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/* stuff needed for libgcc on win32. |
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* |
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* Copyright (C) 1996-2015 Free Software Foundation, Inc. |
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* Written By Steve Chamberlain |
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* |
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* This file is free software; you can redistribute it and/or modify it |
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* under the terms of the GNU General Public License as published by the |
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* Free Software Foundation; either version 3, or (at your option) any |
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* later version. |
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* |
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* This file is distributed in the hope that it will be useful, but |
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* WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* General Public License for more details. |
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* |
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* Under Section 7 of GPL version 3, you are granted additional |
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* permissions described in the GCC Runtime Library Exception, version |
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* 3.1, as published by the Free Software Foundation. |
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* |
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* You should have received a copy of the GNU General Public License and |
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* a copy of the GCC Runtime Library Exception along with this program; |
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* see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
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* . |
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*/ |
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#include "auto-host.h" |
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#ifdef HAVE_GAS_CFI_SECTIONS_DIRECTIVE |
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.cfi_sections .debug_frame |
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# define cfi_startproc() .cfi_startproc |
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# define cfi_endproc() .cfi_endproc |
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# define cfi_adjust_cfa_offset(X) .cfi_adjust_cfa_offset X |
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# define cfi_def_cfa_register(X) .cfi_def_cfa_register X |
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# define cfi_register(D,S) .cfi_register D, S |
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# ifdef __x86_64__ |
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# define cfi_push(X) .cfi_adjust_cfa_offset 8; .cfi_rel_offset X, 0 |
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# define cfi_pop(X) .cfi_adjust_cfa_offset -8; .cfi_restore X |
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# else |
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# define cfi_push(X) .cfi_adjust_cfa_offset 4; .cfi_rel_offset X, 0 |
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# define cfi_pop(X) .cfi_adjust_cfa_offset -4; .cfi_restore X |
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# endif |
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#else |
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# define cfi_startproc() |
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# define cfi_endproc() |
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# define cfi_adjust_cfa_offset(X) |
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# define cfi_def_cfa_register(X) |
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# define cfi_register(D,S) |
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# define cfi_push(X) |
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# define cfi_pop(X) |
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#endif /* HAVE_GAS_CFI_SECTIONS_DIRECTIVE */ |
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#ifdef L_chkstk |
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/* Function prologue calls __chkstk to probe the stack when allocating more |
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than CHECK_STACK_LIMIT bytes in one go. Touching the stack at 4K |
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increments is necessary to ensure that the guard pages used |
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by the OS virtual memory manger are allocated in correct sequence. */ |
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.global ___chkstk |
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.global __alloca |
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#ifdef __x86_64__ |
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/* __alloca is a normal function call, which uses %rcx as the argument. */ |
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cfi_startproc() |
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__alloca: |
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movq %rcx, %rax |
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/* FALLTHRU */ |
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/* ___chkstk is a *special* function call, which uses %rax as the argument. |
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We avoid clobbering the 4 integer argument registers, %rcx, %rdx, |
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%r8 and %r9, which leaves us with %rax, %r10, and %r11 to use. */ |
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.align 4 |
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___chkstk: |
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popq %r11 /* pop return address */ |
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cfi_adjust_cfa_offset(-8) /* indicate return address in r11 */ |
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cfi_register(%rip, %r11) |
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movq %rsp, %r10 |
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cmpq $0x1000, %rax /* > 4k ?*/ |
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jb 2f |
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1: subq $0x1000, %r10 /* yes, move pointer down 4k*/ |
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orl $0x0, (%r10) /* probe there */ |
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subq $0x1000, %rax /* decrement count */ |
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cmpq $0x1000, %rax |
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ja 1b /* and do it again */ |
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2: subq %rax, %r10 |
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movq %rsp, %rax /* hold CFA until return */ |
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cfi_def_cfa_register(%rax) |
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orl $0x0, (%r10) /* less than 4k, just peek here */ |
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movq %r10, %rsp /* decrement stack */ |
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/* Push the return value back. Doing this instead of just |
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jumping to %r11 preserves the cached call-return stack |
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used by most modern processors. */ |
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pushq %r11 |
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ret |
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cfi_endproc() |
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#else |
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cfi_startproc() |
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___chkstk: |
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__alloca: |
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pushl %ecx /* save temp */ |
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cfi_push(%eax) |
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leal 8(%esp), %ecx /* point past return addr */ |
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cmpl $0x1000, %eax /* > 4k ?*/ |
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jb 2f |
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1: subl $0x1000, %ecx /* yes, move pointer down 4k*/ |
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orl $0x0, (%ecx) /* probe there */ |
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subl $0x1000, %eax /* decrement count */ |
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cmpl $0x1000, %eax |
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ja 1b /* and do it again */ |
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2: subl %eax, %ecx |
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orl $0x0, (%ecx) /* less than 4k, just peek here */ |
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movl %esp, %eax /* save current stack pointer */ |
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cfi_def_cfa_register(%eax) |
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movl %ecx, %esp /* decrement stack */ |
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movl (%eax), %ecx /* recover saved temp */ |
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/* Copy the return register. Doing this instead of just jumping to |
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the address preserves the cached call-return stack used by most |
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modern processors. */ |
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pushl 4(%eax) |
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ret |
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cfi_endproc() |
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#endif /* __x86_64__ */ |
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#endif /* L_chkstk */ |
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#ifdef L_chkstk_ms |
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/* ___chkstk_ms is a *special* function call, which uses %rax as the argument. |
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We avoid clobbering any registers. Unlike ___chkstk, it just probes the |
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stack and does no stack allocation. */ |
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.global ___chkstk_ms |
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#ifdef __x86_64__ |
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cfi_startproc() |
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___chkstk_ms: |
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pushq %rcx /* save temps */ |
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cfi_push(%rcx) |
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pushq %rax |
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cfi_push(%rax) |
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cmpq $0x1000, %rax /* > 4k ?*/ |
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leaq 24(%rsp), %rcx /* point past return addr */ |
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jb 2f |
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1: subq $0x1000, %rcx /* yes, move pointer down 4k */ |
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orq $0x0, (%rcx) /* probe there */ |
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subq $0x1000, %rax /* decrement count */ |
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cmpq $0x1000, %rax |
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ja 1b /* and do it again */ |
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2: subq %rax, %rcx |
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orq $0x0, (%rcx) /* less than 4k, just peek here */ |
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popq %rax |
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cfi_pop(%rax) |
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popq %rcx |
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cfi_pop(%rcx) |
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ret |
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cfi_endproc() |
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#else |
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cfi_startproc() |
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___chkstk_ms: |
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pushl %ecx /* save temp */ |
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cfi_push(%ecx) |
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pushl %eax |
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cfi_push(%eax) |
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cmpl $0x1000, %eax /* > 4k ?*/ |
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leal 12(%esp), %ecx /* point past return addr */ |
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jb 2f |
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1: subl $0x1000, %ecx /* yes, move pointer down 4k*/ |
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orl $0x0, (%ecx) /* probe there */ |
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subl $0x1000, %eax /* decrement count */ |
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cmpl $0x1000, %eax |
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ja 1b /* and do it again */ |
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2: subl %eax, %ecx |
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orl $0x0, (%ecx) /* less than 4k, just peek here */ |
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popl %eax |
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cfi_pop(%eax) |
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popl %ecx |
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cfi_pop(%ecx) |
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ret |
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cfi_endproc() |
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#endif /* __x86_64__ */ |
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#endif /* L_chkstk_ms */ |