emit.cpp

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/* src/vm/jit/aarch64/emit.cpp - Aarch64 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 "vm/types.hpp"

#include <cassert>
#include <stdint.h>

#include "md-abi.hpp"

#include "vm/jit/aarch64/codegen.hpp"
#include "vm/jit/aarch64/patcher.hpp"

#include "mm/memory.hpp"

#include "threads/lock.hpp"

#include "vm/descriptor.hpp"            // for typedesc, methoddesc, etc
#include "vm/options.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/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)
{
    AsmEmitter    asme(jd->cd);
    s4            disp;
    s4            reg;

    if (IS_INMEMORY(src->flags)) {
        COUNT_SPILLS;

        disp = src->vv.regoff;

        switch (src->type) {
        case TYPE_INT:
            asme.ild(tempreg, REG_SP, disp);
            break;
        case TYPE_LNG:
            asme.lld(tempreg, REG_SP, disp);
            break;
        case TYPE_ADR:
            asme.ald(tempreg, REG_SP, disp);
            break;
        case TYPE_FLT:
            asme.fld(tempreg, REG_SP, disp);
            break;
        case TYPE_DBL:
            asme.dld(tempreg, REG_SP, disp);
            break;
        default:
            vm_abort("emit_load: unknown type %d", src->type);
            break;
        }

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

    return reg;
}


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

   Emit a possible store for the given variable.

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

void emit_store(jitdata *jd, instruction *iptr, varinfo *dst, s4 d)
{
    AsmEmitter    asme(jd->cd);
    s4            disp;

    if (IS_INMEMORY(dst->flags)) {
        COUNT_SPILLS;

        disp = dst->vv.regoff;

        switch (dst->type) {
        case TYPE_INT:
            asme.ist(d, REG_SP, disp);
            break;
        case TYPE_LNG:
            asme.lst(d, REG_SP, disp);
            break;
        case TYPE_ADR:
            asme.ast(d, REG_SP, disp);
            break;
        case TYPE_FLT:
            asme.fst(d, REG_SP, disp);
            break;
        case TYPE_DBL:
            asme.dst(d, REG_SP, disp);
            break;
        default:
            vm_abort("emit_store: unknown type %d", dst->type);
            break;
        }
    }
}


/* 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) {
            switch (src->type) {
            case TYPE_INT:
            case TYPE_LNG:
            case TYPE_ADR:
                M_MOV(s1, d);
                break;
            case TYPE_FLT:
                M_FMOV(s1, d);
                break;
            case TYPE_DBL:
                M_DMOV(s1, d);
                break;
            default:
                vm_abort("emit_copy: unknown type %d", src->type);
                break;
            }
        }

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


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

   XXX

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

void emit_iconst(codegendata *cd, s4 d, s4 value)
{
    AsmEmitter asme(cd);
    asme.iconst(d, value);
}


/* emit_lconst *****************************************************************

   XXX

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

void emit_lconst(codegendata *cd, s4 d, s8 value)
{
    AsmEmitter asme(cd);
    asme.lconst(d, value);
}


/**
 * Emits code comparing a single register
 */
void emit_icmp_imm(codegendata* cd, int reg, int32_t value) {
    AsmEmitter asme(cd);

    if (value >= 0 && value <= 4095) {
        asme.icmp_imm(reg, value);
    } else if ((-value) >= 0 && (-value) <= 4095) {
        asme.icmn_imm(reg, -value);
    } else {
        asme.iconst(REG_ITMP2, value);
        asme.icmp(reg, REG_ITMP2);
    }
}


/* 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;
    AsmEmitter asme(cd);

    /* calculate the different displacements */

    checkdisp  = disp;
    branchdisp = disp >> 2;

    /* check which branch to generate */

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

        if ((checkdisp < (s4) 0xffe00000) || (checkdisp > (s4) 0x001fffff)) {
            /* if the long-branches flag isn't set yet, do it */

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

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

        if ((checkdisp < (s4) 0xffe00000) || (checkdisp > (s4) 0x001fffff)) {
            /* if the long-branches flag isn't set yet, do it */

