Fix bug with APInt::getBitsNeeded with for base 10 numbers 0-9.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79593 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Erick Tryzelaar 2009-08-21 03:15:28 +00:00
parent bb97531a5a
commit ae8f78d4de
2 changed files with 124 additions and 30 deletions

View File

@ -44,6 +44,35 @@ inline static uint64_t* getMemory(unsigned numWords) {
return result;
}
/// A utility function that converts a character to a digit.
inline static unsigned getDigit(char cdigit, uint8_t radix) {
// Get a digit
unsigned digit = 0;
if (radix == 16) {
if (!isxdigit(cdigit))
llvm_unreachable("Invalid hex digit in string");
if (isdigit(cdigit))
digit = cdigit - '0';
else if (cdigit >= 'a')
digit = cdigit - 'a' + 10;
else if (cdigit >= 'A')
digit = cdigit - 'A' + 10;
else
llvm_unreachable("huh? we shouldn't get here");
} else if (isdigit(cdigit)) {
digit = cdigit - '0';
assert((radix == 10 ||
(radix == 8 && digit != 8 && digit != 9) ||
(radix == 2 && (digit == 0 || digit == 1))) &&
"Invalid digit in string for given radix");
} else {
llvm_unreachable("Invalid character in digit string");
}
return digit;
}
void APInt::initSlowCase(unsigned numBits, uint64_t val, bool isSigned) {
pVal = getClearedMemory(getNumWords());
pVal[0] = val;
@ -611,22 +640,27 @@ unsigned APInt::getBitsNeeded(const StringRef& str, uint8_t radix) {
if (radix == 16)
return slen * 4 + isNegative;
// Otherwise it must be radix == 10, the hard case
assert(radix == 10 && "Invalid radix");
// This is grossly inefficient but accurate. We could probably do something
// with a computation of roughly slen*64/20 and then adjust by the value of
// the first few digits. But, I'm not sure how accurate that could be.
// Compute a sufficient number of bits that is always large enough but might
// be too large. This avoids the assertion in the constructor.
unsigned sufficient = slen*64/18;
// be too large. This avoids the assertion in the constructor. This
// calculation doesn't work appropriately for the numbers 0-9, so just use 4
// bits in that case.
unsigned sufficient = slen == 1 ? 4 : slen * 64/18;
// Convert to the actual binary value.
APInt tmp(sufficient, StringRef(p, slen), radix);
// Compute how many bits are required.
return isNegative + tmp.logBase2() + 1;
// Compute how many bits are required. If the log is infinite, assume we need
// just bit.
unsigned log = tmp.logBase2();
if (log == (unsigned)-1) {
return isNegative + 1;
} else {
return isNegative + log + 1;
}
}
// From http://www.burtleburtle.net, byBob Jenkins.
@ -2039,29 +2073,7 @@ void APInt::fromString(unsigned numbits, const StringRef& str, uint8_t radix) {
// Enter digit traversal loop
for (StringRef::iterator e = str.end(); p != e; ++p) {
// Get a digit
unsigned digit = 0;
char cdigit = *p;
if (radix == 16) {
if (!isxdigit(cdigit))
llvm_unreachable("Invalid hex digit in string");
if (isdigit(cdigit))
digit = cdigit - '0';
else if (cdigit >= 'a')
digit = cdigit - 'a' + 10;
else if (cdigit >= 'A')
digit = cdigit - 'A' + 10;
else
llvm_unreachable("huh? we shouldn't get here");
} else if (isdigit(cdigit)) {
digit = cdigit - '0';
assert((radix == 10 ||
(radix == 8 && digit != 8 && digit != 9) ||
(radix == 2 && (digit == 0 || digit == 1))) &&
"Invalid digit in string for given radix");
} else {
llvm_unreachable("Invalid character in digit string");
}
unsigned digit = getDigit(*p, radix);
// Shift or multiply the value by the radix
if (slen > 1) {

