xref: /llvm-project/llvm/test/Transforms/LoopLoadElim/uncomputable-backedge-taken-count.ll (revision 055fb7795aa219a3d274d280ec9129784f169f56)
1; RUN: opt -passes=loop-load-elim -S < %s | FileCheck %s
2; RUN: opt -aa-pipeline=basic-aa -passes=loop-load-elim -S < %s | FileCheck %s
3
4target datalayout = "e-m:o-i32:64-f80:128-n8:16:32:64-S128"
5
6; TODO
7; Make sure loop-load-elimination triggers for a loop with uncomputable
8; backedge-taken counts when no runtime checks are required.
9define void @load_elim_no_runtime_checks(ptr noalias %A, ptr noalias %B, ptr noalias %C, i32 %N) {
10; CHECK-LABEL: load_elim_no_runtime_checks
11; CHECK-NEXT:  entry:
12; CHECK-NEXT:    br label %for.body
13;
14entry:
15  br label %for.body
16
17for.body:                                         ; preds = %for.body, %entry
18  %indvars.iv = phi i32 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
19  %indvars.iv.next = add nuw nsw i32 %indvars.iv, 1
20
21  %Aidx_next = getelementptr inbounds i32, ptr %A, i32 %indvars.iv.next
22  %Bidx = getelementptr inbounds i32, ptr %B, i32 %indvars.iv
23  %Cidx = getelementptr inbounds i32, ptr %C, i32 %indvars.iv
24  %Aidx = getelementptr inbounds i32, ptr %A, i32 %indvars.iv
25
26  %b = load i32, ptr %Bidx, align 4
27  %a_p1 = add i32 %b, 2
28  store i32 %a_p1, ptr %Aidx_next, align 4
29
30  %a = load i32, ptr %Aidx, align 1
31  %c = mul i32 %a, 2
32  store i32 %c, ptr %Cidx, align 4
33
34  %exitcond = icmp eq i32 %indvars.iv.next, %a
35  br i1 %exitcond, label %for.end, label %for.body
36
37for.end:                                          ; preds = %for.body
38  ret void
39}
40
41; Make sure loop-load-elimination triggers for a loop with uncomputable
42; backedge-taken counts when no runtime checks are required.
43define void @load_elim_wrapping_runtime_checks(ptr noalias %A, ptr noalias %B, ptr noalias %C, i32 %N) {
44; CHECK-LABEL: @load_elim_wrapping_runtime_checks
45; CHECK-NEXT:  entry:
46; CHECK-NEXT:    br label %for.body
47;
48entry:
49  br label %for.body
50
51for.body:                                         ; preds = %for.body, %entry
52  %indvars.iv = phi i32 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
53  %indvars.iv.next = add i32 %indvars.iv, 1
54
55  %Aidx_next = getelementptr inbounds i32, ptr %A, i32 %indvars.iv.next
56  %Bidx = getelementptr inbounds i32, ptr %B, i32 %indvars.iv
57  %Cidx = getelementptr inbounds i32, ptr %C, i32 %indvars.iv
58  %Aidx = getelementptr inbounds i32, ptr %A, i32 %indvars.iv
59
60  %b = load i32, ptr %Bidx, align 4
61  %a_p1 = add i32 %b, 2
62  store i32 %a_p1, ptr %Aidx_next, align 4
63
64  %a = load i32, ptr %Aidx, align 1
65  %c = mul i32 %a, 2
66  store i32 %c, ptr %Cidx, align 4
67
68  %exitcond = icmp eq i32 %indvars.iv.next, %a
69  br i1 %exitcond, label %for.end, label %for.body
70
71for.end:                                          ; preds = %for.body
72  ret void
73}
74
75; Make sure we do not crash when dealing with uncomputable backedge-taken counts
76; and a variable distance between accesses.
77define void @uncomputable_btc_crash(ptr %row, i32 %filter, ptr noalias %exits) local_unnamed_addr #0 {
78; CHECK-LABEL: @uncomputable_btc_crash
79; CHECK-NEXT:  entry:
80; CHECK-NEXT:    getelementptr
81; CHECK-NEXT:    br label %loop
82;
83entry:
84  %add.ptr = getelementptr inbounds i8, ptr %row, i32 %filter
85  br label %loop
86
87loop:
88  %iv = phi i32 [ 0, %entry ], [ %iv.next, %loop ]
89  %add.ptr.gep = getelementptr i8, ptr %add.ptr, i32 %iv
90  %row.gep = getelementptr i8, ptr %row, i32 %iv
91  %l = load i8, ptr %row.gep, align 1
92  store i8 %l, ptr %add.ptr.gep, align 1
93  %iv.next = add i32 %iv, 8
94  %exit.gep = getelementptr i32, ptr %exits, i32 %iv
95  %lv = load i32, ptr %exit.gep
96  %c = icmp eq i32 %lv, 120
97  br i1 %c, label %exit, label %loop
98
99exit:
100  ret void
101}
102