/* src/vm/jit/emit-common.cpp - common code emitter functions

   Copyright (C) 2006, 2007, 2008
   CACAOVM - Verein zur Foerderung der freien virtuellen Maschine CACAO

   This file is part of CACAO.

   This program 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 2, or (at
   your option) any later version.

   This program 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.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
   02110-1301, USA.

*/


#include "config.h"

#include <assert.h>
#include <stdint.h>

#include <algorithm>

#include "vm/types.h"

#include "arch.h"
#include "codegen.h"

#include "toolbox/list.hpp"

#include "vm/options.h"
#include "vm/statistics.h"

#include "vm/jit/emit-common.hpp"
#include "vm/jit/jit.hpp"
#include "vm/jit/patcher-common.hpp"


/* emit_load_s1 ****************************************************************

   Emits a possible load of the first source operand.

*******************************************************************************/

s4 emit_load_s1(jitdata *jd, instruction *iptr, s4 tempreg)
{
	varinfo *src;
	s4       reg;

	src = VAROP(iptr->s1);

	reg = emit_load(jd, iptr, src, tempreg);

	return reg;
}


/* emit_load_s2 ****************************************************************

   Emits a possible load of the second source operand.

*******************************************************************************/

s4 emit_load_s2(jitdata *jd, instruction *iptr, s4 tempreg)
{
	varinfo *src;
	s4       reg;

	src = VAROP(iptr->sx.s23.s2);

	reg = emit_load(jd, iptr, src, tempreg);

	return reg;
}


/* emit_load_s3 ****************************************************************

   Emits a possible load of the third source operand.

*******************************************************************************/

s4 emit_load_s3(jitdata *jd, instruction *iptr, s4 tempreg)
{
	varinfo *src;
	s4       reg;

	src = VAROP(iptr->sx.s23.s3);

	reg = emit_load(jd, iptr, src, tempreg);

	return reg;
}


/* emit_load_s1_low ************************************************************

   Emits a possible load of the low 32-bits of the first long source
   operand.

*******************************************************************************/

#if SIZEOF_VOID_P == 4
s4 emit_load_s1_low(jitdata *jd, instruction *iptr, s4 tempreg)
{
	varinfo *src;
	s4       reg;

	src = VAROP(iptr->s1);

	reg = emit_load_low(jd, iptr, src, tempreg);

	return reg;
}
#endif


/* emit_load_s2_low ************************************************************

   Emits a possible load of the low 32-bits of the second long source
   operand.

*******************************************************************************/

#if SIZEOF_VOID_P == 4
s4 emit_load_s2_low(jitdata *jd, instruction *iptr, s4 tempreg)
{
	varinfo *src;
	s4       reg;

	src = VAROP(iptr->sx.s23.s2);

	reg = emit_load_low(jd, iptr, src, tempreg);

	return reg;
}
#endif


/* emit_load_s3_low ************************************************************

   Emits a possible load of the low 32-bits of the third long source
   operand.

*******************************************************************************/

#if SIZEOF_VOID_P == 4
s4 emit_load_s3_low(jitdata *jd, instruction *iptr, s4 tempreg)
{
	varinfo *src;
	s4       reg;

	src = VAROP(iptr->sx.s23.s3);

	reg = emit_load_low(jd, iptr, src, tempreg);

	return reg;
}
#endif


/* emit_load_s1_high ***********************************************************

   Emits a possible load of the high 32-bits of the first long source
   operand.

*******************************************************************************/

#if SIZEOF_VOID_P == 4
s4 emit_load_s1_high(jitdata *jd, instruction *iptr, s4 tempreg)
{
	varinfo *src;
	s4       reg;

	src = VAROP(iptr->s1);

	reg = emit_load_high(jd, iptr, src, tempreg);

	return reg;
}
#endif


/* emit_load_s2_high ***********************************************************

   Emits a possible load of the high 32-bits of the second long source
   operand.

