1# RUN: llc -march=amdgcn -mcpu=gfx900 -amdgpu-vgpr-index-mode -run-pass=greedy -stress-regalloc=16 -o - %s | FileCheck -check-prefixes=GCN %s
2
3# An interval for a register that was partially defined was split, creating
4# a new use (a COPY) which was reached by the undef point. In particular,
5# there was a subrange of the new register which was reached by an "undef"
6# point. When the code in extendSegmentsToUses verified value numbers between
7# the new and the old live ranges, it did not account for this kind of a
8# situation and asserted expecting the old value to exist. For a PHI node
9# it is legal to have a missing predecessor value as long as the end of
10# the predecessor is jointly dominated by the undefs.
11#
12# A simplified form of this can be illustrated as
13#
14# bb.1:
15#   %0:vreg_64 = IMPLICIT_DEF
16#   ...
17#   S_CBRANCH_SCC1 %bb.2, implicit $vcc
18#   S_BRANCH %bb.3
19#
20# bb.2:
21# ; predecessors: %bb.1, %bb.4
22#   dead %1:vreg_64 = COPY %0:vreg_64 ; This is the point of the inserted split
23#   ...
24#   S_BRANCH %bb.5
25#
26# bb.3:
27# ; predecessors: %bb.1
28#   undef %0.sub0:vreg_64 = COPY %123:sreg_32 ; undef point for %0.sub1
29#   ...
30#   S_BRANCH %bb.4
31#
32# bb.4
33# ; predecessors: %bb.4
34#   ...
35#   S_BRANCH %bb.2
36#
37# This test exposes this scenario which caused previously caused an assert
38
39---
40name:            _amdgpu_ps_main
41tracksRegLiveness: true
42machineFunctionInfo:
43  scratchRSrcReg: $sgpr0_sgpr1_sgpr2_sgpr3
44  stackPtrOffsetReg: $sgpr32
45liveins:
46  - { reg: '$vgpr2', virtual-reg: '%0' }
47  - { reg: '$vgpr3', virtual-reg: '%1' }
48  - { reg: '$vgpr4', virtual-reg: '%2' }
49body: |
50  bb.0:
51    successors: %bb.1(0x40000000), %bb.2(0x40000000)
52    liveins: $vgpr2, $vgpr3, $vgpr4
53    %2:vgpr_32 = COPY $vgpr4
54    %1:vgpr_32 = COPY $vgpr3
55    %0:vgpr_32 = COPY $vgpr2
56    S_CBRANCH_SCC0 %bb.2, implicit undef $scc
57
58  bb.1:
59    successors: %bb.5(0x80000000)
60    undef %3.sub0:vreg_128 = V_MOV_B32_e32 0, implicit $exec
61    %3.sub1:vreg_128 = COPY %3.sub0
62    %3.sub2:vreg_128 = COPY %3.sub0
63    S_BRANCH %bb.5
64
65  bb.2:
66    successors: %bb.3(0x40000000), %bb.4(0x40000000)
67    S_CBRANCH_SCC0 %bb.4, implicit undef $scc
68
69  bb.3:
70    successors: %bb.5(0x80000000)
71    undef %3.sub0:vreg_128 = V_MOV_B32_e32 0, implicit $exec
72    %3.sub1:vreg_128 = COPY %3.sub0
73    S_BRANCH %bb.5
74
75  bb.4:
76    successors: %bb.5(0x80000000)
77    %3:vreg_128 = IMPLICIT_DEF
78
79  bb.5:
80    successors: %bb.6(0x40000000), %bb.22(0x40000000)
81    %4:vgpr_32 = V_MOV_B32_e32 0, implicit $exec
82    S_CBRANCH_SCC1 %bb.22, implicit undef $scc
83    S_BRANCH %bb.6
84
85  bb.6:
86    successors: %bb.8(0x40000000), %bb.11(0x40000000)
87    %5:vgpr_32 = V_MOV_B32_e32 0, implicit $exec
88    dead %6:vgpr_32 = V_MUL_F32_e32 0, undef %7:vgpr_32, implicit $mode, implicit $exec
89    dead %8:vgpr_32 = V_MUL_F32_e32 0, %2, implicit $mode, implicit $exec
90    undef %9.sub1:vreg_64 = V_MUL_F32_e32 0, %1, implicit $mode, implicit $exec
