emit.cpp

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/* src/vm/jit/powerpc64/emit.cpp - PowerPC64 code emitter functions

   Copyright (C) 1996-2014
   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 <cassert>

#include "vm/types.hpp"

#include "mm/memory.hpp"

#include "md-abi.hpp"
#include "vm/jit/powerpc64/codegen.hpp"

#include "threads/lock.hpp"

#include "vm/descriptor.hpp"            // for typedesc, methoddesc, etc
#include "vm/options.hpp"
#include "vm/vm.hpp"
   
#include "vm/jit/abi.hpp"
#include "vm/jit/abi-asm.hpp"
#include "vm/jit/asmpart.hpp"
#include "vm/jit/builtin.hpp"
#include "vm/jit/code.hpp"
#include "vm/jit/codegen-common.hpp"
#include "vm/jit/dseg.hpp"
#include "vm/jit/emit-common.hpp"
#include "vm/jit/jit.hpp"
#include "vm/jit/patcher-common.hpp"
#include "vm/jit/replace.hpp"
#include "vm/jit/trace.hpp"
#include "vm/jit/trap.hpp"

#include "vm/jit/ir/instruction.hpp"


/* emit_load *******************************************************************

   Emits a possible load of an operand.

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

s4 emit_load(jitdata *jd, instruction *iptr, varinfo *src, s4 tempreg)
{
    codegendata  *cd;
    s4            disp;
    s4            reg;

    /* get required compiler data */

    cd = jd->cd;

    if (src->flags & INMEMORY) {
        COUNT_SPILLS;

        disp = src->vv.regoff;

        if (IS_FLT_DBL_TYPE(src->type)) {
            if (IS_2_WORD_TYPE(src->type))
                M_DLD(tempreg, REG_SP, disp);
            else
                M_FLD(tempreg, REG_SP, disp);
        }
        else {
            M_LLD(tempreg, REG_SP, disp);
        }

        reg = tempreg;
    }
    else
        reg = src->vv.regoff;

    return reg;
}


/* emit_store ******************************************************************

   Emits a possible store to a variable.

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

void emit_store(jitdata *jd, instruction *iptr, varinfo *dst, s4 d)
{
    codegendata  *cd;

    /* get required compiler data */

    cd = jd->cd;

    if (dst->flags & INMEMORY) {
        COUNT_SPILLS;

        if (IS_FLT_DBL_TYPE(dst->type)) {
            if (IS_2_WORD_TYPE(dst->type))
                M_DST(d, REG_SP, dst->vv.regoff);
            else
                M_FST(d, REG_SP, dst->vv.regoff);
        }
        else {
            M_LST(d, REG_SP, dst->vv.regoff);
        }
    }
}


/* emit_copy *******************************************************************

   Generates a register/memory to register/memory copy.

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

void emit_copy(jitdata *jd, instruction *iptr)
{
    codegendata *cd;
    varinfo     *src;
    varinfo     *dst;
    s4           s1, d;

    /* get required compiler data */

    cd = jd->cd;

    /* get source and destination variables */

    src = VAROP(iptr->s1);
    dst = VAROP(iptr->dst);

    if ((src->vv.regoff != dst->vv.regoff) ||
        ((src->flags ^ dst->flags) & INMEMORY)) {

        if ((src->type == TYPE_RET) || (dst->type == TYPE_RET)) {
            /* emit nothing, as the value won't be used anyway */
            return;
        }

