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1 ; This tests the optimization of atomic cmpxchg w/ following cmp + branches. | 1 ; This tests the optimization of atomic cmpxchg w/ following cmp + branches. |
2 | 2 |
3 ; RUN: %p2i -i %s --args -O2 --verbose none \ | 3 ; RUN: %p2i -i %s --assemble --disassemble --args -O2 --verbose none \ |
4 ; RUN: | llvm-mc -triple=i686-none-nacl -filetype=obj \ | |
5 ; RUN: | llvm-objdump -d -symbolize -x86-asm-syntax=intel - \ | |
6 ; RUN: | FileCheck --check-prefix=O2 %s | 4 ; RUN: | FileCheck --check-prefix=O2 %s |
7 ; RUN: %p2i -i %s --args -Om1 --verbose none \ | 5 ; RUN: %p2i -i %s --assemble --disassemble --args -Om1 --verbose none \ |
8 ; RUN: | llvm-mc -triple=i686-none-nacl -filetype=obj \ | |
9 ; RUN: | llvm-objdump -d -symbolize -x86-asm-syntax=intel - \ | |
10 ; RUN: | FileCheck --check-prefix=OM1 %s | 6 ; RUN: | FileCheck --check-prefix=OM1 %s |
11 | 7 |
12 declare i32 @llvm.nacl.atomic.cmpxchg.i32(i32*, i32, i32, i32, i32) | 8 declare i32 @llvm.nacl.atomic.cmpxchg.i32(i32*, i32, i32, i32, i32) |
13 | 9 |
14 | 10 |
15 ; Test that a cmpxchg followed by icmp eq and branch can be optimized to | 11 ; Test that a cmpxchg followed by icmp eq and branch can be optimized to |
16 ; reuse the flags set by the cmpxchg instruction itself. | 12 ; reuse the flags set by the cmpxchg instruction itself. |
17 ; This is only expected to work w/ O2, based on lightweight liveness. | 13 ; This is only expected to work w/ O2, based on lightweight liveness. |
18 ; (Or if we had other means to detect the only use). | 14 ; (Or if we had other means to detect the only use). |
19 declare void @use_value(i32) | 15 declare void @use_value(i32) |
20 | 16 |
21 define i32 @test_atomic_cmpxchg_loop(i32 %iptr, i32 %expected, i32 %desired) { | 17 define i32 @test_atomic_cmpxchg_loop(i32 %iptr, i32 %expected, i32 %desired) { |
22 entry: | 18 entry: |
23 br label %loop | 19 br label %loop |
24 | 20 |
25 loop: | 21 loop: |
26 %expected_loop = phi i32 [ %expected, %entry ], [ %old, %loop ] | 22 %expected_loop = phi i32 [ %expected, %entry ], [ %old, %loop ] |
27 %succeeded_first_try = phi i32 [ 1, %entry ], [ 2, %loop ] | 23 %succeeded_first_try = phi i32 [ 1, %entry ], [ 2, %loop ] |
28 %ptr = inttoptr i32 %iptr to i32* | 24 %ptr = inttoptr i32 %iptr to i32* |
29 %old = call i32 @llvm.nacl.atomic.cmpxchg.i32(i32* %ptr, i32 %expected_loop, | 25 %old = call i32 @llvm.nacl.atomic.cmpxchg.i32(i32* %ptr, i32 %expected_loop, |
30 i32 %desired, i32 6, i32 6) | 26 i32 %desired, i32 6, i32 6) |
31 %success = icmp eq i32 %expected_loop, %old | 27 %success = icmp eq i32 %expected_loop, %old |
32 br i1 %success, label %done, label %loop | 28 br i1 %success, label %done, label %loop |
33 | 29 |
34 done: | 30 done: |
35 call void @use_value(i32 %old) | 31 call void @use_value(i32 %old) |
36 ret i32 %succeeded_first_try | 32 ret i32 %succeeded_first_try |
37 } | 33 } |
38 ; O2-LABEL: test_atomic_cmpxchg_loop | 34 ; O2-LABEL: test_atomic_cmpxchg_loop |
39 ; O2: lock | 35 ; O2: lock cmpxchg DWORD PTR [e{{[^a].}}],e{{[^a]}} |
40 ; O2-NEXT: cmpxchg dword ptr [e{{[^a].}}], e{{[^a]}} | |
41 ; O2-NEXT: j{{e|ne}} | 36 ; O2-NEXT: j{{e|ne}} |
