Mercurial > hg > CbC > CbC_gcc
comparison libgo/runtime/go-context.S @ 145:1830386684a0
gcc-9.2.0
| author | anatofuz |
|---|---|
| date | Thu, 13 Feb 2020 11:34:05 +0900 |
| parents | |
| children |
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| 131:84e7813d76e9 | 145:1830386684a0 |
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| 1 // Copyright 2019 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 // This provides a simplified version of getcontext and | |
| 6 // setcontext. They are like the corresponding functions | |
| 7 // in libc, but we only save/restore the callee-save | |
| 8 // registers and PC, SP. Unlike the libc functions, we | |
| 9 // don't save/restore the signal masks and floating point | |
| 10 // environment. | |
| 11 | |
| 12 #if defined(__x86_64__) && defined(__linux__) && !defined(__CET__) | |
| 13 | |
| 14 #define RBP_OFF (0*8) | |
| 15 #define RBX_OFF (1*8) | |
| 16 #define R12_OFF (2*8) | |
| 17 #define R13_OFF (3*8) | |
| 18 #define R14_OFF (4*8) | |
| 19 #define R15_OFF (5*8) | |
| 20 #define SP_OFF (6*8) | |
| 21 #define PC_OFF (7*8) | |
| 22 | |
| 23 .globl __go_getcontext | |
| 24 .text | |
| 25 __go_getcontext: | |
| 26 movq %rbx, RBX_OFF(%rdi) | |
| 27 movq %rbp, RBP_OFF(%rdi) | |
| 28 movq %r12, R12_OFF(%rdi) | |
| 29 movq %r13, R13_OFF(%rdi) | |
| 30 movq %r14, R14_OFF(%rdi) | |
| 31 movq %r15, R15_OFF(%rdi) | |
| 32 | |
| 33 movq (%rsp), %rax // return PC | |
| 34 movq %rax, PC_OFF(%rdi) | |
| 35 leaq 8(%rsp), %rax // the SP before pushing return PC | |
| 36 movq %rax, SP_OFF(%rdi) | |
| 37 | |
| 38 ret | |
| 39 | |
| 40 .globl __go_setcontext | |
| 41 .text | |
| 42 __go_setcontext: | |
| 43 movq RBX_OFF(%rdi), %rbx | |
| 44 movq RBP_OFF(%rdi), %rbp | |
| 45 movq R12_OFF(%rdi), %r12 | |
| 46 movq R13_OFF(%rdi), %r13 | |
| 47 movq R14_OFF(%rdi), %r14 | |
| 48 movq R15_OFF(%rdi), %r15 | |
| 49 movq SP_OFF(%rdi), %rsp | |
| 50 movq PC_OFF(%rdi), %rdx | |
| 51 | |
| 52 jmp *%rdx | |
| 53 | |
| 54 .globl __go_makecontext | |
| 55 .text | |
| 56 __go_makecontext: | |
| 57 addq %rcx, %rdx | |
| 58 | |
| 59 // Align the SP, and push a dummy return address. | |
| 60 andq $~0xf, %rdx | |
| 61 subq $8, %rdx | |
| 62 movq $0, (%rdx) | |
| 63 | |
| 64 movq %rdx, SP_OFF(%rdi) | |
| 65 movq %rsi, PC_OFF(%rdi) | |
| 66 | |
| 67 ret | |
| 68 | |
| 69 .section .note.GNU-split-stack,"",@progbits | |
| 70 .section .note.GNU-no-split-stack,"",@progbits | |
| 71 | |
| 72 #endif | |
| 73 | |
| 74 .section .note.GNU-stack,"",@progbits |