Add compile-time option -DSQLITE_MIXED_ENDIAN_64BIT_FLOAT=1 that uses

mixed-endian doubles.  This is needed on ARM7 to make database file
formats compatible with all other processors.  Tickets #2278 and #2335. (CVS 3913)

FossilOrigin-Name: 2a178d0c7950c9d403c0bc43c2043de945fb24e0

manifest

@@ -1,5 +1,5 @@
-C Rework\saccessPayload()\sfunction\sfor\sclarity.\s(CVS\s3912)
-D 2007-05-04T08:32:14
+C Add\scompile-time\soption\s-DSQLITE_MIXED_ENDIAN_64BIT_FLOAT=1\sthat\suses\nmixed-endian\sdoubles.\s\sThis\sis\sneeded\son\sARM7\sto\smake\sdatabase\sfile\nformats\scompatible\swith\sall\sother\sprocessors.\s\sTickets\s#2278\sand\s#2335.\s(CVS\s3913)
+D 2007-05-04T11:59:32
 F Makefile.in 8cab54f7c9f5af8f22fd97ddf1ecfd1e1860de62
 F Makefile.linux-gcc 2d8574d1ba75f129aba2019f0b959db380a90935
 F README 9c4e2d6706bdcc3efdd773ce752a8cdab4f90028
@@ -99,7 +99,7 @@ F src/server.c 087b92a39d883e3fa113cae259d64e4c7438bc96
 F src/shell.c 762c81655da0f01067514924a5ba8f47a47ada1d
 F src/sqlite.h.in a666300976897eced975b448f722a722b362c6b1
 F src/sqlite3ext.h 7d0d363ea7327e817ef0dfe1b7eee1f171b72890
-F src/sqliteInt.h 0b14d0eae083aafca0562d2261a404e5e5abc5f0
+F src/sqliteInt.h 5a8c0221a4f11998f46aa76364a9559af8d7c1f7
 F src/table.c 6d0da66dde26ee75614ed8f584a1996467088d06
 F src/tclsqlite.c dde509871614d17f8ab5f3b4bc496b0af07280c7
 F src/test1.c 29a39fdde51f4612082ecf3f5af54dac93766f87
@@ -129,7 +129,7 @@ F src/vdbe.c a4abf744b5376372a9be30f02ab4b231f353cab1
 F src/vdbe.h 0025259af1939fb264a545816c69e4b5b8d52691
 F src/vdbeInt.h cb02cbbceddf3b40d49012e9f41576f17bcbec97
 F src/vdbeapi.c 37d793559390bec8a00c556f651f21b5f9e589af
-F src/vdbeaux.c 8c7f22e22d1ea578971f5a3fcd3a56a6882ced64
+F src/vdbeaux.c 51acaab4275b5fddc7af5e7d1d2594044216ac46
 F src/vdbeblob.c ed2f9b46cc2de8de97d2a4a4ec466c5914d68333
 F src/vdbefifo.c 3ca8049c561d5d67cbcb94dc909ae9bb68c0bf8f
 F src/vdbemem.c ba98f8572ec4609846b368fa7580db178022f1bb
@@ -473,7 +473,7 @@ F www/tclsqlite.tcl bb0d1357328a42b1993d78573e587c6dcbc964b9
 F www/vdbe.tcl 87a31ace769f20d3627a64fa1fade7fed47b90d0
 F www/version3.tcl 890248cf7b70e60c383b0e84d77d5132b3ead42b
 F www/whentouse.tcl fc46eae081251c3c181bd79c5faef8195d7991a5
-P e54a49e264ecd54083587f8d3b17cce4c811fddc
-R 6675084e0bd9661ee80adf52bdde8264
-U danielk1977
-Z cda47f0f1385e7692b319bbdf6df8c16
+P 42d07c70ec1eb6dd9619c97d753c9d2824aeae32
+R f96d594e26c58bcc8fee62b7bf4c7bdc
+U drh
+Z 47fadba21691b4be40e7c985b1254595

manifest.uuid

@@ -1 +1 @@
-42d07c70ec1eb6dd9619c97d753c9d2824aeae32
+2a178d0c7950c9d403c0bc43c2043de945fb24e0

src/sqliteInt.h

@@ -11,7 +11,7 @@
 *************************************************************************
 ** Internal interface definitions for SQLite.
 **
-** @(#) $Id: sqliteInt.h,v 1.553 2007/04/26 14:42:36 danielk1977 Exp $
+** @(#) $Id: sqliteInt.h,v 1.554 2007/05/04 11:59:32 drh Exp $
 */
 #ifndef _SQLITEINT_H_
 #define _SQLITEINT_H_
@@ -75,6 +75,7 @@
 # endif
 # define SQLITE_OMIT_DATETIME_FUNCS 1
 # define SQLITE_OMIT_TRACE 1
+# undef SQLITE_MIXED_ENDIAN_64BIT_FLOAT
 #endif
 #ifndef SQLITE_BIG_DBL
 # define SQLITE_BIG_DBL (1e99)

src/vdbeaux.c

@@ -1767,6 +1767,32 @@ int sqlite3VdbeSerialTypeLen(u32 serial_type){
   }
 }
 
+/*
+** If we are on an architecture with mixed-endian floating 
+*** points (ex: ARM7) then swap the lower 4 bytes with the 
+** upper 4 bytes.  Return the result.
+**
+** For most (sane) architectures, this is a no-op.
+*/
+#ifdef SQLITE_MIXED_ENDIAN_64BIT_FLOAT
+static double floatSwap(double in){
+  union {
+    double r;
+    u32 i[2];
+  } u;
+  u32 t;
+
+  u.r = in;
+  t = u.i[0];
+  u.i[0] = u.i[1];
+  u.i[1] = t;
+  return u.r;
+}
+# define swapMixedEndianFloat(X)  X = floatSwap(X)
+#else
+# define swapMixedEndianFloat(X)
+#endif
+
 /*
 ** Write the serialized data blob for the value stored in pMem into 
 ** buf. It is assumed that the caller has allocated sufficient space.
@@ -1795,6 +1821,7 @@ int sqlite3VdbeSerialPut(u8 *buf, int nBuf, Mem *pMem, int file_format){
     int i;
     if( serial_type==7 ){
       assert( sizeof(v)==sizeof(pMem->r) );
+      swapMixedEndianFloat(pMem->r);
       memcpy(&v, &pMem->r, sizeof(v));
     }else{
       v = pMem->u.i;
@@ -1879,11 +1906,15 @@ int sqlite3VdbeSerialGet(
       u32 y;
 #if !defined(NDEBUG) && !defined(SQLITE_OMIT_FLOATING_POINT)
       /* Verify that integers and floating point values use the same
-      ** byte order.  The byte order differs on some (broken) architectures.
+      ** 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;
-      assert( sizeof(r1)==sizeof(t1) && memcmp(&r1, &t1, sizeof(r1))==0 );
+      double r2 = r1;
+      swapMixedEndianFloat(r2);
+      assert( sizeof(r2)==sizeof(t1) && memcmp(&r2, &t1, sizeof(r1))==0 );
 #endif
 
       x = (buf[0]<<24) | (buf[1]<<16) | (buf[2]<<8) | buf[3];
@@ -1895,7 +1926,7 @@ int sqlite3VdbeSerialGet(
       }else{
         assert( sizeof(x)==8 && sizeof(pMem->r)==8 );
         memcpy(&pMem->r, &x, sizeof(x));
-        /* pMem->r = *(double*)&x; */
+        swapMixedEndianFloat(pMem->r);
         pMem->flags = MEM_Real;
       }
       return 8;