statepoint-stack-usage.ll
8.26 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
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
123
124
125
126
127
128
129
130
131
132
133
134
135
136
; RUN: llc -verify-machineinstrs -stack-symbol-ordering=0 < %s | FileCheck %s
target datalayout = "e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-pc-linux-gnu"
; This test is checking to make sure that we reuse the same stack slots
; for GC values spilled over two different call sites. Since the order
; of GC arguments differ, niave lowering code would insert loads and
; stores to rearrange items on the stack. We need to make sure (for
; performance) that this doesn't happen.
define i32 @back_to_back_calls(i32 addrspace(1)* %a, i32 addrspace(1)* %b, i32 addrspace(1)* %c) #1 gc "statepoint-example" {
; CHECK-LABEL: back_to_back_calls
; The exact stores don't matter, but there need to be three stack slots created
; CHECK-DAG: movq %rdi, 16(%rsp)
; CHECK-DAG: movq %rdx, 8(%rsp)
; CHECK-DAG: movq %rsi, (%rsp)
; There should be no more than three moves
; CHECK-NOT: movq
%safepoint_token = tail call token (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* undef, i32 0, i32 0, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i32 0, i32 addrspace(1)* %a, i32 addrspace(1)* %b, i32 addrspace(1)* %c)
%a1 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(token %safepoint_token, i32 12, i32 12)
%b1 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(token %safepoint_token, i32 12, i32 13)
%c1 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(token %safepoint_token, i32 12, i32 14)
; CHECK: callq
; This is the key check. There should NOT be any memory moves here
; CHECK-NOT: movq
%safepoint_token2 = tail call token (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* undef, i32 0, i32 0, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i32 0, i32 addrspace(1)* %c1, i32 addrspace(1)* %b1, i32 addrspace(1)* %a1)
%a2 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(token %safepoint_token2, i32 12, i32 14)
%b2 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(token %safepoint_token2, i32 12, i32 13)
%c2 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(token %safepoint_token2, i32 12, i32 12)
; CHECK: callq
ret i32 1
}
; This test simply checks that minor changes in vm state don't prevent slots
; being reused for gc values.
define i32 @reserve_first(i32 addrspace(1)* %a, i32 addrspace(1)* %b, i32 addrspace(1)* %c) #1 gc "statepoint-example" {
; CHECK-LABEL: reserve_first
; The exact stores don't matter, but there need to be three stack slots created
; CHECK-DAG: movq %rdi, 16(%rsp)
; CHECK-DAG: movq %rdx, 8(%rsp)
; CHECK-DAG: movq %rsi, (%rsp)
%safepoint_token = tail call token (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* undef, i32 0, i32 0, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i32 0, i32 addrspace(1)* %a, i32 addrspace(1)* %b, i32 addrspace(1)* %c)
%a1 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(token %safepoint_token, i32 12, i32 12)
%b1 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(token %safepoint_token, i32 12, i32 13)
%c1 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(token %safepoint_token, i32 12, i32 14)
; CHECK: callq
; This is the key check. There should NOT be any memory moves here
; CHECK-NOT: movq
%safepoint_token2 = tail call token (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* undef, i32 0, i32 0, i32 0, i32 5, i32 addrspace(1)* %a1, i32 0, i32 addrspace(1)* %c1, i32 0, i32 0, i32 addrspace(1)* %c1, i32 addrspace(1)* %b1, i32 addrspace(1)* %a1)
%a2 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(token %safepoint_token2, i32 12, i32 14)
%b2 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(token %safepoint_token2, i32 12, i32 13)
%c2 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(token %safepoint_token2, i32 12, i32 12)
; CHECK: callq
ret i32 1
}
; Check that we reuse the same stack slot across multiple calls. The use of
; more than two calls here is critical. We've had a bug which allowed reuse
; exactly once which went undetected for a long time.
