[llvm-commits] [llvm] r97381 - in /llvm/trunk: include/llvm/ADT/APInt.h include/llvm/ADT/StringRef.h lib/Support/StringRef.cpp
John McCall
rjmccall at apple.com
Sun Feb 28 01:55:58 PST 2010
Author: rjmccall
Date: Sun Feb 28 03:55:58 2010
New Revision: 97381
URL: http://llvm.org/viewvc/llvm-project?rev=97381&view=rev
Log:
Add an override to StringRef::getAsInteger which parses into an APInt.
It gets its own implementation totally divorced from the (presumably
performance-sensitive) routines which parse into a uint64_t.
Add APInt::operator|=(uint64_t), which is situationally much better than
using a full APInt.
Modified:
llvm/trunk/include/llvm/ADT/APInt.h
llvm/trunk/include/llvm/ADT/StringRef.h
llvm/trunk/lib/Support/StringRef.cpp
Modified: llvm/trunk/include/llvm/ADT/APInt.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/ADT/APInt.h?rev=97381&r1=97380&r2=97381&view=diff
==============================================================================
--- llvm/trunk/include/llvm/ADT/APInt.h (original)
+++ llvm/trunk/include/llvm/ADT/APInt.h Sun Feb 28 03:55:58 2010
@@ -150,7 +150,17 @@
return isSingleWord() ? VAL : pVal[whichWord(bitPosition)];
}
+ /// Converts a string into a number. The string must be non-empty
+ /// and well-formed as a number of the given base. The bit-width
+ /// must be sufficient to hold the result.
+ ///
/// This is used by the constructors that take string arguments.
+ ///
+ /// StringRef::getAsInteger is superficially similar but (1) does
+ /// not assume that the string is well-formed and (2) grows the
+ /// result to hold the input.
+ ///
+ /// @param radix 2, 8, 10, or 16
/// @brief Convert a char array into an APInt
void fromString(unsigned numBits, const StringRef &str, uint8_t radix);
@@ -571,6 +581,21 @@
/// @brief Bitwise OR assignment operator.
APInt& operator|=(const APInt& RHS);
+ /// Performs a bitwise OR operation on this APInt and RHS. RHS is
+ /// logically zero-extended or truncated to match the bit-width of
+ /// the LHS.
+ ///
+ /// @brief Bitwise OR assignment operator.
+ APInt& operator|=(uint64_t RHS) {
+ if (isSingleWord()) {
+ VAL |= RHS;
+ clearUnusedBits();
+ } else {
+ pVal[0] |= RHS;
+ }
+ return *this;
+ }
+
/// Performs a bitwise XOR operation on this APInt and RHS. The result is
/// assigned to *this.
/// @returns *this after XORing with RHS.
Modified: llvm/trunk/include/llvm/ADT/StringRef.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/ADT/StringRef.h?rev=97381&r1=97380&r2=97381&view=diff
==============================================================================
--- llvm/trunk/include/llvm/ADT/StringRef.h (original)
+++ llvm/trunk/include/llvm/ADT/StringRef.h Sun Feb 28 03:55:58 2010
@@ -18,6 +18,7 @@
namespace llvm {
template<typename T>
class SmallVectorImpl;
+ class APInt;
/// StringRef - Represent a constant reference to a string, i.e. a character
/// array and a length, which need not be null terminated.
@@ -273,6 +274,19 @@
// TODO: Provide overloads for int/unsigned that check for overflow.
+ /// getAsInteger - Parse the current string as an integer of the
+ /// specified radix, or of an autosensed radix if the radix given
+ /// is 0. The current value in Result is discarded, and the
+ /// storage is changed to be wide enough to store the parsed
+ /// integer.
+ ///
+ /// Returns true if the string does not solely consist of a valid
+ /// non-empty number in the appropriate base.
+ ///
+ /// APInt::fromString is superficially similar but assumes the
+ /// string is well-formed in the given radix.