91    undef %10.sub0:vreg_128 = V_MUL_F32_e32 0, %0, implicit $mode, implicit $exec
92    undef %11.sub0:sgpr_256 = S_MOV_B32 0
93    %11.sub1:sgpr_256 = COPY %11.sub0
94    %11.sub2:sgpr_256 = COPY %11.sub0
95    %11.sub3:sgpr_256 = COPY %11.sub0
96    %11.sub4:sgpr_256 = COPY %11.sub0
97    %11.sub5:sgpr_256 = COPY %11.sub0
98    %11.sub6:sgpr_256 = COPY %11.sub0
99    %11.sub7:sgpr_256 = COPY %11.sub0
100    %12:vreg_128 = IMAGE_SAMPLE_LZ_V4_V2 %9, %11, undef %13:sgpr_128, 15, 0, 0, 0, 0, 0, 0, 0, implicit $exec :: (dereferenceable load (s128) from constant-pool, addrspace 4)
101    %14:vgpr_32 = V_MOV_B32_e32 -1, implicit $exec
102    %15:vreg_128 = IMPLICIT_DEF
103    S_CBRANCH_SCC1 %bb.8, implicit undef $scc
104    S_BRANCH %bb.11
105
106  bb.7:
107    successors: %bb.13(0x80000000)
108
109    ; GCN-LABEL: bb.7:
110    ; GCN:  undef %15.sub0:vreg_128 = V_MOV_B32_e32 0, implicit $exec
111
112    undef %15.sub0:vreg_128 = V_MOV_B32_e32 0, implicit $exec
113    %15.sub1:vreg_128 = COPY %15.sub0
114    %15.sub2:vreg_128 = COPY %15.sub0
115    %5:vgpr_32 = IMPLICIT_DEF
116    S_BRANCH %bb.13
117
118  bb.8:
119    successors: %bb.9(0x40000000), %bb.10(0x40000000)
120    S_CBRANCH_SCC0 %bb.10, implicit undef $scc
121
122  bb.9:
123    successors: %bb.12(0x80000000)
124
125    ; GCN-LABEL: bb.9:
126    ; GCN: undef %15.sub0:vreg_128 = V_MOV_B32_e32 0, implicit $exec
127
128    undef %15.sub0:vreg_128 = V_MOV_B32_e32 0, implicit $exec
129    %15.sub1:vreg_128 = COPY %15.sub0
130    %15.sub2:vreg_128 = COPY %15.sub0
131    S_BRANCH %bb.12
132
133  bb.10:
134    successors: %bb.12(0x80000000)
135
136    ; GCN-LABEL: bb.10:
137    ; GCN: undef %15.sub0:vreg_128 = V_MOV_B32_e32 2143289344, implicit $exec
138
139    undef %15.sub0:vreg_128 = V_MOV_B32_e32 2143289344, implicit $exec
140    %15.sub1:vreg_128 = COPY %15.sub0
141    %15.sub2:vreg_128 = COPY %15.sub0
142    S_BRANCH %bb.12
143
144  bb.11:
145    successors: %bb.7(0x40000000), %bb.13(0x40000000)
146    %16:sreg_64 = V_CMP_NE_U32_e64 0, %14, implicit $exec
147    %17:sreg_64 = S_AND_B64 $exec, %16, implicit-def dead $scc
148    $vcc = COPY %17
149    S_CBRANCH_VCCNZ %bb.7, implicit $vcc
150    S_BRANCH %bb.13
151
152  bb.12:
153    successors: %bb.11(0x80000000)
154    %14:vgpr_32 = V_MOV_B32_e32 0, implicit $exec
155    %5:vgpr_32 = V_MOV_B32_e32 -1, implicit $exec
156    S_BRANCH %bb.11
157
158  bb.13:
159    successors: %bb.15(0x40000000), %bb.14(0x40000000)
160
161    %18:vgpr_32 = V_MAD_F32_e64 0, %10.sub0, 0, target-flags(amdgpu-gotprel) 1073741824, 0, -1082130432, 0, 0, implicit $mode, implicit $exec
162    %19:vgpr_32 = V_MAD_F32_e64 0, %12.sub0, 0, target-flags(amdgpu-gotprel) 0, 0, 0, 0, 0, implicit $mode, implicit $exec
163    %20:sgpr_128 = S_BUFFER_LOAD_DWORDX4_IMM undef %21:sgpr_128, 1040, 0 :: (dereferenceable invariant load (s128))
164    %22:vgpr_32 = V_ADD_F32_e32 0, %19, implicit $mode, implicit $exec
165    %23:vgpr_32 = V_MAD_F32_e64 0, %18, 0, 0, 0, 0, 0, 0, implicit $mode, implicit $exec
166    %24:vgpr_32 = COPY %20.sub3
