[llvm-commits] CVS: llvm/lib/Support/APInt.cpp
Reid Spencer
reid at x10sys.com
Fri Feb 16 19:16:17 PST 2007
Changes in directory llvm/lib/Support:
APInt.cpp updated: 1.14 -> 1.15
---
Log message:
Move static functions closer to their usage.
---
Diffs of the changes: (+295 -295)
APInt.cpp | 590 +++++++++++++++++++++++++++++++-------------------------------
1 files changed, 295 insertions(+), 295 deletions(-)
Index: llvm/lib/Support/APInt.cpp
diff -u llvm/lib/Support/APInt.cpp:1.14 llvm/lib/Support/APInt.cpp:1.15
--- llvm/lib/Support/APInt.cpp:1.14 Fri Feb 16 20:07:07 2007
+++ llvm/lib/Support/APInt.cpp Fri Feb 16 21:16:00 2007
@@ -19,229 +19,6 @@
#include <cstdlib>
using namespace llvm;
-/// mul_1 - This function performs the multiplication operation on a
-/// large integer (represented as an integer array) and a uint64_t integer.
-/// @returns the carry of the multiplication.
-static uint64_t mul_1(uint64_t dest[], uint64_t x[],
- unsigned len, uint64_t y) {
- // Split y into high 32-bit part and low 32-bit part.
- uint64_t ly = y & 0xffffffffULL, hy = y >> 32;
- uint64_t carry = 0, lx, hx;
- for (unsigned i = 0; i < len; ++i) {
- lx = x[i] & 0xffffffffULL;
- hx = x[i] >> 32;
- // hasCarry - A flag to indicate if has carry.
- // hasCarry == 0, no carry
- // hasCarry == 1, has carry
- // hasCarry == 2, no carry and the calculation result == 0.
- uint8_t hasCarry = 0;
- dest[i] = carry + lx * ly;
- // Determine if the add above introduces carry.
- hasCarry = (dest[i] < carry) ? 1 : 0;
- carry = hx * ly + (dest[i] >> 32) + (hasCarry ? (1ULL << 32) : 0);
- // The upper limit of carry can be (2^32 - 1)(2^32 - 1) +
- // (2^32 - 1) + 2^32 = 2^64.
- hasCarry = (!carry && hasCarry) ? 1 : (!carry ? 2 : 0);
-
- carry += (lx * hy) & 0xffffffffULL;
- dest[i] = (carry << 32) | (dest[i] & 0xffffffffULL);
- carry = (((!carry && hasCarry != 2) || hasCarry == 1) ? (1ULL << 32) : 0) +
- (carry >> 32) + ((lx * hy) >> 32) + hx * hy;
- }
-
- return carry;
-}
-
-/// mul - This function multiplies integer array x[] by integer array y[] and
-/// stores the result into integer array dest[].
-/// Note the array dest[]'s size should no less than xlen + ylen.
-static void mul(uint64_t dest[], uint64_t x[], unsigned xlen,
- uint64_t y[], unsigned ylen) {
- dest[xlen] = mul_1(dest, x, xlen, y[0]);
-
- for (unsigned i = 1; i < ylen; ++i) {
- uint64_t ly = y[i] & 0xffffffffULL, hy = y[i] >> 32;
- uint64_t carry = 0, lx, hx;
- for (unsigned j = 0; j < xlen; ++j) {
- lx = x[j] & 0xffffffffULL;
- hx = x[j] >> 32;
- // hasCarry - A flag to indicate if has carry.
- // hasCarry == 0, no carry
- // hasCarry == 1, has carry
- // hasCarry == 2, no carry and the calculation result == 0.
