1; RUN: opt -indvars -S < %s | FileCheck %s
2
3target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
4
5@X = external global [0 x double]
6
7; Indvars should be able to simplify simple comparisons involving
8; induction variables.
9
10; CHECK-LABEL: @foo(
11; CHECK: %cond = and i1 %tobool.not, true
12
13define void @foo(i64 %n, i32* nocapture %p) nounwind {
14entry:
15  %cmp9 = icmp sgt i64 %n, 0
16  br i1 %cmp9, label %pre, label %return
17
18pre:
19  %t3 = load i32, i32* %p
20  %tobool.not = icmp ne i32 %t3, 0
21  br label %loop
22
23loop:
24  %i = phi i64 [ 0, %pre ], [ %inc, %for.inc ]
25  %cmp6 = icmp slt i64 %i, %n
26  %cond = and i1 %tobool.not, %cmp6
27  br i1 %cond, label %if.then, label %for.inc
28
29if.then:
30  %arrayidx = getelementptr [0 x double], [0 x double]* @X, i64 0, i64 %i
31  store double 3.200000e+00, double* %arrayidx
32  br label %for.inc
33
34for.inc:
35  %inc = add nsw i64 %i, 1
36  %exitcond = icmp sge i64 %inc, %n
37  br i1 %exitcond, label %return, label %loop
38
39return:
40  ret void
41}
42
43; Don't eliminate an icmp that's contributing to the loop exit test though.
44
45; CHECK-LABEL: @_ZNK4llvm5APInt3ultERKS0_(
46; CHECK: %tmp99 = icmp sgt i32 %i, -1
47
48define i32 @_ZNK4llvm5APInt3ultERKS0_(i32 %tmp2.i1, i64** %tmp65, i64** %tmp73, i64** %tmp82, i64** %tmp90) {
49entry:
50  br label %bb18
51
52bb13:
53  %tmp66 = load i64*, i64** %tmp65, align 4
54  %tmp68 = getelementptr inbounds i64, i64* %tmp66, i32 %i
55  %tmp69 = load i64, i64* %tmp68, align 4
56  %tmp74 = load i64*, i64** %tmp73, align 4
57  %tmp76 = getelementptr inbounds i64, i64* %tmp74, i32 %i
58  %tmp77 = load i64, i64* %tmp76, align 4
59  %tmp78 = icmp ugt i64 %tmp69, %tmp77
60  br i1 %tmp78, label %bb20.loopexit, label %bb15
61
62bb15:
63  %tmp83 = load i64*, i64** %tmp82, align 4
64  %tmp85 = getelementptr inbounds i64, i64* %tmp83, i32 %i
65  %tmp86 = load i64, i64* %tmp85, align 4
66  %tmp91 = load i64*, i64** %tmp90, align 4
67  %tmp93 = getelementptr inbounds i64, i64* %tmp91, i32 %i
68  %tmp94 = load i64, i64* %tmp93, align 4
69  %tmp95 = icmp ult i64 %tmp86, %tmp94
70  br i1 %tmp95, label %bb20.loopexit, label %bb17
71
72bb17:
73  %tmp97 = add nsw i32 %i, -1
74  br label %bb18
75
76bb18:
77  %i = phi i32 [ %tmp2.i1, %entry ], [ %tmp97, %bb17 ]
78  %tmp99 = icmp sgt i32 %i, -1
79  br i1 %tmp99, label %bb13, label %bb20.loopexit
80
81bb20.loopexit:
82  %tmp.0.ph = phi i32 [ 0, %bb18 ], [ 1, %bb15 ], [ 0, %bb13 ]
83  ret i32 %tmp.0.ph
84}
85
86; Indvars should eliminate the icmp here.
87
88; CHECK-LABEL: @func_10(
89; CHECK-NOT: icmp
90; CHECK: ret void
91
92define void @func_10() nounwind {
93entry:
94  br label %loop
95
96loop:
97  %i = phi i32 [ %i.next, %loop ], [ 0, %entry ]
98  %t0 = icmp slt i32 %i, 0
99  %t1 = zext i1 %t0 to i32
100  %t2 = add i32 %t1, %i
101  %u3 = zext i32 %t2 to i64
102  store i64 %u3, i64* null
103  %i.next = add i32 %i, 1
104  br i1 undef, label %loop, label %return
105
106return:
107  ret void
108}
109
110; PR14432
111; Indvars should not turn the second loop into an infinite one.
