Get the sqlite3VdbeSerialGet() routine to run faster by avoiding the use

of local variables.

FossilOrigin-Name: 8267d82174099e548a4f78d06af0c6324c89b83d

manifest

@@ -1,5 +1,5 @@
-C Change\sa\swhile-loop\sinto\sa\sdo-loop\sin\ssqlite3VdbeSerialPut()\sfor\sa\ssmall\nsize\sreduction\sand\sperformance\simprovement.
+C Get\sthe\ssqlite3VdbeSerialGet()\sroutine\sto\srun\sfaster\sby\savoiding\sthe\suse\nof\slocal\svariables.
-D 2014-08-22T13:22:32.819
+D 2014-08-22T14:34:05.936
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 5eb79e334a5de69c87740edd56af6527dd219308
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -228,7 +228,7 @@ F src/shell.c 728d2226594d356bf4fbdbdfd08538fd78fd06f3
 F src/sqlite.h.in ed9d35990c61f0388ca6405706455c4095310553
 F src/sqlite3.rc 992c9f5fb8285ae285d6be28240a7e8d3a7f2bad
 F src/sqlite3ext.h 886f5a34de171002ad46fae8c36a7d8051c190fc
-F src/sqliteInt.h 641f8fbb65ca2084c8df95b525f6f82c7a1e91ae
+F src/sqliteInt.h 99bd20e5a12dce7ba290e938123d27e87b5eae27
 F src/sqliteLimit.h 164b0e6749d31e0daa1a4589a169d31c0dec7b3d
 F src/status.c 7ac05a5c7017d0b9f0b4bcd701228b784f987158
 F src/table.c 2cd62736f845d82200acfa1287e33feb3c15d62e
@@ -288,7 +288,7 @@ F src/vdbe.c f7f4066e4d6e3858878d76ce9288ea603e12ddf6
 F src/vdbe.h c63fad052c9e7388d551e556e119c0bcf6bebdf8
 F src/vdbeInt.h f5513f2b5ac1e2c5128996c7ea23add256a301df
 F src/vdbeapi.c 7858d7e7cd23267d3fbca18e3a28cce8e0d162a8
-F src/vdbeaux.c 9c9571706aaf0e5debab5b01629ef569cde40920
+F src/vdbeaux.c f83d5c265aea19d2e49ba018beaf99acff934020
 F src/vdbeblob.c 9205ce9d3b064d9600f8418a897fc88b5687d9ac
 F src/vdbemem.c d90a1e8acf8b63dc9d14cbbea12bfec6cec31394
 F src/vdbesort.c f7f5563bf7d4695ca8f3203f3bf9de96d04ed0b3
@@ -1188,7 +1188,10 @@ F tool/vdbe_profile.tcl 67746953071a9f8f2f668b73fe899074e2c6d8c1
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh 0abfd78ceb09b7f7c27c688c8e3fe93268a13b32
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
-P 369c480cda6fa66394b995346bbf51f3298446e1
+P 750bb0a0960606ab24037e0992e9f7a17524cc3e
-R 9c1a6f648ddd3ddf03093ccb99facf2b
+R 6bc6a7681a89a137c23142249db6cf86
+T *branch * experimental
+T *sym-experimental *
+T -sym-trunk *
 U drh
-Z 453b7d6a328e84b291043b75c1b3327d
+Z 612ca7a9b67c6d8d8dbe2b7affb6d3eb

manifest.uuid

@@ -1 +1 @@
-750bb0a0960606ab24037e0992e9f7a17524cc3e
+8267d82174099e548a4f78d06af0c6324c89b83d

src/sqliteInt.h

@@ -153,6 +153,18 @@
 # define SQLITE_PTR_TO_INT(X)  ((int)(X))
 #endif
 
+/*
+** A macro to hint to the compiler that a function should not be
+** inlined.
+*/
+#if defined(__GNUC__)
+#  define SQLITE_NOINLINE  __attribute__((noinline))
+#elif defined(_MSC_VER)
+#  define SQLITE_NOINLINE  __declspec(noinline)
+#else
+#  define SQLITE_NOINLINE
+#endif
+
 /*
 ** The SQLITE_THREADSAFE macro must be defined as 0, 1, or 2.
 ** 0 means mutexes are permanently disable and the library is never

