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
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
|
; RUN: llc %s -o - -enable-shrink-wrap=true | FileCheck %s --check-prefix=CHECK --check-prefix=ENABLE
; RUN: llc %s -o - -enable-shrink-wrap=false | FileCheck %s --check-prefix=CHECK --check-prefix=DISABLE
target datalayout = "e-m:o-i64:64-i128:128-n32:64-S128"
target triple = "x86_64--windows-gnu"
; The output of this function with or without shrink-wrapping
; shouldn't change.
; Indeed, the epilogue block would have been if.else, meaning
; after the pops, we will have additional instruction (jump, mov,
; etc.) prior to the return and this is forbidden for Win64.
; CHECK-LABEL: loopInfoSaveOutsideLoop:
; CHECK: push
; CHECK-NOT: popq
; CHECK: popq
; CHECK-NOT: popq
; CHECK-NEXT: retq
define i32 @loopInfoSaveOutsideLoop(i32 %cond, i32 %N) #0 {
entry:
%tobool = icmp eq i32 %cond, 0
br i1 %tobool, label %if.else, label %for.preheader
for.preheader: ; preds = %entry
tail call void asm "nop", ""()
br label %for.body
for.body: ; preds = %for.body, %for.preheader
%i.05 = phi i32 [ %inc, %for.body ], [ 0, %for.preheader ]
%sum.04 = phi i32 [ %add, %for.body ], [ 0, %for.preheader ]
%call = tail call i32 asm "movl $$1, $0", "=r,~{ebx}"()
%add = add nsw i32 %call, %sum.04
%inc = add nuw nsw i32 %i.05, 1
%exitcond = icmp eq i32 %inc, 10
br i1 %exitcond, label %for.end, label %for.body
for.end: ; preds = %for.body
tail call void asm "nop", "~{ebx}"()
%shl = shl i32 %add, 3
br label %if.end
if.else: ; preds = %entry
%mul = shl nsw i32 %N, 1
br label %if.end
if.end: ; preds = %if.else, %for.end
%sum.1 = phi i32 [ %shl, %for.end ], [ %mul, %if.else ]
ret i32 %sum.1
}
; When we can sink the epilogue of the function into an existing exit block,
; this is Ok for shrink-wrapping to kicks in.
; CHECK-LABEL: loopInfoSaveOutsideLoop2:
; ENABLE: testl %ecx, %ecx
; ENABLE-NEXT: je [[ELSE_LABEL:.LBB[0-9_]+]]
;
; Prologue code.
; Make sure we save the CSR used in the inline asm: rbx.
; CHECK: pushq %rbx
;
; DISABLE: testl %ecx, %ecx
; DISABLE-NEXT: je [[ELSE_LABEL:.LBB[0-9_]+]]
;
; CHECK: nop
; CHECK: xorl [[SUM:%eax]], [[SUM]]
; CHECK-NEXT: movl $10, [[IV:%e[a-z]+]]
;
; CHECK: [[LOOP_LABEL:.LBB[0-9_]+]]: # %for.body
; CHECK: movl $1, [[TMP:%e[a-z]+]]
; CHECK: addl [[TMP]], [[SUM]]
; CHECK-NEXT: decl [[IV]]
; CHECK-NEXT: jne [[LOOP_LABEL]]
; Next BB.
; CHECK: nop
; CHECK: shll $3, [[SUM]]
;
; DISABLE: jmp [[EPILOG_BB:.LBB[0-9_]+]]
;
; ENABLE-NEXT: popq %rbx
; ENABLE-NEXT: retq
;
; CHECK: [[ELSE_LABEL]]: # %if.else
; Shift second argument by one and store into returned register.
; CHECK: addl %edx, %edx
; CHECK: movl %edx, %eax
;
; DISABLE: [[EPILOG_BB]]: # %if.end
; DISABLE-NEXT: popq %rbx
;
; CHECK: retq
;
define i32 @loopInfoSaveOutsideLoop2(i32 %cond, i32 %N) #0 {
entry:
%tobool = icmp eq i32 %cond, 0
br i1 %tobool, label %if.else, label %for.preheader
for.preheader: ; preds = %entry
tail call void asm "nop", ""()
br label %for.body
for.body: ; preds = %for.body, %for.preheader
%i.05 = phi i32 [ %inc, %for.body ], [ 0, %for.preheader ]
%sum.04 = phi i32 [ %add, %for.body ], [ 0, %for.preheader ]
%call = tail call i32 asm "movl $$1, $0", "=r,~{ebx}"()
%add = add nsw i32 %call, %sum.04
%inc = add nuw nsw i32 %i.05, 1
%exitcond = icmp eq i32 %inc, 10
br i1 %exitcond, label %for.end, label %for.body
for.end: ; preds = %for.body
tail call void asm "nop", "~{ebx}"()
%shl = shl i32 %add, 3
ret i32 %shl
if.else: ; preds = %entry
%mul = shl nsw i32 %N, 1
br label %if.end
if.end: ; preds = %if.else, %for.end
ret i32 %mul
}
attributes #0 = { uwtable }
|