        /* If one of the variables resides in memory, we can eliminate
           the register move from/to the temporary register with the
           order of getting the destination register and the load. */

        if (IS_INMEMORY(src->flags)) {
            d  = codegen_reg_of_var(iptr->opc, dst, REG_IFTMP);
            s1 = emit_load(jd, iptr, src, d);
        }
        else {
            s1 = emit_load(jd, iptr, src, REG_IFTMP);
            d  = codegen_reg_of_var(iptr->opc, dst, s1);
        }

        if (s1 != d) {
            if (IS_FLT_DBL_TYPE(src->type))
                M_FMOV(s1, d);
            else
                M_MOV(s1, d);
        }

        emit_store(jd, iptr, dst, d);
    }
}


/* emit_iconst *****************************************************************

   XXX

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

void emit_iconst(codegendata *cd, s4 d, s4 value)
{
    s4 disp;

    if ((value >= -32768) && (value <= 32767)) {
        M_LDA_INTERN(d, REG_ZERO, value);
    } else {
        disp = dseg_add_s4(cd, value);
        M_ILD(d, REG_PV, disp);
    }
}

void emit_lconst(codegendata *cd, s4 d, s8 value)
{
    s4 disp;
    if ((value >= -32768) && (value <= 32767)) {
        M_LDA_INTERN(d, REG_ZERO, value);
    } else {
        disp = dseg_add_s8(cd, value);
        M_LLD(d, REG_PV, disp);
    }
}


/**
 * Emits code updating the condition register by comparing one integer
 * register to an immediate integer value.
 */
void emit_icmp_imm(codegendata* cd, int reg, int32_t value)
{
    int32_t disp;

    if ((value >= -32768) && (value <= 32767)) {
        M_CMPI(reg, value);
    } else {
        assert(reg != REG_ITMP2);
        disp = dseg_add_s4(cd, value);
        M_ILD(REG_ITMP2, REG_PV, disp);
        M_CMP(reg, REG_ITMP2);
    }
}


/**
 * Generates synchronization code to enter a monitor.
 */
void emit_monitor_enter(jitdata* jd, int32_t syncslot_offset)
{
    int32_t p;

    // Get required compiler data.
    methodinfo*  m  = jd->m;
    codegendata* cd = jd->cd;

#if !defined (NDEBUG)
        if (JITDATA_HAS_FLAG_VERBOSECALL(jd)) {
            M_AADD_IMM(REG_SP, -((LA_SIZE_IN_POINTERS + PA_SIZE_IN_POINTERS + ARG_CNT) * 8), REG_SP);

            for (p = 0; p < INT_ARG_CNT; p++)
                M_LST(abi_registers_integer_argument[p], REG_SP, LA_SIZE + PA_SIZE + p * 8);

            for (p = 0; p < FLT_ARG_CNT; p++)
                M_DST(abi_registers_float_argument[p], REG_SP, LA_SIZE + PA_SIZE + (INT_ARG_CNT + p) * 8);

            /* used for LOCK_monitor_exit, adopt size because we created another stackframe */
            syncslot_offset += (LA_SIZE_IN_POINTERS + PA_SIZE_IN_POINTERS + ARG_CNT) * 8;
        }
#endif

        p = dseg_add_functionptr(cd, LOCK_monitor_enter);
        M_ALD(REG_ITMP3, REG_PV, p);
        M_ALD(REG_ITMP3, REG_ITMP3, 0); /* TOC */
        M_MTCTR(REG_ITMP3);

        /* get or test the lock object */

        if (m->flags & ACC_STATIC) {
            p = dseg_add_address(cd, &m->clazz->object.header);
            M_ALD(REG_A0, REG_PV, p);
        }
        else {
            M_TST(REG_A0);
            M_BNE(1);
            M_ALD_INTERN(REG_ZERO, REG_ZERO, TRAP_NullPointerException);
        }

        M_AST(REG_A0, REG_SP, syncslot_offset);
        M_JSR;

#if !defined(NDEBUG)
        if (JITDATA_HAS_FLAG_VERBOSECALL(jd)) {
            for (p = 0; p < INT_ARG_CNT; p++)
                M_LLD(abi_registers_integer_argument[p], REG_SP, LA_SIZE + PA_SIZE + p * 8);

            for (p = 0; p < FLT_ARG_CNT; p++)
                M_DLD(abi_registers_float_argument[p], REG_SP, LA_SIZE + PA_SIZE + (INT_ARG_CNT + p) * 8);

