202105202144

bignumber/include/bignumber.h

@@ -50,7 +50,7 @@ DEFINE_GUID(IID_BIGNUMBER, 0x80dc5305, 0x1ca6, 0x4678, 0xbf, 0xc3, 0xd0, 0x1b, 0
 typedef struct sIBigNumber {
     OBJECT_INTERFACE
     int (*GetBitsCount)(HOBJECT object);
-
+    int (*SetBitsCount)(HOBJECT object, int count);
     int (*GetInt)(HOBJECT object, int* pvalue);
     int (*GetInt64)(HOBJECT object, long long* pvalue);
     int (*GetFloat)(HOBJECT object, float* pvalue);
@@ -93,6 +93,7 @@ typedef struct sIBigNumber {
 
 #define BIGNUMBER_FUNCDECLARE(_obj, _clsid, _localstruct) \
     static int _obj##_bn_GetBitsCount(HOBJECT object); \
+    static int _obj##_bn_SetBitsCount(HOBJECT object, int count); \
     static int _obj##_bn_GetInt(HOBJECT object, int* pvalue); \
     static int _obj##_bn_GetInt64(HOBJECT object, long long* pvalue); \
     static int _obj##_bn_GetFloat(HOBJECT object, float* pvalue); \
@@ -125,6 +126,7 @@ typedef struct sIBigNumber {
     static const IBigNumber _obj##_bn_interface = { \
    	INTERFACE_HEADER(_obj, IBigNumber, _localstruct) \
         _obj##_bn_GetBitsCount, \
+        _obj##_bn_SetBitsCount, \
         _obj##_bn_GetInt, \
         _obj##_bn_GetInt64, \
         _obj##_bn_GetFloat, \

bignumber/src/bignumber.c

@@ -91,13 +91,13 @@ static int actualwidth(unsigned int n)
 {
 	unsigned int c = 1;
 	int ret = 1;
-	if (c & 0x80000000)
+	if (n & 0x80000000)
 		return 32;
-	while (c < n) {
+	while (c <= n) {
 		c <<= 1;
 		ret++;
 	}
-	return ret;
+	return ret-1;
 }
 
 static void bigintDestroy(HOBJECT object)
@@ -134,6 +134,25 @@ static int bigint_bn_GetBitsCount(HOBJECT object)
 	return 0;
 }
 
+static int bigint_bn_SetBitsCount(HOBJECT object, int count)
+{
+	int i, bc;
+	sBigInteger* pobj;
+	pobj = (sBigInteger*)objectThis(object);
+	if (count <= 0) {
+		memset(pobj->buf, 0, pobj->buflen * 4);
+		return 0;
+	}
+	bc = bigint_bn_GetBitsCount(pobj);
+	if (count >= bc)
+		return 0;
+	for (i = (count+31) / 32; i < pobj->buflen; i++) {
+		pobj->buf[i] = 0;
+	}
+	pobj->buf[count / 32] &= 0xffffffff >> (32 - (count & 31));
+	return 0;
+}
+
 static int bigint_bn_GetInt(HOBJECT object, int* pvalue)
 { 
 	sBigInteger* pobj;
@@ -180,6 +199,10 @@ static int bigint_bn_GetStr(HOBJECT object, int base, char* str, int buflen)
 	pobj = (sBigInteger*)objectThis(object);
 	str[0] = 0;
 	bc = bigint_bn_GetBitsCount(object);
+	if (bc == 0) {
+		strcpy(str, "0");
+		return 0;
+	}
 	sprintf(str, "%d'h", bc);
 	i = ((bc + 31) / 32) - 1;
 	ac = actualwidth(pobj->buf[i]);
@@ -554,21 +577,79 @@ static int bigint_bn_Div(HOBJECT object, HOBJECT src)
 static int bigint_bn_SHL(HOBJECT object, int bits)
 { 
 	sBigInteger* pobj;
-	int bc;
+	int bc, blen;
+	int ifrom, ito, i;
+	unsigned long long current, next;
+	unsigned int* buf;
 	pobj = (sBigInteger*)objectThis(object);
+	if (bits == 0)
+		return 0;
+	if (bits < 0)
+		return bigint_bn_SHR(object, -bits);
 	bc = bigint_bn_GetBitsCount(object);
-	while (bc + bits > pobj->buflen * 32) {
-		if (bigint_expandbuf(pobj) != 0)
-			return -1;
+	blen = (bc + bits + 31) / 32;
+	buf = (unsigned int*)malloc(blen * 4);
+	if (buf == NULL)
+		return -1;
+	ito = bits / 32;
+	if (ito > 0) {
+		memset(buf, 0, ito * 4);
 	}
-	/* fixed me */
+	bits -= ito * 32;
+	ifrom = 0;
+	current = pobj->buf[0];
+	current <<= bits;
+	for (i = 1; i < (bc + 31) / 32; i++) {
+		buf[ito++] = (unsigned int)(current & 0xffffffff);
+		current >>= 32;
+		next = pobj->buf[i];
+		next <<= bits;
+		current |= next;
+	}
+	buf[ito] = (unsigned int)(current & 0xffffffff);
+	free(pobj->buf);
+	pobj->buf = buf;
+	pobj->buflen = blen;
 	return 0;
 }
 
