| /* 64 bit S/390-specific implemetation of profiling support. |
| Copyright (C) 2001 Free Software Foundation, Inc. |
| Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com) |
| This file is part of the GNU C Library. |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| The GNU C Library 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 |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library; if not, write to the Free |
| Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 02111-1307 USA. */ |
| |
| #include <sysdep.h> |
| |
| /* How profiling works on 64 bit S/390: |
| On the start of each function _mcount is called with the address of a |
| data word in %r1 (initialized to 0, used for counting). The compiler |
| with the option -p generates code of the form: |
| |
| STM 6,15,24(15) |
| BRAS 13,.LTN0_0 |
| .LT0_0: |
| .LC13: .long .LP0 |
| .data |
| .align 4 |
| .LP0: .long 0 |
| .text |
| # function profiler |
| stg 14,4(15) |
| lg 1,.LC13-.LT0_0(13) |
| brasl 14,_mcount |
| lg 14,4(15) |
| |
| The _mcount implementation now has to call __mcount_internal with the |
| address of .LP0 as first parameter and the return address as second |
| parameter. &.LP0 was loaded to %r1 and the return address is in %r14. |
| _mcount may not modify any register. */ |
| |
| ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME(_mcount) |
| ASM_TYPE_DIRECTIVE(C_SYMBOL_NAME(_mcount), @function) |
| cfi_startproc |
| .align ALIGNARG(4) |
| C_LABEL(_mcount) |
| /* Save the caller-clobbered registers. */ |
| aghi %r15,-224 |
| cfi_adjust_cfa_offset (224) |
| stmg %r14,%r5,160(%r15) |
| cfi_offset (r14, 0) |
| cfi_offset (r15, 8) |
| lg %r2,232(%r15) # callers address = first parameter |
| la %r2,0(%r2) # clear bit 0 |
| la %r3,0(%r14) # callees address = second parameter |
| |
| #ifdef PIC |
| brasl %r14,__mcount_internal@PLT |
| #else |
| brasl %r14,__mcount_internal |
| #endif |
| |
| /* Pop the saved registers. Please note that `mcount' has no |
| return value. */ |
| lmg %r14,%r5,160(%r15) |
| aghi %r15,224 |
| cfi_adjust_cfa_offset (-224) |
| br %r14 |
| cfi_endproc |
| ASM_SIZE_DIRECTIVE(C_SYMBOL_NAME(_mcount)) |
| |
| #undef mcount |
| weak_alias (_mcount, mcount) |
