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Diffstat (limited to 'gcc-4.9/libgcc/config/i386/cygwin.S')
| -rw-r--r-- | gcc-4.9/libgcc/config/i386/cygwin.S | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/gcc-4.9/libgcc/config/i386/cygwin.S b/gcc-4.9/libgcc/config/i386/cygwin.S new file mode 100644 index 000000000..277b59263 --- /dev/null +++ b/gcc-4.9/libgcc/config/i386/cygwin.S @@ -0,0 +1,187 @@ +/* stuff needed for libgcc on win32. + * + * Copyright (C) 1996-2014 Free Software Foundation, Inc. + * Written By Steve Chamberlain + * + * This file is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 3, or (at your option) any + * later version. + * + * This file is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * Under Section 7 of GPL version 3, you are granted additional + * permissions described in the GCC Runtime Library Exception, version + * 3.1, as published by the Free Software Foundation. + * + * You should have received a copy of the GNU General Public License and + * a copy of the GCC Runtime Library Exception along with this program; + * see the files COPYING3 and COPYING.RUNTIME respectively. If not, see + * <http://www.gnu.org/licenses/>. + */ + +#include "auto-host.h" + +#ifdef HAVE_GAS_CFI_SECTIONS_DIRECTIVE + .cfi_sections .debug_frame +# define cfi_startproc() .cfi_startproc +# define cfi_endproc() .cfi_endproc +# define cfi_adjust_cfa_offset(X) .cfi_adjust_cfa_offset X +# define cfi_def_cfa_register(X) .cfi_def_cfa_register X +# define cfi_register(D,S) .cfi_register D, S +# ifdef __x86_64__ +# define cfi_push(X) .cfi_adjust_cfa_offset 8; .cfi_rel_offset X, 0 +# define cfi_pop(X) .cfi_adjust_cfa_offset -8; .cfi_restore X +# else +# define cfi_push(X) .cfi_adjust_cfa_offset 4; .cfi_rel_offset X, 0 +# define cfi_pop(X) .cfi_adjust_cfa_offset -4; .cfi_restore X +# endif +#else +# define cfi_startproc() +# define cfi_endproc() +# define cfi_adjust_cfa_offset(X) +# define cfi_def_cfa_register(X) +# define cfi_register(D,S) +# define cfi_push(X) +# define cfi_pop(X) +#endif /* HAVE_GAS_CFI_SECTIONS_DIRECTIVE */ + +#ifdef L_chkstk +/* Function prologue calls __chkstk to probe the stack when allocating more + than CHECK_STACK_LIMIT bytes in one go. Touching the stack at 4K + increments is necessary to ensure that the guard pages used + by the OS virtual memory manger are allocated in correct sequence. */ + + .global ___chkstk + .global __alloca +#ifdef __x86_64__ +/* __alloca is a normal function call, which uses %rcx as the argument. */ + cfi_startproc() +__alloca: + movq %rcx, %rax + /* FALLTHRU */ + +/* ___chkstk is a *special* function call, which uses %rax as the argument. + We avoid clobbering the 4 integer argument registers, %rcx, %rdx, + %r8 and %r9, which leaves us with %rax, %r10, and %r11 to use. */ + .align 4 +___chkstk: + popq %r11 /* pop return address */ + cfi_adjust_cfa_offset(-8) /* indicate return address in r11 */ + cfi_register(%rip, %r11) + movq %rsp, %r10 + cmpq $0x1000, %rax /* > 4k ?*/ + jb 2f + +1: subq $0x1000, %r10 /* yes, move pointer down 4k*/ + orl $0x0, (%r10) /* probe there */ + subq $0x1000, %rax /* decrement count */ + cmpq $0x1000, %rax + ja 1b /* and do it again */ + +2: subq %rax, %r10 + movq %rsp, %rax /* hold CFA until return */ + cfi_def_cfa_register(%rax) + orl $0x0, (%r10) /* less than 4k, just peek here */ + movq %r10, %rsp /* decrement stack */ + + /* Push the return value back. Doing this instead of just + jumping to %r11 preserves the cached call-return stack + used by most modern processors. */ + pushq %r11 + ret + cfi_endproc() +#else + cfi_startproc() +___chkstk: +__alloca: + pushl %ecx /* save temp */ + cfi_push(%eax) + leal 8(%esp), %ecx /* point past return addr */ + cmpl $0x1000, %eax /* > 4k ?*/ + jb 2f + +1: subl $0x1000, %ecx /* yes, move pointer down 4k*/ + orl $0x0, (%ecx) /* probe there */ + subl $0x1000, %eax /* decrement count */ + cmpl $0x1000, %eax + ja 1b /* and do it again */ + +2: subl %eax, %ecx + orl $0x0, (%ecx) /* less than 4k, just peek here */ + movl %esp, %eax /* save current stack pointer */ + cfi_def_cfa_register(%eax) + movl %ecx, %esp /* decrement stack */ + movl (%eax), %ecx /* recover saved temp */ + + /* Copy the return register. Doing this instead of just jumping to + the address preserves the cached call-return stack used by most + modern processors. */ + pushl 4(%eax) + ret + cfi_endproc() +#endif /* __x86_64__ */ +#endif /* L_chkstk */ + +#ifdef L_chkstk_ms +/* ___chkstk_ms is a *special* function call, which uses %rax as the argument. + We avoid clobbering any registers. Unlike ___chkstk, it just probes the + stack and does no stack allocation. */ + .global ___chkstk_ms +#ifdef __x86_64__ + cfi_startproc() +___chkstk_ms: + pushq %rcx /* save temps */ + cfi_push(%rcx) + pushq %rax + cfi_push(%rax) + cmpq $0x1000, %rax /* > 4k ?*/ + leaq 24(%rsp), %rcx /* point past return addr */ + jb 2f + +1: subq $0x1000, %rcx /* yes, move pointer down 4k */ + orq $0x0, (%rcx) /* probe there */ + subq $0x1000, %rax /* decrement count */ + cmpq $0x1000, %rax + ja 1b /* and do it again */ + +2: subq %rax, %rcx + orq $0x0, (%rcx) /* less than 4k, just peek here */ + + popq %rax + cfi_pop(%rax) + popq %rcx + cfi_pop(%rcx) + ret + cfi_endproc() +#else + cfi_startproc() +___chkstk_ms: + pushl %ecx /* save temp */ + cfi_push(%ecx) + pushl %eax + cfi_push(%eax) + cmpl $0x1000, %eax /* > 4k ?*/ + leal 12(%esp), %ecx /* point past return addr */ + jb 2f + +1: subl $0x1000, %ecx /* yes, move pointer down 4k*/ + orl $0x0, (%ecx) /* probe there */ + subl $0x1000, %eax /* decrement count */ + cmpl $0x1000, %eax + ja 1b /* and do it again */ + +2: subl %eax, %ecx + orl $0x0, (%ecx) /* less than 4k, just peek here */ + + popl %eax + cfi_pop(%eax) + popl %ecx + cfi_pop(%ecx) + ret + cfi_endproc() +#endif /* __x86_64__ */ +#endif /* L_chkstk_ms */ |