1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
|
; RUN: llc -mtriple=x86_64 -o - %s | FileCheck %s
define i1 @try_cmpxchg(i32* %addr, i32 %desired, i32 %new) {
; CHECK-LABEL: try_cmpxchg:
; CHECK: cmpxchgl
; CHECK-NOT: cmp
; CHECK: sete %al
; CHECK: retq
%pair = cmpxchg i32* %addr, i32 %desired, i32 %new seq_cst seq_cst
%success = extractvalue { i32, i1 } %pair, 1
ret i1 %success
}
define void @cmpxchg_flow(i64* %addr, i64 %desired, i64 %new) {
; CHECK-LABEL: cmpxchg_flow:
; CHECK: cmpxchgq
; CHECK-NOT: cmp
; CHECK-NOT: set
; CHECK: {{jne|jeq}}
%pair = cmpxchg i64* %addr, i64 %desired, i64 %new seq_cst seq_cst
%success = extractvalue { i64, i1 } %pair, 1
br i1 %success, label %true, label %false
true:
call void @foo()
ret void
false:
call void @bar()
ret void
}
define i64 @cmpxchg_sext(i32* %addr, i32 %desired, i32 %new) {
; CHECK-LABEL: cmpxchg_sext:
; CHECK-DAG: cmpxchgl
; CHECK-NOT: cmpl
; CHECK: sete %cl
; CHECK: retq
%pair = cmpxchg i32* %addr, i32 %desired, i32 %new seq_cst seq_cst
%success = extractvalue { i32, i1 } %pair, 1
%mask = sext i1 %success to i64
ret i64 %mask
}
define i32 @cmpxchg_zext(i32* %addr, i32 %desired, i32 %new) {
; CHECK-LABEL: cmpxchg_zext:
; CHECK: xorl %e[[R:[a-z]]]x
; CHECK: cmpxchgl
; CHECK-NOT: cmp
; CHECK: sete %[[R]]l
%pair = cmpxchg i32* %addr, i32 %desired, i32 %new seq_cst seq_cst
%success = extractvalue { i32, i1 } %pair, 1
%mask = zext i1 %success to i32
ret i32 %mask
}
define i32 @cmpxchg_use_eflags_and_val(i32* %addr, i32 %offset) {
; CHECK-LABEL: cmpxchg_use_eflags_and_val:
; CHECK: movl (%rdi), %e[[OLDVAL:[a-z0-9]+]]
; CHECK: [[LOOPBB:.?LBB[0-9]+_[0-9]+]]:
; CHECK: leal (%r[[OLDVAL]],%rsi), [[NEW:%[a-z0-9]+]]
; CHECK: cmpxchgl [[NEW]], (%rdi)
; CHECK-NOT: cmpl
; CHECK: jne [[LOOPBB]]
; Result already in %eax
; CHECK: retq
entry:
%init = load atomic i32, i32* %addr seq_cst, align 4
br label %loop
loop:
%old = phi i32 [%init, %entry], [%oldval, %loop]
%new = add i32 %old, %offset
%pair = cmpxchg i32* %addr, i32 %old, i32 %new seq_cst seq_cst
%oldval = extractvalue { i32, i1 } %pair, 0
%success = extractvalue { i32, i1 } %pair, 1
br i1 %success, label %done, label %loop
done:
ret i32 %oldval
}
declare void @foo()
declare void @bar()
|
