Commit d4881da9 authored by Bastian Koppelmann's avatar Bastian Koppelmann
Browse files

target/tricore: Fix tricore_tr_translate_insn 



we now fetch 2 bytes first, check whether we have a 32 bit insn, and only then
fetch another 2 bytes. We also make sure that a 16 bit insn that still fits
into the current page does not end up in the next page.

Reviewed-by: default avatarRichard Henderson <richard.henderson@linaro.org>
Signed-off-by: default avatarBastian Koppelmann <kbastian@mail.uni-paderborn.de>
parent 17ebc8c1

target/tricore/translate.c

+34 −13
Original line number Diff line number Diff line
@@ -8781,17 +8781,9 @@ static void decode_32Bit_opc(DisasContext *ctx) 
    }

}



static void decode_opc(DisasContext *ctx)

static bool tricore_insn_is_16bit(uint32_t insn)

{

    /* 16-Bit Instruction */

    if ((ctx->opcode & 0x1) == 0) {

        ctx->pc_succ_insn = ctx->base.pc_next + 2;

        decode_16Bit_opc(ctx);

    /* 32-Bit Instruction */

    } else {

        ctx->pc_succ_insn = ctx->base.pc_next + 4;

        decode_32Bit_opc(ctx);

    }

    return (insn & 0x1) == 0;

}



static void tricore_tr_init_disas_context(DisasContextBase *dcbase,
@@ -8829,20 +8821,49 @@ static bool tricore_tr_breakpoint_check(DisasContextBase *dcbase, CPUState *cpu, 
    return true;

}



static bool insn_crosses_page(CPUTriCoreState *env, DisasContext *ctx)

{

    /*

     * Return true if the insn at ctx->base.pc_next might cross a page boundary.

     * (False positives are OK, false negatives are not.)

     * Our caller ensures we are only called if dc->base.pc_next is less than

     * 4 bytes from the page boundary, so we cross the page if the first

     * 16 bits indicate that this is a 32 bit insn.

     */

    uint16_t insn = cpu_lduw_code(env, ctx->base.pc_next);



    return !tricore_insn_is_16bit(insn);

}





static void tricore_tr_translate_insn(DisasContextBase *dcbase, CPUState *cpu)

{

    DisasContext *ctx = container_of(dcbase, DisasContext, base);

    CPUTriCoreState *env = cpu->env_ptr;

    uint16_t insn_lo;

    bool is_16bit;



    ctx->opcode = cpu_ldl_code(env, ctx->base.pc_next);

    decode_opc(ctx);

    insn_lo = cpu_lduw_code(env, ctx->base.pc_next);

    is_16bit = tricore_insn_is_16bit(insn_lo);

    if (is_16bit) {

        ctx->opcode = insn_lo;

        ctx->pc_succ_insn = ctx->base.pc_next + 2;

        decode_16Bit_opc(ctx);

    } else {

        uint32_t insn_hi = cpu_lduw_code(env, ctx->base.pc_next + 2);

        ctx->opcode = insn_hi << 16 | insn_lo;

        ctx->pc_succ_insn = ctx->base.pc_next + 4;

        decode_32Bit_opc(ctx);

    }

    ctx->base.pc_next = ctx->pc_succ_insn;



    if (ctx->base.is_jmp == DISAS_NEXT) {

        target_ulong page_start;



        page_start = ctx->base.pc_first & TARGET_PAGE_MASK;

        if (ctx->base.pc_next - page_start >= TARGET_PAGE_SIZE) {

        if (ctx->base.pc_next - page_start >= TARGET_PAGE_SIZE

            || (ctx->base.pc_next - page_start >= TARGET_PAGE_SIZE - 3

                && insn_crosses_page(env, ctx))) {

            ctx->base.is_jmp = DISAS_TOO_MANY;

        }

    }