From: drh <>
Date: Sun, 1 Mar 2026 20:22:08 +0000 (+0000)
Subject: Simplified rounding logic in sqlite3Fp10Convert2().
X-Git-Tag: version-3.52.0~20
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=83de60bd7ba2e101e1c33ae34d1339125e2b453d;p=thirdparty%2Fsqlite.git

Simplified rounding logic in sqlite3Fp10Convert2().

FossilOrigin-Name: 8ac63ebc5c04ba555bbf0d878a70e25deba5fcc75ff44c464600b92c27e5dcb0
---

diff --git a/manifest b/manifest
index fea4c94d67..51a63a8cf2 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Code\schanges\sin\ssqlite3Fp10Convert2()\sfor\seasier\smaintenance.\s\sDoes\snot\naffect\sthe\sgenerated\smachine\scode.
-D 2026-02-28T20:22:10.499
+C Simplified\srounding\slogic\sin\ssqlite3Fp10Convert2().
+D 2026-03-01T20:22:08.292
 F .fossil-settings/binary-glob 61195414528fb3ea9693577e1980230d78a1f8b0a54c78cf1b9b24d0a409ed6a x
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
@@ -803,7 +803,7 @@ F src/trigger.c a40440614bdf523090cc07223f4878f7e3c892bcd1a13afe18f90190daa5945d
 F src/update.c 3e5e7ff66fa19ebe4d1b113d480639a24cc1175adbefabbd1a948a07f28e37cf
 F src/upsert.c 215328c3f91623c520ec8672c44323553f12caeb4f01b1090ebdca99fdf7b4f1
 F src/utf.c 7267c3fb9e2467020507601af3354c2446c61f444387e094c779dccd5ca62165
-F src/util.c 367d14ee23de8f5dd77a5a57ba0eba7f27108feb32750fff191e04317c36a19b
+F src/util.c eccfa8b3b414bb64c6543421c9fd10e5f07e103baae36427a273a9131527694c
 F src/vacuum.c d3d35d8ae893d419ade5fa196d761a83bddcbb62137a1a157ae751ef38b26e82
 F src/vdbe.c 5328c99dd256ee8132383565a86e253543a85daccfd7477c52f20bac6b385a7f
 F src/vdbe.h 966d0677a540b7ea6549b7c4e1312fc0d830fce3a235a58c801f2cc31cf5ecf9
@@ -2195,8 +2195,8 @@ F tool/warnings-clang.sh bbf6a1e685e534c92ec2bfba5b1745f34fb6f0bc2a362850723a9ee
 F tool/warnings.sh d924598cf2f55a4ecbc2aeb055c10bd5f48114793e7ba25f9585435da29e7e98
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
 F tool/winmain.c 00c8fb88e365c9017db14c73d3c78af62194d9644feaf60e220ab0f411f3604c
-P 0780bce854b962fb2d4a1a19c55c9b5790a9669f26e1ff8b5f1f1733cfc647e0
-R 31f541b8320013c073025618707ba1b2
+P 21c8fc7100e23b632b77934cbbafb98dfd3e6e73bab702446ef6345b378c9d36
+R af3efb8f8f323da927b8fb2503c5d89e
 U drh
-Z 27e14806d84c6d235e25b0158b899e3c
+Z 73d1b37c301d10277342aa84d5761b61
 # Remove this line to create a well-formed Fossil manifest.
diff --git a/manifest.uuid b/manifest.uuid
index 485e417c4b..df2b0bf426 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-21c8fc7100e23b632b77934cbbafb98dfd3e6e73bab702446ef6345b378c9d36
+8ac63ebc5c04ba555bbf0d878a70e25deba5fcc75ff44c464600b92c27e5dcb0
diff --git a/src/util.c b/src/util.c
index 1ac2553025..071029173d 100644
--- a/src/util.c
+++ b/src/util.c
@@ -668,9 +668,8 @@ static void sqlite3Fp2Convert10(u64 m, int e, int n, u64 *pD, int *pP){
 */
 static double sqlite3Fp10Convert2(u64 d, int p){
   u64 out;
-  int b;
   int e1;
-  int e2;
+  int lz;
   int lp;
   int x;
   u64 h;
@@ -683,27 +682,26 @@ static double sqlite3Fp10Convert2(u64 d, int p){
   if( p>POWERSOF10_LAST ){
     return INFINITY;
   }
-  b = 64 - countLeadingZeros(d);
+  lz = countLeadingZeros(d);
   lp = pwr10to2(p);
-  e1 = 53 - b - lp;
+  e1 = lz - (lp + 11);
   if( e1>1074 ){
-    if( -(b + lp) >= 1077 ) return 0.0;
+    if( e1>=1130 ) return 0.0;
     e1 = 1074;
   }
-  e2 = e1 - (64-b);
-  h = sqlite3Multiply128(d<<(64-b), powerOfTen(p));
-  x = -(e2 + lp + 3);
+  h = sqlite3Multiply128(d<<lz, powerOfTen(p));
+  x = lz - (e1 + lp + 3);
   assert( x >= 0  );
   assert( x <= 63 );
-  out = (h >> x) | 1;
+  out = h >> x;
   if( out >= U64_BIT(55)-2 ){
-    out = (out>>1) | 1;
+    out >>= 1;
     e1--;
   }
   if( e1<=(-972) ){
     return INFINITY;
   }
-  out = (out + 1) >> 2;
+  out = (out + 2) >> 2;
   if( (out & U64_BIT(52))!=0 ){
     out = (out & ~U64_BIT(52)) | ((u64)(1075-e1)<<52);
   }