[Refactor] #37287 #37353 型の置換。 / Type replacement.

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

diff --git a/src/z-rand.c b/src/z-rand.c
index 699e1fa..258aa67 100644 (file)
--- a/src/z-rand.c
+++ b/src/z-rand.c
@@ -70,6 +70,65 @@ u32b Rand_state[RAND_DEG] = {
 };
 
 
+typedef struct {
+       u32b dw[2];
+} u64b;
+
+static u64b u64b_xor(u64b a, u64b b)
+{
+       u64b result;
+
+       result.dw[0] = a.dw[0] ^ b.dw[0];
+       result.dw[1] = a.dw[1] ^ b.dw[1];
+
+       return result;
+}
+
+static u64b u64b_shiftl(u64b x, int k)
+{
+       u64b result;
+
+       if (k < 32) {
+               result.dw[1] = (x.dw[1] << k) | (x.dw[0] >> (32 - k));
+               result.dw[0] = (x.dw[0] << k);
+       }
+       else {
+               result.dw[1] = (x.dw[0] << (k - 32));
+               result.dw[0] = 0;
+       }
+
+       return result;
+}
+
+static u64b u64b_rotl(u64b x, int k)
+{
+       u64b result;
+
+       if (k < 32) {
+               result.dw[0] = (x.dw[0] << k) | (x.dw[1] >> (32 - k));
+               result.dw[1] = (x.dw[1] << k) | (x.dw[0] >> (32 - k));
+       }
+       else {
+               result.dw[0] = (x.dw[0] >> (64 - k)) | (x.dw[1] << (k - 32));
+               result.dw[1] = (x.dw[1] >> (64 - k)) | (x.dw[0] << (k - 32));
+       }
+
+       return result;
+}
+
+static u64b u64b_add(u64b a, u64b b)
+{
+       u64b result;
+
+       result.dw[0] = a.dw[0] + b.dw[0];
+       result.dw[1] = a.dw[1] + b.dw[1];
+
+       if (result.dw[0] < a.dw[0])
+               result.dw[1] ++;
+
+       return result;
+}
+
 /*
  * Initialize Xorshift Algorithm state
  */
@@ -84,6 +143,7 @@ static void Rand_Xorshift_seed(u32b seed, u32b* state)
        }
 }
 
+#if 0
 /*
  * Xorshift Algorithm
  */
@@ -99,6 +159,23 @@ static u32b Rand_Xorshift(u32b* state)
 
        return state[3];
 }
+#endif
+
+/*
+ * Xoroshiro128+ Algorithm
+ */
+static u32b Rand_Xoroshiro128plus(u32b* state)
+{
+       const u64b s0 = *((u64b*)state);
+       u64b s1 = *((u64b*)state + 1);
+       const u64b result = u64b_add(s0, s1);
+
+       s1 = u64b_xor(s0, s1);
+       *((u64b*)state) = u64b_xor(u64b_xor(u64b_rotl(s0, 55), s1), u64b_shiftl(s1, 14));
+       *((u64b*)state + 1) = u64b_rotl(s1, 36);
+
+       return result.dw[0];
+}
 
 static const u32b Rand_Xorshift_max = 0xFFFFFFFF;
 
@@ -115,23 +192,23 @@ void Rand_state_init(void)
 #ifdef RNG_DEVICE
 
        FILE *fp = fopen(RNG_DEVICE, "r");
-       u32b buf[4];
+       int n;
+       
        do {
-               fread(buf, sizeof(buf[0]), 4, fp);
-       } while ((buf[0] | buf[1] | buf[2] | buf[3]) == 0);
-       memcpy(Rand_state, buf, sizeof(buf));
+               n = fread(Rand_state, sizeof(Rand_state[0]), 4, fp);
+       } while (n != 4 || (Rand_state[0] | Rand_state[1] | Rand_state[2] | Rand_state[3]) == 0);
+       
        fclose(fp);
 
 #elif defined(WINDOWS)
 
        HCRYPTPROV hProvider;
-       u32b buf[4];
 
        CryptAcquireContext(&hProvider, NULL, NULL, PROV_RSA_FULL, 0);
 
        do {
-               CryptGenRandom(hProvider, sizeof(buf[0]) * 4, (BYTE*)buf);
-       } while ((buf[0] | buf[1] | buf[2] | buf[3]) == 0);
+               CryptGenRandom(hProvider, sizeof(Rand_state[0]) * 4, (BYTE*)Rand_state);
+       } while ((Rand_state[0] | Rand_state[1] | Rand_state[2] | Rand_state[3]) == 0);
 
        CryptReleaseContext(hProvider, 0);      
 
@@ -190,7 +267,7 @@ static s32b Rand_div_impl(s32b m, u32b* state)
        past = scaling * m;
 
        do {
-               ret = Rand_Xorshift(state);
+               ret = Rand_Xoroshiro128plus(state);
        } while (ret >= past);
 
        return ret / scaling;
@@ -286,7 +363,7 @@ s16b randnor(int mean, int stand)
        s16b high = RANDNOR_NUM;
 
        /* Paranoia */
-       if (stand < 1) return (mean);
+       if (stand < 1) return (s16b)(mean);
 
        /* Roll for probability */
        tmp = (s16b)randint0(32768);
@@ -305,7 +382,7 @@ s16b randnor(int mean, int stand)
                /* Move left otherwise */
                else
                {
-                       high = mid;
+                       high = (s16b)mid;
                }
        }
 
@@ -328,7 +405,7 @@ s16b damroll(int num, int sides)
 {
        int i, sum = 0;
        for (i = 0; i < num; i++) sum += randint1(sides);
-       return (sum);
+       return (s16b)(sum);
 }
 
 
@@ -387,7 +464,7 @@ s32b Rand_external(s32b m)
        if (!initialized)
        {
                /* Initialize with new seed */
-               u32b seed = time(NULL);
+               u32b seed = (u32b)time(NULL);
                Rand_Xorshift_seed(seed, Rand_state_external);
                initialized = TRUE;
        }