control-flow-fastregalloc.ll
11.9 KB
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
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
; RUN: llc -O0 -mtriple=amdgcn--amdhsa -march=amdgcn -amdgpu-spill-sgpr-to-vgpr=0 -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefix=VMEM -check-prefix=GCN %s
; RUN: llc -O0 -mtriple=amdgcn--amdhsa -march=amdgcn -amdgpu-spill-sgpr-to-vgpr=1 -verify-machineinstrs < %s | FileCheck -enable-var-scope -check-prefix=VGPR -check-prefix=GCN %s
; Verify registers used for tracking exec mask changes when all
; registers are spilled at the end of the block. The SGPR spill
; placement relative to the exec modifications are important.
; FIXME: This checks with SGPR to VGPR spilling disabled, but this may
; not work correctly in cases where no workitems take a branch.
; GCN-LABEL: {{^}}divergent_if_endif:
; VGPR: workitem_private_segment_byte_size = 12{{$}}
; GCN: {{^}}; %bb.0:
; GCN: s_mov_b32 m0, -1
; GCN: ds_read_b32 [[LOAD0:v[0-9]+]]
; Spill load
; GCN: buffer_store_dword [[LOAD0]], off, s[0:3], 0 offset:[[LOAD0_OFFSET:[0-9]+]] ; 4-byte Folded Spill
; GCN: v_cmp_eq_u32_e64 [[CMP0:s\[[0-9]+:[0-9]\]]], s{{[0-9]+}}, v0
; Spill saved exec
; GCN: s_mov_b64 s{{\[}}[[SAVEEXEC_LO:[0-9]+]]:[[SAVEEXEC_HI:[0-9]+]]{{\]}}, exec
; VGPR: v_writelane_b32 [[SPILL_VGPR:v[0-9]+]], s[[SAVEEXEC_LO]], [[SAVEEXEC_LO_LANE:[0-9]+]]
; VGPR: v_writelane_b32 [[SPILL_VGPR]], s[[SAVEEXEC_HI]], [[SAVEEXEC_HI_LANE:[0-9]+]]
; VMEM: v_writelane_b32 v[[V_SAVEEXEC:[0-9]+]], s[[SAVEEXEC_LO]], 0
; VMEM: v_writelane_b32 v[[V_SAVEEXEC]], s[[SAVEEXEC_HI]], 1
; VMEM: buffer_store_dword v[[V_SAVEEXEC]], off, s[0:3], 0 offset:[[V_EXEC_SPILL_OFFSET:[0-9]+]] ; 4-byte Folded Spill
; GCN: s_and_b64 s{{\[}}[[ANDEXEC_LO:[0-9]+]]:[[ANDEXEC_HI:[0-9]+]]{{\]}}, s{{\[}}[[SAVEEXEC_LO]]:[[SAVEEXEC_HI]]{{\]}}, [[CMP0]]
; GCN: s_mov_b64 exec, s{{\[}}[[ANDEXEC_LO]]:[[ANDEXEC_HI]]{{\]}}
; GCN: s_cbranch_execz [[ENDIF:BB[0-9]+_[0-9]+]]
; GCN: ; %bb.{{[0-9]+}}: ; %if
; GCN: buffer_load_dword [[RELOAD_LOAD0:v[0-9]+]], off, s[0:3], 0 offset:[[LOAD0_OFFSET]] ; 4-byte Folded Reload
; GCN: s_mov_b32 m0, -1
; GCN: ds_read_b32 [[LOAD1:v[0-9]+]]
; GCN: s_waitcnt vmcnt(0) lgkmcnt(0)
; Spill val register
; GCN: v_add_i32_e32 [[VAL:v[0-9]+]], vcc, [[LOAD1]], [[RELOAD_LOAD0]]
; GCN: buffer_store_dword [[VAL]], off, s[0:3], 0 offset:[[VAL_OFFSET:[0-9]+]] ; 4-byte Folded Spill
; VMEM: [[ENDIF]]:
; Reload and restore exec mask