 static int bigint_bn_SHR(HOBJECT object, int bits)
-{ 
+{
 	sBigInteger* pobj;
+	int bc;
+	int ifrom, ito, i, zerolen;
+	unsigned long long current, next;
 	pobj = (sBigInteger*)objectThis(object);
+	if (bits == 0)
+		return 0;
+	if (bits < 0)
+		return bigint_bn_SHL(object, -bits);
+	ito = 0;
+	ifrom = bits / 32;
+	if (ifrom >= pobj->buflen) {
+		memset(pobj->buf, 0, pobj->buflen * 4);
+		return 0;
+	}
+	bits -= ifrom * 32;
+	if (ifrom+1 < pobj->buflen) {
+		current = pobj->buf[ifrom+1];
+		current <<= 32;
+	}
+	else {
+		current = 0;
+	}
+	current |= pobj->buf[ifrom];
+	current >>= bits;
+	for (i = ifrom + 1; i < pobj->buflen-1; i++) {
+		pobj->buf[ito++] = (unsigned int)(current & 0xffffffff);
+		current >>= 32;
+		next = pobj->buf[i + 1];
+		next <<= 32-bits;
+		current |= next;
+	}
+	pobj->buf[ito++] = (unsigned int)(current & 0xffffffff);
+	while (ito < pobj->buflen)
+		pobj->buf[ito++] = 0;
 	return 0;
 }
 

examples/testbignumber/testbignumber.c

@@ -34,11 +34,11 @@
 #include "object.h"
 #include "bignumber.h"
 
-const char* testnumber = "43, 4, 128'b0101011111011010100011000101010101010100010101010101010001, 'h94397afc4343, 5'd98";
+const char* testnumber = "77'h4137489137419837408139048137908791875841983274987132, 43, 4, 128'b0101011111011010100011000101010101010100010101010101010001, 'h94397afc4343, 5'd98";
 
 int main(int argc, char* argv[])
 {
-	char buf[128];
+	char buf[256];
 	IBigNumber** bignumber = bigintegerCreate();
 	const char* nstr = testnumber;
 	const char* lstr = testnumber;
@@ -47,5 +47,11 @@ int main(int argc, char* argv[])
 		printf("%s=%s, \nnext=%s\n", lstr, buf, nstr);
 		lstr = nstr;
 	}
+	objectCall2(bignumber, AssignStr, testnumber, &nstr);
+	objectCall3(bignumber, GetStr, 16, buf, 256);
+	printf("n=%s\n", buf);
+	objectCall1(bignumber, SetBitsCount, 9);
+	objectCall3(bignumber, GetStr, 16, buf, 256);
+	printf("n<<68=%s\n", buf);
 	return 0;
 }
\ No newline at end of file