            M_AADD_IMM(REG_SP, (LA_SIZE_IN_POINTERS + PA_SIZE_IN_POINTERS + ARG_CNT) * 8, REG_SP);
        }
#endif
}


/**
 * Generates synchronization code to leave a monitor.
 */
void emit_monitor_exit(jitdata* jd, int32_t syncslot_offset)
{
    int32_t disp;

    // Get required compiler data.
    methodinfo*  m  = jd->m;
    codegendata* cd = jd->cd;

    disp = dseg_add_functionptr(cd, LOCK_monitor_exit);
    M_ALD(REG_ITMP3, REG_PV, disp);
    M_ALD(REG_ITMP3, REG_ITMP3, 0); /* TOC */
    M_MTCTR(REG_ITMP3);

    /* we need to save the proper return value */

    methoddesc* md = m->parseddesc;

    switch (md->returntype.type) {
    case TYPE_LNG:
    case TYPE_INT:
    case TYPE_ADR:
        /* fall through */
        M_LST(REG_RESULT , REG_SP, syncslot_offset + 8);
        break;
    case TYPE_FLT:
        M_FST(REG_FRESULT, REG_SP, syncslot_offset + 8);
        break;
    case TYPE_DBL:
        M_DST(REG_FRESULT, REG_SP, syncslot_offset + 8);
        break;
    case TYPE_VOID:
        break;
    default:
        assert(false);
        break;
    }

    M_ALD(REG_A0, REG_SP, syncslot_offset);
    M_JSR;

    /* and now restore the proper return value */

    switch (md->returntype.type) {
    case TYPE_LNG:
    case TYPE_INT:
    case TYPE_ADR:
        /* fall through */
        M_LLD(REG_RESULT , REG_SP, syncslot_offset + 8);
        break;
    case TYPE_FLT:
        M_FLD(REG_FRESULT, REG_SP, syncslot_offset + 8);
        break;
    case TYPE_DBL:
        M_DLD(REG_FRESULT, REG_SP, syncslot_offset + 8);
        break;
    case TYPE_VOID:
        break;
    default:
        assert(false);
        break;
    }
}


/* emit_verbosecall_enter ******************************************************

   Generates the code for the call trace.

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

#if !defined(NDEBUG)
void emit_verbosecall_enter(jitdata *jd)
{
    methodinfo   *m;
    codegendata  *cd;
    methoddesc   *md;
    int32_t       paramcount;
    int32_t       stackframesize;
    s4            disp;
    s4            i, s;

    /* get required compiler data */

    m  = jd->m;
    cd = jd->cd;

    md = m->parseddesc;
    
    /* mark trace code */

    M_NOP;

    /* align stack to 16-bytes */

    paramcount = md->paramcount;
    ALIGN_2(paramcount);
    stackframesize = LA_SIZE + PA_SIZE + md->paramcount * 8;

    M_MFLR(REG_ZERO);
    M_AST(REG_ZERO, REG_SP, LA_LR_OFFSET);
    M_STDU(REG_SP, REG_SP, -stackframesize);

#if defined(__DARWIN__)
    #warning "emit_verbosecall_enter not implemented"
#else
    /* save argument registers */

    for (i = 0; i < md->paramcount; i++) {
        if (!md->params[i].inmemory) {
            s = md->params[i].regoff;

            switch (md->paramtypes[i].type) {
            case TYPE_ADR:
            case TYPE_INT:
            case TYPE_LNG:
                M_LST(s, REG_SP, LA_SIZE+PA_SIZE+i*8);
                break;
            case TYPE_FLT:
            case TYPE_DBL:
                M_DST(s, REG_SP, LA_SIZE+PA_SIZE+i*8);
                break;
            default:
                assert(false);
                break;
            }
        }
    }
#endif

    disp = dseg_add_address(cd, m);
    M_ALD(REG_A0, REG_PV, disp);
    M_AADD_IMM(REG_SP, LA_SIZE+PA_SIZE, REG_A1);
    M_AADD_IMM(REG_SP, stackframesize + cd->stackframesize * 8, REG_A2);
    /* call via function descriptor, XXX: what about TOC? */
    disp = dseg_add_functionptr(cd, trace_java_call_enter);
    M_ALD(REG_ITMP2, REG_PV, disp);
    M_ALD(REG_ITMP1, REG_ITMP2, 0);
    M_MTCTR(REG_ITMP1);
    M_JSR;