*******************************************************************************/

#if SIZEOF_VOID_P == 4
s4 emit_load_s2_high(jitdata *jd, instruction *iptr, s4 tempreg)
{
	varinfo *src;
	s4       reg;

	src = VAROP(iptr->sx.s23.s2);

	reg = emit_load_high(jd, iptr, src, tempreg);

	return reg;
}
#endif


/* emit_load_s3_high ***********************************************************

   Emits a possible load of the high 32-bits of the third long source
   operand.

*******************************************************************************/

#if SIZEOF_VOID_P == 4
s4 emit_load_s3_high(jitdata *jd, instruction *iptr, s4 tempreg)
{
	varinfo *src;
	s4       reg;

	src = VAROP(iptr->sx.s23.s3);

	reg = emit_load_high(jd, iptr, src, tempreg);

	return reg;
}
#endif


/* emit_store_dst **************************************************************

   This function generates the code to store the result of an
   operation back into a spilled pseudo-variable.  If the
   pseudo-variable has not been spilled in the first place, this
   function will generate nothing.
    
*******************************************************************************/

void emit_store_dst(jitdata *jd, instruction *iptr, s4 d)
{
	emit_store(jd, iptr, VAROP(iptr->dst), d);
}


/* emit_patcher_traps **********************************************************

   Generates the code for the patcher traps.

*******************************************************************************/

void emit_patcher_traps(jitdata *jd)
{
	codegendata *cd;
	codeinfo    *code;
	u1          *savedmcodeptr;
	u1          *tmpmcodeptr;
	uint32_t     mcode;

	/* get required compiler data */

	cd   = jd->cd;
	code = jd->code;

	// Generate patcher traps code.
	for (List<patchref_t>::iterator it = code->patchers->begin(); it != code->patchers->end(); it++) {
		patchref_t& pr = *it;

		/* Calculate the patch position where the original machine
		   code is located and the trap should be placed. */

		tmpmcodeptr = (u1 *) (cd->mcodebase + pr.mpc);

		/* Patch in the trap to call the signal handler (done at
		   compile time). */

		savedmcodeptr = cd->mcodeptr;   /* save current mcodeptr          */
		cd->mcodeptr  = tmpmcodeptr;    /* set mcodeptr to patch position */

		mcode = emit_trap(cd);

		cd->mcodeptr = savedmcodeptr;   /* restore the current mcodeptr   */

		/* Remember the original machine code which is patched
		   back in later (done at runtime). */

		pr.mcode = mcode;
	}
}


/* emit_bccz *******************************************************************

   Emit conditional and unconditional branch instructions on integer
   regiseters.

*******************************************************************************/

void emit_bccz(codegendata *cd, basicblock *target, s4 condition, s4 reg, u4 options)
{
	s4 branchmpc;
	s4 disp;

	/* Target basic block already has an PC, so we can generate the
	   branch immediately. */

	if ((target->mpc >= 0)) {
		STATISTICS(count_branches_resolved++);

		/* calculate the mpc of the branch instruction */

		branchmpc = cd->mcodeptr - cd->mcodebase;
		disp      = target->mpc - branchmpc;

#if defined(ENABLE_STATISTICS)
		count_emit_branch++;
		if ((int8_t)disp == disp)  count_emit_branch_8bit++; 
		else if ((int16_t)disp == disp) count_emit_branch_16bit++;
		else if ((int32_t)disp == disp) count_emit_branch_32bit++;
# if SIZEOF_VOID_P == 8
		else if ((int64_t)disp == disp) count_emit_branch_64bit++;
# endif
#endif

		emit_branch(cd, disp, condition, reg, options);
	}
	else {
		/* current mcodeptr is the correct position,
		   afterwards emit the NOPs */

		codegen_add_branch_ref(cd, target, condition, reg, options);

		/* generate NOPs as placeholder for branch code */

		BRANCH_NOPS;
	}
}


/* emit_bcc ********************************************************************

   Emit conditional and unconditional branch instructions on condition
   codes.

