1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
|
//===- LegalizerTest.cpp --------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/GlobalISel/Legalizer.h"
#include "GISelMITest.h"
#include "llvm/CodeGen/GlobalISel/LostDebugLocObserver.h"
#define DEBUG_TYPE "legalizer-test"
using namespace LegalizeActions;
using namespace LegalizeMutations;
using namespace LegalityPredicates;
namespace {
::testing::AssertionResult isNullMIPtr(const MachineInstr *MI) {
if (MI == nullptr)
return ::testing::AssertionSuccess();
std::string MIBuffer;
raw_string_ostream MISStream(MIBuffer);
MI->print(MISStream, /*IsStandalone=*/true, /*SkipOpers=*/false,
/*SkipDebugLoc=*/false, /*AddNewLine=*/false);
return ::testing::AssertionFailure()
<< "unable to legalize instruction: " << MISStream.str();
}
DefineLegalizerInfo(ALegalizer, {
auto p0 = LLT::pointer(0, 64);
auto s8 = LLT::scalar(8);
auto v2s8 = LLT::fixed_vector(2, 8);
auto v2s16 = LLT::fixed_vector(2, 16);
getActionDefinitionsBuilder(G_LOAD)
.legalForTypesWithMemDesc({{s16, p0, s8, 8}})
.scalarize(0)
.clampScalar(0, s16, s16);
getActionDefinitionsBuilder(G_PTR_ADD).legalFor({{p0, s64}});
getActionDefinitionsBuilder(G_CONSTANT).legalFor({s32, s64});
getActionDefinitionsBuilder(G_BUILD_VECTOR)
.legalFor({{v2s16, s16}})
.clampScalar(1, s16, s16);
getActionDefinitionsBuilder(G_BUILD_VECTOR_TRUNC).legalFor({{v2s8, s16}});
getActionDefinitionsBuilder(G_ANYEXT).legalFor({{s32, s16}});
getActionDefinitionsBuilder(G_ZEXT).legalFor({{s32, s16}});
getActionDefinitionsBuilder(G_SEXT).legalFor({{s32, s16}});
getActionDefinitionsBuilder(G_AND).legalFor({s32});
getActionDefinitionsBuilder(G_SEXT_INREG).lower();
getActionDefinitionsBuilder(G_ASHR).legalFor({{s32, s32}});
getActionDefinitionsBuilder(G_SHL).legalFor({{s32, s32}});
})
TEST_F(AArch64GISelMITest, BasicLegalizerTest) {
StringRef MIRString = R"(
%vptr:_(p0) = COPY $x4
%v:_(<2 x s8>) = G_LOAD %vptr:_(p0) :: (load (<2 x s8>), align 1)
$h4 = COPY %v:_(<2 x s8>)
)";
setUp(MIRString.rtrim(' '));
if (!TM)
return;
ALegalizerInfo LI(MF->getSubtarget());
LostDebugLocObserver LocObserver(DEBUG_TYPE);
Legalizer::MFResult Result = Legalizer::legalizeMachineFunction(
*MF, LI, {&LocObserver}, LocObserver, B);
EXPECT_TRUE(isNullMIPtr(Result.FailedOn));
EXPECT_TRUE(Result.Changed);
StringRef CheckString = R"(
CHECK: %vptr:_(p0) = COPY $x4
CHECK-NEXT: [[LOAD_0:%[0-9]+]]:_(s16) = G_LOAD %vptr:_(p0) :: (load (s8))
CHECK-NEXT: [[OFFSET_1:%[0-9]+]]:_(s64) = G_CONSTANT i64 1
CHECK-NEXT: [[VPTR_1:%[0-9]+]]:_(p0) = G_PTR_ADD %vptr:_, [[OFFSET_1]]:_(s64)
CHECK-NEXT: [[LOAD_1:%[0-9]+]]:_(s16) = G_LOAD [[VPTR_1]]:_(p0) :: (load (s8) from unknown-address + 1)
CHECK-NEXT: %v:_(<2 x s8>) = G_BUILD_VECTOR_TRUNC [[LOAD_0]]:_(s16), [[LOAD_1]]:_(s16)
CHECK-NEXT: $h4 = COPY %v:_(<2 x s8>)
)";
EXPECT_TRUE(CheckMachineFunction(*MF, CheckString)) << *MF;
}
// Making sure the legalization finishes successfully w/o failure to combine
// away all the legalization artifacts regardless of the order of their
// creation.