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

            vm_abort("emit_branch: emit conditional long-branch code");
        }
        else {
            switch (condition) {
            case BRANCH_EQ:
                asme.b_eq(branchdisp);
                break;
            case BRANCH_NE:
                asme.b_ne(branchdisp);
                break;
            case BRANCH_LT:
                asme.b_lt(branchdisp);
                break;
            case BRANCH_GE:
                asme.b_ge(branchdisp);
                break;
            case BRANCH_GT:
                asme.b_gt(branchdisp);
                break;
            case BRANCH_LE:
                asme.b_le(branchdisp);
                break;
            case BRANCH_UGT:
                asme.b_hi(branchdisp);
                break;
            default:
                vm_abort("emit_branch: unknown condition %d", condition);
                break;
            }
        }
    }
}


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

   Emit an ArithmeticException check.

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

void emit_arithmetic_check(codegendata *cd, instruction *iptr, s4 reg)
{
    if (INSTRUCTION_MUST_CHECK(iptr)) {
        AsmEmitter asme(cd);
        asme.cbnz(reg, 2);
        emit_trap(cd, reg, TRAP_ArithmeticException);
    }
}


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

   Emit an ArrayIndexOutOfBoundsException check.

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

void emit_arrayindexoutofbounds_check(codegendata *cd, instruction *iptr, s4 s1, s4 s2)
{
    if (INSTRUCTION_MUST_CHECK(iptr)) {
        AsmEmitter asme(cd);
        asme.ild(REG_ITMP3, s1, OFFSET(java_array_t, size));
        asme.icmp(s2, REG_ITMP3);
        asme.b_cc(2);
        emit_trap(cd, s2, TRAP_ArrayIndexOutOfBoundsException);
    }
}


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

   Emit an ArrayStoreException check.

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

void emit_arraystore_check(codegendata *cd, instruction *iptr)
{
    if (INSTRUCTION_MUST_CHECK(iptr)) {
        AsmEmitter asme(cd);
        asme.cbnz(REG_RESULT, 2);
        emit_trap(cd, REG_RESULT, TRAP_ArrayStoreException);
    }
}


/* 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)) {
        AsmEmitter asme(cd);
        switch (condition) {
        case BRANCH_EQ:
            asme.b_ne(2);
            break;
        case BRANCH_LE:
            asme.b_gt(2);
            break;
        case BRANCH_NE:
            asme.b_eq(2);
            break;
        case BRANCH_GT:
            asme.b_le(2);
            break;
        case BRANCH_LT:
            asme.b_ge(2);
            break;
        default:
            vm_abort("emit_classcast_check: unknown condition %d", condition);
            break;
        }
        emit_trap(cd, s1, TRAP_ClassCastException);
    }
}


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

   Emit a NullPointerException check.

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

void emit_nullpointer_check(codegendata *cd, instruction *iptr, s4 reg)
{
    if (INSTRUCTION_MUST_CHECK(iptr)) {
        AsmEmitter asme(cd);
        asme.cbnz(reg, 2);
        emit_trap(cd, reg, TRAP_NullPointerException);
    }
}


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

   Emit an Exception check.

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

void emit_exception_check(codegendata *cd, instruction *iptr)
{
    if (INSTRUCTION_MUST_CHECK(iptr)) {
        AsmEmitter asme(cd);
        asme.cbnz(REG_RESULT, 2);
        emit_trap(cd, REG_RESULT, TRAP_CHECK_EXCEPTION);
    }
}


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

   Emit a trap instruction which calls the JIT compiler.

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

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

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


/* emit_trap_countdown *********************************************************

   Emit a countdown trap

   counter....absolute address of the counter variable

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

void emit_trap_countdown(codegendata *cd, s4 *counter)
{
    AsmEmitter asme(cd);
    asme.lconst(REG_ITMP1, (s8) counter);

