[llvm] r271380 - Fix off-by-one error in max integer functions

[Dylan McKay via llvm-commits]

Will do.
On 2 Jun 2016 05:05, "David Blaikie" <dblaikie at gmail.com> wrote:

> Please include/provide a test case - these could probably use a bunch of
> unit tests.
>
> On Wed, Jun 1, 2016 at 4:15 AM, Dylan McKay via llvm-commits <
> llvm-commits at lists.llvm.org> wrote:
>
>> Author: dylanmckay
>> Date: Wed Jun  1 06:15:25 2016
>> New Revision: 271380
>>
>> URL: http://llvm.org/viewvc/llvm-project?rev=271380&view=rev
>> Log:
>> Fix off-by-one error in max integer functions
>>
>> I recently added these functions, but implemented them poorly. This
>> fixes that.
>>
>> Sorry for the spam.
>>
>> Modified:
>>     llvm/trunk/include/llvm/Support/MathExtras.h
>>
>> Modified: llvm/trunk/include/llvm/Support/MathExtras.h
>> URL:
>> http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Support/MathExtras.h?rev=271380&r1=271379&r2=271380&view=diff
>>
>> ==============================================================================
>> --- llvm/trunk/include/llvm/Support/MathExtras.h (original)
>> +++ llvm/trunk/include/llvm/Support/MathExtras.h Wed Jun  1 06:15:25 2016
>> @@ -312,22 +312,22 @@ inline bool isShiftedUInt(uint64_t x) {
>>  }
>>
>>  /// Gets the maximum value for a N-bit unsigned integer.
>> -inline uint64_t maxUIntN(uint64_t N) { return UINT64_C(1) << N; }
>> +inline uint64_t maxUIntN(uint64_t N) { return (UINT64_C(1) << N) - 1; }
>>  /// Gets the minimum value for a N-bit signed integer.
>>  inline int64_t minIntN(int64_t N) { return -(INT64_C(1)<<(N-1)); }
>>  /// Gets the maximum value for a N-bit signed integer.
>> -inline int64_t maxIntN(int64_t N) { return INT64_C(1)<<(N-1); }
>> +inline int64_t maxIntN(int64_t N) { return (INT64_C(1)<<(N-1)) - 1; }
>>
>>  /// isUIntN - Checks if an unsigned integer fits into the given (dynamic)
>>  /// bit width.
>>  inline bool isUIntN(unsigned N, uint64_t x) {
>> -  return N >= 64 || x < maxUIntN(N);
>> +  return N >= 64 || x <= maxUIntN(N);
>>  }
>>
>>  /// isIntN - Checks if an signed integer fits into the given (dynamic)
>>  /// bit width.
>>  inline bool isIntN(unsigned N, int64_t x) {
>> -  return N >= 64 || (minIntN(N) <= x && x < maxIntN(N));
>> +  return N >= 64 || (minIntN(N) <= x && x <= maxIntN(N));
>>  }
>>
>>  /// isMask_32 - This function returns true if the argument is a non-empty
>>
>>
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>
>
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