2009-03-02 Rodrigo Kumpera <rkumpera@novell.com>

[mono.git] / mono / metadata / decimal.c

diff --git a/mono/metadata/decimal.c b/mono/metadata/decimal.c
index 60584644d334b3ff07d5d4402a130df5485409d2..6524443eab3d57168325a710d2ac93e05d74671a 100644 (file)
--- a/mono/metadata/decimal.c
+++ b/mono/metadata/decimal.c
@@ -1,12 +1,12 @@
 /* 
-   decimal.c
-
-   conversions and numerical operations for the c# type System.Decimal
-
-   Author: Martin Weindel (martin.weindel@t-online.de)
-
-   (C) 2001 by Martin Weindel
-*/
+ * decimal.c
+ *
+ * conversions and numerical operations for the c# type System.Decimal
+ *
+ * Author: Martin Weindel (martin.weindel@t-online.de)
+ *
+ * (C) 2001 by Martin Weindel
+ */
 
 /*
  * machine dependent configuration for 
@@ -22,6 +22,9 @@
 #ifdef HAVE_MEMORY_H
 #include <memory.h>
 #endif
+#ifdef _MSC_VER
+#include <intrin.h>
+#endif
 
 #ifndef DISABLE_DECIMAL
 
@@ -565,8 +568,26 @@ my_g_bit_nth_msf (gsize mask)
        __asm__("bsrq %1,%0\n\t"
                        : "=r" (r) : "rm" (mask));
        return r;
+#elif defined(__i386__) && defined(_MSC_VER)
+       unsigned long bIndex = 0;
+       if (_BitScanReverse (&bIndex, mask))
+               return bIndex;
+       return -1;
+#elif defined(__x86_64__) && defined(_MSC_VER)
+       unsigned long bIndex = 0;
+       if (_BitScanReverse64 (&bIndex, mask))
+               return bIndex;
+       return -1;
 #else
-       return g_bit_nth_msf (mask, sizeof (gsize) * 8);
+       int i;
+
+       i = sizeof (gsize) * 8;
+       while (i > 0) {
+               i --;
+               if (mask & (1UL << i))
+                       return i;
+       }
+       return -1;
 #endif
 }
 
@@ -659,7 +680,7 @@ DECINLINE static int adjustScale128(guint64* palo, guint64* pahi, int deltaScale
 DECINLINE static int rescale128(guint64* pclo, guint64* pchi, int* pScale, int texp,
                                 int minScale, int maxScale, int roundFlag)
 {
-    guint32 factor, overhang, prev_lo;
+    guint32 factor, overhang;
     int scale, i, rc, roundBit = 0;
 
     PRECONDITION(texp >= 0);
@@ -673,44 +694,35 @@ DECINLINE static int rescale128(guint64* pclo, guint64* pchi, int* pScale, int t
 
                        /* The original loop was this: */
                        /*
-            while (texp > 1 && (overhang > (2<<DECIMAL_MAX_INTFACTORS) || (*pclo & 1) == 0)) {
+            while (texp > 0 && (overhang > (2<<DECIMAL_MAX_INTFACTORS) || (*pclo & 1) == 0)) {
                                if (--texp == 0)
                                        roundBit = (int)(*pclo & 1);
                 rshift128(pclo, pchi);
                 overhang = (guint32)(*pchi >> 32);
             }
                        */
-
-                       /*
-                        * FIXME: This code seems to cause crashes on the x86 buildbot during the
-                        * System.Data.DataSetExtensions tests.
-                       prev_lo = *pclo;
                        if (overhang > 0) {
                                int msf = my_g_bit_nth_msf (overhang);
                                int shift = msf - (DECIMAL_MAX_INTFACTORS + 2);
 
-                               if (shift > texp)
-                                       shift = texp;
+                               if (shift >= texp)
+                                       shift = texp - 1;
 
                                if (shift > 0) {
                                        texp -= shift;
-                                       prev_lo = (*pclo >> (shift - 1));
                                        *pclo = (*pclo >> shift) | ((*pchi & ((1 << shift) - 1)) << (64 - shift));
                                        *pchi >>= shift;
                                        overhang >>= shift;
 
+                                       g_assert (texp > 0);
                                        g_assert (overhang > (2 << DECIMAL_MAX_INTFACTORS));
                                }
                        }
-                       */
             while (texp > 0 && (overhang > (2<<DECIMAL_MAX_INTFACTORS) || (*pclo & 1) == 0)) {
-                               --texp;
-                               prev_lo = *pclo;
+                               if (--texp == 0) roundBit = (int)(*pclo & 1);
                 rshift128(pclo, pchi);
                 overhang >>= 1;
             }
-                       if (texp == 0)
-                               roundBit = (int)(prev_lo & 1);
 
             if (texp > DECIMAL_MAX_INTFACTORS) i = DECIMAL_MAX_INTFACTORS;
             else i = texp;