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412c74541c
unreachable loop. updatePredecessorProfileMetadata in jumpthreading tries to find the first dominating predecessor block for a PHI value by searching upwards the predecessor block chain. But jumpthreading may see some temporary IR state which contains unreachable bb not being cleaned up. If an unreachable loop happens to be on the predecessor block chain, keeping chasing the predecessor block will run into an infinite loop. The patch fixes it. Differential Revision: https://reviews.llvm.org/D65310 llvm-svn: 367154
64 lines
1.8 KiB
LLVM
64 lines
1.8 KiB
LLVM
; RUN: opt -jump-threading -S < %s | FileCheck %s
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; RUN: opt -passes=jump-threading -S < %s | FileCheck %s
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; Check the unreachable loop won't cause infinite loop
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; in jump-threading when it tries to update the predecessors'
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; profile metadata from a phi node.
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define void @unreachable_single_bb_loop() {
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; CHECK-LABEL: @unreachable_single_bb_loop()
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bb:
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%tmp = call i32 @a()
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%tmp1 = icmp eq i32 %tmp, 1
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br i1 %tmp1, label %bb5, label %bb8
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; unreachable single bb loop.
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bb2: ; preds = %bb2
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%tmp4 = icmp ne i32 %tmp, 1
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switch i1 %tmp4, label %bb2 [
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i1 0, label %bb5
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i1 1, label %bb8
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]
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bb5: ; preds = %bb2, %bb
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%tmp6 = phi i1 [ %tmp1, %bb ], [ false, %bb2 ]
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br i1 %tmp6, label %bb8, label %bb7, !prof !0
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bb7: ; preds = %bb5
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br label %bb8
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bb8: ; preds = %bb8, %bb7, %bb5, %bb2
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ret void
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}
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define void @unreachable_multi_bbs_loop() {
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; CHECK-LABEL: @unreachable_multi_bbs_loop()
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bb:
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%tmp = call i32 @a()
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%tmp1 = icmp eq i32 %tmp, 1
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br i1 %tmp1, label %bb5, label %bb8
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; unreachable two bbs loop.
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bb3: ; preds = %bb2
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br label %bb2
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bb2: ; preds = %bb3
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%tmp4 = icmp ne i32 %tmp, 1
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switch i1 %tmp4, label %bb3 [
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i1 0, label %bb5
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i1 1, label %bb8
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]
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bb5: ; preds = %bb2, %bb
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%tmp6 = phi i1 [ %tmp1, %bb ], [ false, %bb2 ]
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br i1 %tmp6, label %bb8, label %bb7, !prof !0
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bb7: ; preds = %bb5
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br label %bb8
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bb8: ; preds = %bb8, %bb7, %bb5, %bb2
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ret void
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}
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declare i32 @a()
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!0 = !{!"branch_weights", i32 2146410443, i32 1073205}
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