167    %25:vgpr_32 = V_MUL_F32_e64 0, target-flags(amdgpu-gotprel32-lo) 0, 0, %20.sub1, 0, 0, implicit $mode, implicit $exec
168    %26:sgpr_128 = S_BUFFER_LOAD_DWORDX4_IMM undef %27:sgpr_128, 1056, 0 :: (dereferenceable invariant load (s128))
169    %28:vgpr_32 = V_MAD_F32_e64 0, %18, 0, %26.sub0, 0, 0, 0, 0, implicit $mode, implicit $exec
170    %29:vgpr_32 = V_ADD_F32_e32 %28, %19, implicit $mode, implicit $exec
171    %30:vgpr_32 = V_RCP_F32_e32 %29, implicit $mode, implicit $exec
172    %25:vgpr_32 = V_MAC_F32_e32 0, %18, %25, implicit $mode, implicit $exec
173    %31:vgpr_32 = V_MAD_F32_e64 0, target-flags(amdgpu-gotprel) 0, 0, %12.sub0, 0, %24, 0, 0, implicit $mode, implicit $exec
174    %32:vgpr_32 = V_ADD_F32_e32 %25, %31, implicit $mode, implicit $exec
175    %33:vgpr_32 = V_MUL_F32_e32 %22, %30, implicit $mode, implicit $exec
176    %34:vgpr_32 = V_MUL_F32_e32 %23, %30, implicit $mode, implicit $exec
177    %35:vgpr_32 = V_MUL_F32_e32 %32, %30, implicit $mode, implicit $exec
178    %36:vgpr_32 = V_MUL_F32_e32 0, %34, implicit $mode, implicit $exec
179    %36:vgpr_32 = V_MAC_F32_e32 0, %33, %36, implicit $mode, implicit $exec
180    %37:vgpr_32 = V_MAD_F32_e64 0, %35, 0, 0, 0, 0, 0, 0, implicit $mode, implicit $exec
181    %38:sreg_64_xexec = V_CMP_NE_U32_e64 0, %5, implicit $exec
182    %39:vgpr_32 = V_CNDMASK_B32_e64 0, 0, 0, 1, %38, implicit $exec
183    V_CMP_NE_U32_e32 1, %39, implicit-def $vcc, implicit $exec
184    $vcc = S_AND_B64 $exec, $vcc, implicit-def dead $scc
185    %40:vgpr_32 = V_ADD_F32_e32 %36, %37, implicit $mode, implicit $exec
186    S_CBRANCH_VCCZ %bb.15, implicit $vcc
187
188  bb.14:
189    successors: %bb.17(0x80000000)
190    S_BRANCH %bb.17
191
192  bb.15:
193    successors: %bb.16(0x40000000), %bb.18(0x40000000)
194    %41:vgpr_32 = V_MAD_F32_e64 0, %40, 0, 0, 0, 0, 0, 0, implicit $mode, implicit $exec
195    %42:sreg_64 = V_CMP_LE_F32_e64 0, 0, 0, %41, 0, implicit $mode, implicit $exec
196    %43:sreg_64 = V_CMP_GE_F32_e64 0, 1065353216, 0, %41, 0, implicit $mode, implicit $exec
197    %44:sreg_64 = S_AND_B64 %43, %43, implicit-def dead $scc
198    %45:sreg_64 = S_AND_B64 %42, %42, implicit-def dead $scc
199    %46:sreg_64 = S_AND_B64 %45, %44, implicit-def dead $scc
200    %47:sreg_64 = COPY $exec, implicit-def $exec
201    %48:sreg_64 = S_AND_B64 %47, %46, implicit-def dead $scc
202    $exec = S_MOV_B64_term %48
203    S_CBRANCH_EXECZ %bb.18, implicit $exec
204    S_BRANCH %bb.16
205
206  bb.16:
207    successors: %bb.18(0x80000000)
208    S_BRANCH %bb.18
209
210  bb.17:
211    successors: %bb.21(0x40000000), %bb.23(0x40000000)
212    %49:sreg_64 = V_CMP_NE_U32_e64 0, %5, implicit $exec
213    %50:sreg_64 = S_AND_B64 $exec, %49, implicit-def dead $scc
214    %51:vreg_128 = IMPLICIT_DEF
215    $vcc = COPY %50
216    S_CBRANCH_VCCNZ %bb.21, implicit $vcc
217    S_BRANCH %bb.23
218
219  bb.18:
220    successors: %bb.20(0x40000000), %bb.19(0x40000000)
221    $exec = S_OR_B64 $exec, %47, implicit-def $scc
