[MSVCRT] Import msvcrt from wine-10.0

Author: tkreuzer

dll/win32/msvcrt/bnum.h

@@ -0,0 +1,137 @@
+/*
+ * Copyright 2020 Piotr Caban for CodeWeavers
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
+ */
+
+#ifndef __WINE_BNUM_H
+#define __WINE_BNUM_H
+
+#define EXP_BITS 11
+#define MANT_BITS 53
+
+static const int p10s[] = { 1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000, 1000000000 };
+
+#define LIMB_DIGITS 9           /* each DWORD stores up to 9 digits */
+#define LIMB_MAX 1000000000     /* 10^9 */
+
+#define BNUM_PREC64 128         /* data size needed to store 64-bit double */
+#define BNUM_PREC80 2048        /* data size needed to store 80-bit double */
+
+/* bnum represents real number with fixed decimal point */
+struct bnum {
+    int b; /* least significant digit position */
+    int e; /* most significant digit position + 1 */
+    int size; /* data buffer size in DWORDS (power of 2) */
+    DWORD data[1]; /* circular buffer, base 10 number */
+};
+
+static inline int bnum_idx(struct bnum *b, int idx)
+{
+    return idx & (b->size - 1);
+}
+
+/* Returns TRUE if new most significant limb was added */
+static inline BOOL bnum_lshift(struct bnum *b, int shift)
+{
+    DWORD rest = 0;
+    ULONGLONG tmp;
+    int i;
+
+    /* The limbs number can change by up to 1 so shift <= 29 */
+    assert(shift <= 29);
+
+    for(i=b->b; i<b->e; i++) {
+        tmp = ((ULONGLONG)b->data[bnum_idx(b, i)] << shift) + rest;
+        rest = tmp / LIMB_MAX;
+        b->data[bnum_idx(b, i)] = tmp % LIMB_MAX;
+
+        if(i == b->b && !b->data[bnum_idx(b, i)])
+            b->b++;
+    }
+
+    if(rest) {
+        b->data[bnum_idx(b, b->e)] = rest;
+        b->e++;
+
+        if(bnum_idx(b, b->b) == bnum_idx(b, b->e)) {
+            if(b->data[bnum_idx(b, b->b)]) b->data[bnum_idx(b, b->b+1)] |= 1;
+            b->b++;
+        }
+        return TRUE;
+    }
+    return FALSE;
+}
+
+/* Returns TRUE if most significant limb was removed */
+static inline BOOL bnum_rshift(struct bnum *b, int shift)
+{
+    DWORD tmp, rest = 0;
+    BOOL ret = FALSE;
+    int i;
+
+    /* Compute LIMB_MAX << shift without accuracy loss */
+    assert(shift <= 9);
+
+    for(i=b->e-1; i>=b->b; i--) {
+        tmp = b->data[bnum_idx(b, i)] & ((1<<shift)-1);
+        b->data[bnum_idx(b, i)] = (b->data[bnum_idx(b, i)] >> shift) + rest;
+        rest = (LIMB_MAX >> shift) * tmp;
+        if(i==b->e-1 && !b->data[bnum_idx(b, i)]) {
+            b->e--;
+            ret = TRUE;
+        }
+    }
+
+    if(rest) {
+        if(bnum_idx(b, b->b-1) == bnum_idx(b, b->e)) {
+            if(rest) b->data[bnum_idx(b, b->b)] |= 1;
+        } else {
+            b->b--;
+            b->data[bnum_idx(b, b->b)] = rest;
+        }
+    }
+    return ret;
+}
+
+static inline void bnum_mult(struct bnum *b, int mult)
+{
+    DWORD rest = 0;
+    ULONGLONG tmp;
+    int i;
+
+    assert(mult <= LIMB_MAX);
+
+    for(i=b->b; i<b->e; i++) {
+        tmp = ((ULONGLONG)b->data[bnum_idx(b, i)] * mult) + rest;
+        rest = tmp / LIMB_MAX;
+        b->data[bnum_idx(b, i)] = tmp % LIMB_MAX;
+
+        if(i == b->b && !b->data[bnum_idx(b, i)])
+            b->b++;
+    }
+
+    if(rest) {
+        b->data[bnum_idx(b, b->e)] = rest;
+        b->e++;
+
+        if(bnum_idx(b, b->b) == bnum_idx(b, b->e)) {
+            if(b->data[bnum_idx(b, b->b)]) b->data[bnum_idx(b, b->b+1)] |= 1;
+            b->b++;
+        }
+    }
+}
+
+#endif /* __WINE_BNUM_H */