1# RUN: llc -mtriple=amdgcn-amd-amdhsa -amdgpu-dce-in-ra=0 -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 $mode, implicit $exec
11# CHECK-NEXT: SI_SPILL_V64_SAVE %7, %stack.0, $sgpr32, 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 $mode, implicit $exec
14
15# CHECK: S_NOP 0, implicit %6.sub1
16# CHECK-NEXT: %8:vreg_64 = SI_SPILL_V64_RESTORE %stack.0, $sgpr32, 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
22machineFunctionInfo:
23  scratchRSrcReg: $sgpr0_sgpr1_sgpr2_sgpr3
24  stackPtrOffsetReg: $sgpr32
25body:             |
26  bb.0:
27    successors: %bb.1
28
29    undef %0.sub1:vreg_64 = V_MAC_F32_e32 0, undef %1:vgpr_32, undef %0.sub1, implicit $mode, implicit $exec
30    undef %2.sub1:vreg_64 = V_MOV_B32_e32 1786773504, implicit $exec
31    dead %3:vgpr_32 = V_MUL_F32_e32 0, %2.sub1, implicit $mode, implicit $exec
32
33  bb.1:
34    S_NOP 0, implicit %2.sub1
35    S_NOP 0, implicit %0.sub1
36    S_NOP 0, implicit undef %0.sub0
37
38...
39
40# Similar assert which happens when trying to rematerialize.
41# https://bugs.llvm.org/show_bug.cgi?id=33884
42---
43# CHECK-LABEL: name: rematerialize_empty_interval_has_reference
44
45# CHECK-NOT: MOV
46# CHECK: undef %1.sub2:vreg_128 = V_MOV_B32_e32 1786773504, implicit $exec
47
48# CHECK: bb.1:
49# CHECK-NEXT: S_NOP 0, implicit %1.sub2
50# CHECK-NEXT: S_NOP 0, implicit undef %4.sub0
51# CHECK-NEXT: undef %2.sub2:vreg_128 = V_MOV_B32_e32 0, implicit $exec
52# CHECK-NEXT: S_NOP 0, implicit %2.sub2
53name: rematerialize_empty_interval_has_reference
54tracksRegLiveness: true
55machineFunctionInfo:
56  scratchRSrcReg: $sgpr0_sgpr1_sgpr2_sgpr3
57  stackPtrOffsetReg: $sgpr32
58body:             |
59  bb.0:
60    successors: %bb.1
61
62    undef %0.sub2:vreg_128 = V_MOV_B32_e32 0, implicit $exec
63    undef %1.sub2:vreg_128 = V_MOV_B32_e32 1786773504, implicit $exec
64
65  bb.1:
66    S_NOP 0, implicit %1.sub2
67    S_NOP 0, implicit undef %0.sub0
68    S_NOP 0, implicit %0.sub2
69
70...
71