Initial commit of LLVM 3.4

lib/Support/APInt.cpp

@@ -692,14 +692,14 @@ unsigned APInt::countLeadingZerosSlowCase() const {
   unsigned i = getNumWords();
   integerPart MSW = pVal[i-1] & MSWMask;
   if (MSW)
-    return CountLeadingZeros_64(MSW) - (APINT_BITS_PER_WORD - BitsInMSW);
+    return llvm::countLeadingZeros(MSW) - (APINT_BITS_PER_WORD - BitsInMSW);
 
   unsigned Count = BitsInMSW;
   for (--i; i > 0u; --i) {
     if (pVal[i-1] == 0)
       Count += APINT_BITS_PER_WORD;
     else {
-      Count += CountLeadingZeros_64(pVal[i-1]);
+      Count += llvm::countLeadingZeros(pVal[i-1]);
       break;
     }
   }
@@ -735,13 +735,13 @@ unsigned APInt::countLeadingOnes() const {
 
 unsigned APInt::countTrailingZeros() const {
   if (isSingleWord())
-    return std::min(unsigned(CountTrailingZeros_64(VAL)), BitWidth);
+    return std::min(unsigned(llvm::countTrailingZeros(VAL)), BitWidth);
   unsigned Count = 0;
   unsigned i = 0;
   for (; i < getNumWords() && pVal[i] == 0; ++i)
     Count += APINT_BITS_PER_WORD;
   if (i < getNumWords())
-    Count += CountTrailingZeros_64(pVal[i]);
+    Count += llvm::countTrailingZeros(pVal[i]);
   return std::min(Count, BitWidth);
 }
 
@@ -1512,7 +1512,7 @@ static void KnuthDiv(unsigned *u, unsigned *v, unsigned *q, unsigned* r,
   // and v so that its high bits are shifted to the top of v's range without
   // overflow. Note that this can require an extra word in u so that u must
   // be of length m+n+1.
-  unsigned shift = CountLeadingZeros_32(v[n-1]);
+  unsigned shift = countLeadingZeros(v[n-1]);
   unsigned v_carry = 0;
   unsigned u_carry = 0;
   if (shift) {
@@ -2304,24 +2304,7 @@ namespace {
   static unsigned int
   partMSB(integerPart value)
   {
-    unsigned int n, msb;
-
-    if (value == 0)
-      return -1U;
-
-    n = integerPartWidth / 2;
-
-    msb = 0;
-    do {
-      if (value >> n) {
-        value >>= n;
-        msb += n;
-      }
-
-      n >>= 1;
-    } while (n);
-
-    return msb;
+    return findLastSet(value, ZB_Max);
   }
 
   /* Returns the bit number of the least significant set bit of a
@@ -2329,24 +2312,7 @@ namespace {
   static unsigned int
   partLSB(integerPart value)
   {
-    unsigned int n, lsb;
-
-    if (value == 0)
-      return -1U;
-
-    lsb = integerPartWidth - 1;
-    n = integerPartWidth / 2;
-
-    do {
-      if (value << n) {
-        value <<= n;
-        lsb -= n;
-      }
-
-      n >>= 1;
-    } while (n);
-
-    return lsb;
+    return findFirstSet(value, ZB_Max);
   }
 }
 
@@ -2888,6 +2854,20 @@ APInt::tcIncrement(integerPart *dst, unsigned int parts)
   return i == parts;
 }
 
+/* Decrement a bignum in-place, return the borrow flag.  */
+integerPart
+APInt::tcDecrement(integerPart *dst, unsigned int parts) {
+  for (unsigned int i = 0; i < parts; i++) {
+    // If the current word is non-zero, then the decrement has no effect on the
+    // higher-order words of the integer and no borrow can occur. Exit early.
+    if (dst[i]--)
+      return 0;
+  }
+  // If every word was zero, then there is a borrow.
+  return 1;
+}
+
+
 /* Set the least significant BITS bits of a bignum, clear the
    rest.  */
 void