summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
Diffstat
-rw-r--r--lib/Support/APInt.cpp72
-rw-r--r--unittests/ADT/APIntTest.cpp82
2 files changed, 124 insertions, 30 deletions
diff --git a/lib/Support/APInt.cpp b/lib/Support/APInt.cpp
index 6b637ba20c..b4e94c9184 100644
--- a/lib/Support/APInt.cpp
+++ b/lib/Support/APInt.cpp
@@ -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) {
diff --git a/unittests/ADT/APIntTest.cpp b/unittests/ADT/APIntTest.cpp
index 8208af30cd..0e094ffaef 100644
--- a/unittests/ADT/APIntTest.cpp
+++ b/unittests/ADT/APIntTest.cpp
@@ -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");
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-20 02:34:12 +0000