#37287 #37353 (2.2.0.89) 型の置換を継続中。 / Ongoing type replacement.

[hengband/hengband.git] / src / z-util.c

diff --git a/src/z-util.c b/src/z-util.c
index e3ded43..2f4c1df 100644 (file)
--- a/src/z-util.c
+++ b/src/z-util.c
@@ -1,4 +1,12 @@
-/* File: z-util.c */
+/* File: z-util.c */
+
+/*
+ * Copyright (c) 1997 Ben Harrison
+ *
+ * This software may be copied and distributed for educational, research,
+ * and not for profit purposes provided that this copyright and statement
+ * are included in all such copies.
+ */
 
 /* Purpose: Low level utilities -BEN- */
 
@@ -132,5 +140,129 @@ void core(cptr str)
 }
 
 
+/*** 64-bit integer operations ***/
+
+/* Add B to A */
+void s64b_add(s32b *A1, u32b *A2, s32b B1, u32b B2)
+{
+       (*A2) += B2;
+
+       /* Overflawed? */
+       if ((*A2) < B2)
+               (*A1) += B1 + 1;
+       else
+               (*A1) += B1;
+}
+
+
+/* Subtract B from A */
+void s64b_sub(s32b *A1, u32b *A2, s32b B1, u32b B2)
+{
+       /* Underflaw? */
+       if ((*A2) < B2)
+               (*A1) -= B1 + 1;
+       else
+               (*A1) -= B1;
+
+       (*A2) -= B2;
+}
+
+
+/*
+ * Multiply A by B
+ *
+ * (A1*2^32 + A2h*2^16 + A2l) * (B1*2^32 + B2h*2^16 + B2l)
+ *  = (A1*B2 & 0xffffffff)*2^32
+ *   +(A2*B1 & 0xffffffff)*2^32
+ *   +(A2h*B2h & 0xffffffff)*2^32
+ *   +(A2h*B2l & 0xffff0000)*2^16
+ *   +(A2l*B2h & 0xffff0000)*2^16
+ *   +(A2*B2 & 0xffffffff)
+ */
+void s64b_mul(s32b *A1, u32b *A2, s32b B1, u32b B2)
+{
+       s32b tmp1;
+       u32b A2val = (*A2);
+
+       u32b B2high = (B2 >> 16);
+       u32b A2high = (A2val >> 16);
+
+       (*A2) *= B2;
+       tmp1 = (*A1) * B2;
+       tmp1 += A2val * B1;
+       tmp1 += A2high * B2high;
+       tmp1 += (A2high * (u16b)B2) >> 16;
+       tmp1 += ((u16b)A2val * B2high) >> 16;
+
+       (*A1) = tmp1;
+}
+
+
+/* Compare A to B */
+int s64b_cmp(s32b A1, u32b A2, s32b B1, u32b B2)
+{
+       if (A1 > B1) return 1;
+       if (A1 < B1) return -1;
+       if (A2 > B2) return 1;
+       if (A2 < B2) return -1;
+       return 0;
+}
+
+/*
+ * Divide A by B
+ *
+ * Assumes that both A and B are positive
+ */
+void s64b_div(s32b *A1, u32b *A2, s32b B1, u32b B2)
+{
+       s32b result1 = 0;
+       u32b result2 = 0;
+       s32b A1val = (*A1);
+       u32b A2val = (*A2);
+       int bit = 0;
+
+       /* No result for B==0 */
+       if (B1 == 0 && B2 == 0) return;
+
+       /*
+        * Find the highest bit of quotient
+        */
+       while (s64b_cmp(A1val, A2val, B1, B2) == 1)
+       {
+               s64b_LSHIFT(B1, B2, 1);
+               bit++;
+       }
+
+       /* Extract bits of quotient one by one */
+       while (bit >= 0)
+       {
+               if (s64b_cmp(A1val, A2val, B1, B2) >= 0)
+               {
+                       if (bit >= 32)
+                               result1 |= (0x00000001L << (bit - 32));
+                       else
+                               result2 |= (0x00000001L << bit);
+
+                       s64b_sub(&A1val, &A2val, B1, B2);
+               }
+       
+               s64b_RSHIFT(B1, B2, 1);
+               bit--;
+       }
+
+       (*A1) = result1;
+       (*A2) = result2;
+}
+
+
+/* Reminder of division (A % B) */
+void s64b_mod(s32b *A1, u32b *A2, s32b B1, u32b B2)
+{
+       s32b tmp1 = (*A1);
+       u32b tmp2 = (*A2);
 
+       s64b_div(&tmp1, &tmp2, B1, B2);
+       s64b_mul(&tmp1, &tmp2, B1, B2);
+       s64b_sub(A1, A2, tmp1, tmp2);
+}