Remove a use of getLowBitsSet that caused the mask used for replacement of
shl/lshr pairs with an AND instruction to be computed incorrectly. Its not
clear exactly why this is the case. This solves the disappearing shifts
problem, but it doesn't fix Regression/C/2003-05-21-UnionBitFields. It
seems there is more going on.

llvm-svn: 35342

llvm-svn: 35341

* Don't assume shift amounts are <= 64 bits
* Avoid creating an extra APInt in SubOne and AddOne by using -- and ++
* Add another use of getLowBitsSet
* Convert a series of if statements to a switch

llvm-svn: 35339

using the facilities of APInt. While this duplicates a tiny fraction of
the constant folding code, it also makes the code easier to read and
avoids large ConstantExpr overhead for simple, known computations.

llvm-svn: 35335

2. Use isStrictlyPositive() instead of isPositive() in two places where
   they need APInt value > 0 not only >=0.

llvm-svn: 35333

APInt with its type mask.

llvm-svn: 35325

* Convert the last use of a uint64_t that should have been an APInt.
* Change ComputeMaskedBits to have a const reference argument for the Mask
  so that recursions don't cause unneeded temporaries. This causes temps
  to be needed in other places (where the mask has to change) but this
  change optimizes for the recursion which is more frequent.
* Remove two instances of &ing a Mask with getAllOnesValue. Its not
  needed any more because APInt is accurate in its bit computations.
* Start using the getLowBitsSet and getHighBits set methods on APInt
  instead of shifting. This makes it more clear in the code what is
  going on.

llvm-svn: 35321

llvm-svn: 35314

llvm-svn: 35297

Convert some calls to ConstantInt::getZExtValue() into getValue() and
use APInt facilities in the subsequent computations.

llvm-svn: 35294

* APIntify visitAdd and visitSelectInst
* Remove unused uint64_t versions of utility functions that have been
  replaced with APInt versions.
This completes most of the changes for APIntification of InstCombine. This
passes llvm-test and llvm/test/Transforms/InstCombine/APInt.

Patch by Zhou Sheng.

llvm-svn: 35287

APIntify visitDiv, visitMul and visitRem.

Patch by Zhou Sheng.

llvm-svn: 35283

llvm-svn: 35282

APIntify several utility functions supporting logical operators and shift
operators.

Patch by Zhou Sheng.

llvm-svn: 35281

llvm-svn: 35276

llvm-svn: 35275

APInt support for logical operators in visitAnd, visitOr, and visitXor.

Patch by Zhou Sheng.

llvm-svn: 35273

* APIntify commonIntCastTransforms
* APIntify visitTrunc
* APIntify visitZExt

Patch by Zhou Sheng.

llvm-svn: 35271

* Re-enable the APInt version of MaskedValueIsZero.
* APIntify the Comput{Un}SignedMinMaxValuesFromKnownBits functions
* APIntify visitICmpInst.

llvm-svn: 35270

llvm-svn: 35265

Analyze GEPs. If the indices are all zero, transfer whether the pointer is
known to be not null through the GEP.

Add a few more cases for xor and shift instructions.

llvm-svn: 35257

* Fix some indentation and comments in InsertRangeTest
* Add an "IsSigned" parameter to AddWithOverflow and make it handle signed
  additions. Also, APIntify this function so it works with any bitwidth.
* For the icmp pred ([us]div %X, C1), C2 transforms, exit early if the
  div instruction's RHS is zero.
* Finally, for icmp pred (sdiv %X, C1), -C2, fix an off-by-one error. The
  HiBound needs to be incremented in order to get the range test correct.

llvm-svn: 35247

instructions (that would have to be split later)

llvm-svn: 35227

llvm-svn: 35224

Use ETForest instead of DominatorSet.

llvm-svn: 35221

llvm-svn: 35211

llvm-svn: 35197

llvm-svn: 35194

llvm-svn: 35190

Patch by Sheng Zhou.

llvm-svn: 35188

Patch by Zhou Sheng.

llvm-svn: 35187

llvm-svn: 35186

2. Replace uses of the "isPositive" utility function with APInt::isPositive

llvm-svn: 35185

Patch by Sheng Zhou.

llvm-svn: 35184

llvm-svn: 35169

implements Transforms/ScalarRepl/memset-aggregate-byte-leader.ll

llvm-svn: 35150

llvm-svn: 35146

Rearrange some code to simplify it now that shifts are binops

llvm-svn: 35145

Add some more micro-optimizations: x * 0 = 0, a - x = a --> x = 0.

llvm-svn: 35138

llvm-svn: 35137