#if defined(__DARWIN__)
    #warning "emit_verbosecall_enter not implemented"
#else
    /* restore argument registers */

    for (i = 0; i < md->paramcount; i++) {
        if (!md->params[i].inmemory) {
            s = md->params[i].regoff;

            switch (md->paramtypes[i].type) {
            case TYPE_ADR:
            case TYPE_INT:
            case TYPE_LNG:
                M_LLD(s, REG_SP, LA_SIZE+PA_SIZE+i*8);
                break;
            case TYPE_FLT:
            case TYPE_DBL:
                M_DLD(s, REG_SP, LA_SIZE+PA_SIZE+i*8);
                break;
            default:
                assert(false);
                break;
            }
        }
    }
#endif

    M_ALD(REG_ZERO, REG_SP, stackframesize + LA_LR_OFFSET);
    M_MTLR(REG_ZERO);
    M_LDA(REG_SP, REG_SP, stackframesize);

    /* mark trace code */

    M_NOP;
}
#endif


/* emit_verbosecall_exit ******************************************************

   Generates the code for the call trace.

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

#if !defined(NDEBUG)
void emit_verbosecall_exit(jitdata *jd)
{
    methodinfo   *m;
    codegendata  *cd;
    methoddesc   *md;
    s4            disp;

    /* get required compiler data */

    m  = jd->m;
    cd = jd->cd;

    md = m->parseddesc;

    /* mark trace code */

    M_NOP;

    M_MFLR(REG_ZERO);
    M_LDA(REG_SP, REG_SP, -(LA_SIZE+PA_SIZE+10*8));
    M_AST(REG_ZERO, REG_SP, LA_SIZE+PA_SIZE+1*8);

    /* save return value */

    switch (md->returntype.type) {
    case TYPE_ADR:
    case TYPE_INT:
    case TYPE_LNG:
        M_LST(REG_RESULT, REG_SP, LA_SIZE+PA_SIZE+0*8);
        break;
    case TYPE_FLT:
    case TYPE_DBL:
        M_DST(REG_FRESULT, REG_SP, LA_SIZE+PA_SIZE+0*8);
        break;
    case TYPE_VOID:
        break;
    default:
        assert(false);
        break;
    }

    disp = dseg_add_address(cd, m);
    M_ALD(REG_A0, REG_PV, disp);
    M_AADD_IMM(REG_SP, LA_SIZE+PA_SIZE, REG_A1);

    disp = dseg_add_functionptr(cd, trace_java_call_exit);
    /* call via function descriptor, XXX: what about TOC ? */
    M_ALD(REG_ITMP2, REG_PV, disp);
    M_ALD(REG_ITMP2, REG_ITMP2, 0);
    M_MTCTR(REG_ITMP2);
    M_JSR;

    /* restore return value */

    switch (md->returntype.type) {
    case TYPE_ADR:
    case TYPE_INT:
    case TYPE_LNG:
        M_LLD(REG_RESULT, REG_SP, LA_SIZE+PA_SIZE+0*8);
        break;
    case TYPE_FLT:
    case TYPE_DBL:
        M_DLD(REG_FRESULT, REG_SP, LA_SIZE+PA_SIZE+0*8);
        break;
    case TYPE_VOID:
        break;
    default:
        assert(false);
        break;
    }

    M_ALD(REG_ZERO, REG_SP, LA_SIZE+PA_SIZE+1*8);
    M_LDA(REG_SP, REG_SP, LA_SIZE+PA_SIZE+10*8);
    M_MTLR(REG_ZERO);

    /* mark trace code */

    M_NOP;
}
#endif


/* emit_branch *****************************************************************

   Emits the code for conditional and unconditional branchs.

