimum.  As this
is the LTS (long-time support) version of OpenSSL community and knowing
that all recent installers referred by OpenSSL upstream don't have
anymore 1.0.1 or older, we could live with that requirement.  In order
to allow the code to compile with OpenSSL 1.1.0, all the flags mentioned
above need to be enabled in pg_config.h.win32.

Author: Michael Paquier
Reviewed-by: Andrew Dunstan
Discussion: https://postgr.es/m/20180529211559.GF6632@paquier.xyz
2018-06-19 09:00:33 +09:00
Tom Lane b929614f5e Remove configure's check for nonstandard "long long" printf modifiers.
We used to claim to support platforms using 'q' or 'I64' as the printf
length modifier for long long int, by dint of replacing snprintf with
our own code which uses the C99 standard 'll' modifier.  But that is
only adequate if we use INT64_MODIFIER only in snprintf-based calls,
not directly with the platform's native printf or fprintf.  Which
hasn't been the case for years.  We had not noticed, partially because
of inadequate test coverage, and partially because the buildfarm is
almost completely bare of machines that won't take 'll'.  The last
one seems to have been frogmouth, which was adjusted recently so that
it will take 'll'.  We might as well just give up on the pretense
that anything else works, and save ourselves some configure cycles.

Discussion: https://postgr.es/m/13103.1526749980@sss.pgh.pa.us
Discussion: https://postgr.es/m/24769.1526772680@sss.pgh.pa.us
2018-05-23 14:19:04 -04:00
Tom Lane 586e4e6df5 Stamp 11beta1. 2018-05-21 17:08:10 -04:00
Tom Lane 06f66cff9e Support platforms where strtoll/strtoull are spelled __strtoll/__strtoull.
Ancient HPUX, for one, does this.  We hadn't noticed due to the lack
of regression tests that required a working strtoll.

(I was slightly tempted to remove the other historical spelling,
strto[u]q, since it seems we have no buildfarm members testing that case.
But I refrained.)

Discussion: https://postgr.es/m/151935568942.1461.14623890240535309745@wrigleys.postgresql.org
2018-05-19 14:22:18 -04:00
Tom Lane a6228128fc Arrange to supply declarations for strtoll/strtoull if needed.
Buildfarm member dromedary is still unhappy about the recently-added
ecpg "long long" tests.  The reason turns out to be that it includes
"-ansi" in its CFLAGS, and in their infinite wisdom Apple have decided
to hide the declarations of strtoll/strtoull in C89-compliant builds.
(I find it pretty curious that they hide those function declarations
when you can nonetheless declare a "long long" variable, but anyway
that is their behavior, both on dromedary's obsolete macOS version and
the newest and shiniest.)  As a result, gcc assumes these functions
return "int", leading naturally to wrong results.

(Looking at dromedary's past build results, it's evident that this
problem also breaks pg_strtouint64() on 32-bit platforms; but we
evidently have no regression tests that exercise that function with
values above 32 bits.)

To fix, supply declarations for these functions when the platform
provides the functions but not the declarations, using the same type
of mechanism as we use for some other similar cases.

Discussion: https://postgr.es/m/151935568942.1461.14623890240535309745@wrigleys.postgresql.org
2018-05-18 22:42:10 -04:00
Tom Lane f586f86389 Recognize that MSVC can support strtoll() and strtoull().
This is needed for full support of "long long" variables in ecpg, but
the previous patch for bug #15080 (commits 51057feaa et al) missed it.
In MSVC versions where the functions don't exist under those names,
we can nonetheless use _strtoi64() and _strtoui64().

Like the previous patch, back-patch all the way.

Dang Minh Huong

Discussion: https://postgr.es/m/151935568942.1461.14623890240535309745@wrigleys.postgresql.org
2018-05-18 12:52:28 -04:00
Tom Lane 6fe25c1358 Change SIZEOF_BOOL to 1 for Windows.
For some reason it was previously defined as 0, which is silly.  The only
effect was to disable use of <stdbool.h>, which commit b2328bf62 intended
to make possible.