- uint8_t hasCarry = 0;
- uint64_t resul = carry + lx * ly;
- hasCarry = (resul < carry) ? 1 : 0;
- carry = (hasCarry ? (1ULL << 32) : 0) + hx * ly + (resul >> 32);
- hasCarry = (!carry && hasCarry) ? 1 : (!carry ? 2 : 0);
-
- carry += (lx * hy) & 0xffffffffULL;
- resul = (carry << 32) | (resul & 0xffffffffULL);
- dest[i+j] += resul;
- carry = (((!carry && hasCarry != 2) || hasCarry == 1) ? (1ULL << 32) : 0)+
- (carry >> 32) + (dest[i+j] < resul ? 1 : 0) +
- ((lx * hy) >> 32) + hx * hy;
- }
- dest[i+xlen] = carry;
- }
-}
-
-/// add_1 - This function adds the integer array x[] by integer y and
-/// returns the carry.
-/// @returns the carry of the addition.
-static uint64_t add_1(uint64_t dest[], uint64_t x[],
- unsigned len, uint64_t y) {
- uint64_t carry = y;
-
- for (unsigned i = 0; i < len; ++i) {
- dest[i] = carry + x[i];
- carry = (dest[i] < carry) ? 1 : 0;
- }
- return carry;
-}
-
-/// add - This function adds the integer array x[] by integer array
-/// y[] and returns the carry.
-static uint64_t add(uint64_t dest[], uint64_t x[],
- uint64_t y[], unsigned len) {
- unsigned carry = 0;
-
- for (unsigned i = 0; i< len; ++i) {
- carry += x[i];
- dest[i] = carry + y[i];
- carry = carry < x[i] ? 1 : (dest[i] < carry ? 1 : 0);
- }
- return carry;
-}
-
-/// sub_1 - This function subtracts the integer array x[] by
-/// integer y and returns the borrow-out carry.
-static uint64_t sub_1(uint64_t x[], unsigned len, uint64_t y) {
- uint64_t cy = y;
-
- for (unsigned i = 0; i < len; ++i) {
- uint64_t X = x[i];
- x[i] -= cy;
- if (cy > X)
- cy = 1;
- else {
- cy = 0;
- break;
- }
- }
-
- return cy;
-}
-
-/// sub - This function subtracts the integer array x[] by
-/// integer array y[], and returns the borrow-out carry.
-static uint64_t sub(uint64_t dest[], uint64_t x[],
- uint64_t y[], unsigned len) {
- // Carry indicator.
- uint64_t cy = 0;
-
- for (unsigned i = 0; i < len; ++i) {
- uint64_t Y = y[i], X = x[i];
- Y += cy;
-
- cy = Y < cy ? 1 : 0;
- Y = X - Y;
- cy += Y > X ? 1 : 0;
- dest[i] = Y;
- }
- return cy;
-}
-
-/// UnitDiv - This function divides N by D,
-/// and returns (remainder << 32) | quotient.
-/// Assumes (N >> 32) < D.
-static uint64_t unitDiv(uint64_t N, unsigned D) {
- uint64_t q, r; // q: quotient, r: remainder.
- uint64_t a1 = N >> 32; // a1: high 32-bit part of N.
- uint64_t a0 = N & 0xffffffffL; // a0: low 32-bit part of N
- if (a1 < ((D - a1 - (a0 >> 31)) & 0xffffffffL)) {
- q = N / D;
- r = N % D;
- }
- else {
- // Compute c1*2^32 + c0 = a1*2^32 + a0 - 2^31*d
- uint64_t c = N - ((uint64_t) D << 31);
- // Divide (c1*2^32 + c0) by d
- q = c / D;
- r = c % D;
- // Add 2^31 to quotient
- q += 1 << 31;
- }
-
- return (r << 32) | (q & 0xFFFFFFFFl);
-}
-
-/// subMul - This function substracts x[len-1:0] * y from
-/// dest[offset+len-1:offset], and returns the most significant
-/// word of the product, minus the borrow-out from the subtraction.