*******************************************************************************/

void emit_bcc(codegendata *cd, basicblock *target, s4 condition, u4 options)
{
	emit_bccz(cd, target, condition, -1, options);
}


/* emit_br *********************************************************************

   Wrapper for unconditional branches.

*******************************************************************************/

void emit_br(codegendata *cd, basicblock *target)
{
	emit_bcc(cd, target, BRANCH_UNCONDITIONAL, BRANCH_OPT_NONE);
}


/* emit_bxxz *******************************************************************

   Wrappers for branches on one integer register.

*******************************************************************************/

#if SUPPORT_BRANCH_CONDITIONAL_ONE_INTEGER_REGISTER

void emit_beqz(codegendata *cd, basicblock *target, s4 reg)
{
	emit_bccz(cd, target, BRANCH_EQ, reg, BRANCH_OPT_NONE);
}

void emit_bnez(codegendata *cd, basicblock *target, s4 reg)
{
	emit_bccz(cd, target, BRANCH_NE, reg, BRANCH_OPT_NONE);
}

void emit_bltz(codegendata *cd, basicblock *target, s4 reg)
{
	emit_bccz(cd, target, BRANCH_LT, reg, BRANCH_OPT_NONE);
}

void emit_bgez(codegendata *cd, basicblock *target, s4 reg)
{
	emit_bccz(cd, target, BRANCH_GE, reg, BRANCH_OPT_NONE);
}

void emit_bgtz(codegendata *cd, basicblock *target, s4 reg)
{
	emit_bccz(cd, target, BRANCH_GT, reg, BRANCH_OPT_NONE);
}

void emit_blez(codegendata *cd, basicblock *target, s4 reg)
{
	emit_bccz(cd, target, BRANCH_LE, reg, BRANCH_OPT_NONE);
}

#endif /* SUPPORT_BRANCH_CONDITIONAL_ONE_INTEGER_REGISTER */


/* emit_bxx ********************************************************************

   Wrappers for branches on two integer registers.

   We use PACK_REGS here, so we don't have to change the branchref
   data structure and the emit_bccz function.

*******************************************************************************/

#if SUPPORT_BRANCH_CONDITIONAL_TWO_INTEGER_REGISTERS

void emit_beq(codegendata *cd, basicblock *target, s4 s1, s4 s2)
{
	emit_bccz(cd, target, BRANCH_EQ, PACK_REGS(s1, s2), BRANCH_OPT_NONE);
}

void emit_bne(codegendata *cd, basicblock *target, s4 s1, s4 s2)
{
	emit_bccz(cd, target, BRANCH_NE, PACK_REGS(s1, s2), BRANCH_OPT_NONE);
}

#endif /* SUPPORT_BRANCH_CONDITIONAL_TWO_INTEGER_REGISTERS */


/* emit_bxx ********************************************************************

   Wrappers for branches on condition codes.

*******************************************************************************/

#if SUPPORT_BRANCH_CONDITIONAL_CONDITION_REGISTER

void emit_beq(codegendata *cd, basicblock *target)
{
	emit_bcc(cd, target, BRANCH_EQ, BRANCH_OPT_NONE);
}

void emit_bne(codegendata *cd, basicblock *target)
{
	emit_bcc(cd, target, BRANCH_NE, BRANCH_OPT_NONE);
}

void emit_blt(codegendata *cd, basicblock *target)
{
	emit_bcc(cd, target, BRANCH_LT, BRANCH_OPT_NONE);
}

void emit_bge(codegendata *cd, basicblock *target)
{
	emit_bcc(cd, target, BRANCH_GE, BRANCH_OPT_NONE);
}

void emit_bgt(codegendata *cd, basicblock *target)
{
	emit_bcc(cd, target, BRANCH_GT, BRANCH_OPT_NONE);
}

void emit_ble(codegendata *cd, basicblock *target)
{
	emit_bcc(cd, target, BRANCH_LE, BRANCH_OPT_NONE);
}

