| /* S/390-specific implemetation of profiling support. |
| Copyright (C) 2000, 2001 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com) |
| |
| 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 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: |
| * .LC12: .long _mcount |
| * .LC13: .long .LP0 |
| * .data |
| * .align 4 |
| * .LP0: .long 0 |
| * .text |
| * # function profiler |
| * st 14,4(15) |
| * l 14,.LC12-.LT0_0(13) |
| * l 1,.LC13-.LT0_0(13) |
| * basr 14,14 |
| * l 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. */ |
| ahi %r15,-128 |
| cfi_adjust_cfa_offset (128) |
| stm %r14,%r5,96(%r15) |
| cfi_offset (r14, 0) |
| cfi_offset (r15, 4) |
| l %r2,132(%r15) # callers address = first parameter |
| la %r2,0(%r2) # clear bit 0 |
| la %r3,0(%r14) # callees address = second parameter |
| |
| #ifdef PIC |
| bras %r14,0f |
| .long _GLOBAL_OFFSET_TABLE_-. |
| 0: al %r14,0(%r14) |
| l %r14,__mcount_internal@GOT(%r14) |
| #else |
| bras %r14,0f |
| .long __mcount_internal |
| 0: l %r14,0(%r14) |
| #endif |
| basr %r14,%r14 |
| |
| /* |
| * Pop the saved registers. Please note that `mcount' has no |
| * return value. |
| */ |
| lm %r14,%r5,96(%r15) |
| ahi %r15,128 |
| cfi_adjust_cfa_offset (-128) |
| br %r14 |
| cfi_endproc |
| ASM_SIZE_DIRECTIVE(C_SYMBOL_NAME(_mcount)) |
| |
| #undef mcount |
| weak_alias (_mcount, mcount) |
