Commit cedbcb01 authored by Emilio G. Cota's avatar Emilio G. Cota Committed by Richard Henderson
Browse files

tcg: Introduce goto_ptr opcode and tcg_gen_lookup_and_goto_ptr 



Instead of exporting goto_ptr directly to TCG frontends, export
tcg_gen_lookup_and_goto_ptr(), which calls goto_ptr with the pointer
returned by the lookup_tb_ptr() helper. This is the only use case
we have for goto_ptr and lookup_tb_ptr, so having this function is
very convenient. Furthermore, it trivially allows us to avoid calling
the lookup helper if goto_ptr is not implemented by the backend.

Reviewed-by: default avatarAlex Bennée <alex.bennee@linaro.org>
Signed-off-by: default avatarEmilio G. Cota <cota@braap.org>
Message-Id: <1493263764-18657-2-git-send-email-cota@braap.org>
Message-Id: <1493263764-18657-3-git-send-email-cota@braap.org>
Message-Id: <1493263764-18657-4-git-send-email-cota@braap.org>
Message-Id: <1493263764-18657-5-git-send-email-cota@braap.org>
[rth: Squashed 4 related commits.]
Signed-off-by: default avatarRichard Henderson <rth@twiddle.net>
parent 374aae65

cpu-exec.c

+2 −4
Original line number Diff line number Diff line
@@ -309,10 +309,8 @@ static bool tb_cmp(const void *p, const void *d) 
    return false;

}



static TranslationBlock *tb_htable_lookup(CPUState *cpu,

                                          target_ulong pc,

                                          target_ulong cs_base,

                                          uint32_t flags)

TranslationBlock *tb_htable_lookup(CPUState *cpu, target_ulong pc,

                                   target_ulong cs_base, uint32_t flags)

{

    tb_page_addr_t phys_pc;

    struct tb_desc desc;

include/exec/exec-all.h

+2 −0
Original line number Diff line number Diff line
@@ -368,6 +368,8 @@ struct TranslationBlock { 
void tb_free(TranslationBlock *tb);

void tb_flush(CPUState *cpu);

void tb_phys_invalidate(TranslationBlock *tb, tb_page_addr_t page_addr);

TranslationBlock *tb_htable_lookup(CPUState *cpu, target_ulong pc,

                                   target_ulong cs_base, uint32_t flags);



#if defined(USE_DIRECT_JUMP)

tcg-runtime.c

+32 −0
Original line number Diff line number Diff line
@@ -27,6 +27,9 @@ 
#include "exec/helper-proto.h"

#include "exec/cpu_ldst.h"

#include "exec/exec-all.h"

#include "exec/tb-hash.h"

#include "disas/disas.h"

#include "exec/log.h"



/* 32-bit helpers */
@@ -141,6 +144,35 @@ uint64_t HELPER(ctpop_i64)(uint64_t arg) 
    return ctpop64(arg);

}



void *HELPER(lookup_tb_ptr)(CPUArchState *env, target_ulong addr)

{

    CPUState *cpu = ENV_GET_CPU(env);

    TranslationBlock *tb;

    target_ulong cs_base, pc;

    uint32_t flags;



    tb = atomic_rcu_read(&cpu->tb_jmp_cache[tb_jmp_cache_hash_func(addr)]);

    if (likely(tb)) {

        cpu_get_tb_cpu_state(env, &pc, &cs_base, &flags);

        if (likely(tb->pc == addr && tb->cs_base == cs_base &&

                   tb->flags == flags)) {

            goto found;

        }

        tb = tb_htable_lookup(cpu, addr, cs_base, flags);

        if (likely(tb)) {

            atomic_set(&cpu->tb_jmp_cache[tb_jmp_cache_hash_func(addr)], tb);

            goto found;

        }

    }

    return tcg_ctx.code_gen_epilogue;

 found:

    qemu_log_mask_and_addr(CPU_LOG_EXEC, addr,

                           "Chain %p [%d: " TARGET_FMT_lx "] %s\n",

                           tb->tc_ptr, cpu->cpu_index, addr,

                           lookup_symbol(addr));

    return tb->tc_ptr;

}



void HELPER(exit_atomic)(CPUArchState *env)

{

    cpu_loop_exit_atomic(ENV_GET_CPU(env), GETPC());

tcg/README

+8 −0
Original line number Diff line number Diff line
@@ -477,6 +477,14 @@ current TB was linked to this TB. Otherwise execute the next 
instructions. Only indices 0 and 1 are valid and tcg_gen_goto_tb may be issued

at most once with each slot index per TB.



* lookup_and_goto_ptr tb_addr



Look up a TB address ('tb_addr') and jump to it if valid. If not valid,

jump to the TCG epilogue to go back to the exec loop.



This operation is optional. If the TCG backend does not implement the

goto_ptr opcode, emitting this op is equivalent to emitting exit_tb(0).



* qemu_ld_i32/i64 t0, t1, flags, memidx

* qemu_st_i32/i64 t0, t1, flags, memidx

tcg/aarch64/tcg-target.h

+1 −0
Original line number Diff line number Diff line
@@ -77,6 +77,7 @@ typedef enum { 
#define TCG_TARGET_HAS_mulsh_i32        0

#define TCG_TARGET_HAS_extrl_i64_i32    0

#define TCG_TARGET_HAS_extrh_i64_i32    0

#define TCG_TARGET_HAS_goto_ptr         0



#define TCG_TARGET_HAS_div_i64          1

#define TCG_TARGET_HAS_rem_i64          1