union.ll
1.27 KB
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
; RUN: opt < %s -dfsan -S | FileCheck %s
target 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-S128"
target triple = "x86_64-unknown-linux-gnu"
@a = common global i32 0
@b = common global i32 0
; Check that we reuse unions where possible.
; CHECK-LABEL: @"dfs$f"
define void @f(i32 %x, i32 %y) {
; CHECK: call{{.*}}__dfsan_union
%xay = add i32 %x, %y
store i32 %xay, i32* @a
; CHECK-NOT: call{{.*}}__dfsan_union
%xmy = mul i32 %x, %y
store i32 %xmy, i32* @b
ret void
}
; In this case, we compute the unions on both sides because neither block
; dominates the other.
; CHECK-LABEL: @"dfs$g"
define void @g(i1 %p, i32 %x, i32 %y) {
br i1 %p, label %l1, label %l2
l1:
; CHECK: call{{.*}}__dfsan_union
%xay = add i32 %x, %y
store i32 %xay, i32* @a
br label %l3
l2:
; CHECK: call{{.*}}__dfsan_union
%xmy = mul i32 %x, %y
store i32 %xmy, i32* @b
br label %l3
l3:
ret void
}
; In this case, we know that the label for %xayax subsumes the label for %xay.
; CHECK-LABEL: @"dfs$h"
define i32 @h(i32 %x, i32 %y) {
; CHECK: call{{.*}}__dfsan_union
%xay = add i32 %x, %y
; CHECK-NOT: call{{.*}}__dfsan_union
%xayax = add i32 %xay, %x
ret i32 %xayax
}