xref: /llvm-project/mlir/test/Analysis/DataFlow/test-liveness-analysis.mlir (revision 232f8eadae18889627bdca75c45e98b0c1460086)
1// RUN: mlir-opt -split-input-file -test-liveness-analysis %s 2>&1 | FileCheck %s
2
3// Positive test: Type (1.a) "is an operand of an op with memory effects"
4// zero is live because it is stored in memory.
5// CHECK-LABEL: test_tag: zero:
6// CHECK-NEXT:  result #0: live
7func.func @test_1_type_1.a(%arg0: memref<i32>) {
8  %c0_i32 = arith.constant {tag = "zero"} 0 : i32
9  memref.store %c0_i32, %arg0[] : memref<i32>
10  return
11}
12
13// -----
14
15// Positive test: Type (1.b) "is a non-forwarded branch operand and a block
16// where its op could take the control has an op with memory effects"
17// %arg2 is live because it can make the control go into a block with a memory
18// effecting op.
19// CHECK-LABEL: test_tag: br:
20// CHECK-NEXT:  operand #0: live
21// CHECK-NEXT:  operand #1: live
22// CHECK-NEXT:  operand #2: live
23func.func @test_2_RegionBranchOpInterface_type_1.b(%arg0: memref<i32>, %arg1: memref<i32>, %arg2: i1) {
24  %c0_i32 = arith.constant 0 : i32
25  cf.cond_br %arg2, ^bb1(%c0_i32 : i32), ^bb2(%c0_i32 : i32) {tag = "br"}
26^bb1(%0 : i32):
27  memref.store %0, %arg0[] : memref<i32>
28  cf.br ^bb3
29^bb2(%1 : i32):
30  memref.store %1, %arg1[] : memref<i32>
31  cf.br ^bb3
32^bb3:
33  return
34}
35
36// -----
37
38// Positive test: Type (1.b) "is a non-forwarded branch operand and a block
39// where its op could take the control has an op with memory effects"
40// %arg0 is live because it can make the control go into a block with a memory
41// effecting op.
42// CHECK-LABEL: test_tag: flag:
43// CHECK-NEXT:  operand #0: live
44func.func @test_3_BranchOpInterface_type_1.b(%arg0: i32, %arg1: memref<i32>, %arg2: memref<i32>) {
45  %c0_i32 = arith.constant 0 : i32
46  cf.switch %arg0 : i32, [
47    default: ^bb1,
48    42: ^bb2
49  ] {tag = "flag"}
50^bb1:
51  memref.store %c0_i32, %arg1[] : memref<i32>
52  cf.br ^bb3
53^bb2:
54  memref.store %c0_i32, %arg2[] : memref<i32>
55  cf.br ^bb3
56^bb3:
57  return
58}
59
60// -----
61
62func.func private @private(%arg0 : i32, %arg1 : i32) {
63  func.return
64}
65
66// Positive test: Type (1.c) "is a non-forwarded call operand"
67// CHECK-LABEL: test_tag: call
68// CHECK-LABEL:  operand #0: not live
69// CHECK-LABEL:  operand #1: not live
70// CHECK-LABEL:  operand #2: live
71func.func @test_4_type_1.c(%arg0: i32, %arg1: i32, %device: i32, %m0: memref<i32>) {
72  test.call_on_device @private(%arg0, %arg1), %device {tag = "call"} : (i32, i32, i32) -> ()
73  return
74}
75
76// -----
77
78// Positive test: Type (2) "is returned by a public function"
79// zero is live because it is returned by a public function.
80// CHECK-LABEL: test_tag: zero:
81// CHECK-NEXT:  result #0: live
82func.func @test_5_type_2() -> (f32){
83  %0 = arith.constant {tag = "zero"} 0.0 : f32
84  return %0 : f32
85}
86
87// -----
88
89// Positive test: Type (3) "is used to compute a value of type (1) or (2)"
90// %arg1 is live because the scf.while has a live result and %arg1 is a
91// non-forwarded branch operand.
92// %arg2 is live because it is forwarded to the live result of the scf.while
93// op.
94// %arg5 is live because it is forwarded to %arg8 which is live.
95// %arg8 is live because it is forwarded to %arg4 which is live as it writes
96// to memory.
97// Negative test:
98// %arg3 is not live even though %arg1, %arg2, and %arg5 are live because it
99// is neither a non-forwarded branch operand nor a forwarded operand that
100// forwards to a live value. It actually is a forwarded operand that forwards
101// to non-live values %0#1 and %arg7.
102// CHECK-LABEL: test_tag: condition:
103// CHECK-NEXT:  operand #0: live
104// CHECK-NEXT:  operand #1: live
105// CHECK-NEXT:  operand #2: not live
106// CHECK-NEXT:  operand #3: live
107// CHECK-LABEL: test_tag: add:
108// CHECK-NEXT:  operand #0: live
109func.func @test_6_RegionBranchTerminatorOpInterface_type_3(%arg0: memref<i32>, %arg1: i1) -> (i32) {
110  %c0_i32 = arith.constant 0 : i32
111  %c1_i32 = arith.constant 1 : i32
112  %c2_i32 = arith.constant 2 : i32
113  %0:3 = scf.while (%arg2 = %c0_i32, %arg3 = %c1_i32, %arg4 = %c2_i32, %arg5 = %c2_i32) : (i32, i32, i32, i32) -> (i32, i32, i32) {
114    memref.store %arg4, %arg0[] : memref<i32>
115    scf.condition(%arg1) {tag = "condition"} %arg2, %arg3, %arg5 : i32, i32, i32
116  } do {
117  ^bb0(%arg6: i32, %arg7: i32, %arg8: i32):
118    %1 = arith.addi %arg8, %arg8 {tag = "add"} : i32
119    %c3_i32 = arith.constant 3 : i32
120    scf.yield %arg6, %arg7, %arg8, %c3_i32 : i32, i32, i32, i32
121  }
122  return %0#0 : i32
123}
124
125// -----
126
127func.func private @private0(%0 : i32) -> i32 {
128  %1 = arith.addi %0, %0 {tag = "in_private0"} : i32
129  func.return %1 : i32
130}
131
132// Positive test: Type (3) "is used to compute a value of type (1) or (2)"
133// zero, ten, and one are live because they are used to decide the number of
134// times the `for` loop executes, which in turn decides the value stored in
135// memory.
