# [Fwd: [ZEND-ENGINE-CVS] cvs: ZendEngine2 / zend_strtod.c] - Thread: https://externals.io/message/39415 - Original archive: https://news-web.php.net/php.internals/39415 - Started by Stanislav Malyshev on 2008-07-28T19:38:52+00:00 - Messages: 8 - Reply by email to internals@lists.php.net - More for agents: search with https://externals.io/search.md?q={query} · JSON API at https://externals.io/api · documentation at https://externals.io/llms.txt --- ## #39415 — Stanislav Malyshev — 2008-07-28T19:38:52+00:00 URL: https://externals.io/message/39415#39415 Hi! I wanted to ask people here about this patch. See history in http://bugs.php.net/bug.php?id=43487 but basically there's some gcc out there that miscompiles zend_strtod.c. We can fix it, probably at some marginal performance cost, but the question is - should we? It's pre-release compiler and not in the latest version. So can anyone using non-prerelease gcc of any recent version - or non-gcc compiler even - reproduce this? Should we keep the change or just tell people "use working compiler"? -------- Original Message -------- Subject: [ZEND-ENGINE-CVS] cvs: ZendEngine2 / zend_strtod.c Date: Sun, 27 Jul 2008 11:29:59 -0000 From: Dmitry Stogov To: zend-engine-cvs@lists.php.net dmitry Sun Jul 27 11:29:59 2008 UTC Modified files: /ZendEngine2 zend_strtod.c Log: Fix for bug #43487 (Wrong conversion of float to string) http://cvs.php.net/viewvc.cgi/ZendEngine2/zend_strtod.c?r1=1.37&r2=1.38&diff_format=u Index: ZendEngine2/zend_strtod.c diff -u ZendEngine2/zend_strtod.c:1.37 ZendEngine2/zend_strtod.c:1.38 --- ZendEngine2/zend_strtod.c:1.37 Wed Mar 26 14:23:02 2008 +++ ZendEngine2/zend_strtod.c Sun Jul 27 11:29:59 2008 @@ -89,7 +89,7 @@ * directly -- and assumed always to succeed. */ -/* $Id: zend_strtod.c,v 1.37 2008/03/26 14:23:02 scottmac Exp $ */ +/* $Id: zend_strtod.c,v 1.38 2008/07/27 11:29:59 dmitry Exp $ */ #include #include @@ -991,9 +991,9 @@ static double ulp (double _x) /* {{{ */ { - _double x; + volatile _double x; register Long L; - _double a; + volatile _double a; value(x) = _x; L = (word0(x) & Exp_mask) - (P-1)*Exp_msk1; @@ -1035,7 +1035,7 @@ { ULong *xa, *xa0, w, y, z; int k; - _double d; + volatile _double d; #ifdef VAX ULong d0, d1; #else @@ -1101,7 +1101,7 @@ Bigint *b; int de, i, k; ULong *x, y, z; - _double d; + volatile _double d; #ifdef VAX ULong d0, d1; #endif @@ -1223,7 +1223,7 @@ static double ratio (Bigint *a, Bigint *b) /* {{{ */ { - _double da, db; + volatile _double da, db; int k, ka, kb; value(da) = b2d(a, &ka); @@ -1492,7 +1492,7 @@ Bigint *b, *b1, *delta, *mlo, *mhi, *S, *tmp; double ds; char *s, *s0; - _double d, d2, eps; + volatile _double d, d2, eps; value(d) = _d; @@ -2056,7 +2056,7 @@ e, e1, esign, i, j, k, nd, nd0, nf, nz, nz0, sign; CONST char *s, *s0, *s1; double aadj, aadj1, adj; - _double rv, rv0; + volatile _double rv, rv0; Long L; ULong y, z; Bigint *bb, *bb1, *bd, *bd0, *bs, *delta, *tmp; -- Zend Engine CVS Mailing List (http://cvs.php.net/) -- Stanislav Malyshev, Zend Software Architect stas@zend.com http://www.zend.com/ (408)253-8829 MSN: stas@zend.com --- ## #39417 — Jani Taskinen — 2008-07-28T19:55:27+00:00 URL: https://externals.io/message/39415#39417 · In reply to: #39415 Stanislav Malyshev kirjoitti: > Hi! > > I wanted to ask people here about this patch. See history in > http://bugs.php.net/bug.php?id=43487 but basically there's some gcc out > there that miscompiles zend_strtod.c. We can fix it, probably at some > marginal performance cost, but the question is - should we? It's > pre-release compiler and not in the latest version. The