two's complement bignum arithmetic. They could be used to
implement much of APInt, but the idea is they are enough to
implement APFloat as well, which the current APInt interface
is not suited for.
Patch by Neil Booth!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@41124 91177308-0d34-0410-b5e6-96231b3b80d8
can't use getZExtValue() to extract the low order bits for each digit.
Instead, we need to access the low order word directly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37242 91177308-0d34-0410-b5e6-96231b3b80d8
not being generated correctly because the shl operator does not mutate its
object but returns a new value. Also, make the distinction between radix
16 and the others more clear.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37111 91177308-0d34-0410-b5e6-96231b3b80d8
types:
1. Functions to compute div/rem at the same time.
2. Further assurance that an APInt with 0 bitwidth cannot be constructed.
3. Left and right rotate operations.
4. An exactLogBase2 function which requires an exact power of two or it
returns -1.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37025 91177308-0d34-0410-b5e6-96231b3b80d8
shift amount is 0. Previously this code would do a lshr by the bit width
which can lead to incorrect results.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37010 91177308-0d34-0410-b5e6-96231b3b80d8
this to a NOTE: because pari/gp results start to get rounded incorrectly
after 192 bits of precision. APInt and pari/gp never differ by more than
1, but APInt is more accurate because it does not lose precision after 192
bits as does pari/gp.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34834 91177308-0d34-0410-b5e6-96231b3b80d8
the bit width of negative numbers by computing the minimum bit width for a
negative value. E.g. 0x1800000000000000 could be just 0x8000000000000000
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34695 91177308-0d34-0410-b5e6-96231b3b80d8
1. Add unsigned and signed versions of methods so a "bool" argument doesn't
need to be passed in.
2. Make the various getMin/getMax functions all be inline since they are
so simple.
3. Simplify sdiv and srem code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34680 91177308-0d34-0410-b5e6-96231b3b80d8
2. Change RoundDoubleToAPInt to take a bit width parameter. Use that
parameter to limit the bit width of the result.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34673 91177308-0d34-0410-b5e6-96231b3b80d8
2. Rewrite operator=(const APInt& RHS) to allow the RHS to be a different
bit width than the LHS. This makes it possible to use APInt as the key
of a DenseMap, as needed for the IntConstants map in Constants.cpp
3. Fix operator=(uint64_t) to clear unused bits in case the client assigns
a value that has more bits than the APInt allows.
4. Assert that bit widths are equal in operator==
5. Revise getHashValue() to put the bit width in the low order six bits.
This should help to make i1 0, i2 0, ... i64 0 all distinct in the
IntConstants DenseMap.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34646 91177308-0d34-0410-b5e6-96231b3b80d8
2. Fix countTrailingZeros to use a faster algorithm.
3. Simplify sext() slightly by using isNegative().
4. Implement ashr using word-at-a-time logic instead of bit-at-a-time
5. Rename locals named isNegative so they don't clash with method name.
6. Fix fromString to compute negated value correctly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34629 91177308-0d34-0410-b5e6-96231b3b80d8
2. Implement the trunc, sext, and zext operations.
3. Improve fromString to accept negative values as input.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34616 91177308-0d34-0410-b5e6-96231b3b80d8
2. Move comments for methods to .h file, delete them in .cpp file.
3. All places that were doing manual clear of high order bits now call the
clearUnusedBits() method in order to not depend on undefined behavior
of the >> operator when the number of bits shifted equals the word size.
4. Reduced # of loc by using the new result of clearUnusedBits() method.
5. Simplified logic (decreased indentation) in a few places.
6. Added code comments to larger functions that needed them.
7. Added FIXME notes about weak implementations of things (e.g. bit-by-bit
shift right is sub-optimal).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34603 91177308-0d34-0410-b5e6-96231b3b80d8