Thomas Munro

Discussion: https://postgr.es/m/CAEepm%3D3%3DTDYEXUEcHpEx%2BTwc31wo7PA0oBAiNt6sWmq93MW02A%40mail.gmail.com
2018-05-02 00:21:21 -04:00
Tom Lane b2328bf62b Fix some assorted compiler warnings on Windows.
Don't overflow the result type of constant expressions.  Don't negate
unsigned types.  Define HAVE_STDBOOL_H for Visual C++ 2013 and later.

Thomas Munro
Reviewed-By: Michael Paquier and Tom Lane

Discussion: https://postgr.es/m/CAEepm%3D3%3DTDYEXUEcHpEx%2BTwc31wo7PA0oBAiNt6sWmq93MW02A%40mail.gmail.com
2018-05-01 19:38:26 -04:00
Heikki Linnakangas 638a199fa9 Also fix the descriptions in pg_config.h.win32.
I missed pg_config.h.win32 in the previous commit that fixed these in
pg_config.h.in.
2018-04-04 11:33:39 +03:00
Peter Eisentraut 9a95a77d9d Use stdbool.h if suitable
Using the standard bool type provided by C allows some recent compilers
and debuggers to give better diagnostics.  Also, some extension code and
third-party headers are increasingly pulling in stdbool.h, so it's
probably saner if everyone uses the same definition.

But PostgreSQL code is not prepared to handle bool of a size other than
1, so we keep our own old definition if we encounter a stdbool.h with a
bool of a different size.  (Among current build farm members, this only
applies to old macOS versions on PowerPC.)

To check that the used bool is of the right size, add a static
assertions about size of GinTernaryValue vs bool.  This is currently the
only place that assumes that bool and char are of the same size.

Discussion: https://www.postgresql.org/message-id/flat/3a0fe7e1-5ed1-414b-9230-53bbc0ed1f49@2ndquadrant.com
2018-03-22 20:42:25 -04:00
Andres Freund 5b2526c838 Add configure infrastructure (--with-llvm) to enable LLVM support.
LLVM will be used for *optional* Just-in-time compilation
support. This commit just adds the configure infrastructure that
detects LLVM.

No documentation has been added for the --with-llvm flag, that'll be
added after the actual supporting code has been added.

Author: Andres Freund
Discussion: https://postgr.es/m/20170901064131.tazjxwus3k2w3ybh@alap3.anarazel.de
2018-03-20 17:26:25 -07:00
Tom Lane 51057feaa6 Fix up ecpg's configuration so it handles "long long int" in MSVC builds.
Although configure-based builds correctly define HAVE_LONG_LONG_INT when
appropriate (in both pg_config.h and ecpg_config.h), builds using the MSVC
scripts failed to do so.  This currently has no impact on the backend,
since it uses that symbol nowhere; but it does prevent ecpg from
supporting "long long int".  Fix that.

Also, adjust Solution.pm so that in the constructed ecpg_config.h file,
the "#if (_MSC_VER > 1200)" covers only the LONG_LONG_INT-related
#defines, not the whole file.  AFAICS this was a thinko on somebody's
part: ENABLE_THREAD_SAFETY should always be defined in Windows builds,
and in branches using USE_INTEGER_DATETIMES, the setting of that shouldn't
depend on the compiler version either.  If I'm wrong, I imagine the
buildfarm will say so.

Per bug #15080 from Jonathan Allen; issue diagnosed by Michael Meskes
and Andrew Gierth.  Back-patch to all supported branches.

Discussion: https://postgr.es/m/151935568942.1461.14623890240535309745@wrigleys.postgresql.org
2018-02-27 16:46:52 -05:00
Andres Freund 4d6ad31257 Provide overflow safe integer math inline functions.
It's not easy to get signed integer overflow checks correct and
fast. Therefore abstract the necessary infrastructure into a common
header providing addition, subtraction and multiplication for 16, 32,
64 bit signed integers.

The new macros aren't yet used, but a followup commit will convert
several open coded overflow checks.

Author: Andres Freund, with some code stolen from Greg Stark
Reviewed-By: Robert Haas
Discussion: https://postgr.es/m/20171024103954.ztmatprlglz3rwke@alap3.anarazel.de
2017-12-12 16:55:37 -08:00
Tom Lane 7518049980 Prevent int128 from requiring more than MAXALIGN alignment.
Our initial work with int128 neglected alignment considerations, an
oversight that came back to bite us in bug #14897 from Vincent Lachenal.
It is unsurprising that int128 might have a 16-byte alignment requirement;
what's slightly more surprising is that even notoriously lax Intel chips
sometimes enforce that.