222    %52:vgpr_32 = V_MAD_F32_e64 0, %3.sub1, 0, target-flags(amdgpu-gotprel32-lo) 0, 1, %3.sub0, 0, 0, implicit $mode, implicit $exec
223    %53:vgpr_32 = V_MUL_F32_e32 -2147483648, %3.sub1, implicit $mode, implicit $exec
224    %53:vgpr_32 = V_MAC_F32_e32 target-flags(amdgpu-gotprel32-hi) 1065353216, %3.sub2, %53, implicit $mode, implicit $exec
225    %54:vgpr_32 = V_MUL_F32_e32 %53, %53, implicit $mode, implicit $exec
226    %54:vgpr_32 = V_MAC_F32_e32 %52, %52, %54, implicit $mode, implicit $exec
227    %55:vgpr_32 = V_SQRT_F32_e32 %54, implicit $mode, implicit $exec
228    %5:vgpr_32 = V_MOV_B32_e32 0, implicit $exec
229    %56:vgpr_32 = V_MOV_B32_e32 981668463, implicit $exec
230    %57:sreg_64 = V_CMP_NGT_F32_e64 0, %55, 0, %56, 0, implicit $mode, implicit $exec
231    %58:sreg_64 = S_AND_B64 $exec, %57, implicit-def dead $scc
232    $vcc = COPY %58
233    S_CBRANCH_VCCZ %bb.20, implicit $vcc
234
235  bb.19:
236    successors: %bb.17(0x80000000)
237    S_BRANCH %bb.17
238
239  bb.20:
240    successors: %bb.17(0x80000000)
241    S_BRANCH %bb.17
242
243  bb.21:
244    successors: %bb.23(0x80000000)
245    %59:sreg_32 = S_MOV_B32 0
246    undef %51.sub0:vreg_128 = COPY %59
247    S_BRANCH %bb.23
248
249  bb.22:
250    successors: %bb.24(0x80000000)
251    S_BRANCH %bb.24
252
253  bb.23:
254    successors: %bb.22(0x80000000)
255    undef %60.sub1:vreg_64 = V_CVT_I32_F32_e32 %1, implicit $mode, implicit $exec
256    %60.sub0:vreg_64 = V_CVT_I32_F32_e32 %0, implicit $mode, implicit $exec
257    undef %61.sub0:sgpr_256 = S_MOV_B32 0
258    %61.sub1:sgpr_256 = COPY %61.sub0
259    %61.sub2:sgpr_256 = COPY %61.sub0
260    %61.sub3:sgpr_256 = COPY %61.sub0
261    %61.sub4:sgpr_256 = COPY %61.sub0
262    %61.sub5:sgpr_256 = COPY %61.sub0
263    %61.sub6:sgpr_256 = COPY %61.sub0
264    %61.sub7:sgpr_256 = COPY %61.sub0
265    %62:vgpr_32 = V_MOV_B32_e32 1033100696, implicit $exec
266    %63:vgpr_32 = V_MUL_F32_e32 1060575065, %15.sub1, implicit $mode, implicit $exec
267    %63:vgpr_32 = V_MAC_F32_e32 1046066128, %15.sub0, %63, implicit $mode, implicit $exec
268    %64:vgpr_32 = IMAGE_LOAD_V1_V2 %60, %61, 1, -1, 0, 0, 0, 0, 0, 0, implicit $exec :: (dereferenceable load (s128) from constant-pool, addrspace 4)
269    %64:vgpr_32 = V_MAC_F32_e32 target-flags(amdgpu-gotprel) 0, %51.sub0, %64, implicit $mode, implicit $exec
270    %65:vgpr_32 = V_MUL_F32_e32 0, %64, implicit $mode, implicit $exec
271    %66:vgpr_32 = V_MUL_F32_e32 0, %65, implicit $mode, implicit $exec
272    %67:vgpr_32 = V_MAD_F32_e64 0, %66, 0, %62, 0, 0, 0, 0, implicit $mode, implicit $exec
273    %63:vgpr_32 = V_MAC_F32_e32 %15.sub2, %62, %63, implicit $mode, implicit $exec
274    %4:vgpr_32 = V_ADD_F32_e32 %63, %67, implicit $mode, implicit $exec
275    S_BRANCH %bb.22
276
277  bb.24:
278    %68:vgpr_32 = V_MUL_F32_e32 0, %4, implicit $mode, implicit $exec
279    %69:vgpr_32 = V_CVT_PKRTZ_F16_F32_e64 0, undef %70:vgpr_32, 0, %68, 0, 0, implicit $mode, implicit $exec
280    EXP 0, undef %71:vgpr_32, %69, undef %72:vgpr_32, undef %73:vgpr_32, -1, -1, 15, implicit $exec
281    S_ENDPGM 0
282...
283