    // Simple load-sub-store loop
    asme.ildxr(REG_ITMP2, REG_ITMP1);
    asme.isub_imm(REG_ITMP2, REG_ITMP2, 1);
    asme.istxr(REG_ITMP3, REG_ITMP2, REG_ITMP1);
    asme.icbnz(REG_ITMP3, -3);

    asme.icbnz(REG_ITMP2, 2);
    emit_trap(cd, REG_METHODPTR, TRAP_COUNTDOWN);
}


/* 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);

    emit_trap(cd, 0, TRAP_PATCHER);

    return mcode;
}


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

    AsmEmitter asme(cd);
    asme.lda(REG_PV, REG_RA, -disp);
}


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

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

#if !defined(NDEBUG)
    if (JITDATA_HAS_FLAG_VERBOSECALL(jd)) {
        asme.lda(REG_SP, REG_SP, -(INT_ARG_CNT + FLT_ARG_CNT) * 8);

        for (p = 0; p < INT_ARG_CNT; p++)
            asme.lst(abi_registers_integer_argument[p], REG_SP, p * 8);

        for (p = 0; p < FLT_ARG_CNT; p++)
            asme.dst(abi_registers_float_argument[p], REG_SP, (INT_ARG_CNT + p) * 8);

        syncslot_offset += (INT_ARG_CNT + FLT_ARG_CNT) * 8;
    }
#endif /* !defined(NDEBUG) */

    /* decide which monitor enter function to call */

    if (m->flags & ACC_STATIC) {
        disp = dseg_add_address(cd, &m->clazz->object.header);
        asme.lld(REG_A0, REG_PV, disp);
    }
    else {
        asme.cbnz(REG_A0, 2);
        emit_trap(cd, REG_ZERO, TRAP_NullPointerException);
    }

    asme.lst(REG_A0, REG_SP, syncslot_offset);
    disp = dseg_add_functionptr(cd, LOCK_monitor_enter);
    asme.lld(REG_PV, REG_PV, disp);
    asme.blr(REG_PV);
    emit_recompute_pv(cd);

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

        for (p = 0; p < FLT_ARG_CNT; p++)
            asme.dld(abi_registers_float_argument[p], REG_SP, (INT_ARG_CNT + p) * 8);

        asme.lda(REG_SP, REG_SP, (INT_ARG_CNT + FLT_ARG_CNT) * 8);
    }
#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;
    AsmEmitter asme(cd);

    methoddesc* md = m->parseddesc;

    switch (md->returntype.type) {
    case TYPE_INT:
    case TYPE_LNG:
    case TYPE_ADR:
        asme.lst(REG_RESULT, REG_SP, syncslot_offset + 8);
        break;
    case TYPE_FLT:
    case TYPE_DBL:
        asme.dst(REG_FRESULT, REG_SP, syncslot_offset + 8);
        break;
    case TYPE_VOID:
        break;
    default:
        assert(false);
        break;
    }

    asme.lld(REG_A0, REG_SP, syncslot_offset);
    disp = dseg_add_functionptr(cd, LOCK_monitor_exit);
    asme.lld(REG_PV, REG_PV, disp);
    asme.blr(REG_PV);
    emit_recompute_pv(cd);

    switch (md->returntype.type) {
    case TYPE_INT:
    case TYPE_LNG:
    case TYPE_ADR:
        asme.lld(REG_RESULT, REG_SP, syncslot_offset + 8);
        break;
    case TYPE_FLT:
    case TYPE_DBL:
        asme.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;
    codeinfo     *code;
    codegendata  *cd;
    registerdata *rd;
    methoddesc   *md;
    int32_t       stackframesize;
    s4            disp;
    s4            i, j, s;

    /* get required compiler data */

    m    = jd->m;
    code = jd->code;
    cd   = jd->cd;
    rd   = jd->rd;

    md = m->parseddesc;
    AsmEmitter asme(cd);

    /* mark trace code */

    asme.nop();

    stackframesize = ARG_CNT + TMP_CNT + md->paramcount + 1;
    stackframesize += stackframesize % 2;

    asme.lda(REG_SP, REG_SP, -(stackframesize * 8));
    asme.ast(REG_RA, REG_SP, 0 * 8);

    /* save all argument and temporary registers for leaf methods */

    if (code_is_leafmethod(code)) {
        j = 1 + md->paramcount;

        for (i = 0; i < INT_ARG_CNT; i++, j++)
            asme.lst(abi_registers_integer_argument[i], REG_SP, j * 8);

        for (i = 0; i < FLT_ARG_CNT; i++, j++)
            asme.dst(abi_registers_float_argument[i], REG_SP, j * 8);

        for (i = 0; i < INT_TMP_CNT; i++, j++)
            asme.lst(rd->tmpintregs[i], REG_SP, j * 8);

        for (i = 0; i < FLT_TMP_CNT; i++, j++)
            asme.dst(rd->tmpfltregs[i], REG_SP, j * 8);
    }

