From: drh <>
Date: Sat, 11 Oct 2025 15:45:47 +0000 (+0000)
Subject: Improvements to the (rarely used) home-grown varients of seriesCeil()
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=11878165f624c756b676c97bdad630870f9f677b;p=thirdparty%2Fsqlite.git

Improvements to the (rarely used) home-grown varients of seriesCeil()
and seriesFloor() based on ideas from
[forum:/forumpost/2025-10-11T12:36:56z|forum post 2025-10-11T12:36:56z].

FossilOrigin-Name: e6b9bfdb6f8f86d4d2891d65fee4274dcbc61c9e998d81f90232153c05788cab
---

diff --git a/ext/misc/series.c b/ext/misc/series.c
index 3e4b635e11..c42a150f81 100644
--- a/ext/misc/series.c
+++ b/ext/misc/series.c
@@ -363,32 +363,39 @@ static sqlite3_uint64 seriesSteps(series_cursor *pCur){
 
 #if defined(SQLITE_ENABLE_MATH_FUNCTIONS) || defined(_WIN32)
 /*
-** Use the ceil() and floor() from the standard math library.
+** Case 1 (the most common case):
+** The standard math library is available so use ceil() and floor() from there.
 */
 static double seriesCeil(double r){ return ceil(r); }
 static double seriesFloor(double r){ return floor(r); }
 #elif defined(__GNUC__) && !defined(SQLITE_DISABLE_INTRINSIC)
 /*
-** If the standard library is not available, try to use GCC builtins
+** Case 2 (2nd most common): Use GCC/Clang builtins
 */
 static double seriesCeil(double r){ return __builtin_ceil(r); }
 static double seriesFloor(double r){ return __builtin_floor(r); }
 #else
 /*
-** If there is no standard library and we are not using GCC, then
-** use an approximation.  Results are not exact, but
-** that is the best we can do.
+** Case 3 (rarely happens): Use home-grown ceil() and floor() routines.
 */
 static double seriesCeil(double r){
-  sqlite3_int64 x = (sqlite3_int64)r;
+  sqlite3_int64 x;
+  if( r!=r ) return r;
+  if( r<=(-4503599627370496.0) ) return r;
+  if( r>=(+4503599627370496.0) ) return r;
+  x = (sqlite3_int64)r;
   if( r==(double)x ) return r;
-  if( r<0.0 ) x++;
+  if( r>(double)x ) x++;
   return (double)x;
 }
 static double seriesFloor(double r){
-  sqlite3_int64 x = (sqlite3_int64)r;
+  sqlite3_int64 x;
+  if( r!=r ) return r;
+  if( r<=(-4503599627370496.0) ) return r;
+  if( r>=(+4503599627370496.0) ) return r;
+  x = (sqlite3_int64)r;
   if( r==(double)x ) return r;
-  if( r>0.0 ) x--;
+  if( r<(double)x ) x--;
   return (double)x;
 }
 #endif
diff --git a/manifest b/manifest
index 7b0a19f292..7e8969aa38 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Provide\salternative\simplementations\sof\sceil()\sand\sfloor()\sto\sthe\ngenerate_series()\sfunction\sso\sthat\sit\swill\sbuild\seven\swhen\sSQLite\sis\ncompiled\susing\s--disable-math.\n[forum:/forumpost/91690fa646|Forum\spost\s91690fa646].
-D 2025-10-10T19:43:03.506
+C Improvements\sto\sthe\s(rarely\sused)\shome-grown\svarients\sof\sseriesCeil()\nand\sseriesFloor()\sbased\son\sideas\sfrom\n[forum:/forumpost/2025-10-11T12:36:56z|forum\spost\s2025-10-11T12:36:56z].
+D 2025-10-11T15:45:47.813
 F .fossil-settings/binary-glob 61195414528fb3ea9693577e1980230d78a1f8b0a54c78cf1b9b24d0a409ed6a x
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
@@ -390,7 +390,7 @@ F ext/misc/regexp.c 548151f3e57506fda678e6a65e85a763f4eece653287e1ad44e167f9485e
 F ext/misc/remember.c add730f0f7e7436cd15ea3fd6a90fd83c3f706ab44169f7f048438b7d6baa69c
 F ext/misc/rot13.c 51ac5f51e9d5fd811db58a9c23c628ad5f333c173f1fc53c8491a3603d38556c
 F ext/misc/scrub.c 2a44b0d44c69584c0580ad2553f6290a307a49df4668941d2812135bfb96a946
-F ext/misc/series.c 85874485c36dff3c6ea5d236f860e31775b709052a017add23ad9503ad286674
+F ext/misc/series.c 4017451155f1b792346f2601f3242132368f670f0a14db11b26170ad6baaeb60
 F ext/misc/sha1.c cb5002148c2661b5946f34561701e9105e9d339b713ec8ac057fd888b196dcb9
 F ext/misc/shathree.c fd22d70620f86a0467acfdd3acd8435d5cb54eb1e2d9ff36ae44e389826993df
 F ext/misc/showauth.c 732578f0fe4ce42d577e1c86dc89dd14a006ab52
@@ -2169,8 +2169,8 @@ F tool/version-info.c 33d0390ef484b3b1cb685d59362be891ea162123cea181cb8e6d2cf6dd
 F tool/warnings-clang.sh bbf6a1e685e534c92ec2bfba5b1745f34fb6f0bc2a362850723a9ee87c1b31a7
 F tool/warnings.sh 1ad0169b022b280bcaaf94a7fa231591be96b514230ab5c98fbf15cd7df842dd
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
-P ea29180797aa4bb25180432e75a372277a6f6e2262906a9e765a3bddf8ca79d7
-R f66b4b2fbe19b1c6a42732547da0b69d
+P 97d6fd2c99578adb6a1e9b879ba5ae5ad798a8ef8f0646bf0102747d52148bff
+R 5a1f1568144db6c07cdc521048596f2c
 U drh
-Z 66d7804c79c61408dbcb9030c8856ced
+Z d9315927b0ee8637a85e19835f7205c7
 # Remove this line to create a well-formed Fossil manifest.
diff --git a/manifest.uuid b/manifest.uuid
index 70fb435072..c54c86da21 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-97d6fd2c99578adb6a1e9b879ba5ae5ad798a8ef8f0646bf0102747d52148bff
+e6b9bfdb6f8f86d4d2891d65fee4274dcbc61c9e998d81f90232153c05788cab