#if SUPPORT_BRANCH_CONDITIONAL_UNSIGNED_CONDITIONS
void emit_bult(codegendata *cd, basicblock *target)
{
	emit_bcc(cd, target, BRANCH_ULT, BRANCH_OPT_NONE);
}

void emit_bule(codegendata *cd, basicblock *target)
{
	emit_bcc(cd, target, BRANCH_ULE, BRANCH_OPT_NONE);
}

void emit_buge(codegendata *cd, basicblock *target)
{
	emit_bcc(cd, target, BRANCH_UGE, BRANCH_OPT_NONE);
}

void emit_bugt(codegendata *cd, basicblock *target)
{
	emit_bcc(cd, target, BRANCH_UGT, BRANCH_OPT_NONE);
}
#endif

#if defined(__POWERPC__) || defined(__POWERPC64__)
void emit_bnan(codegendata *cd, basicblock *target)
{
	emit_bcc(cd, target, BRANCH_NAN, BRANCH_OPT_NONE);
}
#endif

#endif /* SUPPORT_BRANCH_CONDITIONAL_CONDITION_REGISTER */


/* emit_label_bccz *************************************************************

   Emit a branch to a label.  Possibly emit the branch, if it is a
   backward branch.

*******************************************************************************/

void emit_label_bccz(codegendata *cd, s4 label, s4 condition, s4 reg, u4 options)
{
	// Search if the label is already in the list.
	DumpList<branch_label_ref_t*>::iterator it;
	for (it = cd->brancheslabel->begin(); it != cd->brancheslabel->end(); it++) {
		branch_label_ref_t* br = *it;

		/* is this entry the correct label? */

		if (br->label == label)
			break;
	}

	if (it == cd->brancheslabel->end()) {
		/* current mcodeptr is the correct position,
		   afterwards emit the NOPs */

		codegen_branch_label_add(cd, label, condition, reg, options);

		/* generate NOPs as placeholder for branch code */

		BRANCH_NOPS;
		return;
	}

	// Branch reference was found.
	branch_label_ref_t* br = *it;

	/* calculate the mpc of the branch instruction */

	int32_t mpc  = cd->mcodeptr - cd->mcodebase;
	int32_t disp = br->mpc - mpc;

#if defined(ENABLE_STATISTICS)
	count_emit_branch++;
	if ((int8_t)disp == disp)  count_emit_branch_8bit++; 
	else if ((int16_t)disp == disp) count_emit_branch_16bit++;
	else if ((int32_t)disp == disp) count_emit_branch_32bit++;
# if SIZEOF_VOID_P == 8
	else if ((int64_t)disp == disp) count_emit_branch_64bit++;
# endif
#endif

	emit_branch(cd, disp, condition, reg, options);

	// Now remove the branch reference.
	cd->brancheslabel->remove(br);
}


/* emit_label ******************************************************************

   Emit a label for a branch.  Possibly emit the branch, if it is a
   forward branch.

*******************************************************************************/

void emit_label(codegendata *cd, s4 label)
{
	u1* mcodeptr;

	// Search if the label is already in the list.
	DumpList<branch_label_ref_t*>::iterator it;
	for (it = cd->brancheslabel->begin(); it != cd->brancheslabel->end(); it++) {
		branch_label_ref_t* br = *it;

		/* is this entry the correct label? */

		if (br->label == label)
			break;
	}

	if (it == cd->brancheslabel->end()) {
		/* No branch reference found, add the label to the list (use
		   invalid values for condition and register). */

		codegen_branch_label_add(cd, label, -1, -1, BRANCH_OPT_NONE );
		return;
	}

	// Branch reference was found.
	branch_label_ref_t* br = *it;

	// Calculate the mpc of the branch instruction.
	int32_t mpc  = cd->mcodeptr - cd->mcodebase;
	int32_t disp = mpc - br->mpc;