; VGPR: v_readlane_b32 s[[S_RELOAD_SAVEEXEC_LO:[0-9]+]], [[SPILL_VGPR]], [[SAVEEXEC_LO_LANE]]
; VGPR: v_readlane_b32 s[[S_RELOAD_SAVEEXEC_HI:[0-9]+]], [[SPILL_VGPR]], [[SAVEEXEC_HI_LANE]]
; VMEM: buffer_load_dword v[[V_RELOAD_SAVEEXEC:[0-9]+]], off, s[0:3], 0 offset:[[V_EXEC_SPILL_OFFSET]] ; 4-byte Folded Reload
; VMEM: s_waitcnt vmcnt(0)
; VMEM: v_readlane_b32 s[[S_RELOAD_SAVEEXEC_LO:[0-9]+]], v[[V_RELOAD_SAVEEXEC]], 0
; VMEM: v_readlane_b32 s[[S_RELOAD_SAVEEXEC_HI:[0-9]+]], v[[V_RELOAD_SAVEEXEC]], 1
; GCN: s_or_b64 exec, exec, s{{\[}}[[S_RELOAD_SAVEEXEC_LO]]:[[S_RELOAD_SAVEEXEC_HI]]{{\]}}
; Restore val
; GCN: buffer_load_dword [[RELOAD_VAL:v[0-9]+]], off, s[0:3], 0 offset:[[VAL_OFFSET]] ; 4-byte Folded Reload
; GCN: flat_store_dword v{{\[[0-9]+:[0-9]+\]}}, [[RELOAD_VAL]]
define amdgpu_kernel void @divergent_if_endif(i32 addrspace(1)* %out) #0 {
entry:
%tid = call i32 @llvm.amdgcn.workitem.id.x()
%load0 = load volatile i32, i32 addrspace(3)* undef
%cmp0 = icmp eq i32 %tid, 0
br i1 %cmp0, label %if, label %endif
if:
%load1 = load volatile i32, i32 addrspace(3)* undef
%val = add i32 %load0, %load1
br label %endif
endif:
%tmp4 = phi i32 [ %val, %if ], [ 0, %entry ]
store i32 %tmp4, i32 addrspace(1)* %out
ret void
}
; GCN-LABEL: {{^}}divergent_loop:
; VGPR: workitem_private_segment_byte_size = 16{{$}}
; GCN: {{^}}; %bb.0:
; GCN-DAG: s_mov_b32 m0, -1
; GCN-DAG: v_mov_b32_e32 [[PTR0:v[0-9]+]], 0{{$}}
; GCN: ds_read_b32 [[LOAD0:v[0-9]+]], [[PTR0]]
; GCN: v_cmp_eq_u32_e64 [[CMP0:s\[[0-9]+:[0-9]+\]]], s{{[0-9]+}}, v0
; Spill load
; GCN: buffer_store_dword [[LOAD0]], off, s[0:3], 0 offset:[[LOAD0_OFFSET:[0-9]+]] ; 4-byte Folded Spill
; GCN: s_mov_b64 s{{\[}}[[SAVEEXEC_LO:[0-9]+]]:[[SAVEEXEC_HI:[0-9]+]]{{\]}}, exec
; Spill saved exec
; VGPR: v_writelane_b32 [[SPILL_VGPR:v[0-9]+]], s[[SAVEEXEC_LO]], [[SAVEEXEC_LO_LANE:[0-9]+]]
; VGPR: v_writelane_b32 [[SPILL_VGPR]], s[[SAVEEXEC_HI]], [[SAVEEXEC_HI_LANE:[0-9]+]]
; VMEM: v_writelane_b32 v[[V_SAVEEXEC:[0-9]+]], s[[SAVEEXEC_LO]], 0
; VMEM: v_writelane_b32 v[[V_SAVEEXEC]], s[[SAVEEXEC_HI]], 1
; VMEM: buffer_store_dword v[[V_SAVEEXEC]], off, s[0:3], 0 offset:[[V_EXEC_SPILL_OFFSET:[0-9]+]] ; 4-byte Folded Spill
; GCN: s_and_b64 s{{\[}}[[ANDEXEC_LO:[0-9]+]]:[[ANDEXEC_HI:[0-9]+]]{{\]}}, s{{\[}}[[SAVEEXEC_LO:[0-9]+]]:[[SAVEEXEC_HI:[0-9]+]]{{\]}}, [[CMP0]]
; GCN: s_mov_b64 exec, s{{\[}}[[ANDEXEC_LO]]:[[ANDEXEC_HI]]{{\]}}
; GCN-NEXT: s_cbranch_execz [[END:BB[0-9]+_[0-9]+]]
