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authorAndrew Trick <atrick@apple.com>2011-06-21 03:22:38 +0000
committerAndrew Trick <atrick@apple.com>2011-06-21 03:22:38 +0000
commit2fabd464ae9fd33f068066e3fc3d0caa7ea2279d (patch)
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parenta88a0ca8082006b37d14d8aee4a644b20bae8bc9 (diff)
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indvars -disable-iv-rewrite: Adds support for eliminating identity
ops. This is a rewrite of the IV simplification algorithm used by -disable-iv-rewrite. To avoid perturbing the default mode, I temporarily split the driver and created SimplifyIVUsersNoRewrite. The idea is to avoid doing opcode/pattern matching inside IndVarSimplify. SCEV already does it. We want to optimize with the full generality of SCEV, but optimize def-use chains top down on-demand rather than rewriting the entire expression bottom-up. This was easy to do for operations that SCEV can prove are identity function. So we're now eliminating bitmasks and zero extends this way. A result of this rewrite is that indvars -disable-iv-rewrite no longer requires IVUsers. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133502 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test/Transforms/IndVarSimplify/iv-zext.ll')
-rw-r--r--test/Transforms/IndVarSimplify/iv-zext.ll1
1 files changed, 1 insertions, 0 deletions
diff --git a/test/Transforms/IndVarSimplify/iv-zext.ll b/test/Transforms/IndVarSimplify/iv-zext.ll
index 00018ec..3a05c89 100644
--- a/test/Transforms/IndVarSimplify/iv-zext.ll
+++ b/test/Transforms/IndVarSimplify/iv-zext.ll
@@ -1,4 +1,5 @@
; RUN: opt < %s -indvars -S | FileCheck %s
+; RUN: opt < %s -indvars -disable-iv-rewrite -S | FileCheck %s
; CHECK-NOT: and
; CHECK-NOT: zext