analyze-branch.ll
2.25 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
; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc -mtriple=riscv32 -verify-machineinstrs < %s \
; RUN: | FileCheck -check-prefix=RV32I %s
; This test checks that LLVM can do basic stripping and reapplying of branches
; to basic blocks.
declare void @test_true()
declare void @test_false()
; !0 corresponds to a branch being taken, !1 to not being takne.
!0 = !{!"branch_weights", i32 64, i32 4}
!1 = !{!"branch_weights", i32 4, i32 64}
define void @test_bcc_fallthrough_taken(i32 %in) nounwind {
; RV32I-LABEL: test_bcc_fallthrough_taken:
; RV32I: # %bb.0:
; RV32I-NEXT: addi sp, sp, -16
; RV32I-NEXT: sw ra, 12(sp)
; RV32I-NEXT: addi a1, zero, 42
; RV32I-NEXT: bne a0, a1, .LBB0_3
; RV32I-NEXT: # %bb.1: # %true
; RV32I-NEXT: call test_true
; RV32I-NEXT: .LBB0_2: # %true
; RV32I-NEXT: lw ra, 12(sp)
; RV32I-NEXT: addi sp, sp, 16
; RV32I-NEXT: ret
; RV32I-NEXT: .LBB0_3: # %false
; RV32I-NEXT: call test_false
; RV32I-NEXT: j .LBB0_2
%tst = icmp eq i32 %in, 42
br i1 %tst, label %true, label %false, !prof !0
; Expected layout order is: Entry, TrueBlock, FalseBlock
; Entry->TrueBlock is the common path, which should be taken whenever the
; conditional branch is false.
true:
call void @test_true()
ret void
false:
call void @test_false()
ret void
}
define void @test_bcc_fallthrough_nottaken(i32 %in) nounwind {
; RV32I-LABEL: test_bcc_fallthrough_nottaken:
; RV32I: # %bb.0:
; RV32I-NEXT: addi sp, sp, -16
; RV32I-NEXT: sw ra, 12(sp)
; RV32I-NEXT: addi a1, zero, 42
; RV32I-NEXT: beq a0, a1, .LBB1_3
; RV32I-NEXT: # %bb.1: # %false
; RV32I-NEXT: call test_false
; RV32I-NEXT: .LBB1_2: # %true
; RV32I-NEXT: lw ra, 12(sp)
; RV32I-NEXT: addi sp, sp, 16
; RV32I-NEXT: ret
; RV32I-NEXT: .LBB1_3: # %true
; RV32I-NEXT: call test_true
; RV32I-NEXT: j .LBB1_2
%tst = icmp eq i32 %in, 42
br i1 %tst, label %true, label %false, !prof !1
; Expected layout order is: Entry, FalseBlock, TrueBlock
; Entry->FalseBlock is the common path, which should be taken whenever the
; conditional branch is false
true:
call void @test_true()
ret void
false:
call void @test_false()
ret void
}
; TODO: how can we expand the coverage of the branch analysis functions?