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33bc19d30e
git-archimport-id: bonzini@gnu.org--2004b/lightning--stable--1.2--patch-15 git-archimport-id: bonzini@gnu.org--2004b/lightning--stable--1.2--patch-16
93 lines
3.3 KiB
C
93 lines
3.3 KiB
C
/******************************** -*- C -*- ****************************
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*
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* Simple example of recursion and forward references
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*
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***********************************************************************/
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/***********************************************************************
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*
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* Copyright 2000, 2004 Free Software Foundation, Inc.
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* Written by Paolo Bonzini and Laurent Michel.
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*
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* This file is part of GNU lightning.
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*
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* GNU lightning is free software; you can redistribute it and/or modify it
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* under the terms of the GNU Lesser General Public License as published
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* by the Free Software Foundation; either version 2.1, or (at your option)
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* any later version.
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*
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* GNU lightning is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
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* License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* along with GNU lightning; see the file COPYING.LESSER; if not, write to the
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* Free Software Foundation, 51 Franklin Street, Fifth Floor, Boston,
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* MA 02110-1301, USA.
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*
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***********************************************************************/
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#include <stdio.h>
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#ifdef HAVE_CONFIG_H
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#include "config.h"
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#endif
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#include "lightning.h"
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static jit_insn codeBuffer[1024];
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typedef int (*pifi)(int); /* Pointer to Int Function of Int */
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int main()
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{
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pifi nfibs = (pifi) (jit_set_ip(codeBuffer).iptr);
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int in; /* offset of the argument */
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jit_insn *ref; /* to patch the forward reference */
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jit_insn *mref; /* ref of move to backpatch */
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jit_insn *tp; /* location to patch */
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jit_prolog (1);
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in = jit_arg_ui ();
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jit_getarg_ui(JIT_V0, in); /* V0 = n */
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mref= jit_movi_p(JIT_V2,jit_forward ()); /* Generate a dumb movi */
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jit_jmpr(JIT_V2);
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/* generate some dump filler that will never be executed!*/
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jit_addi_ui(JIT_V0,JIT_V0,1);
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jit_addi_ui(JIT_V0,JIT_V0,1);
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jit_addi_ui(JIT_V0,JIT_V0,1);
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jit_addi_ui(JIT_V0,JIT_V0,1);
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tp = jit_get_label ();
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ref = jit_blti_ui (jit_forward(), JIT_V0, 2);
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jit_subi_ui (JIT_V1, JIT_V0, 1); /* V1 = n-1 */
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jit_subi_ui (JIT_V2, JIT_V0, 2); /* V2 = n-2 */
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jit_prepare (1);
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jit_pusharg_ui(JIT_V1);
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jit_finish(nfibs);
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jit_retval(JIT_V1); /* V1 = nfibs(n-1) */
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jit_prepare(1);
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jit_pusharg_ui(JIT_V2);
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jit_finish(nfibs);
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jit_retval(JIT_V2); /* V2 = nfibs(n-2) */
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jit_addi_ui(JIT_V1, JIT_V1, 1);
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jit_addr_ui(JIT_RET, JIT_V1, JIT_V2); /* RET = V1 + V2 + 1 */
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jit_ret();
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jit_patch(ref); /* patch jump */
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jit_movi_i(JIT_RET, 1); /* RET = 1 */
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jit_ret();
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jit_patch_movi(mref,tp); /* Ok. Do the back-patching */
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/* call the generated code, passing 32 as an argument */
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jit_flush_code(codeBuffer, jit_get_ip().ptr);
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#ifdef LIGHTNING_DISASSEMBLE
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disassemble(stderr, (char *)codeBuffer, jit_get_ip().ptr);
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#endif
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#ifndef LIGHTNING_CROSS
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printf("nfibs(%d) = %d\n", 32, nfibs(32));
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#endif
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return 0;
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}
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