	/* temporary set the mcodeptr */

	mcodeptr     = cd->mcodeptr;
	cd->mcodeptr = cd->mcodebase + br->mpc;

#if defined(ENABLE_STATISTICS)
	count_emit_branch++;
	if ((int8_t)disp == disp)  count_emit_branch_8bit++; 
	else if ((int16_t)disp == disp) count_emit_branch_16bit++;
	else if ((int32_t)disp == disp) count_emit_branch_32bit++;
# if SIZEOF_VOID_P == 8
	else if ((int64_t)disp == disp) count_emit_branch_64bit++;
# endif
#endif

	emit_branch(cd, disp, br->condition, br->reg, br->options);

	/* restore mcodeptr */

	cd->mcodeptr = mcodeptr;

	// Now remove the branch reference.
	cd->brancheslabel->remove(br);
}


/* emit_label_bcc **************************************************************

   Emit conditional and unconditional label-branch instructions on
   condition codes.

*******************************************************************************/

void emit_label_bcc(codegendata *cd, s4 label, s4 condition, u4 options)
{
	emit_label_bccz(cd, label, condition, -1, options);
}


/* emit_label_br ***************************************************************

   Wrapper for unconditional label-branches.

*******************************************************************************/

void emit_label_br(codegendata *cd, s4 label)
{
	emit_label_bcc(cd, label, BRANCH_UNCONDITIONAL, BRANCH_OPT_NONE);
}


/* emit_label_bxxz *************************************************************

   Wrappers for label-branches on one integer register.

*******************************************************************************/

#if SUPPORT_BRANCH_CONDITIONAL_ONE_INTEGER_REGISTER

void emit_label_beqz(codegendata *cd, s4 label, s4 reg)
{
	emit_label_bccz(cd, label, BRANCH_EQ, reg, BRANCH_OPT_NONE);
}

void emit_label_bnez(codegendata *cd, s4 label, s4 reg)
{
	emit_label_bccz(cd, label, BRANCH_NE, reg, BRANCH_OPT_NONE);
}

#endif /* SUPPORT_BRANCH_CONDITIONAL_ONE_INTEGER_REGISTER */


/* emit_label_bxx **************************************************************

   Wrappers for label-branches on condition codes.

*******************************************************************************/

#if SUPPORT_BRANCH_CONDITIONAL_CONDITION_REGISTER

void emit_label_beq(codegendata *cd, s4 label)
{
	emit_label_bcc(cd, label, BRANCH_EQ, BRANCH_OPT_NONE);
}

void emit_label_bne(codegendata *cd, s4 label)
{
	emit_label_bcc(cd, label, BRANCH_NE, BRANCH_OPT_NONE);
}

void emit_label_blt(codegendata *cd, s4 label)
{
	emit_label_bcc(cd, label, BRANCH_LT, BRANCH_OPT_NONE);
}

void emit_label_bge(codegendata *cd, s4 label)
{
	emit_label_bcc(cd, label, BRANCH_GE, BRANCH_OPT_NONE);
}

void emit_label_bgt(codegendata *cd, s4 label)
{
	emit_label_bcc(cd, label, BRANCH_GT, BRANCH_OPT_NONE);
}

void emit_label_ble(codegendata *cd, s4 label)
{
	emit_label_bcc(cd, label, BRANCH_LE, BRANCH_OPT_NONE);
}

#endif /* SUPPORT_BRANCH_CONDITIONAL_CONDITION_REGISTER */


/*
 * These are local overrides for various environment variables in Emacs.
 * Please do not remove this and leave it at the end of the file, where
 * Emacs will automagically detect them.
 * ---------------------------------------------------------------------
 * Local variables:
 * mode: c++
 * indent-tabs-mode: t
 * c-basic-offset: 4
 * tab-width: 4
 * End:
 * vim:noexpandtab:sw=4:ts=4:
 */