Raising MAXALIGN seems out of the question: the costs in wasted disk and
memory space would be significant, and there would also be an on-disk
compatibility break.  Nor does it seem very practical to try to allow some
data structures to have more-than-MAXALIGN alignment requirement, as we'd
have to push knowledge of that throughout various code that copies data
structures around.

The only way out of the box is to make type int128 conform to the system's
alignment assumptions.  Fortunately, gcc supports that via its
__attribute__(aligned()) pragma; and since we don't currently support
int128 on non-gcc-workalike compilers, we shouldn't be losing any platform
support this way.

Although we could have just done pg_attribute_aligned(MAXIMUM_ALIGNOF) and
called it a day, I did a little bit of extra work to make the code more
portable than that: it will also support int128 on compilers without
__attribute__(aligned()), if the native alignment of their 128-bit-int
type is no more than that of int64.

Add a regression test case that exercises the one known instance of the
problem, in parallel aggregation over a bigint column.

This will need to be back-patched, along with the preparatory commit
91aec93e6.  But let's see what the buildfarm makes of it first.

Discussion: https://postgr.es/m/20171110185747.31519.28038@wrigleys.postgresql.org
2017-11-14 15:03:55 -05:00
Andres Freund 91d5f1a4a3 Use C99 restrict via pg_restrict, rather than restrict directly.
Unfortunately using 'restrict' plainly causes problems with MSVC,
which supports restrict only as '__restrict'. Defining 'restrict' to
'__restrict' unfortunately causes a conflict with MSVC's usage of
__declspec(restrict) in headers.

Therefore define pg_restrict to the appropriate keyword instead, and
replace existing usages.

This replaces the temporary workaround introduced in 36b4b91ba0.

Author: Andres Freund
Discussion: https://postgr.es/m/2656.1507830907@sss.pgh.pa.us
2017-10-12 16:17:35 -07:00
Andres Freund 36b4b91ba0 Temporary attempt at a workaround for further MSVC restrict build failures.
It appears some versions of msvc use __declspec(restrict) in stdlib.h
and subsidiary headers. Including those after defining 'restrict' to
'__restrict' doesn't work.  Try to get the buildfarm green to see
whether there's further problems, by including stdlib.h just before
said define.
2017-10-11 19:06:29 -07:00
Andres Freund 0b974dba2d Add configure infrastructure to detect support for C99's restrict.
Will be used in later commits improving performance for a few key
routines where information about aliasing allows for significantly
better code generation.

This allows to use the C99 'restrict' keyword without breaking C89, or
for that matter C++, compilers. If not supported it's defined to be
empty.

Author: Andres Freund
Discussion: https://postgr.es/m/20170914063418.sckdzgjfrsbekae4@alap3.anarazel.de
2017-10-11 16:01:52 -07:00
Andres Freund fffd651e83 Rewrite strnlen replacement implementation from 8a241792f9.
The previous placement of the fallback implementation in libpgcommon
was problematic, because libpqport functions need strnlen
functionality.

Move replacement into libpgport. Provide strnlen() under its posix
name, instead of pg_strnlen(). Fix stupid configure bug, executing the
test only when compiled with threading support.

Author: Andres Freund
Discussion: https://postgr.es/m/E1e1gR2-0005fB-SI@gemulon.postgresql.org
2017-10-10 14:50:30 -07:00
Andres Freund 8a241792f9 Add pg_strnlen() a portable implementation of strlen.
As the OS version is likely going to be more optimized, fall back to
it if available, as detected by configure.
2017-10-09 15:20:42 -07:00
Andres Freund 510b8cbff1 Extend & revamp pg_bswap.h infrastructure.
Upcoming patches are going to address performance issues that involve
slow system provided ntohs/htons etc. To address that expand
pg_bswap.h to provide pg_ntoh{16,32,64}, pg_hton{16,32,64} and
optimize their respective implementations by using compiler intrinsics
for gcc compatible compilers and msvc. Fall back to manual
implementations using shifts etc otherwise.

