| lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame^] | 1 | /* Copyright (C) 2011-2015 Free Software Foundation, Inc. |
| 2 | This file is part of the GNU C Library. |
| 3 | |
| 4 | The GNU C Library is free software; you can redistribute it and/or |
| 5 | modify it under the terms of the GNU Lesser General Public |
| 6 | License as published by the Free Software Foundation; either |
| 7 | version 2.1 of the License, or (at your option) any later version. |
| 8 | |
| 9 | The GNU C Library is distributed in the hope that it will be useful, |
| 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 12 | Lesser General Public License for more details. |
| 13 | |
| 14 | You should have received a copy of the GNU Lesser General Public |
| 15 | License along with the GNU C Library; if not, see |
| 16 | <http://www.gnu.org/licenses/>. */ |
| 17 | |
| 18 | #define _SYSDEPS_SYSDEP_H 1 |
| 19 | #include <bits/hwcap.h> |
| 20 | |
| 21 | #ifdef __ASSEMBLER__ |
| 22 | |
| 23 | #define SPARC_PIC_THUNK(reg) \ |
| 24 | .ifndef __sparc_get_pc_thunk.reg; \ |
| 25 | .section .text.__sparc_get_pc_thunk.reg,"axG",@progbits,__sparc_get_pc_thunk.reg,comdat; \ |
| 26 | .align 32; \ |
| 27 | .weak __sparc_get_pc_thunk.reg; \ |
| 28 | .hidden __sparc_get_pc_thunk.reg; \ |
| 29 | .type __sparc_get_pc_thunk.reg, #function; \ |
| 30 | __sparc_get_pc_thunk.reg: \ |
| 31 | jmp %o7 + 8; \ |
| 32 | add %o7, %reg, %##reg; \ |
| 33 | .previous; \ |
| 34 | .endif; |
| 35 | |
| 36 | /* The "-4" and "+4" offsets against _GLOBAL_OFFSET_TABLE_ are |
| 37 | critical since they represent the offset from the thunk call to the |
| 38 | instruction containing the _GLOBAL_OFFSET_TABLE_ reference. |
| 39 | Therefore these instructions cannot be moved around without |
| 40 | appropriate adjustments to those offsets. |
| 41 | |
| 42 | Furthermore, these expressions are special in another regard. When |
| 43 | the assembler sees a reference to _GLOBAL_OFFSET_TABLE_ inside of |
| 44 | a %hi() or %lo(), it emits a PC-relative relocation. This causes |
| 45 | R_SPARC_HI22 to turn into R_SPARC_PC22, and R_SPARC_LO10 to turn into |
| 46 | R_SPARC_PC10, respectively. |
| 47 | |
| 48 | Even when v9 we use a call sequence instead of using "rd %pc" because |
| 49 | RDPC is extremely expensive and incurs a full pipeline flush. */ |
| 50 | |
| 51 | #define SPARC_PIC_THUNK_CALL(reg) \ |
| 52 | sethi %hi(_GLOBAL_OFFSET_TABLE_-4), %##reg; \ |
| 53 | call __sparc_get_pc_thunk.reg; \ |
| 54 | or %##reg, %lo(_GLOBAL_OFFSET_TABLE_+4), %##reg; |
| 55 | |
| 56 | #define SETUP_PIC_REG(reg) \ |
| 57 | SPARC_PIC_THUNK(reg) \ |
| 58 | SPARC_PIC_THUNK_CALL(reg) |
| 59 | |
| 60 | #define SETUP_PIC_REG_LEAF(reg, tmp) \ |
| 61 | SPARC_PIC_THUNK(reg) \ |
| 62 | mov %o7, %##tmp; \ |
| 63 | SPARC_PIC_THUNK_CALL(reg); \ |
| 64 | mov %##tmp, %o7; |
| 65 | |
| 66 | #undef ENTRY |
| 67 | #define ENTRY(name) \ |
| 68 | .align 4; \ |
| 69 | .global C_SYMBOL_NAME(name); \ |
| 70 | .type name, @function; \ |
| 71 | C_LABEL(name) \ |
| 72 | cfi_startproc; |
| 73 | |
| 74 | #undef END |
| 75 | #define END(name) \ |
| 76 | cfi_endproc; \ |
| 77 | .size name, . - name |
| 78 | |
| 79 | #undef LOC |
| 80 | #define LOC(name) .L##name |
| 81 | |
| 82 | #endif /* __ASSEMBLER__ */ |