Factor the code for collecting IV users out of LSR into an IVUsers class,

and generalize it so that it can be used by IndVarSimplify. Implement the
base IndVarSimplify transformation code using IVUsers. This removes
TestOrigIVForWrap and associated code, as ScalarEvolution now has enough
builtin overflow detection and folding logic to handle all the same cases,
and more. Run "opt -iv-users -analyze -disable-output" on your favorite
loop for an example of what IVUsers does.

This lets IndVarSimplify eliminate IV casts and compute trip counts in
more cases. Also, this happens to finally fix the remaining testcases
in PR1301.

Now that IndVarSimplify is being more aggressive, it occasionally runs
into the problem where ScalarEvolutionExpander's code for avoiding
duplicate expansions makes it difficult to ensure that all expanded
instructions dominate all the instructions that will use them. As a
temporary measure, IndVarSimplify now uses a FixUsesBeforeDefs function
to fix up instructions inserted by SCEVExpander. Fortunately, this code
is contained, and can be easily removed once a more comprehensive
solution is available.

llvm-svn: 71535

1 files changed, 1 insertions, 1 deletions

diff --git a/llvm/test/Transforms/LoopStrengthReduce/2009-04-28-no-reduce-mul.ll b/llvm/test/Transforms/LoopStrengthReduce/2009-04-28-no-reduce-mul.ll
index 153a1811e63..f873b3d73e2 100644
--- a/llvm/test/Transforms/LoopStrengthReduce/2009-04-28-no-reduce-mul.ll
+++ b/llvm/test/Transforms/LoopStrengthReduce/2009-04-28-no-reduce-mul.ll
@@ -1,4 +1,4 @@
-; RUN: llvm-as < %s | opt -loop-reduce | llvm-dis | grep mul | count 3
+; RUN: llvm-as < %s | opt -loop-reduce | llvm-dis | grep {mul.*%lsr.iv} | count 2
 ; The multiply in bb2 must not be reduced to an add, as the sext causes the
 ; %1 argument to become negative after a while.
 ; ModuleID = '<stdin>'