-static unsigned subMul(unsigned dest[], unsigned offset,
- unsigned x[], unsigned len, unsigned y) {
- uint64_t yl = (uint64_t) y & 0xffffffffL;
- unsigned carry = 0;
- unsigned j = 0;
- do {
- uint64_t prod = ((uint64_t) x[j] & 0xffffffffL) * yl;
- unsigned prod_low = (unsigned) prod;
- unsigned prod_high = (unsigned) (prod >> 32);
- prod_low += carry;
- carry = (prod_low < carry ? 1 : 0) + prod_high;
- unsigned x_j = dest[offset+j];
- prod_low = x_j - prod_low;
- if (prod_low > x_j) ++carry;
- dest[offset+j] = prod_low;
- } while (++j < len);
- return carry;
-}
-
-/// div - This is basically Knuth's formulation of the classical algorithm.
-/// Correspondance with Knuth's notation:
-/// Knuth's u[0:m+n] == zds[nx:0].
-/// Knuth's v[1:n] == y[ny-1:0]
-/// Knuth's n == ny.
-/// Knuth's m == nx-ny.
-/// Our nx == Knuth's m+n.
-/// Could be re-implemented using gmp's mpn_divrem:
-/// zds[nx] = mpn_divrem (&zds[ny], 0, zds, nx, y, ny).
-static void div(unsigned zds[], unsigned nx, unsigned y[], unsigned ny) {
- unsigned j = nx;
- do { // loop over digits of quotient
- // Knuth's j == our nx-j.
- // Knuth's u[j:j+n] == our zds[j:j-ny].
- unsigned qhat; // treated as unsigned
- if (zds[j] == y[ny-1])
- qhat = -1U; // 0xffffffff
- else {
- uint64_t w = (((uint64_t)(zds[j])) << 32) +
- ((uint64_t)zds[j-1] & 0xffffffffL);
- qhat = (unsigned) unitDiv(w, y[ny-1]);
- }
- if (qhat) {
- unsigned borrow = subMul(zds, j - ny, y, ny, qhat);
- unsigned save = zds[j];
- uint64_t num = ((uint64_t)save&0xffffffffL) -
- ((uint64_t)borrow&0xffffffffL);
- while (num) {
- qhat--;
- uint64_t carry = 0;
- for (unsigned i = 0; i < ny; i++) {
- carry += ((uint64_t) zds[j-ny+i] & 0xffffffffL)
- + ((uint64_t) y[i] & 0xffffffffL);
- zds[j-ny+i] = (unsigned) carry;
- carry >>= 32;
- }
- zds[j] += carry;
- num = carry - 1;
- }
- }
- zds[j] = qhat;
- } while (--j >= ny);
-}
-
#if 0
/// lshift - This function shift x[0:len-1] left by shiftAmt bits, and
/// store the len least significant words of the result in
@@ -313,78 +90,6 @@
fromString(numbits, Val.c_str(), Val.size(), radix);
}
-/// @brief Converts a char array into an integer.
-void APInt::fromString(unsigned numbits, const char *StrStart, unsigned slen,
- uint8_t radix) {
- assert((radix == 10 || radix == 8 || radix == 16 || radix == 2) &&
- "Radix should be 2, 8, 10, or 16!");
- assert(StrStart && "String is null?");
- unsigned size = 0;
- // If the radix is a power of 2, read the input
- // from most significant to least significant.
- if ((radix & (radix - 1)) == 0) {
- unsigned nextBitPos = 0, bits_per_digit = radix / 8 + 2;
- uint64_t resDigit = 0;
- BitWidth = slen * bits_per_digit;
- if (getNumWords() > 1)
- assert((pVal = new uint64_t[getNumWords()]) &&
- "APInt memory allocation fails!");
- for (int i = slen - 1; i >= 0; --i) {
- uint64_t digit = StrStart[i] - 48; // '0' == 48.
- resDigit |= digit << nextBitPos;
- nextBitPos += bits_per_digit;
- if (nextBitPos >= 64) {
- if (isSingleWord()) {
- VAL = resDigit;
- break;
- }
- pVal[size++] = resDigit;
- nextBitPos -= 64;
- resDigit = digit >> (bits_per_digit - nextBitPos);
- }
- }
- if (!isSingleWord() && size <= getNumWords())
- pVal[size] = resDigit;
- } else { // General case. The radix is not a power of 2.