; GCN: [[LOOP:BB[0-9]+_[0-9]+]]:
; GCN: buffer_load_dword v[[VAL_LOOP_RELOAD:[0-9]+]], off, s[0:3], 0 offset:[[LOAD0_OFFSET]] ; 4-byte Folded Reload
; GCN: v_subrev_i32_e32 [[VAL_LOOP:v[0-9]+]], vcc, v{{[0-9]+}}, v[[VAL_LOOP_RELOAD]]
; GCN: s_cmp_lg_u32
; GCN: buffer_store_dword [[VAL_LOOP]], off, s[0:3], 0 offset:{{[0-9]+}} ; 4-byte Folded Spill
; GCN-NEXT: s_cbranch_scc1 [[LOOP]]
; GCN: buffer_store_dword [[VAL_LOOP]], off, s[0:3], 0 offset:[[VAL_SUB_OFFSET:[0-9]+]] ; 4-byte Folded Spill
; GCN: [[END]]:
; VGPR: v_readlane_b32 s[[S_RELOAD_SAVEEXEC_LO:[0-9]+]], [[SPILL_VGPR]], [[SAVEEXEC_LO_LANE]]
; VGPR: v_readlane_b32 s[[S_RELOAD_SAVEEXEC_HI:[0-9]+]], [[SPILL_VGPR]], [[SAVEEXEC_HI_LANE]]
; VMEM: buffer_load_dword v[[V_RELOAD_SAVEEXEC:[0-9]+]], off, s[0:3], 0 offset:[[V_EXEC_SPILL_OFFSET]] ; 4-byte Folded Reload
; VMEM: s_waitcnt vmcnt(0)
; VMEM: v_readlane_b32 s[[S_RELOAD_SAVEEXEC_LO:[0-9]+]], v[[V_RELOAD_SAVEEXEC]], 0
; VMEM: v_readlane_b32 s[[S_RELOAD_SAVEEXEC_HI:[0-9]+]], v[[V_RELOAD_SAVEEXEC]], 1
; GCN: s_or_b64 exec, exec, s{{\[}}[[S_RELOAD_SAVEEXEC_LO]]:[[S_RELOAD_SAVEEXEC_HI]]{{\]}}
; GCN: buffer_load_dword v[[VAL_END:[0-9]+]], off, s[0:3], 0 offset:[[VAL_SUB_OFFSET]] ; 4-byte Folded Reload
; GCN: flat_store_dword v{{\[[0-9]+:[0-9]+\]}}, v[[VAL_END]]
define amdgpu_kernel void @divergent_loop(i32 addrspace(1)* %out) #0 {
entry:
%tid = call i32 @llvm.amdgcn.workitem.id.x()
%load0 = load volatile i32, i32 addrspace(3)* null
%cmp0 = icmp eq i32 %tid, 0
br i1 %cmp0, label %loop, label %end
loop:
%i = phi i32 [ %i.inc, %loop ], [ 0, %entry ]
%val = phi i32 [ %val.sub, %loop ], [ %load0, %entry ]
%load1 = load volatile i32, i32 addrspace(3)* undef
%i.inc = add i32 %i, 1
%val.sub = sub i32 %val, %load1
%cmp1 = icmp ne i32 %i, 256
br i1 %cmp1, label %loop, label %end
end:
%tmp4 = phi i32 [ %val.sub, %loop ], [ 0, %entry ]
store i32 %tmp4, i32 addrspace(1)* %out
ret void
}
; GCN-LABEL: {{^}}divergent_if_else_endif:
; GCN: {{^}}; %bb.0:
; GCN-DAG: s_mov_b32 m0, -1
; GCN-DAG: v_mov_b32_e32 [[PTR0:v[0-9]+]], 0{{$}}
; GCN: ds_read_b32 [[LOAD0:v[0-9]+]], [[PTR0]]
; Spill load
; GCN: buffer_store_dword [[LOAD0]], off, s[0:3], 0 offset:[[LOAD0_OFFSET:[0-9]+]] ; 4-byte Folded Spill
; GCN: s_mov_b32 [[ZERO:s[0-9]+]], 0
; GCN: v_cmp_ne_u32_e64 [[CMP0:s\[[0-9]+:[0-9]\]]], [[ZERO]], v0
; GCN: s_mov_b64 s{{\[}}[[SAVEEXEC_LO:[0-9]+]]:[[SAVEEXEC_HI:[0-9]+]]{{\]}}, exec
