1 // Copyright 2016 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 .file "gcc_s390x.S"
6
7 /*
8 * void crosscall_s390x(void (*fn)(void), void *g)
9 *
10 * Calling into the go tool chain, where all registers are caller save.
11 * Called from standard s390x C ABI, where r6-r13, r15, and f8-f15 are
12 * callee-save, so they must be saved explicitly.
13 */
14 .globl crosscall_s390x
15 crosscall_s390x:
16 /* save r6-r15 in the register save area of the calling function */
17 stmg %r6, %r15, 48(%r15)
18
19 /* allocate 64 bytes of stack space to save f8-f15 */
20 lay %r15, -64(%r15)
21
22 /* save callee-saved floating point registers */
23 std %f8, 0(%r15)
24 std %f9, 8(%r15)
25 std %f10, 16(%r15)
26 std %f11, 24(%r15)
27 std %f12, 32(%r15)
28 std %f13, 40(%r15)
29 std %f14, 48(%r15)
30 std %f15, 56(%r15)
31
32 /* restore g pointer */
33 lgr %r13, %r3
34
35 /* call fn */
36 basr %r14, %r2
37
38 /* restore floating point registers */
39 ld %f8, 0(%r15)
40 ld %f9, 8(%r15)
41 ld %f10, 16(%r15)
42 ld %f11, 24(%r15)
43 ld %f12, 32(%r15)
44 ld %f13, 40(%r15)
45 ld %f14, 48(%r15)
46 ld %f15, 56(%r15)
47
48 /* de-allocate stack frame */
49 la %r15, 64(%r15)
50
51 /* restore general purpose registers */
52 lmg %r6, %r15, 48(%r15)
53
54 br %r14 /* restored by lmg */
55
56 #ifdef __ELF__
57 .section .note.GNU-stack,"",%progbits
58 #endif
59
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