arbitrary iteration.
The patch:
1) changes SCEVSDivExpr into SCEVUDivExpr,
2) replaces PartialFact() function with BinomialCoefficient(); the
computations (essentially, the division) in BinomialCoefficient() are
performed with the apprioprate bitwidth necessary to avoid overflow;
unsigned division is used instead of the signed one.
Computations in BinomialCoefficient() require support from the code
generator for APInts. Currently, we use a hack rounding up the
neccessary bitwidth to the nearest power of 2. The hack is easy to turn
off in future.
One remaining issue: we assume the divisor of the binomial coefficient
formula can be computed accurately using 16 bits. It means we can handle
AddRecs of length up to 9. In future, we should use APInts to evaluate
the divisor.
Thanks to Nicholas for cooperation!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46955 91177308-0d34-0410-b5e6-96231b3b80d8
is disabled in the sense that it will refuse to create one from a UDiv
instruction, until the code is better tested.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44163 91177308-0d34-0410-b5e6-96231b3b80d8
Always pass the constant as the second parameter to HowManyLessThans.
Remove obsolete "isSigned" parameter.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@39893 91177308-0d34-0410-b5e6-96231b3b80d8
This created an ambiguity for expandInTy to decide when to use
sign-extension or zero-extension, but it turns out that most of its callers
don't actually need a type conversion, now that LLVM types don't have
explicit signedness. Drop expandInTy in favor of plain expand, and change
the few places that actually need a type conversion to do it themselves.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37591 91177308-0d34-0410-b5e6-96231b3b80d8
This patch removes the SetCC instructions and replaces them with the ICmp
and FCmp instructions. The SetCondInst instruction has been removed and
been replaced with ICmpInst and FCmpInst.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@32751 91177308-0d34-0410-b5e6-96231b3b80d8
rework the hacks that had us passing OStream in. We pass in std::ostream*
instead, check for null, and then dispatch to the correct print() method.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@32636 91177308-0d34-0410-b5e6-96231b3b80d8
Make necessary changes to support DIV -> [SUF]Div. This changes llvm to
have three division instructions: signed, unsigned, floating point. The
bytecode and assembler are bacwards compatible, however.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31195 91177308-0d34-0410-b5e6-96231b3b80d8
PR726 by performing consistent signed division, not consistent unsigned
division when evaluating scev's. Do not touch udivs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@27326 91177308-0d34-0410-b5e6-96231b3b80d8
