1// Copyright 2021 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5// Macros for transitioning from the host ABI to Go ABI0.
6//
7// These save the frame pointer, so in general, functions that use
8// these should have zero frame size to suppress the automatic frame
9// pointer, though it's harmless to not do this.
10
11#ifdef GOOS_windows
12
13// REGS_HOST_TO_ABI0_STACK is the stack bytes used by
14// PUSH_REGS_HOST_TO_ABI0.
15#define REGS_HOST_TO_ABI0_STACK (28*8 + 8)
16
17// PUSH_REGS_HOST_TO_ABI0 prepares for transitioning from
18// the host ABI to Go ABI0 code. It saves all registers that are
19// callee-save in the host ABI and caller-save in Go ABI0 and prepares
20// for entry to Go.
21//
22// Save DI SI BP BX R12 R13 R14 R15 X6-X15 registers and the DF flag.
23// Clear the DF flag for the Go ABI.
24// MXCSR matches the Go ABI, so we don't have to set that,
25// and Go doesn't modify it, so we don't have to save it.
26#define PUSH_REGS_HOST_TO_ABI0() \
27 PUSHFQ \
28 CLD \
29 ADJSP $(REGS_HOST_TO_ABI0_STACK - 8) \
30 MOVQ DI, (0*0)(SP) \
31 MOVQ SI, (1*8)(SP) \
32 MOVQ BP, (2*8)(SP) \
33 MOVQ BX, (3*8)(SP) \
34 MOVQ R12, (4*8)(SP) \
35 MOVQ R13, (5*8)(SP) \
36 MOVQ R14, (6*8)(SP) \
37 MOVQ R15, (7*8)(SP) \
38 MOVUPS X6, (8*8)(SP) \
39 MOVUPS X7, (10*8)(SP) \
40 MOVUPS X8, (12*8)(SP) \
41 MOVUPS X9, (14*8)(SP) \
42 MOVUPS X10, (16*8)(SP) \
43 MOVUPS X11, (18*8)(SP) \
44 MOVUPS X12, (20*8)(SP) \
45 MOVUPS X13, (22*8)(SP) \
46 MOVUPS X14, (24*8)(SP) \
47 MOVUPS X15, (26*8)(SP)
48
49#define POP_REGS_HOST_TO_ABI0() \
50 MOVQ (0*0)(SP), DI \
51 MOVQ (1*8)(SP), SI \
52 MOVQ (2*8)(SP), BP \
53 MOVQ (3*8)(SP), BX \
54 MOVQ (4*8)(SP), R12 \
55 MOVQ (5*8)(SP), R13 \
56 MOVQ (6*8)(SP), R14 \
57 MOVQ (7*8)(SP), R15 \
58 MOVUPS (8*8)(SP), X6 \
59 MOVUPS (10*8)(SP), X7 \
60 MOVUPS (12*8)(SP), X8 \
61 MOVUPS (14*8)(SP), X9 \
62 MOVUPS (16*8)(SP), X10 \
63 MOVUPS (18*8)(SP), X11 \
64 MOVUPS (20*8)(SP), X12 \
65 MOVUPS (22*8)(SP), X13 \
66 MOVUPS (24*8)(SP), X14 \
67 MOVUPS (26*8)(SP), X15 \
68 ADJSP $-(REGS_HOST_TO_ABI0_STACK - 8) \
69 POPFQ
70
71#else
72// SysV ABI
73
74#define REGS_HOST_TO_ABI0_STACK (6*8)
75
76// SysV MXCSR matches the Go ABI, so we don't have to set that,
77// and Go doesn't modify it, so we don't have to save it.
78// Both SysV and Go require DF to be cleared, so that's already clear.
79// The SysV and Go frame pointer conventions are compatible.
80#define PUSH_REGS_HOST_TO_ABI0() \
81 ADJSP $(REGS_HOST_TO_ABI0_STACK) \
82 MOVQ BP, (5*8)(SP) \
83 LEAQ (5*8)(SP), BP \
84 MOVQ BX, (0*8)(SP) \
85 MOVQ R12, (1*8)(SP) \
86 MOVQ R13, (2*8)(SP) \
87 MOVQ R14, (3*8)(SP) \
88 MOVQ R15, (4*8)(SP)
89
90#define POP_REGS_HOST_TO_ABI0() \
91 MOVQ (0*8)(SP), BX \
92 MOVQ (1*8)(SP), R12 \
93 MOVQ (2*8)(SP), R13 \
94 MOVQ (3*8)(SP), R14 \
95 MOVQ (4*8)(SP), R15 \
96 MOVQ (5*8)(SP), BP \
97 ADJSP $-(REGS_HOST_TO_ABI0_STACK)
98
99#endif
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