xref: /aosp_15_r20/art/test/596-checker-dead-phi/smali/IrreducibleLoop.smali (revision 795d594fd825385562da6b089ea9b2033f3abf5a)
1# Copyright (C) 2016 The Android Open Source Project
2#
3# Licensed under the Apache License, Version 2.0 (the "License");
4# you may not use this file except in compliance with the License.
5# You may obtain a copy of the License at
6#
7#      http://www.apache.org/licenses/LICENSE-2.0
8#
9# Unless required by applicable law or agreed to in writing, software
10# distributed under the License is distributed on an "AS IS" BASIS,
11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12# See the License for the specific language governing permissions and
13# limitations under the License.
14
15.class public LIrreducibleLoop;
16
17.super Ljava/lang/Object;
18
19# Test case where liveness analysis produces linear order where loop blocks are
20# not adjacent. This revealed a bug in our SSA builder, where a dead loop phi would
21# be replaced by its incoming input during SsaRedundantPhiElimination.
22
23# Check that the outer loop suspend check environment only has the two parameter vregs.
24## CHECK-START: int IrreducibleLoop.liveness(int, int) builder (after)
25## CHECK-DAG:     <<Phi1:i\d+>> Phi reg:3 loop:{{B\d+}} irreducible:false
26## CHECK-DAG:     <<Phi2:i\d+>> Phi reg:4 loop:{{B\d+}} irreducible:false
27## CHECK-DAG:     SuspendCheck env:[[_,_,_,<<Phi1>>,<<Phi2>>]] loop:{{B\d+}} irreducible:false
28
29# Check that the linear order has non-adjacent loop blocks.
30## CHECK-START: int IrreducibleLoop.liveness(int, int) liveness (after)
31## CHECK-DAG:     Mul liveness:<<LPreEntry2:\d+>>
32## CHECK-DAG:     Add liveness:<<LBackEdge1:\d+>>
33## CHECK-EVAL:    <<LBackEdge1>> < <<LPreEntry2>>
34
35.method public static liveness(II)I
36    .registers 5
37
38    const-string v1, "MyString"
39
40    :header1
41    if-eqz p0, :body1
42
43    :exit
44    return p0
45
46    :body1
47    # The test will generate an incorrect linear order when the following IF swaps
48    # its successors. To do that, load a boolean value and compare NotEqual to 1.
49    sget-boolean v2, LIrreducibleLoop;->f:Z
50    const v3, 1
51    if-ne v2, v3, :pre_header2
52
53    :pre_entry2
54    # Add a marker on the irreducible loop entry. Here we use p1 because p0 is a
55    # known constant and we eliminate the Mul otherwise.
56    mul-int/2addr p1, p1
57    goto :back_edge2
58
59    :back_edge2
60    goto :header2
61
62    :header2
63    if-eqz p0, :back_edge2
64
65    :back_edge1
66    # Add a marker on the outer loop back edge. Here we use p1 because p0 is a
67    # known constant and we eliminate the Add otherwise.
68    add-int/2addr p1, p1
69    # Set a wide register, to have v1 undefined at the back edge.
70    const-wide/16 v0, 0x1
71    goto :header1
72
73    :pre_header2
74    goto :header2
75.end method
76
77.field public static f:Z
78