Re-implement the main strength-reduction portion of LoopStrengthReduction.
This new version is much more aggressive about doing "full" reduction in
cases where it reduces register pressure, and also more aggressive about
rewriting induction variables to count down (or up) to zero when doing so
reduces register pressure.
It currently uses fairly simplistic algorithms for finding reuse
opportunities, but it introduces a new framework allows it to combine
multiple strategies at once to form hybrid solutions, instead of doing
all full-reduction or all base+index.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94061 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Transforms/LoopStrengthReduce/count-to-zero.ll b/test/Transforms/LoopStrengthReduce/count-to-zero.ll
index 8cc3b5c..feb79f8 100644
--- a/test/Transforms/LoopStrengthReduce/count-to-zero.ll
+++ b/test/Transforms/LoopStrengthReduce/count-to-zero.ll
@@ -19,7 +19,7 @@
%tmp4 = add i32 %c_addr.1, -1 ; <i32> [#uses=1]
%c_addr.1.be = select i1 %tmp2, i32 %tmp3, i32 %tmp4 ; <i32> [#uses=1]
%indvar.next = add i32 %indvar, 1 ; <i32> [#uses=1]
-; CHECK: sub i32 %lsr.iv, 1
+; CHECK: add i32 %lsr.iv, -1
br label %bb6
bb6: ; preds = %bb3, %entry