112
113; CHECK-LABEL: @func_11(
114; CHECK: %tmp5 = icmp slt i32 %__key6.0, 10
115; CHECK-NOT: br i1 true, label %noassert68, label %unrolledend
116
117define i32 @func_11() nounwind uwtable {
118entry:
119  br label %forcond
120
121forcond:                                          ; preds = %noassert, %entry
122  %__key6.0 = phi i32 [ 2, %entry ], [ %tmp37, %noassert ]
123  %tmp5 = icmp slt i32 %__key6.0, 10
124  br i1 %tmp5, label %noassert, label %forcond38.preheader
125
126forcond38.preheader:                              ; preds = %forcond
127  br label %forcond38
128
129noassert:                                         ; preds = %forbody
130  %tmp13 = sdiv i32 -32768, %__key6.0
131  %tmp2936 = shl i32 %tmp13, 24
132  %sext23 = shl i32 %tmp13, 24
133  %tmp32 = icmp eq i32 %tmp2936, %sext23
134  %tmp37 = add i32 %__key6.0, 1
135  br i1 %tmp32, label %forcond, label %assert33
136
137assert33:                                         ; preds = %noassert
138  tail call void @llvm.trap()
139  unreachable
140
141forcond38:                                        ; preds = %noassert68, %forcond38.preheader
142  %__key8.0 = phi i32 [ %tmp81, %noassert68 ], [ 2, %forcond38.preheader ]
143  %tmp46 = icmp slt i32 %__key8.0, 10
144  br i1 %tmp46, label %noassert68, label %unrolledend
145
146noassert68:                                       ; preds = %forbody39
147  %tmp57 = sdiv i32 -32768, %__key8.0
148  %sext34 = shl i32 %tmp57, 16
149  %sext21 = shl i32 %tmp57, 16
150  %tmp76 = icmp eq i32 %sext34, %sext21
151  %tmp81 = add i32 %__key8.0, 1
152  br i1 %tmp76, label %forcond38, label %assert77
153
154assert77:                                         ; preds = %noassert68
155  tail call void @llvm.trap()
156  unreachable
157
158unrolledend:                                      ; preds = %forcond38
159  ret i32 0
160}
161
162declare void @llvm.trap() noreturn nounwind
163
164; In this case the second loop only has a single iteration, fold the header away
165; CHECK-LABEL: @func_12(
166; CHECK: %tmp5 = icmp slt i32 %__key6.0, 10
167; CHECK: br i1 true, label %noassert68, label %unrolledend
168define i32 @func_12() nounwind uwtable {
169entry:
170  br label %forcond
171
172forcond:                                          ; preds = %noassert, %entry
173  %__key6.0 = phi i32 [ 2, %entry ], [ %tmp37, %noassert ]
174  %tmp5 = icmp slt i32 %__key6.0, 10
175  br i1 %tmp5, label %noassert, label %forcond38.preheader
176
177forcond38.preheader:                              ; preds = %forcond
178  br label %forcond38
179
180noassert:                                         ; preds = %forbody
181  %tmp13 = sdiv i32 -32768, %__key6.0
182  %tmp2936 = shl i32 %tmp13, 24
183  %sext23 = shl i32 %tmp13, 24
184  %tmp32 = icmp eq i32 %tmp2936, %sext23
185  %tmp37 = add i32 %__key6.0, 1
186  br i1 %tmp32, label %forcond, label %assert33
187
188assert33:                                         ; preds = %noassert
189  tail call void @llvm.trap()
190  unreachable
191
192forcond38:                                        ; preds = %noassert68, %forcond38.preheader
193  %__key8.0 = phi i32 [ %tmp81, %noassert68 ], [ 2, %forcond38.preheader ]
194  %tmp46 = icmp slt i32 %__key8.0, 10
195  br i1 %tmp46, label %noassert68, label %unrolledend
196
197noassert68:                                       ; preds = %forbody39
198  %tmp57 = sdiv i32 -32768, %__key8.0
199  %sext34 = shl i32 %tmp57, 16
200  %sext21 = shl i32 %tmp57, 16
201  %tmp76 = icmp ne i32 %sext34, %sext21
202  %tmp81 = add i32 %__key8.0, 1
203  br i1 %tmp76, label %forcond38, label %assert77
204
205assert77:                                         ; preds = %noassert68
206  tail call void @llvm.trap()
207  unreachable
208
209unrolledend:                                      ; preds = %forcond38
210  ret i32 0
211}
212