xref: /llvm-project/llvm/test/CodeGen/BPF/remove_truncate_1.ll (revision c5037db4acd95790a0ca5061c8fa79c5c291607e)
1; RUN: llc < %s -mtriple=bpf -mcpu=v1 -verify-machineinstrs | FileCheck %s
2
3; Source code:
4; struct xdp_md {
5;   unsigned data;
6;   unsigned data_end;
7; };
8;
9; int gbl;
10; int xdp_dummy(struct xdp_md *xdp)
11; {
12;   char tmp;
13;   long addr;
14;
15;   if (gbl) {
16;     long addr1 = (long)xdp->data;
17;     tmp = *(char *)addr1;
18;     if (tmp == 1)
19;       return 3;
20;   } else {
21;     tmp = *(volatile char *)(long)xdp->data_end;
22;     if (tmp == 1)
23;       return 2;
24;   }
25;   addr = (long)xdp->data;
26;   tmp = *(volatile char *)addr;
27;   if (tmp == 0)
28;     return 1;
29;   return 0;
30; }
31
32%struct.xdp_md = type { i32, i32 }
33
34@gbl = common local_unnamed_addr global i32 0, align 4
35
36; Function Attrs: norecurse nounwind
37define i32 @xdp_dummy(ptr nocapture readonly %xdp) local_unnamed_addr #0 {
38entry:
39  %0 = load i32, ptr @gbl, align 4
40  %tobool = icmp eq i32 %0, 0
41  br i1 %tobool, label %if.else, label %if.then
42
43if.then:                                          ; preds = %entry
44  %1 = load i32, ptr %xdp, align 4
45  %conv = zext i32 %1 to i64
46  %2 = inttoptr i64 %conv to ptr
47  %3 = load i8, ptr %2, align 1
48  %cmp = icmp eq i8 %3, 1
49  br i1 %cmp, label %cleanup20, label %if.end12
50; CHECK:  r1 = *(u32 *)(r1 + 0)
51; CHECK:  r2 = *(u8 *)(r1 + 0)
52
53if.else:                                          ; preds = %entry
54  %data_end = getelementptr inbounds %struct.xdp_md, ptr %xdp, i64 0, i32 1
55  %4 = load i32, ptr %data_end, align 4
56  %conv6 = zext i32 %4 to i64
57; CHECK:  r2 = *(u32 *)(r1 + 4)
58  %5 = inttoptr i64 %conv6 to ptr
59  %6 = load volatile i8, ptr %5, align 1
60  %cmp8 = icmp eq i8 %6, 1
61  br i1 %cmp8, label %cleanup20, label %if.else.if.end12_crit_edge
62
63if.else.if.end12_crit_edge:                       ; preds = %if.else
64  %.pre = load i32, ptr %xdp, align 4
65  br label %if.end12
66; CHECK: r1 = *(u32 *)(r1 + 0)
67
68if.end12:                                         ; preds = %if.else.if.end12_crit_edge, %if.then
69  %7 = phi i32 [ %.pre, %if.else.if.end12_crit_edge ], [ %1, %if.then ]
70  %conv14 = zext i32 %7 to i64
71; CHECK-NOT: r1 <<= 32
72; CHECK-NOT: r1 >>= 32
73  %8 = inttoptr i64 %conv14 to ptr
74  %9 = load volatile i8, ptr %8, align 1
75; CHECK:  r1 = *(u8 *)(r1 + 0)
76  %cmp16 = icmp eq i8 %9, 0
77  %.28 = zext i1 %cmp16 to i32
78  br label %cleanup20
79
80cleanup20:                                        ; preds = %if.then, %if.end12, %if.else
81  %retval.1 = phi i32 [ 3, %if.then ], [ 2, %if.else ], [ %.28, %if.end12 ]
82  ret i32 %retval.1
83}
84
85attributes #0 = { norecurse nounwind }
86