+ bool getAsInteger(unsigned Radix, APInt &Result) const;
+
/// @}
/// @name Substring Operations
/// @{
Modified: llvm/trunk/lib/Support/StringRef.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/StringRef.cpp?rev=97381&r1=97380&r2=97381&view=diff
==============================================================================
--- llvm/trunk/lib/Support/StringRef.cpp (original)
+++ llvm/trunk/lib/Support/StringRef.cpp Sun Feb 28 03:55:58 2010
@@ -8,6 +8,7 @@
//===----------------------------------------------------------------------===//
#include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/APInt.h"
using namespace llvm;
@@ -172,23 +173,28 @@
return Count;
}
+static unsigned GetAutoSenseRadix(StringRef &Str) {
+ if (Str.startswith("0x")) {
+ Str = Str.substr(2);
+ return 16;
+ } else if (Str.startswith("0b")) {
+ Str = Str.substr(2);
+ return 2;
+ } else if (Str.startswith("0")) {
+ return 8;
+ } else {
+ return 10;
+ }
+}
+
+
/// GetAsUnsignedInteger - Workhorse method that converts a integer character
/// sequence of radix up to 36 to an unsigned long long value.
static bool GetAsUnsignedInteger(StringRef Str, unsigned Radix,
unsigned long long &Result) {
// Autosense radix if not specified.
- if (Radix == 0) {
- if (Str.startswith("0x")) {
- Str = Str.substr(2);
- Radix = 16;
- } else if (Str.startswith("0b")) {
- Str = Str.substr(2);
- Radix = 2;
- } else if (Str.startswith("0"))
- Radix = 8;
- else
- Radix = 10;
- }
+ if (Radix == 0)
+ Radix = GetAutoSenseRadix(Str);
// Empty strings (after the radix autosense) are invalid.
if (Str.empty()) return true;
@@ -272,3 +278,78 @@
Result = Val;
return false;
}
+
+bool StringRef::getAsInteger(unsigned Radix, APInt &Result) const {
+ StringRef Str = *this;
+
+ // Autosense radix if not specified.
+ if (Radix == 0)
+ Radix = GetAutoSenseRadix(Str);
+
+ assert(Radix > 1 && Radix <= 36);
+
+ // Empty strings (after the radix autosense) are invalid.
+ if (Str.empty()) return true;
+
+ // Skip leading zeroes. This can be a significant improvement if
+ // it means we don't need > 64 bits.
+ while (!Str.empty() && Str.front() == '0')
+ Str = Str.substr(1);
+
+ // If it was nothing but zeroes....
+ if (Str.empty()) {
+ Result = APInt(64, 0);
+ return false;
+ }
+
+ // (Over-)estimate the required number of bits.
+ unsigned Log2Radix = 0;
+ while ((1U << Log2Radix) < Radix) Log2Radix++;
+ bool IsPowerOf2Radix = ((1U << Log2Radix) == Radix);
+
+ unsigned BitWidth = Log2Radix * Str.size();
+ if (BitWidth < Result.getBitWidth())
+ BitWidth = Result.getBitWidth(); // don't shrink the result
+ else
+ Result.zext(BitWidth);
+
+ APInt RadixAP, CharAP; // unused unless !IsPowerOf2Radix
+ if (!IsPowerOf2Radix) {
+ // These must have the same bit-width as Result.
+ RadixAP = APInt(BitWidth, Radix);
+ CharAP = APInt(BitWidth, 0);
+ }
+
+ // Parse all the bytes of the string given this radix.
+ Result = 0;
+ while (!Str.empty()) {
+ unsigned CharVal;
+ if (Str[0] >= '0' && Str[0] <= '9')
+ CharVal = Str[0]-'0';
+ else if (Str[0] >= 'a' && Str[0] <= 'z')
+ CharVal = Str[0]-'a'+10;
+ else if (Str[0] >= 'A' && Str[0] <= 'Z')
+ CharVal = Str[0]-'A'+10;
+ else
+ return true;
+
+ // If the parsed value is larger than the integer radix, the string is
+ // invalid.
+ if (CharVal >= Radix)
+ return true;
+
+ // Add in this character.
+ if (IsPowerOf2Radix) {
+ Result <<= Log2Radix;
+ Result |= CharVal;
+ } else {
+ Result *= RadixAP;
+ CharAP = CharVal;
+ Result += CharAP;
+ }
+
+ Str = Str.substr(1);
+ }
+
+ return false;
+}
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