From: drh <>
Date: Thu, 19 Oct 2023 13:35:22 +0000 (+0000)
Subject: Simplification to sqlite3GetVarint32() to avoid confusing gcov.
X-Git-Tag: version-3.44.0~87
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=058838579962fd4831ef2f4115da9c2d1e1972b1;p=thirdparty%2Fsqlite.git

Simplification to sqlite3GetVarint32() to avoid confusing gcov.

FossilOrigin-Name: 89862c51ad9715bedf5b029db484602e740f0db7404970d482ce503c1b9a0ed2
---

diff --git a/manifest b/manifest
index 722e3176eb..0d2df1c196 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Fix\san\serror\sin\sa\sdebugging\sroutine\sused\sinside\sof\stestcase().\s\sDoes\snot\nappear\sin\sproduction.\s\sProblem\sdiscovered\sby\sscan-build.
-D 2023-10-19T13:00:41.210
+C Simplification\sto\ssqlite3GetVarint32()\sto\savoid\sconfusing\sgcov.
+D 2023-10-19T13:35:22.869
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -786,7 +786,7 @@ F src/trigger.c 5286019b152f622a38900284109e4aae1e5f566deb7ad9ba7e931f0660771f32
 F src/update.c 6904814dd62a7a93bbb86d9f1419c7f134a9119582645854ab02b36b676d9f92
 F src/upsert.c fa125a8d3410ce9a97b02cb50f7ae68a2476c405c76aa692d3acf6b8586e9242
 F src/utf.c ee39565f0843775cc2c81135751ddd93eceb91a673ea2c57f61c76f288b041a0
-F src/util.c e87f66258c37f87724f46e849572c3ece4c74ef5614ba41eb221e98f0dbc95de
+F src/util.c b22cc9f203a8c0b9ee5338a67f8860347d14845864c10248bebe84518a781677
 F src/vacuum.c 604fcdaebe76f3497c855afcbf91b8fa5046b32de3045bab89cc008d68e40104
 F src/vdbe.c 300b1ac9339a5b7db9ccd48c1a13c3d71722da13352a38ee042ca0a399b4dd7e
 F src/vdbe.h 41485521f68e9437fdb7ec4a90f9d86ab294e9bb8281e33b235915e29122cfc0
@@ -2133,8 +2133,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 8b6fffb552c30f9cbf7102c2e26a7b486c4c9edd9f494d803de7004db3018277
-R 4aca618a679e8419cd172eea36c7911d
+P c6c9d7ed6dbc71b998aeaaa1bdeb36b1bb9b902f9d6088ad36db29f8ea8b7ef6
+R 2d6d822f4f032385b3965cf0ea67965f
 U drh
-Z 1bb915481df03cc399372db91bbfa483
+Z 984079d068cf9e399e4e739b1e691268
 # Remove this line to create a well-formed Fossil manifest.
diff --git a/manifest.uuid b/manifest.uuid
index 0e3a256c2b..8b7d689343 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-c6c9d7ed6dbc71b998aeaaa1bdeb36b1bb9b902f9d6088ad36db29f8ea8b7ef6
\ No newline at end of file
+89862c51ad9715bedf5b029db484602e740f0db7404970d482ce503c1b9a0ed2
\ No newline at end of file
diff --git a/src/util.c b/src/util.c
index 58591590dc..e9c7cccb03 100644
--- a/src/util.c
+++ b/src/util.c
@@ -1367,121 +1367,32 @@ u8 sqlite3GetVarint(const unsigned char *p, u64 *v){
 ** this function assumes the single-byte case has already been handled.
 */
 u8 sqlite3GetVarint32(const unsigned char *p, u32 *v){
-  u32 a,b;
+  u64 v64;
+  u8 n;
 