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

void emit_branch(codegendata *cd, s4 disp, s4 condition, s4 reg, u4 opt)
{
    s4 checkdisp;
    s4 branchdisp;

    /* calculate the different displacements */

    checkdisp  =  disp + 4;
    branchdisp = (disp - 4) >> 2;

    /* check which branch to generate */

    if (condition == BRANCH_UNCONDITIONAL) {
        /* check displacement for overflow */

        if ((checkdisp < (s4) 0xfe000000) || (checkdisp > (s4) 0x01fffffc)) {
            /* if the long-branches flag isn't set yet, do it */

            if (!CODEGENDATA_HAS_FLAG_LONGBRANCHES(cd)) {
                cd->flags |= (CODEGENDATA_FLAG_ERROR |
                              CODEGENDATA_FLAG_LONGBRANCHES);
            }

            vm_abort("emit_branch: emit unconditional long-branch code");
        }
        else {
            M_BR(branchdisp);
        }
    }
    else {
        /* and displacement for overflow */

        if ((checkdisp < (s4) 0xffff8000) || (checkdisp > (s4) 0x00007fff)) {
            /* if the long-branches flag isn't set yet, do it */

            if (!CODEGENDATA_HAS_FLAG_LONGBRANCHES(cd)) {
                cd->flags |= (CODEGENDATA_FLAG_ERROR |
                              CODEGENDATA_FLAG_LONGBRANCHES);
            }

            // Subtract 1 instruction from the displacement as the
            // actual branch is the second instruction.
            checkdisp  = checkdisp - 4;
            branchdisp = branchdisp - 1;

            if ((checkdisp < (int32_t) 0xfe000000) || (checkdisp > (int32_t) 0x01fffffc)) {
                vm_abort("emit_branch: emit conditional long-branch code");
            }
            else {
                switch (condition) {
                case BRANCH_EQ:
                    M_BNE(1);
                    M_BR(branchdisp);
                    break;
                case BRANCH_NE:
                    M_BEQ(1);
                    M_BR(branchdisp);
                    break;
                case BRANCH_LT:
                    M_BGE(1);
                    M_BR(branchdisp);
                    break;
                case BRANCH_GE:
                    M_BLT(1);
                    M_BR(branchdisp);
                    break;
                case BRANCH_GT:
                    M_BLE(1);
                    M_BR(branchdisp);
                    break;
                case BRANCH_LE:
                    M_BGT(1);
                    M_BR(branchdisp);
                    break;
                case BRANCH_NAN:
                    vm_abort("emit_branch: long BRANCH_NAN");
                    break;
                default:
                    vm_abort("emit_branch: unknown condition %d", condition);
                    break;
                }
            }
        }
        else {
            switch (condition) {
            case BRANCH_EQ:
                M_BEQ(branchdisp);
                break;
            case BRANCH_NE:
                M_BNE(branchdisp);
                break;
            case BRANCH_LT:
                M_BLT(branchdisp);
                break;
            case BRANCH_GE:
                M_BGE(branchdisp);
                break;
            case BRANCH_GT:
                M_BGT(branchdisp);
                break;
            case BRANCH_LE:
                M_BLE(branchdisp);
                break;
            case BRANCH_NAN:
                M_BNAN(branchdisp);
                break;
            default:
                vm_abort("emit_branch: unknown condition %d", condition);
                break;
            }
        }
    }
}

/* emit_arrayindexoutofbounds_check ********************************************

   Emit a ArrayIndexOutOfBoundsException check.

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

void emit_arrayindexoutofbounds_check(codegendata *cd, instruction *iptr, s4 s1, s4 s2)
{
    if (checkbounds) {
        M_ILD(REG_ITMP3, s1, OFFSET(java_array_t, size));
        M_CMPU(s2, REG_ITMP3);
        M_BLT(1);
        /* ALD is 4 byte aligned, ILD 2, onyl LWZ is byte aligned */
        M_LWZ(s2, REG_ZERO, TRAP_ArrayIndexOutOfBoundsException);
    }
}


/* emit_arraystore_check *******************************************************

   Emit an ArrayStoreException check.

