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| author | Chris Lattner <sabre@nondot.org> | 2010-12-14 08:01:53 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2010-12-14 08:01:53 +0000 |
| commit | 60d410d7bb2eb11f36a004237e5948ffc5aff5a6 (patch) | |
| tree | 41aa1ddee919eadb28ff342de596e69ebc5d22b3 /test/Transforms/SimplifyCFG/PhiBlockMerge.ll | |
| parent | 071edc81f2a34ff689a2008e327ce7bce3a8edbf (diff) | |
| download | external_llvm-60d410d7bb2eb11f36a004237e5948ffc5aff5a6.zip external_llvm-60d410d7bb2eb11f36a004237e5948ffc5aff5a6.tar.gz external_llvm-60d410d7bb2eb11f36a004237e5948ffc5aff5a6.tar.bz2 | |
fix two significant issues with FoldTwoEntryPHINode:
first, it can kick in on blocks whose conditions have been
folded to a constant, even though one of the edges will be
trivially folded.
second, it doesn't clean up the "if diamond" that it just
eliminated away. This is a problem because other simplifycfg
xforms kick in depending on the order of block visitation,
causing pointless work.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121762 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test/Transforms/SimplifyCFG/PhiBlockMerge.ll')
| -rw-r--r-- | test/Transforms/SimplifyCFG/PhiBlockMerge.ll | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/test/Transforms/SimplifyCFG/PhiBlockMerge.ll b/test/Transforms/SimplifyCFG/PhiBlockMerge.ll index a648efd..c28d0ba 100644 --- a/test/Transforms/SimplifyCFG/PhiBlockMerge.ll +++ b/test/Transforms/SimplifyCFG/PhiBlockMerge.ll @@ -1,12 +1,14 @@ ; Test merging of blocks that only have PHI nodes in them ; -; RUN: opt < %s -simplifycfg -S | not grep N: +; RUN: opt < %s -simplifycfg -S | FileCheck %s ; define i32 @test(i1 %a, i1 %b) { -; <label>:0 +; CHECK: br i1 %a br i1 %a, label %M, label %O O: ; preds = %0 +; CHECK: select i1 %b, i32 0, i32 1 +; CHECK-NOT: phi br i1 %b, label %N, label %Q Q: ; preds = %O br label %N @@ -15,6 +17,7 @@ N: ; preds = %Q, %O %Wp = phi i32 [ 0, %O ], [ 1, %Q ] ; <i32> [#uses=1] br label %M M: ; preds = %N, %0 +; CHECK: %W = phi i32 %W = phi i32 [ %Wp, %N ], [ 2, %0 ] ; <i32> [#uses=1] %R = add i32 %W, 1 ; <i32> [#uses=1] ret i32 %R |