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1; REQUIRES: asserts
2;
3; The Cortext-A57 machine model will avoid scheduling load instructions in
4; succession because loads on the A57 have a latency of 4 cycles and they all
5; issue to the same pipeline. Instead, it will move other instructions between
6; the loads to avoid unnecessary stalls. The generic machine model schedules 4
7; loads consecutively for this case and will cause stalls.
8;
9; RUN: llc < %s -mtriple=arm64-linux-gnu -mcpu=cortex-a57 -enable-misched -verify-misched -debug-only=machine-scheduler -o - 2>&1 > /dev/null | FileCheck %s
10; CHECK: ********** MI Scheduling **********
11; CHECK: main:%bb.2
12; CHECK: LDR
13; CHECK: Latency : 4
14; CHECK: *** Final schedule for %bb.2 ***
15; CHECK: LDR
16; CHECK: LDR
17; CHECK-NOT: LDR
18; CHECK: {{.*}}
19; CHECK: ********** MI Scheduling **********
20
21@main.x = private unnamed_addr constant [8 x i32] [i32 1, i32 1, i32 1, i32 1, i32 1, i32 1, i32 1, i32 1], align 4
22@main.y = private unnamed_addr constant [8 x i32] [i32 2, i32 2, i32 2, i32 2, i32 2, i32 2, i32 2, i32 2], align 4
23
24; Function Attrs: nounwind
25define i32 @main() #0 {
26entry:
27  %retval = alloca i32, align 4
28  %x = alloca [8 x i32], align 4
29  %y = alloca [8 x i32], align 4
30  %i = alloca i32, align 4
31  %xx = alloca i32, align 4
32  %yy = alloca i32, align 4
33  store i32 0, i32* %retval
34  %0 = bitcast [8 x i32]* %x to i8*
35  call void @llvm.memcpy.p0i8.p0i8.i64(i8* align 4 %0, i8* align 4 bitcast ([8 x i32]* @main.x to i8*), i64 32, i1 false)
36  %1 = bitcast [8 x i32]* %y to i8*
37  call void @llvm.memcpy.p0i8.p0i8.i64(i8* align 4 %1, i8* align 4 bitcast ([8 x i32]* @main.y to i8*), i64 32, i1 false)
38  store i32 0, i32* %xx, align 4
39  store i32 0, i32* %yy, align 4
40  store i32 0, i32* %i, align 4
41  br label %for.cond
42
43for.cond:                                         ; preds = %for.inc, %entry
44  %2 = load i32, i32* %i, align 4
45  %cmp = icmp slt i32 %2, 8
46  br i1 %cmp, label %for.body, label %for.end
47
48for.body:                                         ; preds = %for.cond
49  %3 = load i32, i32* %yy, align 4
50  %4 = load i32, i32* %i, align 4
51  %idxprom = sext i32 %4 to i64
52  %arrayidx = getelementptr inbounds [8 x i32], [8 x i32]* %x, i32 0, i64 %idxprom
53  %5 = load i32, i32* %arrayidx, align 4
54  %add = add nsw i32 %5, 1
55  store i32 %add, i32* %xx, align 4
56  %6 = load i32, i32* %xx, align 4
57  %add1 = add nsw i32 %6, 12
58  store i32 %add1, i32* %xx, align 4
59  %7 = load i32, i32* %xx, align 4
60  %add2 = add nsw i32 %7, 23
61  store i32 %add2, i32* %xx, align 4
62  %8 = load i32, i32* %xx, align 4
63  %add3 = add nsw i32 %8, 34
64  store i32 %add3, i32* %xx, align 4
65  %9 = load i32, i32* %i, align 4
66  %idxprom4 = sext i32 %9 to i64
67  %arrayidx5 = getelementptr inbounds [8 x i32], [8 x i32]* %y, i32 0, i64 %idxprom4
68  %10 = load i32, i32* %arrayidx5, align 4
69
70  %add4 = add nsw i32 %9, %add
71  %add5 = add nsw i32 %10, %add1
72  %add6 = add nsw i32 %add4, %add5
73
74  %add7 = add nsw i32 %9, %add3
75  %add8 = add nsw i32 %10, %add4
76  %add9 = add nsw i32 %add7, %add8
77
78  %add10 = add nsw i32 %9, %add6
79  %add11 = add nsw i32 %10, %add7
80  %add12 = add nsw i32 %add10, %add11
81
82  %add13 = add nsw i32 %9, %add9
83  %add14 = add nsw i32 %10, %add10
84  %add15 = add nsw i32 %add13, %add14
85
86  store i32 %add15, i32* %xx, align 4
87
88  %div = sdiv i32 %4, %5
89
90  store i32 %div, i32* %yy, align 4
91
92  br label %for.inc
93
94for.inc:                                          ; preds = %for.body
95  %11 = load i32, i32* %i, align 4
96  %inc = add nsw i32 %11, 1
97  store i32 %inc, i32* %i, align 4
98  br label %for.cond
99
100for.end:                                          ; preds = %for.cond
101  %12 = load i32, i32* %xx, align 4
102  %13 = load i32, i32* %yy, align 4
103  %add67 = add nsw i32 %12, %13
104  ret i32 %add67
105}
106
107
108; Function Attrs: nounwind
109declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture readonly, i64, i1) #1
110
111attributes #0 = { nounwind "less-precise-fpmad"="false" "frame-pointer"="all" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
112attributes #1 = { nounwind }
113