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Factor out constant expressions in sqlite3GetVarint() to work around

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nuisance warning messages from the RVT compiler.

FossilOrigin-Name: 83e47ca0069de259e98798d84d88301a5b4b6d2e
This commit is contained in:
drh
2010-03-03 15:18:38 +00:00
parent 0f831771c3
commit 0b2864cb34
3 changed files with 45 additions and 18 deletions
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37
src/util.c
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@@ -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;