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| author | Nadav Rotem <nrotem@apple.com> | 2012-09-04 10:25:04 +0000 |
|---|---|---|
| committer | Nadav Rotem <nrotem@apple.com> | 2012-09-04 10:25:04 +0000 |
| commit | 7765492a7a7e6eab36bc43558ea7c1f91e57cfec (patch) | |
| tree | 9c5cb82bd89c30a288cc00c830e1e1b74969f93d /test/Transforms/LICM | |
| parent | 68d92bdcc99e647546f40cfce5cfbeb904be2985 (diff) | |
| download | llvm-7765492a7a7e6eab36bc43558ea7c1f91e57cfec.tar.gz llvm-7765492a7a7e6eab36bc43558ea7c1f91e57cfec.tar.bz2 llvm-7765492a7a7e6eab36bc43558ea7c1f91e57cfec.tar.xz | |
LICM may hoist an instruction with undefined behavior above a trap.
Scan the body of the loop and find instructions that may trap.
Use this information when deciding if it is safe to hoist or sink instructions.
Notice that we can optimize the search of instructions that may throw in the case of nested loops.
rdar://11518836
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163132 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test/Transforms/LICM')
| -rw-r--r-- | test/Transforms/LICM/hoisting.ll | 28 |
1 files changed, 27 insertions, 1 deletions
diff --git a/test/Transforms/LICM/hoisting.ll b/test/Transforms/LICM/hoisting.ll index 6f28d53af6..98f93345e3 100644 --- a/test/Transforms/LICM/hoisting.ll +++ b/test/Transforms/LICM/hoisting.ll @@ -29,7 +29,7 @@ Out: ; preds = %LoopTail } -declare void @foo2(i32) +declare void @foo2(i32) nounwind ;; It is ok and desirable to hoist this potentially trapping instruction. @@ -64,3 +64,29 @@ Out: ; preds = %Loop %C = sub i32 %A, %B ; <i32> [#uses=1] ret i32 %C } + +; CHECK: @test4 +; CHECK: call +; CHECK: sdiv +; CHECK: ret +define i32 @test4(i32 %x, i32 %y) nounwind uwtable ssp { +entry: + br label %for.body + +for.body: ; preds = %entry, %for.body + %i.02 = phi i32 [ 0, %entry ], [ %inc, %for.body ] + %n.01 = phi i32 [ 0, %entry ], [ %add, %for.body ] + call void @foo_may_call_exit(i32 0) + %div = sdiv i32 %x, %y + %add = add nsw i32 %n.01, %div + %inc = add nsw i32 %i.02, 1 + %cmp = icmp slt i32 %inc, 10000 + br i1 %cmp, label %for.body, label %for.end + +for.end: ; preds = %for.body + %n.0.lcssa = phi i32 [ %add, %for.body ] + ret i32 %n.0.lcssa +} + +declare void @foo_may_call_exit(i32) + |