| 1 | /* Machine-specific calling sequence for `mcount' profiling function. alpha |
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| 2 | Copyright (C) 1995-2024 Free Software Foundation, Inc. |
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| 3 | This file is part of the GNU C Library. |
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| 4 | |
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| 5 | The GNU C Library is free software; you can redistribute it and/or |
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| 6 | modify it under the terms of the GNU Lesser General Public |
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| 7 | License as published by the Free Software Foundation; either |
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| 8 | version 2.1 of the License, or (at your option) any later version. |
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| 9 | |
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| 10 | The GNU C Library is distributed in the hope that it will be useful, |
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| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 13 | Lesser General Public License for more details. |
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| 14 | |
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| 15 | You should have received a copy of the GNU Lesser General Public |
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| 16 | License along with the GNU C Library. If not, see |
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| 17 | <https://www.gnu.org/licenses/>. */ |
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| 18 | |
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| 19 | /* Assembly stub to invoke _mcount(). Compiler generated code calls |
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| 20 | this stub after executing a function's prologue and without saving any |
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| 21 | registers. It is therefore necessary to preserve a0..a5 as they may |
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| 22 | contain function arguments. To work correctly with frame- less |
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| 23 | functions, it is also necessary to preserve ra. Finally, division |
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| 24 | routines are invoked with a special calling convention and the |
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| 25 | compiler treats those calls as if they were instructions. In |
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| 26 | particular, it doesn't save any of the temporary registers (caller |
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| 27 | saved registers). It is therefore necessary to preserve all |
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| 28 | caller-saved registers as well. |
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| 29 | |
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| 30 | Upon entering _mcount, register $at holds the return address and ra |
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| 31 | holds the return address of the function's caller (selfpc and frompc, |
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| 32 | respectively in gmon.c language...). */ |
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| 33 | |
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| 34 | #include <sysdep.h> |
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| 35 | |
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| 36 | .set noat |
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| 37 | .set noreorder |
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| 38 | |
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| 39 | LEAF(_mcount, 0xb0) |
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| 40 | subq sp, 0xb0, sp |
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| 41 | .prologue 0 |
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| 42 | stq a0, 0x00(sp) |
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| 43 | mov ra, a0 # a0 = caller-pc |
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| 44 | stq a1, 0x08(sp) |
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| 45 | mov $at, a1 # a1 = self-pc |
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| 46 | stq $at, 0x10(sp) |
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| 47 | |
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| 48 | stq a2, 0x18(sp) |
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| 49 | stq a3, 0x20(sp) |
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| 50 | stq a4, 0x28(sp) |
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| 51 | stq a5, 0x30(sp) |
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| 52 | stq ra, 0x38(sp) |
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| 53 | stq gp, 0x40(sp) |
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| 54 | |
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| 55 | br gp, 1f |
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| 56 | 1: ldgp gp, 0(gp) |
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| 57 | |
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| 58 | stq t0, 0x48(sp) |
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| 59 | stq t1, 0x50(sp) |
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| 60 | stq t2, 0x58(sp) |
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| 61 | stq t3, 0x60(sp) |
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| 62 | stq t4, 0x68(sp) |
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| 63 | stq t5, 0x70(sp) |
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| 64 | stq t6, 0x78(sp) |
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| 65 | |
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| 66 | stq t7, 0x80(sp) |
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| 67 | stq t8, 0x88(sp) |
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| 68 | stq t9, 0x90(sp) |
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| 69 | stq t10, 0x98(sp) |
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| 70 | stq t11, 0xa0(sp) |
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| 71 | stq v0, 0xa8(sp) |
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| 72 | |
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| 73 | jsr ra, __mcount |
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| 74 | |
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| 75 | ldq a0, 0x00(sp) |
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| 76 | ldq a1, 0x08(sp) |
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| 77 | ldq $at, 0x10(sp) # restore self-pc |
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| 78 | ldq a2, 0x18(sp) |
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| 79 | ldq a3, 0x20(sp) |
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| 80 | ldq a4, 0x28(sp) |
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| 81 | ldq a5, 0x30(sp) |
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| 82 | ldq ra, 0x38(sp) |
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| 83 | ldq gp, 0x40(sp) |
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| 84 | mov $at, pv # make pv point to return address |
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| 85 | ldq t0, 0x48(sp) # this is important under OSF/1 to |
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| 86 | ldq t1, 0x50(sp) # ensure that the code that we return |
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| 87 | ldq t2, 0x58(sp) # can correctly compute its gp |
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| 88 | ldq t3, 0x60(sp) |
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| 89 | ldq t4, 0x68(sp) |
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| 90 | ldq t5, 0x70(sp) |
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| 91 | ldq t6, 0x78(sp) |
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| 92 | ldq t7, 0x80(sp) |
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| 93 | ldq t8, 0x88(sp) |
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| 94 | ldq t9, 0x90(sp) |
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| 95 | ldq t10, 0x98(sp) |
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| 96 | ldq t11, 0xa0(sp) |
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| 97 | ldq v0, 0xa8(sp) |
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| 98 | |
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| 99 | addq sp, 0xb0, sp |
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| 100 | ret zero,($at),1 |
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| 101 | |
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| 102 | END(_mcount) |
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| 103 | |
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| 104 | weak_alias (_mcount, mcount) |
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| 105 | |
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