Additionally remove multiple evaluation hazards from the existing
BSWAP32/64 macros, by replacing them with inline functions when
necessary. In the course of that the naming scheme is changed to
pg_bswap16/32/64.

Author: Andres Freund
Discussion: https://postgr.es/m/20170927172019.gheidqy6xvlxb325@alap3.anarazel.de
2017-09-29 17:24:39 -07:00
Tom Lane 899bd785c0 Avoid SIGBUS on Linux when a DSM memory request overruns tmpfs.
On Linux, shared memory segments created with shm_open() are backed by
swap files created in tmpfs.  If the swap file needs to be extended,
but there's no tmpfs space left, you get a very unfriendly SIGBUS trap.
To avoid this, force allocation of the full request size when we create
the segment.  This adds a few cycles, but none that we wouldn't expend
later anyway, assuming the request isn't hugely bigger than the actual
need.

Make this code #ifdef __linux__, because (a) there's not currently a
reason to think the same problem exists on other platforms, and (b)
applying posix_fallocate() to an FD created by shm_open() isn't very
portable anyway.

Back-patch to 9.4 where the DSM code came in.

Thomas Munro, per a bug report from Amul Sul

Discussion: https://postgr.es/m/1002664500.12301802.1471008223422.JavaMail.yahoo@mail.yahoo.com
2017-09-25 16:09:19 -04:00
Tom Lane 85feb77aa0 Assume wcstombs(), towlower(), and sibling functions are always present.
These functions are required by SUS v2, which is our minimum baseline
for Unix platforms, and are present on all interesting Windows versions
as well.  Even our oldest buildfarm members have them.  Thus, we were not
testing the "!USE_WIDE_UPPER_LOWER" code paths, which explains why the bug
fixed in commit e6023ee7f escaped detection.  Per discussion, there seems
to be no more real-world value in maintaining this option.  Hence, remove
the configure-time tests for wcstombs() and towlower(), remove the
USE_WIDE_UPPER_LOWER symbol, and remove all the !USE_WIDE_UPPER_LOWER code.
There's not actually all that much of the latter, but simplifying the #if
nests is a win in itself.

Discussion: https://postgr.es/m/20170921052928.GA188913@rfd.leadboat.com
2017-09-22 11:00:58 -04:00
Tom Lane 9d6b160d7d Make [U]INT64CONST safe for use in #if conditions.
Instead of using a cast to force the constant to be the right width,
assume we can plaster on an L, UL, LL, or ULL suffix as appropriate.
The old approach to this is very hoary, dating from before we were
willing to require compilers to have working int64 types.

This fix makes the PG_INT64_MIN, PG_INT64_MAX, and PG_UINT64_MAX
constants safe to use in preprocessor conditions, where a cast
doesn't work.  Other symbolic constants that might be defined using
[U]INT64CONST are likewise safer than before.

Also fix the SIZE_MAX macro to be similarly safe, if we are forced
to provide a definition for that.  The test added in commit 2e70d6b5e
happens to do what we want even with the hack "(size_t) -1" definition,
but we could easily get burnt on other tests in future.

Back-patch to all supported branches, like the previous commits.

Discussion: https://postgr.es/m/15883.1504278595@sss.pgh.pa.us
2017-09-01 15:14:46 -04:00
Tom Lane 9f14dc393b Stamp HEAD as 11devel.
Note that we no longer require any manual adjustments to shared-library
minor version numbers, cf commit a3bce17ef.  So this should be everything.
2017-08-14 18:08:30 -04:00
Peter Eisentraut d6391b03b3 Reject use of ucol_strcollUTF8() before ICU 53
Various bugs can cause crashes, so don't use that function before ICU
53.  It will fall back to the code path used for other encodings.

Since we now tie the function availability to an ICU version, we don't
need the configure test anymore.  That also resolves the issue that the
test result was previously hardcoded for Windows.

researched by Daniel Verite <daniel@manitou-mail.org>, Peter Geoghegan
<pg@bowt.ie>, Tom Lane <tgl@sss.pgh.pa.us>

Discussion: https://www.postgresql.org/message-id/flat/f1438ec6-22aa-4029-9a3b-26f79d330e72%40manitou-mail.org
2017-08-10 22:14:00 -04:00
Tom Lane 8d6442377d Stamp 10beta3. 2017-08-07 17:08:19 -04:00