    /* 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:
                asme.lst(s, REG_SP, (1 + i) * 8);
                break;
            case TYPE_FLT:
            case TYPE_DBL:
                asme.dst(s, REG_SP, (1 + i) * 8);
                break;
            default:
                assert(false);
                break;
            }
        }
    }

    disp = dseg_add_address(cd, m);
    asme.lld(REG_A0, REG_PV, disp);
    asme.ladd_imm(REG_A1, REG_SP, 1 * 8);
    asme.lda(REG_A2, REG_SP, stackframesize * 8 + cd->stackframesize * 8);

    disp = dseg_add_functionptr(cd, trace_java_call_enter);
    asme.lld(REG_PV, REG_PV, disp);
    asme.blr(REG_PV);
    disp = (s4) (cd->mcodeptr - cd->mcodebase);
    asme.lda(REG_PV, REG_RA, -disp);
    asme.lld(REG_RA, REG_SP, 0 * 8);

    /* 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:
                asme.lld(s, REG_SP, (1 + i) * 8);
                break;
            case TYPE_FLT:
            case TYPE_DBL:
                asme.dld(s, REG_SP, (1 + i) * 8);
                break;
            default:
                assert(false);
                break;
            }
        }
    }

    /* restore all argument and temporary registers for leaf methods */

    if (code_is_leafmethod(code)) {
        j = 1 + md->paramcount;

        for (i = 0; i < INT_ARG_CNT; i++, j++)
            asme.lld(abi_registers_integer_argument[i], REG_SP, j * 8);

        for (i = 0; i < FLT_ARG_CNT; i++, j++)
            asme.dld(abi_registers_float_argument[i], REG_SP, j * 8);

        for (i = 0; i < INT_TMP_CNT; i++, j++)
            asme.lld(rd->tmpintregs[i], REG_SP, j * 8);

        for (i = 0; i < FLT_TMP_CNT; i++, j++)
            asme.dld(rd->tmpfltregs[i], REG_SP, j * 8);
    }

    asme.lda(REG_SP, REG_SP, stackframesize * 8);

    /* mark trace code */

    asme.nop();
}
#endif /* !defined(NDEBUG) */


/* 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;
    AsmEmitter asme(cd);

    /* mark trace code */

    asme.nop();

    asme.lsub_imm(REG_SP, REG_SP, 2 * 8);
    asme.lst(REG_RA, REG_SP, 0 * 8);

    /* save return value */

    switch (md->returntype.type) {
    case TYPE_ADR:
    case TYPE_INT:
    case TYPE_LNG:
        asme.lst(REG_RESULT, REG_SP, 1 * 8);
        break;
    case TYPE_FLT:
    case TYPE_DBL:
        asme.dst(REG_FRESULT, REG_SP, 1 * 8);
        break;
    case TYPE_VOID:
        break;
    default:
        assert(false);
        break;
    }

    disp = dseg_add_address(cd, m);
    asme.lld(REG_A0, REG_PV, disp);
    asme.ladd_imm(REG_A1, REG_SP, 1 * 8);

    disp = dseg_add_functionptr(cd, trace_java_call_exit);
    asme.lld(REG_PV, REG_PV, disp);
    asme.blr(REG_PV);
    disp = (cd->mcodeptr - cd->mcodebase);
    asme.lda(REG_PV, REG_RA, -disp);

    /* restore return value */

    switch (md->returntype.type) {
    case TYPE_ADR:
    case TYPE_INT:
    case TYPE_LNG:
        asme.lld(REG_RESULT, REG_SP, 1 * 8);
        break;
    case TYPE_FLT:
    case TYPE_DBL:
        asme.dld(REG_FRESULT, REG_SP, 1 * 8);
        break;
    case TYPE_VOID:
        break;
    default:
        assert(false);
        break;
    }

    asme.lld(REG_RA, REG_SP, 0 * 8);
    asme.ladd_imm(REG_SP, REG_SP, 2 * 8);

    /* mark trace code */

    asme.nop();
}
#endif /* !defined(NDEBUG) */


/*
 * 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:
 */