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| author | Dan Gohman <gohman@apple.com> | 2010-08-14 00:29:42 +0000 |
|---|---|---|
| committer | Dan Gohman <gohman@apple.com> | 2010-08-14 00:29:42 +0000 |
| commit | e2c6d131d12c779a410740e0a90545def75e0f48 (patch) | |
| tree | e899545fbab9934f663643c00460d582f83819de /test/Transforms/SimplifyCFG | |
| parent | 3d72367d30c9ce6f387764a028763f7a366cc443 (diff) | |
| download | external_llvm-e2c6d131d12c779a410740e0a90545def75e0f48.zip external_llvm-e2c6d131d12c779a410740e0a90545def75e0f48.tar.gz external_llvm-e2c6d131d12c779a410740e0a90545def75e0f48.tar.bz2 | |
Teach SimplifyCFG how to simplify indirectbr instructions.
- Eliminate redundant successors.
- Convert an indirectbr with one successor into a direct branch.
Also, generalize SimplifyCFG to be able to be run on a function entry block.
It knows quite a few simplifications which are applicable to the entry
block, and it only needs a few checks to avoid trouble with the entry block.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111060 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test/Transforms/SimplifyCFG')
| -rw-r--r-- | test/Transforms/SimplifyCFG/basictest.ll | 1 | ||||
| -rw-r--r-- | test/Transforms/SimplifyCFG/indirectbr.ll | 51 |
2 files changed, 51 insertions, 1 deletions
diff --git a/test/Transforms/SimplifyCFG/basictest.ll b/test/Transforms/SimplifyCFG/basictest.ll index 83a9fa7..7315ff6 100644 --- a/test/Transforms/SimplifyCFG/basictest.ll +++ b/test/Transforms/SimplifyCFG/basictest.ll @@ -54,6 +54,5 @@ bb1: ; preds = %entry return: ; preds = %entry ret void ; CHECK: @test5 -; CHECK-NEXT: bb: ; CHECK-NEXT: ret void } diff --git a/test/Transforms/SimplifyCFG/indirectbr.ll b/test/Transforms/SimplifyCFG/indirectbr.ll new file mode 100644 index 0000000..b13433c --- /dev/null +++ b/test/Transforms/SimplifyCFG/indirectbr.ll @@ -0,0 +1,51 @@ +; RUN: opt -S -simplifycfg < %s | FileCheck %s + +; SimplifyCFG should eliminate redundant indirectbr edges. + +; CHECK: indbrtest0 +; CHECK: indirectbr i8* %t, [label %BB0, label %BB1, label %BB2] +; CHECK: %x = phi i32 [ 0, %BB0 ], [ 1, %entry ] + +declare void @foo() +declare void @A() +declare void @B(i32) +declare void @C() + +define void @indbrtest0(i8** %P, i8** %Q) { +entry: + store i8* blockaddress(@indbrtest0, %BB0), i8** %P + store i8* blockaddress(@indbrtest0, %BB1), i8** %P + store i8* blockaddress(@indbrtest0, %BB2), i8** %P + call void @foo() + %t = load i8** %Q + indirectbr i8* %t, [label %BB0, label %BB1, label %BB2, label %BB0, label %BB1, label %BB2] +BB0: + call void @A() + br label %BB1 +BB1: + %x = phi i32 [ 0, %BB0 ], [ 1, %entry ], [ 1, %entry ] + call void @B(i32 %x) + ret void +BB2: + call void @C() + ret void +} + +; SimplifyCFG should convert the indirectbr into a directbr. It would be even +; better if it removed the branch altogether, but simplifycfdg currently misses +; that because the predecessor is the entry block. + +; CHECK: indbrtest1 +; CHECK: br label %BB0 + +define void @indbrtest1(i8** %P, i8** %Q) { +entry: + store i8* blockaddress(@indbrtest1, %BB0), i8** %P + call void @foo() + %t = load i8** %Q + indirectbr i8* %t, [label %BB0, label %BB0] +BB0: + call void @A() + ret void +} + |