42 ; Make sure the call isn't accidentally deleted. | 37 ; Make sure the call isn't accidentally deleted. |
43 ; O2: call | 38 ; O2: call |
44 ; | 39 ; |
45 ; Check that the unopt version does have a cmp | 40 ; Check that the unopt version does have a cmp |
46 ; OM1-LABEL: test_atomic_cmpxchg_loop | 41 ; OM1-LABEL: test_atomic_cmpxchg_loop |
47 ; OM1: lock | 42 ; OM1: lock cmpxchg DWORD PTR [e{{[^a].}}],e{{[^a]}} |
48 ; OM1-NEXT: cmpxchg dword ptr [e{{[^a].}}], e{{[^a]}} | |
49 ; OM1: cmp | 43 ; OM1: cmp |
50 ; OM1: je | 44 ; OM1: je |
51 ; OM1: call | 45 ; OM1: call |
52 | 46 |
53 ; Still works if the compare operands are flipped. | 47 ; Still works if the compare operands are flipped. |
54 define i32 @test_atomic_cmpxchg_loop2(i32 %iptr, i32 %expected, i32 %desired) { | 48 define i32 @test_atomic_cmpxchg_loop2(i32 %iptr, i32 %expected, i32 %desired) { |
55 entry: | 49 entry: |
56 br label %loop | 50 br label %loop |
57 | 51 |
58 loop: | 52 loop: |
59 %expected_loop = phi i32 [ %expected, %entry ], [ %old, %loop ] | 53 %expected_loop = phi i32 [ %expected, %entry ], [ %old, %loop ] |
60 %ptr = inttoptr i32 %iptr to i32* | 54 %ptr = inttoptr i32 %iptr to i32* |
61 %old = call i32 @llvm.nacl.atomic.cmpxchg.i32(i32* %ptr, i32 %expected_loop, | 55 %old = call i32 @llvm.nacl.atomic.cmpxchg.i32(i32* %ptr, i32 %expected_loop, |
62 i32 %desired, i32 6, i32 6) | 56 i32 %desired, i32 6, i32 6) |
63 %success = icmp eq i32 %old, %expected_loop | 57 %success = icmp eq i32 %old, %expected_loop |
64 br i1 %success, label %done, label %loop | 58 br i1 %success, label %done, label %loop |
65 | 59 |
66 done: | 60 done: |
67 ret i32 %old | 61 ret i32 %old |
68 } | 62 } |
69 ; O2-LABEL: test_atomic_cmpxchg_loop2 | 63 ; O2-LABEL: test_atomic_cmpxchg_loop2 |
70 ; O2: lock | 64 ; O2: lock cmpxchg DWORD PTR [e{{[^a].}}],e{{[^a]}} |
71 ; O2-NEXT: cmpxchg dword ptr [e{{[^a].}}], e{{[^a]}} | |
72 ; O2-NOT: cmp | 65 ; O2-NOT: cmp |
73 ; O2: jne | 66 ; O2: jne |
74 | 67 |
75 | 68 |
76 ; Still works if the compare operands are constants. | 69 ; Still works if the compare operands are constants. |
77 define i32 @test_atomic_cmpxchg_loop_const(i32 %iptr, i32 %desired) { | 70 define i32 @test_atomic_cmpxchg_loop_const(i32 %iptr, i32 %desired) { |
78 entry: | 71 entry: |
79 br label %loop | 72 br label %loop |
80 | 73 |
81 loop: | 74 loop: |
82 %succeeded_first_try = phi i32 [ 1, %entry ], [ 0, %loop ] | 75 %succeeded_first_try = phi i32 [ 1, %entry ], [ 0, %loop ] |
83 %ptr = inttoptr i32 %iptr to i32* | 76 %ptr = inttoptr i32 %iptr to i32* |
84 %old = call i32 @llvm.nacl.atomic.cmpxchg.i32(i32* %ptr, i32 0, | 77 %old = call i32 @llvm.nacl.atomic.cmpxchg.i32(i32* %ptr, i32 0, |
85 i32 %desired, i32 6, i32 6) | 78 i32 %desired, i32 6, i32 6) |
86 %success = icmp eq i32 %old, 0 | 79 %success = icmp eq i32 %old, 0 |
87 br i1 %success, label %done, label %loop | 80 br i1 %success, label %done, label %loop |
88 | 81 |
89 done: | 82 done: |
90 ret i32 %succeeded_first_try | 83 ret i32 %succeeded_first_try |
91 } | 84 } |
92 ; O2-LABEL: test_atomic_cmpxchg_loop_const | 85 ; O2-LABEL: test_atomic_cmpxchg_loop_const |
93 ; O2: lock | 86 ; O2: lock cmpxchg DWORD PTR [e{{[^a].}}],e{{[^a]}} |
94 ; O2-NEXT: cmpxchg dword ptr [e{{[^a].}}], e{{[^a]}} | |
