1# RUN: llc -mtriple=amdgcn-amd-amdhsa -verify-machineinstrs -stress-regalloc=1 -start-before=simple-register-coalescing -stop-after=greedy -o - %s | FileCheck %s
2# https://bugs.llvm.org/show_bug.cgi?id=33620
3
4---
5# This would assert due to the empty live interval created for %9
6# on the last S_NOP with an undef subreg use.
7
8# CHECK-LABEL: name: expecting_non_empty_interval
9
10# CHECK: undef %7.sub1:vreg_64 = V_MAC_F32_e32 0, undef %1:vgpr_32, undef %7.sub1, implicit $exec
11# CHECK-NEXT: SI_SPILL_V64_SAVE %7, %stack.0, $sgpr0_sgpr1_sgpr2_sgpr3, $sgpr5, 0, implicit $exec :: (store 8 into %stack.0, align 4, addrspace 5)
12# CHECK-NEXT: undef %5.sub1:vreg_64 = V_MOV_B32_e32 1786773504, implicit $exec
13# CHECK-NEXT: dead %3:vgpr_32 = V_MUL_F32_e32 0, %5.sub1, implicit $exec
14
15# CHECK: S_NOP 0, implicit %6.sub1
16# CHECK-NEXT: %8:vreg_64 = SI_SPILL_V64_RESTORE %stack.0, $sgpr0_sgpr1_sgpr2_sgpr3, $sgpr5, 0, implicit $exec :: (load 8 from %stack.0, align 4, addrspace 5)
17# CHECK-NEXT: S_NOP 0, implicit %8.sub1
18# CHECK-NEXT: S_NOP 0, implicit undef %9.sub0
19
20name: expecting_non_empty_interval
21tracksRegLiveness: true
22body:             |
23  bb.0:
24    successors: %bb.1
25
26    undef %0.sub1:vreg_64 = V_MAC_F32_e32 0, undef %1:vgpr_32, undef %0.sub1, implicit $exec
27    undef %2.sub1:vreg_64 = V_MOV_B32_e32 1786773504, implicit $exec
28    dead %3:vgpr_32 = V_MUL_F32_e32 0, %2.sub1, implicit $exec
29
30  bb.1:
31    S_NOP 0, implicit %2.sub1
32    S_NOP 0, implicit %0.sub1
33    S_NOP 0, implicit undef %0.sub0
34
35...
36
37# Similar assert which happens when trying to rematerialize.
38# https://bugs.llvm.org/show_bug.cgi?id=33884
39---
40# CHECK-LABEL: name: rematerialize_empty_interval_has_reference
41
42# CHECK-NOT: MOV
43# CHECK: undef %1.sub2:vreg_128 = V_MOV_B32_e32 1786773504, implicit $exec
44
45# CHECK: bb.1:
46# CHECK-NEXT: S_NOP 0, implicit %1.sub2
47# CHECK-NEXT: S_NOP 0, implicit undef %4.sub0
48# CHECK-NEXT: undef %2.sub2:vreg_128 = V_MOV_B32_e32 0, implicit $exec
49# CHECK-NEXT: S_NOP 0, implicit %2.sub2
50name: rematerialize_empty_interval_has_reference
51tracksRegLiveness: true
52body:             |
53  bb.0:
54    successors: %bb.1
55
56    undef %0.sub2:vreg_128 = V_MOV_B32_e32 0, implicit $exec
57    undef %1.sub2:vreg_128 = V_MOV_B32_e32 1786773504, implicit $exec
58
59  bb.1:
60    S_NOP 0, implicit %1.sub2
61    S_NOP 0, implicit undef %0.sub0
62    S_NOP 0, implicit %0.sub2
63
64...
65