From 0b5e944480c7054582f4ebc7526c0bf2ab3f3a01 Mon Sep 17 00:00:00 2001
From: drh <>
Date: Tue, 17 Feb 2026 00:37:12 +0000
Subject: [PATCH] Faster conversion of integers to text, by converting two
 digits at a time.

FossilOrigin-Name: 90300e02f0de45b57d53976cae72928b3e56532d90b8b8cdc988e14762777930
---
 manifest      | 12 ++++----
 manifest.uuid |  2 +-
 src/util.c    | 81 ++++++++++++++++++++++++++++++---------------------
 3 files changed, 55 insertions(+), 40 deletions(-)

diff --git a/manifest b/manifest
index d472bbb667..204e1e699f 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Simplifications\sto\ssqlite3AtoF(),\sresulting\sin\sslightly\sfaster\sperformance\nand\sslightly\ssmaller\ssize.
-D 2026-02-16T23:52:51.130
+C Faster\sconversion\sof\sintegers\sto\stext,\sby\sconverting\stwo\sdigits\sat\sa\stime.
+D 2026-02-17T00:37:12.629
 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 06313141ca1d9cf6a80961a6a2084e1f682dfecc741b5c2f527f257f47d61b0a
+F src/util.c a5d1c01e9ac773b2a783db45169fc7674ed2f6e05dadc88052702273ec94928c
 F src/vacuum.c d3d35d8ae893d419ade5fa196d761a83bddcbb62137a1a157ae751ef38b26e82
 F src/vdbe.c 5328c99dd256ee8132383565a86e253543a85daccfd7477c52f20bac6b385a7f
 F src/vdbe.h 966d0677a540b7ea6549b7c4e1312fc0d830fce3a235a58c801f2cc31cf5ecf9
@@ -2194,8 +2194,8 @@ F tool/warnings-clang.sh bbf6a1e685e534c92ec2bfba5b1745f34fb6f0bc2a362850723a9ee
 F tool/warnings.sh d924598cf2f55a4ecbc2aeb055c10bd5f48114793e7ba25f9585435da29e7e98
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
 F tool/winmain.c 00c8fb88e365c9017db14c73d3c78af62194d9644feaf60e220ab0f411f3604c
-P a4540582b5b704af13b570b3dc609dbacada719302372a038cf74eee3688d5e7
-R b9f18dca12593a3b130cb73988b798a1
+P 6b9ab641763bc1620a01beec71589506b3b0827bff1c6cd98a5d17c6070050b3
+R 576ef9ddbda75f09f3eafbf37da65a3c
 U drh
-Z c47bffdb8f799c234ea9ad61d838f43a
+Z 308ac5fa17afdaa5c0816c0d53c230b6
 # Remove this line to create a well-formed Fossil manifest.
diff --git a/manifest.uuid b/manifest.uuid
index 5b11965ef0..586fb1f5fc 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-6b9ab641763bc1620a01beec71589506b3b0827bff1c6cd98a5d17c6070050b3
+90300e02f0de45b57d53976cae72928b3e56532d90b8b8cdc988e14762777930
diff --git a/src/util.c b/src/util.c
index 47d6dbee91..4bed8dda8f 100644
--- a/src/util.c
+++ b/src/util.c
@@ -839,7 +839,25 @@ int sqlite3AtoF(const char *z, double *pResult){
 #pragma warning(default : 4756)
 #endif
 
-
+/*
+** Digit pairs used to convert a U64 or I64 into text, two digits
+** at a time.
+*/
+static const union {
+  char a[200];
+  short int forceAlignment;
+} sqlite3DigitPairs = {
+  "00010203040506070809"
+  "10111213141516171819"
+  "20212223242526272829"
+  "30313233343536373839"
+  "40414243444546474849"
+  "50515253545556575859"
+  "60616263646566676869"
+  "70717273747576777879"
+  "80818283848586878889"
+  "90919293949596979899"
+};
 
 
 /*
@@ -853,23 +871,35 @@ int sqlite3AtoF(const char *z, double *pResult){
 int sqlite3Int64ToText(i64 v, char *zOut){
   int i;
   u64 x;
-  char zTemp[22];
-  if( v<0 ){
-    x = (v==SMALLEST_INT64) ? ((u64)1)<<63 : (u64)-v;
-  }else{
+  union {
+    char a[23];
+    u16 forceAlignment;
+  } u;
+  if( v>0 ){
     x = v;
+  }else if( v==0 ){
+    zOut[0] = '0';
+    zOut[1] = 0;
+    return 1;
+  }else{
+    x = (v==SMALLEST_INT64) ? ((u64)1)<<63 : (u64)-v;
   }
-  i = sizeof(zTemp)-2;
-  zTemp[sizeof(zTemp)-1] = 0;
-  while( 1 /*exit-by-break*/ ){
-    zTemp[i] = (x%10) + '0';
-    x = x/10;
-    if( x==0 ) break;
-    i--;
-  };
-  if( v<0 ) zTemp[--i] = '-';
-  memcpy(zOut, &zTemp[i], sizeof(zTemp)-i);
-  return sizeof(zTemp)-1-i;
+  i = sizeof(u.a)-1;
+  u.a[i] = 0;
+  while( x>=10 ){
+    int kk = (x%100)*2;
+    assert( TWO_BYTE_ALIGNMENT(&sqlite3DigitPairs.a[kk]) );
+    assert( TWO_BYTE_ALIGNMENT(&u.a[i-2]) );
+    *(u16*)(&u.a[i-2]) = *(u16*)&sqlite3DigitPairs.a[kk];
+    i -= 2;
+    x /= 100;
+  }
+  if( x ){
+    u.a[--i] = x + '0';
+  }
+  if( v<0 ) u.a[--i] = '-';
+  memcpy(zOut, &u.a[i], sizeof(u.a)-i);
+  return sizeof(u.a)-1-i;
 }
 
 /*
@@ -1184,25 +1214,10 @@ void sqlite3FpDecode(FpDecode *p, double r, int iRound, int mxRound){
   i = sizeof(p->zBuf)-1;
   assert( v>0 );
   while( v>=10 ){
-    static const union {
-      char a[200];
-      short int forAlignment;
-    } dig = {
-      "00010203040506070809"
-      "10111213141516171819"
-      "20212223242526272829"
-      "30313233343536373839"
-      "40414243444546474849"
-      "50515253545556575859"
-      "60616263646566676869"
-      "70717273747576777879"
-      "80818283848586878889"
-      "90919293949596979899"
-    };
     int kk = (v%100)*2;
-    assert( TWO_BYTE_ALIGNMENT(&dig.a[kk]) );
+    assert( TWO_BYTE_ALIGNMENT(&sqlite3DigitPairs.a[kk]) );
     assert( TWO_BYTE_ALIGNMENT(&p->zBuf[i-1]) );
-    *(u16*)(&p->zBuf[i-1]) = *(u16*)&dig.a[kk];
+    *(u16*)(&p->zBuf[i-1]) = *(u16*)&sqlite3DigitPairs.a[kk];
     i -= 2;
     v /= 100;
   }
-- 
2.47.3