95 ; O2-NEXT: j{{e|ne}} | 87 ; O2-NEXT: j{{e|ne}} |
96 | 88 |
97 ; This is a case where the flags cannot be reused (compare is for some | 89 ; This is a case where the flags cannot be reused (compare is for some |
98 ; other condition). | 90 ; other condition). |
99 define i32 @test_atomic_cmpxchg_no_opt(i32 %iptr, i32 %expected, i32 %desired) { | 91 define i32 @test_atomic_cmpxchg_no_opt(i32 %iptr, i32 %expected, i32 %desired) { |
100 entry: | 92 entry: |
101 br label %loop | 93 br label %loop |
102 | 94 |
103 loop: | 95 loop: |
104 %expected_loop = phi i32 [ %expected, %entry ], [ %old, %loop ] | 96 %expected_loop = phi i32 [ %expected, %entry ], [ %old, %loop ] |
105 %ptr = inttoptr i32 %iptr to i32* | 97 %ptr = inttoptr i32 %iptr to i32* |
106 %old = call i32 @llvm.nacl.atomic.cmpxchg.i32(i32* %ptr, i32 %expected_loop, | 98 %old = call i32 @llvm.nacl.atomic.cmpxchg.i32(i32* %ptr, i32 %expected_loop, |
107 i32 %desired, i32 6, i32 6) | 99 i32 %desired, i32 6, i32 6) |
108 %success = icmp sgt i32 %old, %expected | 100 %success = icmp sgt i32 %old, %expected |
109 br i1 %success, label %done, label %loop | 101 br i1 %success, label %done, label %loop |
110 | 102 |
111 done: | 103 done: |
112 ret i32 %old | 104 ret i32 %old |
113 } | 105 } |
114 ; O2-LABEL: test_atomic_cmpxchg_no_opt | 106 ; O2-LABEL: test_atomic_cmpxchg_no_opt |
115 ; O2: lock | 107 ; O2: lock cmpxchg DWORD PTR [e{{[^a].}}],e{{[^a]}} |
116 ; O2-NEXT: cmpxchg dword ptr [e{{[^a].}}], e{{[^a]}} | |
117 ; O2: cmp | 108 ; O2: cmp |
118 ; O2: jle | 109 ; O2: jle |
119 | 110 |
120 ; Another case where the flags cannot be reused (the comparison result | 111 ; Another case where the flags cannot be reused (the comparison result |
121 ; is used somewhere else). | 112 ; is used somewhere else). |
122 define i32 @test_atomic_cmpxchg_no_opt2(i32 %iptr, i32 %expected, i32 %desired)
{ | 113 define i32 @test_atomic_cmpxchg_no_opt2(i32 %iptr, i32 %expected, i32 %desired)
{ |
123 entry: | 114 entry: |
124 br label %loop | 115 br label %loop |
125 | 116 |
126 loop: | 117 loop: |
127 %expected_loop = phi i32 [ %expected, %entry ], [ %old, %loop ] | 118 %expected_loop = phi i32 [ %expected, %entry ], [ %old, %loop ] |
128 %ptr = inttoptr i32 %iptr to i32* | 119 %ptr = inttoptr i32 %iptr to i32* |
129 %old = call i32 @llvm.nacl.atomic.cmpxchg.i32(i32* %ptr, i32 %expected_loop, | 120 %old = call i32 @llvm.nacl.atomic.cmpxchg.i32(i32* %ptr, i32 %expected_loop, |
130 i32 %desired, i32 6, i32 6) | 121 i32 %desired, i32 6, i32 6) |
131 %success = icmp eq i32 %old, %expected | 122 %success = icmp eq i32 %old, %expected |
132 br i1 %success, label %done, label %loop | 123 br i1 %success, label %done, label %loop |
133 | 124 |
134 done: | 125 done: |
135 %r = zext i1 %success to i32 | 126 %r = zext i1 %success to i32 |
136 ret i32 %r | 127 ret i32 %r |
137 } | 128 } |
138 ; O2-LABEL: test_atomic_cmpxchg_no_opt2 | 129 ; O2-LABEL: test_atomic_cmpxchg_no_opt2 |
139 ; O2: lock | 130 ; O2: lock cmpxchg DWORD PTR [e{{[^a].}}],e{{[^a]}} |
140 ; O2-NEXT: cmpxchg dword ptr [e{{[^a].}}], e{{[^a]}} | |
141 ; O2: mov {{.*}} | 131 ; O2: mov {{.*}} |
142 ; O2: cmp | 132 ; O2: cmp |
143 ; O2: je | 133 ; O2: je |
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