BranchPredict.ll
2.66 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
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
; RUN: llc -march=hexagon -ifcvt-limit=0 -hexagon-initial-cfg-cleanup=0 < %s | FileCheck %s
; Check if the branch probabilities are reflected in the instructions:
; The basic block placement pass should place the more probable successor
; block as the fall-through block. The unconditional jump in the predecessor
; should then get the right hint (not_taken or ":nt")
@j = external global i32
define i32 @foo(i32 %a) nounwind {
; CHECK: if (!p{{[0-3]}}.new) jump:nt
entry:
%tobool = icmp eq i32 %a, 0
br i1 %tobool, label %if.else, label %if.then, !prof !0
if.then: ; preds = %entry
%add = add nsw i32 %a, 10
%call = tail call i32 bitcast (i32 (...)* @foobar to i32 (i32)*)(i32 %add) nounwind
br label %return
if.else: ; preds = %entry
%call2 = tail call i32 bitcast (i32 (...)* @foobar to i32 (i32)*)(i32 4) nounwind
br label %return
return: ; preds = %if.else, %if.then
%retval.0 = phi i32 [ %call, %if.then ], [ %call2, %if.else ]
ret i32 %retval.0
}
declare i32 @foobar(...)
define i32 @bar(i32 %a) nounwind {
; CHECK: if (p{{[0-3]}}.new) jump:nt
entry:
%tobool = icmp eq i32 %a, 0
br i1 %tobool, label %if.else, label %if.then, !prof !1
if.then: ; preds = %entry
%add = add nsw i32 %a, 10
%call = tail call i32 bitcast (i32 (...)* @foobar to i32 (i32)*)(i32 %add) nounwind
br label %return
if.else: ; preds = %entry
%call2 = tail call i32 bitcast (i32 (...)* @foobar to i32 (i32)*)(i32 4) nounwind
br label %return
return: ; preds = %if.else, %if.then
%retval.0 = phi i32 [ %call, %if.then ], [ %call2, %if.else ]
ret i32 %retval.0
}
define i32 @foo_bar(i32 %a, i16 signext %b) nounwind {
; CHECK: if (!cmp.eq(r{{[0-9]*}}.new,#0)) jump:nt
entry:
%0 = load i32, i32* @j, align 4
%tobool = icmp eq i32 %0, 0
br i1 %tobool, label %if.else, label %if.then, !prof !0
if.then: ; preds = %entry
%add = add nsw i32 %a, 10
%call = tail call i32 bitcast (i32 (...)* @foobar to i32 (i32)*)(i32 %add) nounwind
br label %return
if.else: ; preds = %entry
%add1 = add nsw i32 %a, 4
%call2 = tail call i32 bitcast (i32 (...)* @foobar to i32 (i32)*)(i32 %add1) nounwind
br label %return
return: ; preds = %if.else, %if.then
%retval.0 = phi i32 [ %call, %if.then ], [ %call2, %if.else ]
ret i32 %retval.0
}
!0 = !{!"branch_weights", i32 64, i32 4}
!1 = !{!"branch_weights", i32 4, i32 64}