Files
llvm-6502/lib/Analysis
Hans Wennborg e13563e5ba Merging r228957:
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r228957 | bsteinbr | 2015-02-12 13:04:22 -0800 (Thu, 12 Feb 2015) | 14 lines

Fix a crash in the assumption cache when inlining indirect function calls

Summary:
Instances of the AssumptionCache are per function, so we can't re-use
the same AssumptionCache instance when recursing in the CallAnalyzer to
analyze a different function. Instead we have to pass the
AssumptionCacheTracker to the CallAnalyzer so it can get the right
AssumptionCache on demand.

Reviewers: hfinkel

Subscribers: llvm-commits, hans

Differential Revision: http://reviews.llvm.org/D7533
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_36@228965 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-12 21:28:02 +00:00
..
2015-02-12 21:28:02 +00:00
2015-01-22 16:58:19 +00:00
2015-02-09 03:35:35 +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))

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