TEST_F(AArch64GISelMITest, UnorderedArtifactCombiningTest) {
StringRef MIRString = R"(
%vptr:_(p0) = COPY $x4
%v:_(<2 x s8>) = G_LOAD %vptr:_(p0) :: (load (<2 x s8>), align 1)
%v0:_(s8), %v1:_(s8) = G_UNMERGE_VALUES %v:_(<2 x s8>)
%v0_ext:_(s16) = G_ANYEXT %v0:_(s8)
$h4 = COPY %v0_ext:_(s16)
)";
setUp(MIRString.rtrim(' '));
if (!TM)
return;
ALegalizerInfo LI(MF->getSubtarget());
LostDebugLocObserver LocObserver(DEBUG_TYPE);
// The events here unfold as follows:
// 1. First, the function is scanned pre-forming the worklist of artifacts:
//
// UNMERGE (1): pushed into the worklist first, will be processed last.
// |
// ANYEXT (2)
//
// 2. Second, the load is scalarized, and then its destination is widened,
// forming the following chain of legalization artifacts:
//
// TRUNC (4): created last, will be processed first.
// |
// BUILD_VECTOR (3)
// |
// UNMERGE (1): pushed into the worklist first, will be processed last.
// |
// ANYEXT (2)
//
// 3. Third, the artifacts are attempted to be combined in pairs, looking
// through the def-use chain from the roots towards the leafs, visiting the
// roots in order they happen to be in the worklist:
// (4) - (trunc): can not be combined;
// (3) - (build_vector (trunc)): can not be combined;
// (2) - (anyext (unmerge)): can not be combined;
// (1) - (unmerge (build_vector)): combined and eliminated;
//
// leaving the function in the following state:
//
// TRUNC (1): moved to non-artifact instructions worklist first.
// |
// ANYEXT (2): also moved to non-artifact instructions worklist.
//
// Every other instruction is successfully legalized in full.
// If combining (unmerge (build_vector)) does not re-insert every artifact
// that had its def-use chain modified (shortened) into the artifact
// worklist (here it's just ANYEXT), the process moves on onto the next
// outer loop iteration of the top-level legalization algorithm here, w/o
// performing all the artifact combines possible. Let's consider this
// scenario first:
// 4.A. Neither TRUNC, nor ANYEXT can be legalized in isolation, both of them
// get moved to the retry worklist, but no additional artifacts were
// created in the process, thus algorithm concludes no progress could be
// made, and fails.
// 4.B. If, however, combining (unmerge (build_vector)) had re-inserted
// ANYEXT into the worklist (as ANYEXT's source changes, not by value,
// but by implementation), (anyext (trunc)) combine happens next, which
// fully eliminates all the artifacts and legalization succeeds.
//
// We're looking into making sure that (4.B) happens here, not (4.A). Note
// that in that case the first scan through the artifacts worklist, while not
// being done in any guaranteed order, only needs to find the innermost
// pair(s) of artifacts that could be immediately combined out. After that
// the process follows def-use chains, making them shorter at each step, thus
// combining everything that can be combined in O(n) time.
