1; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
2; RUN: llc -O3 < %s -mtriple=riscv32 | FileCheck %s
3
4; These tests demonstrate optimizations involving copies from VLENB.
5
6define void @unused_copy_is_dead() {
7; CHECK-LABEL: unused_copy_is_dead:
8; CHECK:       # %bb.0: # %entry
9; CHECK-NEXT:    ret
10entry:
11  call i32 @llvm.read_register.i32(metadata !0)
12  ret void
13}
14
15define i32 @simple_cse() {
16; CHECK-LABEL: simple_cse:
17; CHECK:       # %bb.0: # %entry
18; CHECK-NEXT:    csrr a0, vlenb
19; CHECK-NEXT:    csrr a1, vlenb
20; CHECK-NEXT:    sub a0, a0, a1
21; CHECK-NEXT:    ret
22entry:
23  %v1 = call i32 @llvm.read_register.i32(metadata !0)
24  %v2 = call i32 @llvm.read_register.i32(metadata !0)
25  %sub = sub i32 %v1, %v2
26  ret i32 %sub
27}
28
29define i32 @sink_to_use_branch(i1 %c) {
30; CHECK-LABEL: sink_to_use_branch:
31; CHECK:       # %bb.0: # %entry
32; CHECK-NEXT:    andi a0, a0, 1
33; CHECK-NEXT:    beqz a0, .LBB2_2
34; CHECK-NEXT:  # %bb.1: # %used
35; CHECK-NEXT:    csrr a0, vlenb
36; CHECK-NEXT:  .LBB2_2: # %unused
37; CHECK-NEXT:    ret
38entry:
39  %v1 = call i32 @llvm.read_register.i32(metadata !0)
40  br i1 %c, label %used, label %unused
41used:
42  ret i32 %v1
43unused:
44  ret i32 0
45}
46
47define i32 @sink_to_use_call() {
48; CHECK-LABEL: sink_to_use_call:
49; CHECK:       # %bb.0: # %entry
50; CHECK-NEXT:    addi sp, sp, -16
51; CHECK-NEXT:    .cfi_def_cfa_offset 16
52; CHECK-NEXT:    sw ra, 12(sp) # 4-byte Folded Spill
53; CHECK-NEXT:    sw s0, 8(sp) # 4-byte Folded Spill
54; CHECK-NEXT:    .cfi_offset ra, -4
55; CHECK-NEXT:    .cfi_offset s0, -8
56; CHECK-NEXT:    csrr s0, vlenb
57; CHECK-NEXT:    call unknown@plt
58; CHECK-NEXT:    mv a0, s0
59; CHECK-NEXT:    lw ra, 12(sp) # 4-byte Folded Reload
60; CHECK-NEXT:    lw s0, 8(sp) # 4-byte Folded Reload
61; CHECK-NEXT:    addi sp, sp, 16
62; CHECK-NEXT:    ret
63entry:
64  %v1 = call i32 @llvm.read_register.i32(metadata !0)
65  call void @unknown() ; maythrow
66  ret i32 %v1
67}
68
69define void @machine_licm() {
70; CHECK-LABEL: machine_licm:
71; CHECK:       # %bb.0: # %entry
72; CHECK-NEXT:    addi sp, sp, -16
73; CHECK-NEXT:    .cfi_def_cfa_offset 16
74; CHECK-NEXT:    sw ra, 12(sp) # 4-byte Folded Spill
75; CHECK-NEXT:    .cfi_offset ra, -4
76; CHECK-NEXT:  .LBB4_1: # %loop
77; CHECK-NEXT:    # =>This Inner Loop Header: Depth=1
78; CHECK-NEXT:    csrr a0, vlenb
79; CHECK-NEXT:    call use@plt
80; CHECK-NEXT:    j .LBB4_1
81entry:
82  br label %loop
83
84loop:
85  %v1 = call i32 @llvm.read_register.i32(metadata !0)
86  call void @use(i32 %v1)
87  br label %loop
88}
89
90
91declare i32 @llvm.read_register.i32(metadata) nounwind
92declare void @unknown()
93declare void @use(i32)
94
95!0 = !{!"vlenb"}
96