define i32 @back_to_back_deopt(i32 %a, i32 %b, i32 %c) #1
gc "statepoint-example" {
; CHECK-LABEL: back_to_back_deopt
; The exact stores don't matter, but there need to be three stack slots created
; CHECK-DAG: movl %edi, 12(%rsp)
; CHECK-DAG: movl %esi, 8(%rsp)
; CHECK-DAG: movl %edx, 4(%rsp)
; CHECK: callq
; CHECK-DAG: movl %ebx, 12(%rsp)
; CHECK-DAG: movl %ebp, 8(%rsp)
; CHECK-DAG: movl %r14d, 4(%rsp)
; CHECK: callq
; CHECK-DAG: movl %ebx, 12(%rsp)
; CHECK-DAG: movl %ebp, 8(%rsp)
; CHECK-DAG: movl %r14d, 4(%rsp)
; CHECK: callq
; CHECK-DAG: movl %ebx, 12(%rsp)
; CHECK-DAG: movl %ebp, 8(%rsp)
; CHECK-DAG: movl %r14d, 4(%rsp)
; CHECK: callq
call token (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* undef, i32 0, i32 0, i32 0, i32 3, i32 %a, i32 %b, i32 %c)
call token (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* undef, i32 0, i32 0, i32 0, i32 3, i32 %a, i32 %b, i32 %c)
call token (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* undef, i32 0, i32 0, i32 0, i32 3, i32 %a, i32 %b, i32 %c)
call token (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* undef, i32 0, i32 0, i32 0, i32 3, i32 %a, i32 %b, i32 %c)
ret i32 1
}
; Test that stack slots are reused for invokes
define i32 @back_to_back_invokes(i32 addrspace(1)* %a, i32 addrspace(1)* %b, i32 addrspace(1)* %c) #1 gc "statepoint-example" personality i32 ()* @"personality_function" {
; CHECK-LABEL: back_to_back_invokes
entry:
; The exact stores don't matter, but there need to be three stack slots created
; CHECK-DAG: movq %rdi, 16(%rsp)
; CHECK-DAG: movq %rdx, 8(%rsp)
; CHECK-DAG: movq %rsi, (%rsp)
; CHECK: callq
%safepoint_token = invoke token (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* undef, i32 0, i32 0, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i32 0, i32 addrspace(1)* %a, i32 addrspace(1)* %b, i32 addrspace(1)* %c)
to label %normal_return unwind label %exceptional_return
normal_return:
%a1 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(token %safepoint_token, i32 12, i32 12)
%b1 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(token %safepoint_token, i32 12, i32 13)
%c1 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(token %safepoint_token, i32 12, i32 14)
; Should work even through bitcasts
%c1.casted = bitcast i32 addrspace(1)* %c1 to i8 addrspace(1)*
; This is the key check. There should NOT be any memory moves here
; CHECK-NOT: movq
; CHECK: callq
%safepoint_token2 = invoke token (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* undef, i32 0, i32 0, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i32 0, i8 addrspace(1)* %c1.casted, i32 addrspace(1)* %b1, i32 addrspace(1)* %a1)
to label %normal_return2 unwind label %exceptional_return2
normal_return2:
%a2 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(token %safepoint_token2, i32 12, i32 14)
%b2 = tail call coldcc i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(token %safepoint_token2, i32 12, i32 13)
%c2 = tail call coldcc i8 addrspace(1)* @llvm.experimental.gc.relocate.p1i8(token %safepoint_token2, i32 12, i32 12)
ret i32 1
exceptional_return:
%landing_pad = landingpad { i8*, i32 }
cleanup
ret i32 0
exceptional_return2:
%landing_pad2 = landingpad { i8*, i32 }
cleanup
ret i32 0
}
; Function Attrs: nounwind
declare i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(token, i32, i32) #3
declare i8 addrspace(1)* @llvm.experimental.gc.relocate.p1i8(token, i32, i32) #3
declare token @llvm.experimental.gc.statepoint.p0f_isVoidf(i64, i32, void ()*, i32, i32, ...)
declare i32 @"personality_function"()
attributes #1 = { uwtable }