Legalizer::MFResult Result = Legalizer::legalizeMachineFunction(
*MF, LI, {&LocObserver}, LocObserver, B);
EXPECT_TRUE(isNullMIPtr(Result.FailedOn));
EXPECT_TRUE(Result.Changed);
StringRef CheckString = R"(
CHECK: %vptr:_(p0) = COPY $x4
CHECK-NEXT: [[LOAD_0:%[0-9]+]]:_(s16) = G_LOAD %vptr:_(p0) :: (load (s8))
CHECK: $h4 = COPY [[LOAD_0]]:_(s16)
)";
EXPECT_TRUE(CheckMachineFunction(*MF, CheckString)) << *MF;
}
TEST_F(AArch64GISelMITest, UnorderedArtifactCombiningManyCopiesTest) {
StringRef MIRString = R"(
%vptr:_(p0) = COPY $x4
%v:_(<2 x s8>) = G_LOAD %vptr:_(p0) :: (load (<2 x s8>), align 1)
%vc0:_(<2 x s8>) = COPY %v:_(<2 x s8>)
%vc1:_(<2 x s8>) = COPY %v:_(<2 x s8>)
%vc00:_(s8), %vc01:_(s8) = G_UNMERGE_VALUES %vc0:_(<2 x s8>)
%vc10:_(s8), %vc11:_(s8) = G_UNMERGE_VALUES %vc1:_(<2 x s8>)
%v0t:_(s8) = COPY %vc00:_(s8)
%v0:_(s8) = COPY %v0t:_(s8)
%v1t:_(s8) = COPY %vc11:_(s8)
%v1:_(s8) = COPY %v1t:_(s8)
%v0_zext:_(s32) = G_ZEXT %v0:_(s8)
%v1_sext:_(s32) = G_SEXT %v1:_(s8)
$w4 = COPY %v0_zext:_(s32)
$w5 = COPY %v1_sext:_(s32)
)";
setUp(MIRString.rtrim(' '));
if (!TM)
return;
ALegalizerInfo LI(MF->getSubtarget());
LostDebugLocObserver LocObserver(DEBUG_TYPE);
Legalizer::MFResult Result = Legalizer::legalizeMachineFunction(
*MF, LI, {&LocObserver}, LocObserver, B);
EXPECT_TRUE(isNullMIPtr(Result.FailedOn));
EXPECT_TRUE(Result.Changed);
StringRef CheckString = R"(
CHECK: %vptr:_(p0) = COPY $x4
CHECK-NEXT: [[LOAD_0:%[0-9]+]]:_(s16) = G_LOAD %vptr:_(p0) :: (load (s8))
CHECK-NEXT: [[OFFSET_1:%[0-9]+]]:_(s64) = G_CONSTANT i64 1
CHECK-NEXT: [[VPTR_1:%[0-9]+]]:_(p0) = G_PTR_ADD %vptr:_, [[OFFSET_1]]:_(s64)
CHECK-NEXT: [[LOAD_1:%[0-9]+]]:_(s16) = G_LOAD [[VPTR_1]]:_(p0) :: (load (s8) from unknown-address + 1)
CHECK-NEXT: [[FF_MASK:%[0-9]+]]:_(s32) = G_CONSTANT i32 255
CHECK-NEXT: [[V0_EXT:%[0-9]+]]:_(s32) = G_ANYEXT [[LOAD_0]]:_(s16)
CHECK-NEXT: %v0_zext:_(s32) = G_AND [[V0_EXT]]:_, [[FF_MASK]]:_
CHECK-NEXT: [[V1_EXT:%[0-9]+]]:_(s32) = G_ANYEXT [[LOAD_1]]:_(s16)
CHECK-NEXT: [[SHAMNT:%[0-9]+]]:_(s32) = G_CONSTANT i32 24
CHECK-NEXT: [[V1_SHL:%[0-9]+]]:_(s32) = G_SHL [[V1_EXT]]:_, [[SHAMNT]]:_(s32)
CHECK-NEXT: %v1_sext:_(s32) = G_ASHR [[V1_SHL]]:_, [[SHAMNT]]:_(s32)
CHECK-NEXT: $w4 = COPY %v0_zext:_(s32)
CHECK-NEXT: $w5 = COPY %v1_sext:_(s32)
)";
EXPECT_TRUE(CheckMachineFunction(*MF, CheckString)) << *MF;
}
} // namespace
|