; GCN: s_and_b64 s{{\[}}[[ANDEXEC_LO:[0-9]+]]:[[ANDEXEC_HI:[0-9]+]]{{\]}}, s{{\[}}[[SAVEEXEC_LO:[0-9]+]]:[[SAVEEXEC_HI:[0-9]+]]{{\]}}, [[CMP0]]
; GCN: s_xor_b64 s{{\[}}[[SAVEEXEC_LO]]:[[SAVEEXEC_HI]]{{\]}}, s{{\[}}[[ANDEXEC_LO]]:[[ANDEXEC_HI]]{{\]}}, s{{\[}}[[SAVEEXEC_LO]]:[[SAVEEXEC_HI]]{{\]}}
; Spill saved exec
; VGPR: v_writelane_b32 [[SPILL_VGPR:v[0-9]+]], s[[SAVEEXEC_LO]], [[SAVEEXEC_LO_LANE:[0-9]+]]
; VGPR: v_writelane_b32 [[SPILL_VGPR]], s[[SAVEEXEC_HI]], [[SAVEEXEC_HI_LANE:[0-9]+]]
; VMEM: v_writelane_b32 v[[V_SAVEEXEC:[0-9]+]], s[[SAVEEXEC_LO]], 0
; VMEM: v_writelane_b32 v[[V_SAVEEXEC]], s[[SAVEEXEC_HI]], 1
; VMEM: buffer_store_dword v[[V_SAVEEXEC]], off, s[0:3], 0 offset:[[SAVEEXEC_OFFSET:[0-9]+]] ; 4-byte Folded Spill
; GCN: s_mov_b64 exec, [[CMP0]]
; FIXME: It makes no sense to put this skip here
; GCN: s_cbranch_execz [[FLOW:BB[0-9]+_[0-9]+]]
; GCN-NEXT: s_branch [[ELSE:BB[0-9]+_[0-9]+]]
; GCN: [[FLOW]]: ; %Flow
; VGPR: v_readlane_b32 s[[FLOW_S_RELOAD_SAVEEXEC_LO:[0-9]+]], [[SPILL_VGPR]], [[SAVEEXEC_LO_LANE]]
; VGPR: v_readlane_b32 s[[FLOW_S_RELOAD_SAVEEXEC_HI:[0-9]+]], [[SPILL_VGPR]], [[SAVEEXEC_HI_LANE]]
; VMEM: buffer_load_dword v[[FLOW_V_RELOAD_SAVEEXEC:[0-9]+]], off, s[0:3], 0 offset:[[SAVEEXEC_OFFSET]]
; VMEM: s_waitcnt vmcnt(0)
; VMEM: v_readlane_b32 s[[FLOW_S_RELOAD_SAVEEXEC_LO:[0-9]+]], v[[FLOW_V_RELOAD_SAVEEXEC]], 0
; VMEM: v_readlane_b32 s[[FLOW_S_RELOAD_SAVEEXEC_HI:[0-9]+]], v[[FLOW_V_RELOAD_SAVEEXEC]], 1
; GCN: s_or_saveexec_b64 s{{\[}}[[FLOW_S_RELOAD_SAVEEXEC_LO_SAVEEXEC:[0-9]+]]:[[FLOW_S_RELOAD_SAVEEXEC_HI_SAVEEXEC:[0-9]+]]{{\]}}, s{{\[}}[[FLOW_S_RELOAD_SAVEEXEC_LO]]:[[FLOW_S_RELOAD_SAVEEXEC_HI]]{{\]}}
; Regular spill value restored after exec modification
; GCN: buffer_load_dword [[FLOW_VAL:v[0-9]+]], off, s[0:3], 0 offset:[[FLOW_VAL_OFFSET:[0-9]+]] ; 4-byte Folded Reload
; Spill saved exec
; VGPR: v_writelane_b32 [[SPILL_VGPR]], s[[FLOW_S_RELOAD_SAVEEXEC_LO_SAVEEXEC]], [[FLOW_SAVEEXEC_LO_LANE:[0-9]+]]
; VGPR: v_writelane_b32 [[SPILL_VGPR]], s[[FLOW_S_RELOAD_SAVEEXEC_HI_SAVEEXEC]], [[FLOW_SAVEEXEC_HI_LANE:[0-9]+]]
; VMEM: v_writelane_b32 v[[FLOW_V_SAVEEXEC:[0-9]+]], s[[FLOW_S_RELOAD_SAVEEXEC_LO_SAVEEXEC]], 0
; VMEM: v_writelane_b32 v[[FLOW_V_SAVEEXEC]], s[[FLOW_S_RELOAD_SAVEEXEC_HI_SAVEEXEC]], 1
; VMEM: buffer_store_dword v[[FLOW_V_SAVEEXEC]], off, s[0:3], 0 offset:[[FLOW_SAVEEXEC_OFFSET:[0-9]+]] ; 4-byte Folded Spill
; GCN: buffer_store_dword [[FLOW_VAL]], off, s[0:3], 0 offset:[[RESULT_OFFSET:[0-9]+]] ; 4-byte Folded Spill