- // For 10-radix, the max value of 64-bit integer is 18446744073709551615,
- // and its digits number is 20.
- const unsigned chars_per_word = 20;
- if (slen < chars_per_word ||
- (slen == chars_per_word && // In case the value <= 2^64 - 1
- strcmp(StrStart, "18446744073709551615") <= 0)) {
- BitWidth = 64;
- VAL = strtoull(StrStart, 0, 10);
- } else { // In case the value > 2^64 - 1
- BitWidth = (slen / chars_per_word + 1) * 64;
- assert((pVal = new uint64_t[getNumWords()]) &&
- "APInt memory allocation fails!");
- memset(pVal, 0, getNumWords() * 8);
- unsigned str_pos = 0;
- while (str_pos < slen) {
- unsigned chunk = slen - str_pos;
- if (chunk > chars_per_word - 1)
- chunk = chars_per_word - 1;
- uint64_t resDigit = StrStart[str_pos++] - 48; // 48 == '0'.
- uint64_t big_base = radix;
- while (--chunk > 0) {
- resDigit = resDigit * radix + StrStart[str_pos++] - 48;
- big_base *= radix;
- }
-
- uint64_t carry;
- if (!size)
- carry = resDigit;
- else {
- carry = mul_1(pVal, pVal, size, big_base);
- carry += add_1(pVal, pVal, size, resDigit);
- }
-
- if (carry) pVal[size++] = carry;
- }
- }
- }
-}
-
APInt::APInt(const APInt& APIVal)
: BitWidth(APIVal.BitWidth) {
if (isSingleWord()) VAL = APIVal.VAL;
@@ -428,6 +133,19 @@
return *this;
}
+/// add_1 - This function adds the integer array x[] by integer y and
+/// returns the carry.
+/// @returns the carry of the addition.
+static uint64_t add_1(uint64_t dest[], uint64_t x[], unsigned len, uint64_t y) {
+ uint64_t carry = y;
+
+ for (unsigned i = 0; i < len; ++i) {
+ dest[i] = carry + x[i];
+ carry = (dest[i] < carry) ? 1 : 0;
+ }
+ return carry;
+}
+
/// @brief Prefix increment operator. Increments the APInt by one.
APInt& APInt::operator++() {
if (isSingleWord())
@@ -438,6 +156,25 @@
return *this;
}
+/// sub_1 - This function subtracts the integer array x[] by
+/// integer y and returns the borrow-out carry.
+static uint64_t sub_1(uint64_t x[], unsigned len, uint64_t y) {
+ uint64_t cy = y;
+
+ for (unsigned i = 0; i < len; ++i) {
+ uint64_t X = x[i];
+ x[i] -= cy;
+ if (cy > X)
+ cy = 1;
+ else {
+ cy = 0;
+ break;
+ }
+ }
+
+ return cy;
+}
+
/// @brief Prefix decrement operator. Decrements the APInt by one.
APInt& APInt::operator--() {
if (isSingleWord()) --VAL;
@@ -447,6 +184,20 @@
return *this;
}
+/// add - This function adds the integer array x[] by integer array
+/// y[] and returns the carry.
+static uint64_t add(uint64_t dest[], uint64_t x[],
+ uint64_t y[], unsigned len) {
+ unsigned carry = 0;
+
+ for (unsigned i = 0; i< len; ++i) {
+ carry += x[i];
+ dest[i] = carry + y[i];
+ carry = carry < x[i] ? 1 : (dest[i] < carry ? 1 : 0);
+ }
+ return carry;
+}
+
/// @brief Addition assignment operator. Adds this APInt by the given APInt&
/// RHS and assigns the result to this APInt.
APInt& APInt::operator+=(const APInt& RHS) {
@@ -468,6 +219,25 @@
return *this;
}
+/// sub - This function subtracts the integer array x[] by
+/// integer array y[], and returns the borrow-out carry.