136// in_private0 and x are also live because they decide the value stored in
137// memory.
138// Negative test:
139// y is not live even though the non-forwarded branch operand and x are live.
140// CHECK-LABEL: test_tag: in_private0:
141// CHECK-NEXT:  operand #0: live
142// CHECK-NEXT:  operand #1: live
143// CHECK-NEXT:  result #0: live
144// CHECK-LABEL: test_tag: zero:
145// CHECK-NEXT:  result #0: live
146// CHECK-LABEL: test_tag: ten:
147// CHECK-NEXT:  result #0: live
148// CHECK-LABEL: test_tag: one:
149// CHECK-NEXT:  result #0: live
150// CHECK-LABEL: test_tag: x:
151// CHECK-NEXT:  result #0: live
152// CHECK-LABEL: test_tag: y:
153// CHECK-NEXT:  result #0: not live
154func.func @test_7_type_3(%arg0: memref<i32>) {
155  %c0 = arith.constant {tag = "zero"} 0 : index
156  %c10 = arith.constant {tag = "ten"} 10 : index
157  %c1 = arith.constant {tag = "one"} 1 : index
158  %x = arith.constant {tag = "x"} 0 : i32
159  %y = arith.constant {tag = "y"} 1 : i32
160  %0:2 = scf.for %arg1 = %c0 to %c10 step %c1 iter_args(%arg2 = %x, %arg3 = %y) -> (i32, i32) {
161    %1 = arith.addi %x, %x : i32
162    %2 = func.call @private0(%1) : (i32) -> i32
163    scf.yield %2, %arg3 : i32, i32
164  }
165  memref.store %0#0, %arg0[] : memref<i32>
166  return
167}
168
169// -----
170
171func.func private @private1(%0 : i32) -> i32 {
172  %1 = func.call @private2(%0) : (i32) -> i32
173  %2 = arith.muli %0, %1 {tag = "in_private1"} : i32
174  func.return %2 : i32
175}
176
177func.func private @private2(%0 : i32) -> i32 {
178  %cond = arith.index_cast %0 {tag = "in_private2"} : i32 to index
179  %1 = scf.index_switch %cond -> i32
180  case 1 {
181    %ten = arith.constant 10 : i32
182    scf.yield %ten : i32
183  }
184  case 2 {
185    %twenty = arith.constant 20 : i32
186    scf.yield %twenty : i32
187  }
188  default {
189    %thirty = arith.constant 30 : i32
190    scf.yield %thirty : i32
191  }
192  func.return %1 : i32
193}
194
195// Positive test: Type (3) "is used to compute a value of type (1) or (2)"
196// in_private1, in_private2, and final are live because they are used to compute
197// the value returned by this public function.
198// CHECK-LABEL: test_tag: in_private1:
199// CHECK-NEXT:  operand #0: live
200// CHECK-NEXT:  operand #1: live
201// CHECK-NEXT:  result #0: live
202// CHECK-LABEL: test_tag: in_private2:
203// CHECK-NEXT:  operand #0: live
204// CHECK-NEXT:  result #0: live
205// CHECK-LABEL: test_tag: final:
206// CHECK-NEXT:  operand #0: live
207// CHECK-NEXT:  operand #1: live
208// CHECK-NEXT:  result #0: live
209func.func @test_8_type_3(%arg: i32) -> (i32) {
210  %0 = func.call @private1(%arg) : (i32) -> i32
211  %final = arith.muli %0, %arg {tag = "final"} : i32
212  return %final : i32
213}
214
215// -----
216
217// Negative test: None of the types (1), (2), or (3)
218// zero is not live because it has no effect outside the program: it doesn't
219// affect the memory or the program output.
220// CHECK-LABEL: test_tag: zero:
221// CHECK-NEXT:  result #0: not live
222// CHECK-LABEL: test_tag: one:
223// CHECK-NEXT:  result #0: live
224func.func @test_9_negative() -> (f32){
225  %0 = arith.constant {tag = "zero"} 0.0 : f32
226  %1 = arith.constant {tag = "one"} 1.0 : f32
227  return %1 : f32
228}
229
230// -----
231
232// Negative test: None of the types (1), (2), or (3)
233// %1 is not live because it has no effect outside the program: it doesn't
234// affect the memory or the program output. Even though it is returned by the
235// function `@private_1`, it is never used by the caller.
236// Note that this test clearly shows how this liveness analysis utility differs
237// from the existing liveness utility present at
238// llvm-project/mlir/include/mlir/Analysis/Liveness.h. The latter marks %1 as
239// live as it exists the block of function `@private_1`, simply because it is
240// computed inside and returned by the block, irrespective of whether or not it
241// is used by the caller.
242// CHECK-LABEL: test_tag: one:
243// CHECK:  result #0: not live
244func.func private @private_1() -> (i32, i32) {
245  %0 = arith.constant 0 : i32
246  %1 = arith.addi %0, %0 {tag = "one"} : i32
247  return %0, %1 : i32, i32
248}
249func.func @test_10_negative() -> (i32) {
250  %0:2 = func.call @private_1() : () -> (i32, i32)
251  return %0#0 : i32
252}
253