; GCN: s_xor_b64 exec, exec, s{{\[}}[[FLOW_S_RELOAD_SAVEEXEC_LO_SAVEEXEC]]:[[FLOW_S_RELOAD_SAVEEXEC_HI_SAVEEXEC]]{{\]}}
; GCN-NEXT: s_cbranch_execz [[ENDIF:BB[0-9]+_[0-9]+]]
; GCN: ; %bb.{{[0-9]+}}: ; %if
; GCN: buffer_load_dword v[[LOAD0_RELOAD:[0-9]+]], off, s[0:3], 0 offset:[[LOAD0_OFFSET]] ; 4-byte Folded Reload
; GCN: ds_read_b32
; GCN: v_add_i32_e32 [[ADD:v[0-9]+]], vcc, v{{[0-9]+}}, v[[LOAD0_RELOAD]]
; GCN: buffer_store_dword [[ADD]], off, s[0:3], 0 offset:[[RESULT_OFFSET]] ; 4-byte Folded Spill
; GCN-NEXT: s_branch [[ENDIF:BB[0-9]+_[0-9]+]]
; GCN: [[ELSE]]: ; %else
; GCN: buffer_load_dword v[[LOAD0_RELOAD:[0-9]+]], off, s[0:3], 0 offset:[[LOAD0_OFFSET]] ; 4-byte Folded Reload
; GCN: v_subrev_i32_e32 [[SUB:v[0-9]+]], vcc, v{{[0-9]+}}, v[[LOAD0_RELOAD]]
; GCN: buffer_store_dword [[ADD]], off, s[0:3], 0 offset:[[FLOW_RESULT_OFFSET:[0-9]+]] ; 4-byte Folded Spill
; GCN-NEXT: s_branch [[FLOW]]
; GCN: [[ENDIF]]:
; VGPR: v_readlane_b32 s[[S_RELOAD_SAVEEXEC_LO:[0-9]+]], [[SPILL_VGPR]], [[FLOW_SAVEEXEC_LO_LANE]]
; VGPR: v_readlane_b32 s[[S_RELOAD_SAVEEXEC_HI:[0-9]+]], [[SPILL_VGPR]], [[FLOW_SAVEEXEC_HI_LANE]]
; VMEM: buffer_load_dword v[[V_RELOAD_SAVEEXEC:[0-9]+]], off, s[0:3], 0 offset:[[FLOW_SAVEEXEC_OFFSET]] ; 4-byte Folded Reload
; VMEM: s_waitcnt vmcnt(0)
; VMEM: v_readlane_b32 s[[S_RELOAD_SAVEEXEC_LO:[0-9]+]], v[[V_RELOAD_SAVEEXEC]], 0
; VMEM: v_readlane_b32 s[[S_RELOAD_SAVEEXEC_HI:[0-9]+]], v[[V_RELOAD_SAVEEXEC]], 1
; GCN: s_or_b64 exec, exec, s{{\[}}[[S_RELOAD_SAVEEXEC_LO]]:[[S_RELOAD_SAVEEXEC_HI]]{{\]}}
; GCN: buffer_load_dword v[[RESULT:[0-9]+]], off, s[0:3], 0 offset:[[RESULT_OFFSET]] ; 4-byte Folded Reload
; GCN: flat_store_dword v{{\[[0-9]+:[0-9]+\]}}, v[[RESULT]]
define amdgpu_kernel void @divergent_if_else_endif(i32 addrspace(1)* %out) #0 {
entry:
%tid = call i32 @llvm.amdgcn.workitem.id.x()
%load0 = load volatile i32, i32 addrspace(3)* null
%cmp0 = icmp eq i32 %tid, 0
br i1 %cmp0, label %if, label %else
if:
%load1 = load volatile i32, i32 addrspace(3)* undef
%val0 = add i32 %load0, %load1
br label %endif
else:
%load2 = load volatile i32, i32 addrspace(3)* undef
%val1 = sub i32 %load0, %load2
br label %endif
endif:
%result = phi i32 [ %val0, %if ], [ %val1, %else ]
store i32 %result, i32 addrspace(1)* %out
ret void
}
declare i32 @llvm.amdgcn.workitem.id.x() #1
attributes #0 = { nounwind }
attributes #1 = { nounwind readnone }