+static uint64_t sub(uint64_t dest[], uint64_t x[],
+ uint64_t y[], unsigned len) {
+ // Carry indicator.
+ uint64_t cy = 0;
+
+ for (unsigned i = 0; i < len; ++i) {
+ uint64_t Y = y[i], X = x[i];
+ Y += cy;
+
+ cy = Y < cy ? 1 : 0;
+ Y = X - Y;
+ cy += Y > X ? 1 : 0;
+ dest[i] = Y;
+ }
+ return cy;
+}
+
/// @brief Subtraction assignment operator. Subtracts this APInt by the given
/// APInt &RHS and assigns the result to this APInt.
APInt& APInt::operator-=(const APInt& RHS) {
@@ -490,6 +260,73 @@
return *this;
}
+/// mul_1 - This function performs the multiplication operation on a
+/// large integer (represented as an integer array) and a uint64_t integer.
+/// @returns the carry of the multiplication.
+static uint64_t mul_1(uint64_t dest[], uint64_t x[],
+ unsigned len, uint64_t y) {
+ // Split y into high 32-bit part and low 32-bit part.
+ uint64_t ly = y & 0xffffffffULL, hy = y >> 32;
+ uint64_t carry = 0, lx, hx;
+ for (unsigned i = 0; i < len; ++i) {
+ lx = x[i] & 0xffffffffULL;
+ hx = x[i] >> 32;
+ // hasCarry - A flag to indicate if has carry.
+ // hasCarry == 0, no carry
+ // hasCarry == 1, has carry
+ // hasCarry == 2, no carry and the calculation result == 0.
+ uint8_t hasCarry = 0;
+ dest[i] = carry + lx * ly;
+ // Determine if the add above introduces carry.
+ hasCarry = (dest[i] < carry) ? 1 : 0;
+ carry = hx * ly + (dest[i] >> 32) + (hasCarry ? (1ULL << 32) : 0);
+ // The upper limit of carry can be (2^32 - 1)(2^32 - 1) +
+ // (2^32 - 1) + 2^32 = 2^64.
+ hasCarry = (!carry && hasCarry) ? 1 : (!carry ? 2 : 0);
+
+ carry += (lx * hy) & 0xffffffffULL;
+ dest[i] = (carry << 32) | (dest[i] & 0xffffffffULL);
+ carry = (((!carry && hasCarry != 2) || hasCarry == 1) ? (1ULL << 32) : 0) +
+ (carry >> 32) + ((lx * hy) >> 32) + hx * hy;
+ }
+
+ return carry;
+}
+
+/// mul - This function multiplies integer array x[] by integer array y[] and
+/// stores the result into integer array dest[].
+/// Note the array dest[]'s size should no less than xlen + ylen.
+static void mul(uint64_t dest[], uint64_t x[], unsigned xlen,
+ uint64_t y[], unsigned ylen) {
+ dest[xlen] = mul_1(dest, x, xlen, y[0]);
+
+ for (unsigned i = 1; i < ylen; ++i) {
+ uint64_t ly = y[i] & 0xffffffffULL, hy = y[i] >> 32;
+ uint64_t carry = 0, lx, hx;
+ for (unsigned j = 0; j < xlen; ++j) {
+ lx = x[j] & 0xffffffffULL;
+ hx = x[j] >> 32;
+ // hasCarry - A flag to indicate if has carry.
+ // hasCarry == 0, no carry
+ // hasCarry == 1, has carry
+ // hasCarry == 2, no carry and the calculation result == 0.
