xref: /llvm-project/llvm/test/CodeGen/BPF/remove_truncate_4.ll (revision c5037db4acd95790a0ca5061c8fa79c5c291607e)
1; RUN: llc < %s -mtriple=bpf -verify-machineinstrs | FileCheck %s
2
3; Source code:
4;struct __sk_buff;
5;unsigned long long
6;load_byte(ptr skb, unsigned long long off) asm("llvm.bpf.load.byte");
7;unsigned long long
8;load_half(ptr skb, unsigned long long off) asm("llvm.bpf.load.half");
9;typedef unsigned char      uint8_t;
10;typedef unsigned short     uint16_t;
11;
12;int func_b(struct __sk_buff *skb)
13;{
14;    uint8_t t = load_byte(skb, 0);
15;    return t;
16;}
17;
18;int func_h(struct __sk_buff *skb)
19;{
20;    uint16_t t = load_half(skb, 0);
21;    return t;
22;}
23;
24;int func_w(struct __sk_buff *skb)
25;{
26;    uint32_t t = load_word(skb, 0);
27;    return t;
28;}
29
30%struct.__sk_buff = type opaque
31
32; Function Attrs: nounwind readonly
33define i32 @func_b(ptr %skb) local_unnamed_addr #0 {
34entry:
35  %call = tail call i64 @llvm.bpf.load.byte(ptr %skb, i64 0)
36  %conv = trunc i64 %call to i32
37  %conv1 = and i32 %conv, 255
38; CHECK-NOT:  r0 &= 255
39  ret i32 %conv1
40}
41
42; Function Attrs: nounwind readonly
43declare i64 @llvm.bpf.load.byte(ptr, i64) #1
44
45; Function Attrs: nounwind readonly
46define i32 @func_h(ptr %skb) local_unnamed_addr #0 {
47entry:
48  %call = tail call i64 @llvm.bpf.load.half(ptr %skb, i64 0)
49  %conv = trunc i64 %call to i32
50  %conv1 = and i32 %conv, 65535
51; CHECK-NOT:  r0 &= 65535
52  ret i32 %conv1
53}
54
55; Function Attrs: nounwind readonly
56declare i64 @llvm.bpf.load.half(ptr, i64) #1
57