bb8e02325f
When the single branch target of a block has been removed try updating it to target a block that is kept (by scanning forward in the sequence) instead of replacing the branch with a return instruction. Doing so reduces the risk of breaking loop structures meaning that when the loop is 'interesting' these reductions should have more blocks eliminated. Differential Revision: https://reviews.llvm.org/D125766
31 lines
692 B
LLVM
31 lines
692 B
LLVM
; RUN: llvm-reduce --delta-passes=basic-blocks --test %python --test-arg %p/remove-bbs-sequence.py %s -o %t
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; RUN: cat %t | FileCheck %s
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; The interestingness test is that the CFG contains a loop. Verify that the
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; unnecessary bb2 and bb3 are removed while still maintaining a loop.
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define void @main() {
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bb0:
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br label %bb1
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bb1:
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br label %bb2
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bb2:
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br label %bb3
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bb3:
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%phi = phi i32 [ undef, %bb2 ]
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br label %bb4
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bb4:
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br label %bb1
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}
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; CHECK:define void @main() {
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; CHECK-NEXT: bb0:
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; CHECK-NEXT: br label %bb1
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; CHECK-EMPTY:
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; CHECK-NEXT: bb1:
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; CHECK-NEXT: br label %bb4
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; CHECK-EMPTY:
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; CHECK-NEXT: bb4:
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; CHECK-NEXT: br label %bb1
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; CHECK-NEXT:}
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