+ uint8_t hasCarry = 0;
+ uint64_t resul = carry + lx * ly;
+ hasCarry = (resul < carry) ? 1 : 0;
+ carry = (hasCarry ? (1ULL << 32) : 0) + hx * ly + (resul >> 32);
+ hasCarry = (!carry && hasCarry) ? 1 : (!carry ? 2 : 0);
+
+ carry += (lx * hy) & 0xffffffffULL;
+ resul = (carry << 32) | (resul & 0xffffffffULL);
+ dest[i+j] += resul;
+ carry = (((!carry && hasCarry != 2) || hasCarry == 1) ? (1ULL << 32) : 0)+
+ (carry >> 32) + (dest[i+j] < resul ? 1 : 0) +
+ ((lx * hy) >> 32) + hx * hy;
+ }
+ dest[i+xlen] = carry;
+ }
+}
+
/// @brief Multiplication assignment operator. Multiplies this APInt by the
/// given APInt& RHS and assigns the result to this APInt.
APInt& APInt::operator*=(const APInt& RHS) {
@@ -1134,6 +971,96 @@
return API;
}
+/// subMul - This function substracts x[len-1:0] * y from
+/// dest[offset+len-1:offset], and returns the most significant
+/// word of the product, minus the borrow-out from the subtraction.
+static unsigned subMul(unsigned dest[], unsigned offset,
+ unsigned x[], unsigned len, unsigned y) {
+ uint64_t yl = (uint64_t) y & 0xffffffffL;
+ unsigned carry = 0;
+ unsigned j = 0;
+ do {
+ uint64_t prod = ((uint64_t) x[j] & 0xffffffffL) * yl;
+ unsigned prod_low = (unsigned) prod;
+ unsigned prod_high = (unsigned) (prod >> 32);
+ prod_low += carry;
+ carry = (prod_low < carry ? 1 : 0) + prod_high;
+ unsigned x_j = dest[offset+j];
+ prod_low = x_j - prod_low;
+ if (prod_low > x_j) ++carry;
+ dest[offset+j] = prod_low;
+ } while (++j < len);
+ return carry;
+}
+
+/// unitDiv - This function divides N by D,
+/// and returns (remainder << 32) | quotient.
+/// Assumes (N >> 32) < D.
+static uint64_t unitDiv(uint64_t N, unsigned D) {
+ uint64_t q, r; // q: quotient, r: remainder.
+ uint64_t a1 = N >> 32; // a1: high 32-bit part of N.
+ uint64_t a0 = N & 0xffffffffL; // a0: low 32-bit part of N
+ if (a1 < ((D - a1 - (a0 >> 31)) & 0xffffffffL)) {
+ q = N / D;
+ r = N % D;
+ }
+ else {
+ // Compute c1*2^32 + c0 = a1*2^32 + a0 - 2^31*d
+ uint64_t c = N - ((uint64_t) D << 31);
+ // Divide (c1*2^32 + c0) by d
+ q = c / D;
+ r = c % D;
+ // Add 2^31 to quotient
+ q += 1 << 31;
+ }
+
+ return (r << 32) | (q & 0xFFFFFFFFl);
+}
+
+/// div - This is basically Knuth's formulation of the classical algorithm.
+/// Correspondance with Knuth's notation:
+/// Knuth's u[0:m+n] == zds[nx:0].
+/// Knuth's v[1:n] == y[ny-1:0]
+/// Knuth's n == ny.
+/// Knuth's m == nx-ny.
+/// Our nx == Knuth's m+n.
+/// Could be re-implemented using gmp's mpn_divrem:
+/// zds[nx] = mpn_divrem (&zds[ny], 0, zds, nx, y, ny).
+static void div(unsigned zds[], unsigned nx, unsigned y[], unsigned ny) {
+ unsigned j = nx;
+ do { // loop over digits of quotient
+ // Knuth's j == our nx-j.
+ // Knuth's u[j:j+n] == our zds[j:j-ny].
