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
| ; PR23538
; RUN: opt < %s -indvars -loop-deletion -S | FileCheck %s
; Check IndVarSimplify should not replace exit value because or else
; udiv will be introduced by expand and the cost will be high.
declare void @_Z3mixRjj(i32* dereferenceable(4), i32)
declare void @llvm.lifetime.start.p0i8(i64, i8* nocapture)
declare void @llvm.lifetime.end.p0i8(i64, i8* nocapture)
define i32 @_Z3fooPKcjj(i8* nocapture readonly %s, i32 %len, i32 %c) {
; CHECK-LABEL: @_Z3fooPKcjj(
; CHECK-NOT: udiv
entry:
%a = alloca i32, align 4
%tmp = bitcast i32* %a to i8*
call void @llvm.lifetime.start.p0i8(i64 4, i8* %tmp)
store i32 -1640531527, i32* %a, align 4
%cmp8 = icmp ugt i32 %len, 11
br i1 %cmp8, label %while.body.lr.ph, label %while.end
while.body.lr.ph: ; preds = %entry
br label %while.body
while.body: ; preds = %while.body, %while.body.lr.ph
%keylen.010 = phi i32 [ %len, %while.body.lr.ph ], [ %sub, %while.body ]
%s.addr.09 = phi i8* [ %s, %while.body.lr.ph ], [ %add.ptr, %while.body ]
%tmp1 = bitcast i8* %s.addr.09 to i32*
%tmp2 = load i32, i32* %tmp1, align 4
%shl.i = shl i32 %tmp2, 1
%and.i = and i32 %shl.i, 16843008
%tmp3 = load i32, i32* %a, align 4
%sub.i = add i32 %tmp3, %tmp2
%add = sub i32 %sub.i, %and.i
store i32 %add, i32* %a, align 4
%add.ptr = getelementptr inbounds i8, i8* %s.addr.09, i64 12
%sub = add i32 %keylen.010, -12
%cmp = icmp ugt i32 %sub, 11
br i1 %cmp, label %while.body, label %while.cond.while.end_crit_edge
while.cond.while.end_crit_edge: ; preds = %while.body
%sub.lcssa = phi i32 [ %sub, %while.body ]
br label %while.end
while.end: ; preds = %while.cond.while.end_crit_edge, %entry
%keylen.0.lcssa = phi i32 [ %sub.lcssa, %while.cond.while.end_crit_edge ], [ %len, %entry ]
call void @_Z3mixRjj(i32* dereferenceable(4) %a, i32 %keylen.0.lcssa)
%tmp4 = load i32, i32* %a, align 4
call void @llvm.lifetime.end.p0i8(i64 4, i8* %tmp)
ret i32 %tmp4
}
define i32 @zero_backedge_count_test(i32 %unknown_init, i32* %unknown_mem) {
; CHECK-LABEL: @zero_backedge_count_test(
entry:
br label %loop
loop:
%iv = phi i32 [ 0, %entry], [ %iv.inc, %loop ]
%unknown_phi = phi i32 [ %unknown_init, %entry ], [ %unknown_next, %loop ]
%iv.inc = add i32 %iv, 1
%be_taken = icmp ne i32 %iv.inc, 1
%unknown_next = load volatile i32, i32* %unknown_mem
br i1 %be_taken, label %loop, label %leave
leave:
; We can fold %unknown_phi even though the backedge value for it is completely
; unknown, since we can prove that the loop's backedge taken count is 0.
; CHECK: leave:
; CHECK: ret i32 %unknown_init
%exit_val = phi i32 [ %unknown_phi, %loop ]
ret i32 %exit_val
}
|