src/vdbeaux.c

@@ -2965,14 +2965,55 @@ u32 sqlite3VdbeSerialPut(u8 *buf, Mem *pMem, u32 serial_type){
 /*
 ** Deserialize the data blob pointed to by buf as serial type serial_type
 ** and store the result in pMem.  Return the number of bytes read.
+**
+** This function is implemented as two separate routines for performance.
+** The few cases that require local variables are broken out into a separate
+** routine so that in most cases the overhead of moving the stack pointer
+** is avoided.
 */ 
-u32 sqlite3VdbeSerialGet(
+static u32 SQLITE_NOINLINE serialGet(
   const unsigned char *buf,     /* Buffer to deserialize from */
   u32 serial_type,              /* Serial type to deserialize */
   Mem *pMem                     /* Memory cell to write value into */
 ){
   u64 x;
-  u32 y;
+  u32 y = FOUR_BYTE_UINT(buf);
+  if( serial_type==4 ){
+    pMem->u.i = (i64)*(int*)&y;
+    pMem->flags = MEM_Int;
+    testcase( pMem->u.i<0 );
+    return 4;
+  }
+  x = (((u64)y)<<32)|FOUR_BYTE_UINT(buf+4);
+  if( serial_type==6 ){
+    pMem->u.i = *(i64*)&x;
+    pMem->flags = MEM_Int;
+    testcase( pMem->u.i<0 );
+  }else{
+#if !defined(NDEBUG) && !defined(SQLITE_OMIT_FLOATING_POINT)
+    /* Verify that integers and floating point values use the same
+    ** byte order.  Or, that if SQLITE_MIXED_ENDIAN_64BIT_FLOAT is
+    ** defined that 64-bit floating point values really are mixed
+    ** endian.
+    */
+    static const u64 t1 = ((u64)0x3ff00000)<<32;
+    static const double r1 = 1.0;
+    u64 t2 = t1;
+    swapMixedEndianFloat(t2);
+    assert( sizeof(r1)==sizeof(t2) && memcmp(&r1, &t2, sizeof(r1))==0 );
+#endif
+    assert( sizeof(x)==8 && sizeof(pMem->r)==8 );
+    swapMixedEndianFloat(x);
+    memcpy(&pMem->r, &x, sizeof(x));
+    pMem->flags = sqlite3IsNaN(pMem->r) ? MEM_Null : MEM_Real;
+  }
+  return 8;
+}
+u32 sqlite3VdbeSerialGet(
+  const unsigned char *buf,     /* Buffer to deserialize from */
+  u32 serial_type,              /* Serial type to deserialize */
+  Mem *pMem                     /* Memory cell to write value into */
+){
   switch( serial_type ){
     case 10:   /* Reserved for future use */
     case 11:   /* Reserved for future use */
@@ -2998,47 +3039,19 @@ u32 sqlite3VdbeSerialGet(
       testcase( pMem->u.i<0 );
       return 3;
     }
-    case 4: { /* 4-byte signed integer */
-      y = FOUR_BYTE_UINT(buf);
-      pMem->u.i = (i64)*(int*)&y;
-      pMem->flags = MEM_Int;
-      testcase( pMem->u.i<0 );
-      return 4;
-    }
     case 5: { /* 6-byte signed integer */
       pMem->u.i = FOUR_BYTE_UINT(buf+2) + (((i64)1)<<32)*TWO_BYTE_INT(buf);
       pMem->flags = MEM_Int;
       testcase( pMem->u.i<0 );
       return 6;
     }
+    case 4:   /* 4-byte signed integer */
     case 6:   /* 8-byte signed integer */
     case 7: { /* IEEE floating point */
-#if !defined(NDEBUG) && !defined(SQLITE_OMIT_FLOATING_POINT)
+      /* These three cases require local variables, so do them in a 
-      /* Verify that integers and floating point values use the same
+      ** separate routine to avoid having to move the frame pointer in
-      ** byte order.  Or, that if SQLITE_MIXED_ENDIAN_64BIT_FLOAT is
+      ** the common case */
-      ** defined that 64-bit floating point values really are mixed
+      return serialGet(buf,serial_type,pMem);
-      ** endian.
-      */
-      static const u64 t1 = ((u64)0x3ff00000)<<32;
-      static const double r1 = 1.0;
-      u64 t2 = t1;
-      swapMixedEndianFloat(t2);
-      assert( sizeof(r1)==sizeof(t2) && memcmp(&r1, &t2, sizeof(r1))==0 );
-#endif
-      x = FOUR_BYTE_UINT(buf);
-      y = FOUR_BYTE_UINT(buf+4);
-      x = (x<<32) | y;
-      if( serial_type==6 ){
-        pMem->u.i = *(i64*)&x;
-        pMem->flags = MEM_Int;
-        testcase( pMem->u.i<0 );
-      }else{
-        assert( sizeof(x)==8 && sizeof(pMem->r)==8 );
-        swapMixedEndianFloat(x);
-        memcpy(&pMem->r, &x, sizeof(x));
-        pMem->flags = sqlite3IsNaN(pMem->r) ? MEM_Null : MEM_Real;
-      }
-      return 8;
     }
     case 8:    /* Integer 0 */
     case 9: {  /* Integer 1 */
@@ -3048,17 +3061,15 @@ u32 sqlite3VdbeSerialGet(
     }
     default: {
       static const u16 aFlag[] = { MEM_Blob|MEM_Ephem, MEM_Str|MEM_Ephem };
-      u32 len = (serial_type-12)/2;
       pMem->z = (char *)buf;
-      pMem->n = len;
+      pMem->n = (serial_type-12)/2;
       pMem->xDel = 0;
       pMem->flags = aFlag[serial_type&1];
-      return len;
+      return pMem->n;
     }
   }
   return 0;
 }
-
 /*
 ** This routine is used to allocate sufficient space for an UnpackedRecord
 ** structure large enough to be used with sqlite3VdbeRecordUnpack() if