problem was experienced by 5 persons at least. "Fixing" it would cost everybody, not fixing propably very marginal group using out-dated and buggy gcc.. > So can anyone using non-prerelease gcc of any recent version - or > non-gcc compiler even - reproduce this? Should we keep the change or > just tell people "use working compiler"? It was reported to happen with GCC 4.2.1..but is that recent enough? I would go with that "Get a working compiler" option..but you know me.. :D --Jani --- ## #39418 — Nuno Lopes — 2008-07-28T20:48:48+00:00 URL: https://externals.io/message/39415#39418 · In reply to: #39415 I already expressed my opinion.. If you know what's the buggy gcc version, just fail at configure time if it's present. Nuno > Hi! > > I wanted to ask people here about this patch. See history in > http://bugs.php.net/bug.php?id=43487 but basically there's some gcc out > there that miscompiles zend_strtod.c. We can fix it, probably at some > marginal performance cost, but the question is - should we? It's pre-release > compiler and not in the latest version. > > So can anyone using non-prerelease gcc of any recent version - or non-gcc > compiler even - reproduce this? Should we keep the change or just tell > people "use working compiler"? > > -------- Original Message -------- > Subject: [ZEND-ENGINE-CVS] cvs: ZendEngine2 / zend_strtod.c > Date: Sun, 27 Jul 2008 11:29:59 -0000 > From: Dmitry Stogov > To: zend-engine-cvs@lists.php.net > > dmitry Sun Jul 27 11:29:59 2008 UTC > > Modified files: > /ZendEngine2 zend_strtod.c > Log: > Fix for bug #43487 (Wrong conversion of float to string) > > > http://cvs.php.net/viewvc.cgi/ZendEngine2/zend_strtod.c?r1=1.37&r2=1.38&diff_format=u > Index: ZendEngine2/zend_strtod.c > diff -u ZendEngine2/zend_strtod.c:1.37 ZendEngine2/zend_strtod.c:1.38 > --- ZendEngine2/zend_strtod.c:1.37 Wed Mar 26 14:23:02 2008 > +++ ZendEngine2/zend_strtod.c Sun Jul 27 11:29:59 2008 > @@ -89,7 +89,7 @@ > * directly -- and assumed always to succeed. > */ > > -/* $Id: zend_strtod.c,v 1.37 2008/03/26 14:23:02 scottmac Exp $ */ > +/* $Id: zend_strtod.c,v 1.38 2008/07/27 11:29:59 dmitry Exp $ */ > > #include > #include > @@ -991,9 +991,9 @@ > > static double ulp (double _x) /* {{{ */ > { > - _double x; > + volatile _double x; > register Long L; > - _double a; > + volatile _double a; > > value(x) = _x; > L = (word0(x) & Exp_mask) - (P-1)*Exp_msk1; > @@ -1035,7 +1035,7 @@ > { > ULong *xa, *xa0, w, y, z; > int k; > - _double d; > + volatile _double d; > #ifdef VAX > ULong d0, d1; > #else > @@ -1101,7 +1101,7 @@ > Bigint *b; > int de, i, k; > ULong *x, y, z; > - _double d; > + volatile _double d; > #ifdef VAX > ULong d0, d1; > #endif > @@ -1223,7 +1223,7 @@ > > static double ratio (Bigint *a, Bigint *b) /* {{{ */ > { > - _double da, db; > + volatile _double da, db; > int k, ka, kb; > > value(da) = b2d(a, &ka); > @@ -1492,7 +1492,7 @@ > Bigint *b, *b1, *delta, *mlo, *mhi, *S, *tmp; > double ds; > char *s, *s0; > - _double d, d2, eps; > + volatile _double d, d2, eps; > > value(d) = _d; > > @@ -2056,7 +2056,7 @@ > e, e1, esign, i, j, k, nd, nd0, nf, nz, nz0, sign; > CONST char *s, *s0, *s1; > double aadj, aadj1, adj; > - _double rv, rv0; > + volatile _double rv, rv0; > Long L; > ULong y, z; > Bigint *bb, *bb1, *bd, *bd0, *bs, *delta, *tmp; > > > > -- > Zend Engine CVS Mailing List (http://cvs.php.net/) > > > > -- > Stanislav Malyshev, Zend Software Architect > stas@zend.com http://www.zend.com/ > (408)253-8829 MSN: stas@zend.com --- ## #39419 — Stanislav Malyshev — 2008-07-28T21:11:21+00:00 URL: https://externals.io/message/39415#39419 · In reply to: #39417 Hi! > The problem was experienced by 5 persons at least. How many persons is not very important, what important is how many different compilers they used and how recent those are, in other words - how frequently you could hit this bug in the wild. If it's just some pre-release of Mandrake - then it's probably not that important. If it's some widely used distro - then we'd better be on the safe side, just in case, or at least put an error message into the code. > It was reported to happen with GCC 4.2.1..but is that recent enough? 4.2.1 prerelease as it seems. 4.1.2 doesn't seem to have this problem. I'm not sure I have any machine with 4.2.1 around, but probably somebody on the list does :) -- Stanislav Malyshev, Zend Software Architect stas@zend.com http://www.zend.com/ (408)253-8829 MSN: stas@zend.com --- ## #39420 — Alan Knowles — 2008-07-28T23:34:31+00:00 URL: https://externals.io/message/39415#39420 · In reply to: #39418 Nuno Lopes wrote: > I already expressed my opinion.. If you know what's the buggy gcc > version, just fail at configure time if it's present. > With a notice and reference to the bug number - so If people are stuck with that compiler they can see a work around... Regards Alan > Nuno > > > > > > […] --- ## #39421 — crrodriguez@suse.de — 2008-07-29T00:57:09+00:00 URL: https://externals.io/message/39415#39421 · In reply to: #39419 Stanislav Malyshev escribió: > 4.2.1 prerelease as it seems. 4.1.2 doesn't seem to have this problem. > I'm not sure I have any machine with 4.2.1 around, but probably somebody > on the list does :) No such problem with gcc --version gcc (GCC) 4.2.1 (SUSE Linux) -- "A computer is like an Old Testament god, with a lot of rules and no mercy. " Cristian Rodríguez R. Platform/OpenSUSE - Core Services SUSE LINUX Products GmbH Research & Development http://www.opensuse.org/ --- ## #39427 — Hartmut Holzgraefe — 2008-07-29T07:20:42+00:00 URL: https://externals.io/message/39415#39427 · In reply to: #39418 Nuno Lopes wrote: > I already expressed my opinion.. If you know what's the buggy gcc > version, just fail at configure time if it's present. but with a test for the actual buggy behavior, not just the gcc version i'd assume? (thing "regression" ;) -- Hartmut Holzgraefe, MySQL Regional Support Manager EMEA Sun Microsystems GmbH, Sonnenallee 1, 85551 Kirchheim-Heimstetten Amtsgericht Muenchen: HRB161028 Geschaeftsfuehrer: Thomas Schroeder, Wolfgang Engels, Dr. Roland Boemer Vorsitzender des Aufsichtsrates: Martin Haering --- ## #39434 — Arnaud Le Blanc — 2008-07-29T14:07:06+00:00 URL: https://externals.io/message/39415#39434 · In reply to: #39419 On Monday 28 July 2008 23:11:21 Stanislav Malyshev wrote: > Hi! > > > […] > > How many persons is not very important, what important is how many > different compilers they used and how recent those are, in other words - > how frequently you could hit this bug in the wild. If it's just some > pre-release of Mandrake - then it's probably not that important. If it's > some widely used distro - then we'd better be on the safe side, just in > case, or at least put an error message into the code. > > > […] > > 4.2.1 prerelease as it seems. 4.1.2 doesn't seem to have this problem. > I'm not sure I have any machine with 4.2.1 around, but probably somebody > on the list does :) > -- > Stanislav Malyshev, Zend Software Architect > stas@zend.com http://www.zend.com/ > (408)253-8829 MSN: stas@zend.com > > -- > > > > > Hi, On Debian with 4.1.3, 4.2.4, and 4.3.1, not reproducible. On Mandriva with 4.2.2 and 4.2.3 this is reproducible. Regards, Arnaud