Summary: This patch fixes step D4 of Knuth's division algorithm implementation. Negative sign of the step result was not always detected due to incorrect "borrow" handling.
Test Plan: Unit test that reveals the bug included.
Reviewers: chandlerc, yaron.keren
Reviewed By: yaron.keren
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D9196
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235699 91177308-0d34-0410-b5e6-96231b3b80d8
APInt uses Knuth's D algorithm for long division. In rare cases the
implementation applied a transformation that was not needed.
Added unit tests for long division. KnuthDiv() procedure is fully covered.
There is a case in APInt::divide() that I believe is never used (marked with
a comment) as all users of divide() handle trivial cases earlier.
Patch by Pawel Bylica!
http://reviews.llvm.org/D8448
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To complement getSplat. This is more general than the binary
decomposition method as it also handles non-pow2 splat sizes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233195 91177308-0d34-0410-b5e6-96231b3b80d8
Now that SmallString is a first-class citizen, most SmallString::str()
calls are not required. This patch removes a whole bunch of them, yet
there are lots more.
There are two use cases where str() is really needed:
1) To use one of StringRef member functions which is not available in
SmallString.
2) To convert to std::string, as StringRef implicitly converts while
SmallString do not. We may wish to change this, but it may introduce
ambiguity.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232622 91177308-0d34-0410-b5e6-96231b3b80d8
This mirrors the behavior of APInt::udiv and APInt::urem. Some
architectures, like X86, have a single instruction which can compute
both division and remainder.
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We have a transform that changes:
(x lshr C1) udiv C2
into:
x udiv (C2 << C1)
However, it is unsafe to do so if C2 << C1 discards any of C2's bits.
This fixes PR21255.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219634 91177308-0d34-0410-b5e6-96231b3b80d8
Sweep the codebase for common typos. Includes some changes to visible function
names that were misspelt.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200018 91177308-0d34-0410-b5e6-96231b3b80d8
Sooooo many of these had incorrect or strange main module includes.
I have manually inspected all of these, and fixed the main module
include to be the nearest plausible thing I could find. If you own or
care about any of these source files, I encourage you to take some time
and check that these edits were sensible. I can't have broken anything
(I strictly added headers, and reordered them, never removed), but they
may not be the headers you'd really like to identify as containing the
API being implemented.
Many forward declarations and missing includes were added to a header
files to allow them to parse cleanly when included first. The main
module rule does in fact have its merits. =]
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new hash_value infrastructure, and replace their implementations using
hash_combine. This removes a complete copy of Jenkin's lookup3 hash
function (which is both significantly slower and lower quality than the
one implemented in hash_combine) along with a somewhat scary xor-only
hash function.
Now that APInt and APFloat can be passed directly to hash_combine,
simplify the rest of the LLVMContextImpl hashing to use the new
infrastructure.
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errors like the one corrected by r135261. Migrate all LLVM callers of the old
constructor to the new one.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135431 91177308-0d34-0410-b5e6-96231b3b80d8
toString() now takes an optional bool argument that,
depending on the radix, adds the appropriate prefix
to the integer's string representation that makes it into a
meaningful C literal, e.g.:
hexademical: '-f' becomes '-0xf'
octal: '77' becomes '077'
binary: '110' becomes '0b110'
Patch by nobled@dreamwidth.org!
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