+ unsigned qhat; // treated as unsigned
+ if (zds[j] == y[ny-1])
+ qhat = -1U; // 0xffffffff
+ else {
+ uint64_t w = (((uint64_t)(zds[j])) << 32) +
+ ((uint64_t)zds[j-1] & 0xffffffffL);
+ qhat = (unsigned) unitDiv(w, y[ny-1]);
+ }
+ if (qhat) {
+ unsigned borrow = subMul(zds, j - ny, y, ny, qhat);
+ unsigned save = zds[j];
+ uint64_t num = ((uint64_t)save&0xffffffffL) -
+ ((uint64_t)borrow&0xffffffffL);
+ while (num) {
+ qhat--;
+ uint64_t carry = 0;
+ for (unsigned i = 0; i < ny; i++) {
+ carry += ((uint64_t) zds[j-ny+i] & 0xffffffffL)
+ + ((uint64_t) y[i] & 0xffffffffL);
+ zds[j-ny+i] = (unsigned) carry;
+ carry >>= 32;
+ }
+ zds[j] += carry;
+ num = carry - 1;
+ }
+ }
+ zds[j] = qhat;
+ } while (--j >= ny);
+}
+
/// Unsigned divide this APInt by APInt RHS.
/// @brief Unsigned division function for APInt.
APInt APInt::udiv(const APInt& RHS) const {
@@ -1235,3 +1162,76 @@
}
return Result;
}
+
+/// @brief Converts a char array into an integer.
+void APInt::fromString(unsigned numbits, const char *StrStart, unsigned slen,
+ uint8_t radix) {
+ assert((radix == 10 || radix == 8 || radix == 16 || radix == 2) &&
+ "Radix should be 2, 8, 10, or 16!");
+ assert(StrStart && "String is null?");
+ unsigned size = 0;
+ // If the radix is a power of 2, read the input
+ // from most significant to least significant.
+ if ((radix & (radix - 1)) == 0) {
+ unsigned nextBitPos = 0, bits_per_digit = radix / 8 + 2;
+ uint64_t resDigit = 0;
+ BitWidth = slen * bits_per_digit;
+ if (getNumWords() > 1)
+ assert((pVal = new uint64_t[getNumWords()]) &&
+ "APInt memory allocation fails!");
+ for (int i = slen - 1; i >= 0; --i) {
+ uint64_t digit = StrStart[i] - 48; // '0' == 48.
+ resDigit |= digit << nextBitPos;
+ nextBitPos += bits_per_digit;
+ if (nextBitPos >= 64) {
+ if (isSingleWord()) {
+ VAL = resDigit;
+ break;
+ }
+ pVal[size++] = resDigit;
+ nextBitPos -= 64;
+ resDigit = digit >> (bits_per_digit - nextBitPos);
+ }
+ }
+ if (!isSingleWord() && size <= getNumWords())
+ pVal[size] = resDigit;
+ } else { // General case. The radix is not a power of 2.
+ // For 10-radix, the max value of 64-bit integer is 18446744073709551615,
+ // and its digits number is 20.
+ const unsigned chars_per_word = 20;
+ if (slen < chars_per_word ||
+ (slen == chars_per_word && // In case the value <= 2^64 - 1
+ strcmp(StrStart, "18446744073709551615") <= 0)) {
+ BitWidth = 64;
+ VAL = strtoull(StrStart, 0, 10);
+ } else { // In case the value > 2^64 - 1
+ BitWidth = (slen / chars_per_word + 1) * 64;
+ assert((pVal = new uint64_t[getNumWords()]) &&
+ "APInt memory allocation fails!");
+ memset(pVal, 0, getNumWords() * 8);
+ unsigned str_pos = 0;
+ while (str_pos < slen) {
+ unsigned chunk = slen - str_pos;
+ if (chunk > chars_per_word - 1)
+ chunk = chars_per_word - 1;
+ uint64_t resDigit = StrStart[str_pos++] - 48; // 48 == '0'.
+ uint64_t big_base = radix;
+ while (--chunk > 0) {
+ resDigit = resDigit * radix + StrStart[str_pos++] - 48;
+ big_base *= radix;
+ }
+
+ uint64_t carry;
+ if (!size)
+ carry = resDigit;
+ else {
+ carry = mul_1(pVal, pVal, size, big_base);
+ carry += add_1(pVal, pVal, size, resDigit);
+ }
+
+ if (carry) pVal[size++] = carry;
+ }
+ }
+ }
+}
+
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