-  /* The 1-byte case.  Overwhelmingly the most common.  Handled inline
-  ** by the getVarin32() macro */
-  a = *p;
-  /* a: p0 (unmasked) */
-#ifndef getVarint32
-  if (!(a&0x80))
-  {
-    /* Values between 0 and 127 */
-    *v = a;
-    return 1;
-  }
-#endif
+  /* Assume that the single-byte case has already been handled by
+  ** the getVarint32() macro */
+  assert( (p[0] & 0x80)!=0 );
 
-  /* The 2-byte case */
-  p++;
-  b = *p;
-  /* b: p1 (unmasked) */
-  if (!(b&0x80))
-  {
-    /* Values between 128 and 16383 */
-    a &= 0x7f;
-    a = a<<7;
-    *v = a | b;
+  if( (p[1] & 0x80)==0 ){
+    /* This is the two-byte case */
+    *v = ((p[0]&0x7f)<<7) | p[1];
     return 2;
   }
-
-  /* The 3-byte case */
-  p++;
-  a = a<<14;
-  a |= *p;
-  /* a: p0<<14 | p2 (unmasked) */
-  if (!(a&0x80))
-  {
-    /* Values between 16384 and 2097151 */
-    a &= (0x7f<<14)|(0x7f);
-    b &= 0x7f;
-    b = b<<7;
-    *v = a | b;
+  if( (p[2] & 0x80)==0 ){
+    /* This is the three-byte case */
+    *v = ((p[0]&0x7f)<<14) | ((p[1]&0x7f)<<7) | p[2];
     return 3;
   }
-
-  /* A 32-bit varint is used to store size information in btrees.
-  ** Objects are rarely larger than 2MiB limit of a 3-byte varint.
-  ** A 3-byte varint is sufficient, for example, to record the size
-  ** of a 1048569-byte BLOB or string.
-  **
-  ** We only unroll the first 1-, 2-, and 3- byte cases.  The very
-  ** rare larger cases can be handled by the slower 64-bit varint
-  ** routine.
-  */
-#if 1
-  {
-    u64 v64;
-    u8 n;
-
-    n = sqlite3GetVarint(p-2, &v64);
-    assert( n>3 && n<=9 );
-    if( (v64 & SQLITE_MAX_U32)!=v64 ){
-      *v = 0xffffffff;
-    }else{
-      *v = (u32)v64;
-    }
-    return n;
-  }
-
-#else
-  /* For following code (kept for historical record only) shows an
-  ** unrolling for the 3- and 4-byte varint cases.  This code is
-  ** slightly faster, but it is also larger and much harder to test.
-  */
-  p++;
-  b = b<<14;
-  b |= *p;
-  /* b: p1<<14 | p3 (unmasked) */
-  if (!(b&0x80))
-  {
-    /* Values between 2097152 and 268435455 */
-    b &= (0x7f<<14)|(0x7f);
-    a &= (0x7f<<14)|(0x7f);
-    a = a<<7;
-    *v = a | b;
-    return 4;
-  }
-
-  p++;
-  a = a<<14;
-  a |= *p;
-  /* a: p0<<28 | p2<<14 | p4 (unmasked) */
-  if (!(a&0x80))
-  {
-    /* Values  between 268435456 and 34359738367 */
-    a &= SLOT_4_2_0;
-    b &= SLOT_4_2_0;
-    b = b<<7;
-    *v = a | b;
-    return 5;
-  }
-
-  /* We can only reach this point when reading a corrupt database
-  ** file.  In that case we are not in any hurry.  Use the (relatively
-  ** slow) general-purpose sqlite3GetVarint() routine to extract the
-  ** value. */
-  {
-    u64 v64;
-    u8 n;
-
-    p -= 4;
-    n = sqlite3GetVarint(p, &v64);
-    assert( n>5 && n<=9 );
+  /* four or more bytes */
+  n = sqlite3GetVarint(p, &v64);
+  assert( n>3 && n<=9 );
+  if( (v64 & SQLITE_MAX_U32)!=v64 ){
+    *v = 0xffffffff;
+  }else{
     *v = (u32)v64;
-    return n;
   }
-#endif
+  return n;
 }
 
 /*