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

void emit_arraystore_check(codegendata *cd, instruction *iptr)
{
    if (INSTRUCTION_MUST_CHECK(iptr))   {
        M_TST(REG_RESULT);
        M_BNE(1);
        /* ALD is 4 byte aligned, ILD 2, onyl LWZ is byte aligned */
        M_LWZ(REG_ZERO, REG_ZERO, TRAP_ArrayStoreException);
    }
}


/* emit_arithmetic_check *******************************************************

   Emit an ArithmeticException check.

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

void emit_arithmetic_check(codegendata *cd, instruction *iptr, s4 reg)
{
    if (INSTRUCTION_MUST_CHECK(iptr))   {
        M_TST(reg);
        M_BNE(1);
        /* ALD is 4 byte aligned, ILD 2, onyl LWZ is byte aligned */
        M_LWZ(REG_ZERO, REG_ZERO, TRAP_ArithmeticException);
    }
}


/* emit_classcast_check ********************************************************

   Emit a ClassCastException check.

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

void emit_classcast_check(codegendata *cd, instruction *iptr, s4 condition, s4 reg, s4 s1)
{
    if (INSTRUCTION_MUST_CHECK(iptr))   {
        switch(condition)   {
        case BRANCH_LE:
            M_BGT(1);
            break;
        case BRANCH_EQ:
            M_BNE(1);
            break;
        case BRANCH_NE:
            M_BEQ(1);
            break;
        case BRANCH_GT:
            M_BLE(1);
            break;
        default:
            vm_abort("emit_classcast_check: unknown condition %d", condition);
            break;
        }

        /* ALD is 4 byte aligned, ILD 2, onyl LWZ is byte aligned */
        M_LWZ(s1, REG_ZERO, TRAP_ClassCastException);
    }
}


/* emit_nullpointer_check ******************************************************

   Emit a NullPointerException check.

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

void emit_nullpointer_check(codegendata *cd, instruction *iptr, s4 reg)
{
    if (INSTRUCTION_MUST_CHECK(iptr))   {
        M_TST(reg);
        M_BNE(1);
        /* ALD is 4 byte aligned, ILD 2, onyl LWZ is byte aligned */
        M_LWZ(REG_ZERO, REG_ZERO, TRAP_NullPointerException);
    }
}

/* emit_exception_check ********************************************************

   Emit an Exception check.

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

void emit_exception_check(codegendata *cd, instruction *iptr)
{
    if (INSTRUCTION_MUST_CHECK(iptr))   {
        M_TST(REG_RESULT);
        M_BNE(1);
        /* ALD is 4 byte aligned, ILD 2, onyl LWZ is byte aligned */
        M_LWZ(REG_ZERO, REG_ZERO, TRAP_CHECK_EXCEPTION);
    }
}


/* emit_trap_compiler **********************************************************

   Emit a trap instruction which calls the JIT compiler.

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

void emit_trap_compiler(codegendata *cd)
{
    M_LWZ(REG_METHODPTR, REG_ZERO, TRAP_COMPILER);
}

void emit_abstractmethoderror_trap(codegendata *cd)
{
    M_LWZ(REG_METHODPTR, REG_ZERO, TRAP_AbstractMethodError);
}


/* emit_trap *******************************************************************

   Emit a trap instruction and return the original machine code.

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

uint32_t emit_trap(codegendata *cd)
{
    // Get machine code which is patched back in later. The trap is 1
    // instruction word long.
    uint32_t mcode = *((uint32_t*) cd->mcodeptr);

    M_ILLEGAL;

    return mcode;
}


/**
 * Emit code to recompute the procedure vector.
 */
void emit_recompute_pv(codegendata *cd)
{
    int32_t disp = (int32_t) (cd->mcodeptr - cd->mcodebase);

    M_MFLR(REG_ITMP1);
    M_LDA(REG_PV, REG_ITMP1, -disp);
}


/*
 * 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:
 */