llvm/lib/Analysis
Chandler Carruth b7742df420 [PM/AA] Suffix lots of member variables that directly use enumeration
names for counts with the word 'Count' to make them less ambiguous.

This will be an actual error if we use unscoped enums for any of these,
and generally this seems much clearer to read.

Also, use clang-format to normalize the formatting of this code which
seems to have been needlessly odd.

No functionality changed here.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239887 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-17 07:21:41 +00:00
..

Analysis Opportunities:

//===---------------------------------------------------------------------===//

In test/Transforms/LoopStrengthReduce/quadradic-exit-value.ll, the
ScalarEvolution expression for %r is this:

  {1,+,3,+,2}<loop>

Outside the loop, this could be evaluated simply as (%n * %n), however
ScalarEvolution currently evaluates it as

  (-2 + (2 * (trunc i65 (((zext i64 (-2 + %n) to i65) * (zext i64 (-1 + %n) to i65)) /u 2) to i64)) + (3 * %n))

In addition to being much more complicated, it involves i65 arithmetic,
which is very inefficient when expanded into code.

//===---------------------------------------------------------------------===//

In formatValue in test/CodeGen/X86/lsr-delayed-fold.ll,

ScalarEvolution is forming this expression:

((trunc i64 (-1 * %arg5) to i32) + (trunc i64 %arg5 to i32) + (-1 * (trunc i64 undef to i32)))

This could be folded to

(-1 * (trunc i64 undef to i32))

//===---------------------------------------------------------------------===//