View File

@ -235,6 +235,88 @@ TEST(APIntTest, fromString) {
EXPECT_EQ(APInt(32, -32), APInt(32, "-20", 16));
}
TEST(APIntTest, StringBitsNeeded2) {
EXPECT_EQ(1U, APInt::getBitsNeeded( "0", 2));
EXPECT_EQ(1U, APInt::getBitsNeeded( "1", 2));
EXPECT_EQ(2U, APInt::getBitsNeeded( "10", 2));
EXPECT_EQ(2U, APInt::getBitsNeeded( "11", 2));
EXPECT_EQ(3U, APInt::getBitsNeeded("100", 2));
EXPECT_EQ(1U, APInt::getBitsNeeded( "+0", 2));
EXPECT_EQ(1U, APInt::getBitsNeeded( "+1", 2));
EXPECT_EQ(2U, APInt::getBitsNeeded( "+10", 2));
EXPECT_EQ(2U, APInt::getBitsNeeded( "+11", 2));
EXPECT_EQ(3U, APInt::getBitsNeeded("+100", 2));
EXPECT_EQ(2U, APInt::getBitsNeeded( "-0", 2));
EXPECT_EQ(2U, APInt::getBitsNeeded( "-1", 2));
EXPECT_EQ(3U, APInt::getBitsNeeded( "-10", 2));
EXPECT_EQ(3U, APInt::getBitsNeeded( "-11", 2));
EXPECT_EQ(4U, APInt::getBitsNeeded("-100", 2));
}
TEST(APIntTest, StringBitsNeeded8) {
EXPECT_EQ(3U, APInt::getBitsNeeded( "0", 8));
EXPECT_EQ(3U, APInt::getBitsNeeded( "7", 8));
EXPECT_EQ(6U, APInt::getBitsNeeded("10", 8));
EXPECT_EQ(6U, APInt::getBitsNeeded("17", 8));
EXPECT_EQ(6U, APInt::getBitsNeeded("20", 8));
EXPECT_EQ(3U, APInt::getBitsNeeded( "+0", 8));
EXPECT_EQ(3U, APInt::getBitsNeeded( "+7", 8));
EXPECT_EQ(6U, APInt::getBitsNeeded("+10", 8));
EXPECT_EQ(6U, APInt::getBitsNeeded("+17", 8));
EXPECT_EQ(6U, APInt::getBitsNeeded("+20", 8));
EXPECT_EQ(4U, APInt::getBitsNeeded( "-0", 8));
EXPECT_EQ(4U, APInt::getBitsNeeded( "-7", 8));
EXPECT_EQ(7U, APInt::getBitsNeeded("-10", 8));
EXPECT_EQ(7U, APInt::getBitsNeeded("-17", 8));
EXPECT_EQ(7U, APInt::getBitsNeeded("-20", 8));
}
TEST(APIntTest, StringBitsNeeded10) {
EXPECT_EQ(1U, APInt::getBitsNeeded( "0", 10));
EXPECT_EQ(2U, APInt::getBitsNeeded( "3", 10));
EXPECT_EQ(4U, APInt::getBitsNeeded( "9", 10));
EXPECT_EQ(4U, APInt::getBitsNeeded("10", 10));
EXPECT_EQ(5U, APInt::getBitsNeeded("19", 10));
EXPECT_EQ(5U, APInt::getBitsNeeded("20", 10));
EXPECT_EQ(1U, APInt::getBitsNeeded( "+0", 10));
EXPECT_EQ(4U, APInt::getBitsNeeded( "+9", 10));
EXPECT_EQ(4U, APInt::getBitsNeeded("+10", 10));
EXPECT_EQ(5U, APInt::getBitsNeeded("+19", 10));
EXPECT_EQ(5U, APInt::getBitsNeeded("+20", 10));
EXPECT_EQ(2U, APInt::getBitsNeeded( "-0", 10));
EXPECT_EQ(5U, APInt::getBitsNeeded( "-9", 10));
EXPECT_EQ(5U, APInt::getBitsNeeded("-10", 10));
EXPECT_EQ(6U, APInt::getBitsNeeded("-19", 10));
EXPECT_EQ(6U, APInt::getBitsNeeded("-20", 10));
}
TEST(APIntTest, StringBitsNeeded16) {
EXPECT_EQ(4U, APInt::getBitsNeeded( "0", 16));
EXPECT_EQ(4U, APInt::getBitsNeeded( "F", 16));
EXPECT_EQ(8U, APInt::getBitsNeeded("10", 16));
EXPECT_EQ(8U, APInt::getBitsNeeded("1F", 16));
EXPECT_EQ(8U, APInt::getBitsNeeded("20", 16));
EXPECT_EQ(4U, APInt::getBitsNeeded( "+0", 16));
EXPECT_EQ(4U, APInt::getBitsNeeded( "+F", 16));
EXPECT_EQ(8U, APInt::getBitsNeeded("+10", 16));
EXPECT_EQ(8U, APInt::getBitsNeeded("+1F", 16));
EXPECT_EQ(8U, APInt::getBitsNeeded("+20", 16));
EXPECT_EQ(5U, APInt::getBitsNeeded( "-0", 16));
EXPECT_EQ(5U, APInt::getBitsNeeded( "-F", 16));
EXPECT_EQ(9U, APInt::getBitsNeeded("-10", 16));
EXPECT_EQ(9U, APInt::getBitsNeeded("-1F", 16));
EXPECT_EQ(9U, APInt::getBitsNeeded("-20", 16));
}
#ifdef GTEST_HAS_DEATH_TEST
TEST(APIntTest, StringDeath) {
EXPECT_DEATH(APInt(0, "", 0), "Bitwidth too small");