From: drh <drh@noemail.net>
Date: Wed, 3 Mar 2010 15:18:38 +0000 (+0000)
Subject: Factor out constant expressions in sqlite3GetVarint() to work around
X-Git-Tag: version-3.7.2~566
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=0b2864cb34ea9cc23c78ac92960d88214f54e67f;p=thirdparty%2Fsqlite.git

Factor out constant expressions in sqlite3GetVarint() to work around
nuisance warning messages from the RVT compiler.

FossilOrigin-Name: 83e47ca0069de259e98798d84d88301a5b4b6d2e
---

diff --git a/manifest b/manifest
index 11feacd3f8..a6d89f82f9 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,8 @@
-C Modify\sthe\scommand\sline\stool\sto\sdisable\sall\smutexes.\sThe\scommand\sline\stool\sis\ssingle-threaded.
-D 2010-03-03T07:23:13
+-----BEGIN PGP SIGNED MESSAGE-----
+Hash: SHA1
+
+C Factor\sout\sconstant\sexpressions\sin\ssqlite3GetVarint()\sto\swork\saround\nnuisance\swarning\smessages\sfrom\sthe\sRVT\scompiler.
+D 2010-03-03T15:18:38
 F Makefile.arm-wince-mingw32ce-gcc fcd5e9cd67fe88836360bb4f9ef4cb7f8e2fb5a0
 F Makefile.in 4f2f967b7e58a35bb74fb7ec8ae90e0f4ca7868b
 F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
@@ -209,7 +212,7 @@ F src/tokenize.c 25ceb0f0a746ea1d0f9553787f3f0a56853cfaeb
 F src/trigger.c 340c9eca0fb24b1197468d96ba059f867c9834c7
 F src/update.c c0dc6b75ad28b76b619042d934f337b02acee208
 F src/utf.c dad16adcc0c35ef2437dca125a4b07419d361052
-F src/util.c 0a28d634d41031be63da19cc7cdfbc4a7e0bfea6
+F src/util.c 23c2e2a05ae1a2a8b848e6b145cc506d8f9ff223
 F src/vacuum.c b1d542c8919d4d11119f78069e1906a1ad07e0ee
 F src/vdbe.c 8b705e48cf4b6d0493ad0f109763d60c1b429487
 F src/vdbe.h 471f6a3dcec4817ca33596fe7f6654d56c0e75f3
@@ -792,7 +795,14 @@ F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
 F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P 9daf4e7d07769f25b3a579d80e7fada4e52344b1
-R 859cf9b209862d32a71f4ee0365fe351
-U dan
-Z fafbabd08193cd28bca0509d29b6e94b
+P 00e5679047a0a96dc4396aae5e061909faf3b81d
+R d5279b0f0440c162ac13b57ad638ff10
+U drh
+Z 7a56c2200dee81fc4fcb29db9cc92e1e
+-----BEGIN PGP SIGNATURE-----
+Version: GnuPG v1.4.6 (GNU/Linux)
+
+iD8DBQFLjn3XoxKgR168RlERAk+wAKCIrMiXPhEryGElvlKVi8+iIR5PHACfQJjd
+3YnU+1KeqqESzTSJszdAYpA=
+=A+ES
+-----END PGP SIGNATURE-----
diff --git a/manifest.uuid b/manifest.uuid
index aa72821de6..6536a2bd1a 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-00e5679047a0a96dc4396aae5e061909faf3b81d
\ No newline at end of file
+83e47ca0069de259e98798d84d88301a5b4b6d2e
\ No newline at end of file
diff --git a/src/util.c b/src/util.c
index 647ecb9029..e76ed879ee 100644
--- a/src/util.c
+++ b/src/util.c
@@ -650,6 +650,19 @@ int sqlite3PutVarint32(unsigned char *p, u32 v){
   return sqlite3PutVarint(p, v);
 }
 
