59 lines
1.3 KiB
LLVM
59 lines
1.3 KiB
LLVM
; RUN: opt -jump-threading -S %s | FileCheck %s
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; Check that we thread arg2neg -> checkpos -> end.
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;
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; LazyValueInfo would previously fail to analyze the value of %arg in arg2neg
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; because its predecessing blocks (checkneg) hadn't been processed yet (PR21238)
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; CHECK-LABEL: @test_jump_threading
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; CHECK: arg2neg:
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; CHECK-NEXT: br i1 %arg1, label %end, label %checkpos.thread
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; CHECK: checkpos.thread:
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; CHECK-NEXT: br label %end
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define i32 @test_jump_threading(i1 %arg1, i32 %arg2) {
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checkneg:
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%cmp = icmp slt i32 %arg2, 0
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br i1 %cmp, label %arg2neg, label %checkpos
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arg2neg:
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br i1 %arg1, label %end, label %checkpos
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checkpos:
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%cmp2 = icmp sgt i32 %arg2, 0
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br i1 %cmp2, label %arg2pos, label %end
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arg2pos:
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br label %end
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end:
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%0 = phi i32 [ 1, %arg2neg ], [ 2, %checkpos ], [ 3, %arg2pos ]
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ret i32 %0
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}
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; arg2neg has an edge back to itself. If LazyValueInfo is not careful when
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; visiting predecessors, it could get into an infinite loop.
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; CHECK-LABEL: test_infinite_loop
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define i32 @test_infinite_loop(i1 %arg1, i32 %arg2) {
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checkneg:
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%cmp = icmp slt i32 %arg2, 0
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br i1 %cmp, label %arg2neg, label %checkpos
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arg2neg:
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br i1 %arg1, label %arg2neg, label %checkpos
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checkpos:
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%cmp2 = icmp sgt i32 %arg2, 0
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br i1 %cmp2, label %arg2pos, label %end
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arg2pos:
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br label %end
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end:
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%0 = phi i32 [ 2, %checkpos ], [ 3, %arg2pos ]
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ret i32 %0
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}
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