+/*
+** Bitmasks used by sqlite3GetVarint().  These precomputed constants
+** are defined here rather than simply putting the constant expressions
+** inline in order to work around bugs in the RVT compiler.
+**
+** SLOT_2_0     A mask for  (0x7f<<14) | 0x7f
+**
+** SLOT_4_2_0   A mask for  (0x7f<<28) | SLOT_2_0
+*/
+#define SLOT_2_0     0x001fc07f
+#define SLOT_4_2_0   0xf01fc07f
+
+
 /*
 ** Read a 64-bit variable-length integer from memory starting at p[0].
 ** Return the number of bytes read.  The value is stored in *v.
@@ -677,13 +690,17 @@ u8 sqlite3GetVarint(const unsigned char *p, u64 *v){
     return 2;
   }
 
+  /* Verify that constants are precomputed correctly */
+  assert( SLOT_2_0 == ((0x7f<<14) | (0x7f)) );
+  assert( SLOT_4_2_0 == ((0xf<<28) | (0x7f<<14) | (0x7f)) );
+
   p++;
   a = a<<14;
   a |= *p;
   /* a: p0<<14 | p2 (unmasked) */
   if (!(a&0x80))
   {
-    a &= (0x7f<<14)|(0x7f);
+    a &= SLOT_2_0;
     b &= 0x7f;
     b = b<<7;
     a |= b;
@@ -692,14 +709,14 @@ u8 sqlite3GetVarint(const unsigned char *p, u64 *v){
   }
 
   /* CSE1 from below */
-  a &= (0x7f<<14)|(0x7f);
+  a &= SLOT_2_0;
   p++;
   b = b<<14;
   b |= *p;
   /* b: p1<<14 | p3 (unmasked) */
   if (!(b&0x80))
   {
-    b &= (0x7f<<14)|(0x7f);
+    b &= SLOT_2_0;
     /* moved CSE1 up */
     /* a &= (0x7f<<14)|(0x7f); */
     a = a<<7;
@@ -713,7 +730,7 @@ u8 sqlite3GetVarint(const unsigned char *p, u64 *v){
   /* 1:save off p0<<21 | p1<<14 | p2<<7 | p3 (masked) */
   /* moved CSE1 up */
   /* a &= (0x7f<<14)|(0x7f); */
-  b &= (0x7f<<14)|(0x7f);
+  b &= SLOT_2_0;
   s = a;
   /* s: p0<<14 | p2 (masked) */
 
@@ -746,7 +763,7 @@ u8 sqlite3GetVarint(const unsigned char *p, u64 *v){
   {
     /* we can skip this cause it was (effectively) done above in calc'ing s */
     /* b &= (0x7f<<28)|(0x7f<<14)|(0x7f); */
-    a &= (0x7f<<14)|(0x7f);
+    a &= SLOT_2_0;
     a = a<<7;
     a |= b;
     s = s>>18;
@@ -760,8 +777,8 @@ u8 sqlite3GetVarint(const unsigned char *p, u64 *v){
   /* a: p2<<28 | p4<<14 | p6 (unmasked) */
   if (!(a&0x80))
   {
-    a &= (0x1f<<28)|(0x7f<<14)|(0x7f);
-    b &= (0x7f<<14)|(0x7f);
+    a &= SLOT_4_2_0;
+    b &= SLOT_2_0;
     b = b<<7;
     a |= b;
     s = s>>11;
@@ -770,14 +787,14 @@ u8 sqlite3GetVarint(const unsigned char *p, u64 *v){
   }
 
   /* CSE2 from below */
-  a &= (0x7f<<14)|(0x7f);
+  a &= SLOT_2_0;
   p++;
   b = b<<14;
   b |= *p;
   /* b: p3<<28 | p5<<14 | p7 (unmasked) */
   if (!(b&0x80))
   {
-    b &= (0x1f<<28)|(0x7f<<14)|(0x7f);
+    b &= SLOT_4_2_0;
     /* moved CSE2 up */
     /* a &= (0x7f<<14)|(0x7f); */
     a = a<<7;
@@ -794,7 +811,7 @@ u8 sqlite3GetVarint(const unsigned char *p, u64 *v){
 
   /* moved CSE2 up */
   /* a &= (0x7f<<29)|(0x7f<<15)|(0xff); */
-  b &= (0x7f<<14)|(0x7f);
+  b &= SLOT_2_0;
   b = b<<8;
   a |= b;