Re: [PATCH v4 36/43] tcg/riscv: Support split-wx code generation

[Alistair Francis]

On Mon, Dec 14, 2020 at 6:13 AM Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

Alistair

> ---
>  tcg/riscv/tcg-target.h     |  2 +-
>  tcg/riscv/tcg-target.c.inc | 41 +++++++++++++++++++++-----------------
>  2 files changed, 24 insertions(+), 19 deletions(-)
>
> diff --git a/tcg/riscv/tcg-target.h b/tcg/riscv/tcg-target.h
> index 785fe37f9b..60b6a1a3fc 100644
> --- a/tcg/riscv/tcg-target.h
> +++ b/tcg/riscv/tcg-target.h
> @@ -170,6 +170,6 @@ void tb_target_set_jmp_target(uintptr_t, uintptr_t, 
> uintptr_t, uintptr_t);
>  #define TCG_TARGET_NEED_POOL_LABELS
>
>  #define TCG_TARGET_HAS_MEMORY_BSWAP 0
> -#define TCG_TARGET_SUPPORT_MIRROR   0
> +#define TCG_TARGET_SUPPORT_MIRROR   1
>
>  #endif
> diff --git a/tcg/riscv/tcg-target.c.inc b/tcg/riscv/tcg-target.c.inc
> index 02beb86977..5c1e0f8fc1 100644
> --- a/tcg/riscv/tcg-target.c.inc
> +++ b/tcg/riscv/tcg-target.c.inc
> @@ -425,41 +425,44 @@ static void tcg_out_nop_fill(tcg_insn_unit *p, int 
> count)
>   * Relocations
>   */
>
> -static bool reloc_sbimm12(tcg_insn_unit *code_ptr, tcg_insn_unit *target)
> +static bool reloc_sbimm12(tcg_insn_unit *src_rw, const tcg_insn_unit *target)
>  {
> -    intptr_t offset = (intptr_t)target - (intptr_t)code_ptr;
> +    const tcg_insn_unit *src_rx = tcg_splitwx_to_rx(src_rw);
> +    intptr_t offset = (intptr_t)target - (intptr_t)src_rx;
>
>      tcg_debug_assert((offset & 1) == 0);
>      if (offset == sextreg(offset, 0, 12)) {
> -        code_ptr[0] |= encode_sbimm12(offset);
> +        *src_rw |= encode_sbimm12(offset);
>          return true;
>      }
>
>      return false;
>  }
>
> -static bool reloc_jimm20(tcg_insn_unit *code_ptr, tcg_insn_unit *target)
> +static bool reloc_jimm20(tcg_insn_unit *src_rw, const tcg_insn_unit *target)
>  {
> -    intptr_t offset = (intptr_t)target - (intptr_t)code_ptr;
> +    const tcg_insn_unit *src_rx = tcg_splitwx_to_rx(src_rw);
> +    intptr_t offset = (intptr_t)target - (intptr_t)src_rx;
>
>      tcg_debug_assert((offset & 1) == 0);
>      if (offset == sextreg(offset, 0, 20)) {
> -        code_ptr[0] |= encode_ujimm20(offset);
> +        *src_rw |= encode_ujimm20(offset);
>          return true;
>      }
>
>      return false;
>  }
>
> -static bool reloc_call(tcg_insn_unit *code_ptr, const tcg_insn_unit *target)
> +static bool reloc_call(tcg_insn_unit *src_rw, const tcg_insn_unit *target)
>  {
> -    intptr_t offset = (intptr_t)target - (intptr_t)code_ptr;
> +    const tcg_insn_unit *src_rx = tcg_splitwx_to_rx(src_rw);
> +    intptr_t offset = (intptr_t)target - (intptr_t)src_rx;
>      int32_t lo = sextreg(offset, 0, 12);
>      int32_t hi = offset - lo;
>
>      if (offset == hi + lo) {
> -        code_ptr[0] |= encode_uimm20(hi);
> -        code_ptr[1] |= encode_imm12(lo);
> +        src_rw[0] |= encode_uimm20(hi);
> +        src_rw[1] |= encode_imm12(lo);
>          return true;
>      }
>
> @@ -532,7 +535,7 @@ static void tcg_out_movi(TCGContext *s, TCGType type, 
> TCGReg rd,
>      if (tmp == (int32_t)tmp) {
>          tcg_out_opc_upper(s, OPC_AUIPC, rd, 0);
>          tcg_out_opc_imm(s, OPC_ADDI, rd, rd, 0);
> -        ret = reloc_call(s->code_ptr - 2, (tcg_insn_unit *)val);
> +        ret = reloc_call(s->code_ptr - 2, (const tcg_insn_unit *)val);
>          tcg_debug_assert(ret == true);
>          return;
>      }
> @@ -917,7 +920,7 @@ QEMU_BUILD_BUG_ON(TCG_TARGET_REG_BITS < TARGET_LONG_BITS);
>  QEMU_BUILD_BUG_ON(TLB_MASK_TABLE_OFS(0) > 0);
>  QEMU_BUILD_BUG_ON(TLB_MASK_TABLE_OFS(0) < -(1 << 11));
>
> -static void tcg_out_goto(TCGContext *s, tcg_insn_unit *target)
> +static void tcg_out_goto(TCGContext *s, const tcg_insn_unit *target)
>  {
>      tcg_out_opc_jump(s, OPC_JAL, TCG_REG_ZERO, 0);
>      bool ok = reloc_jimm20(s->code_ptr - 1, target);
> @@ -993,7 +996,8 @@ static void add_qemu_ldst_label(TCGContext *s, int is_ld, 
> TCGMemOpIdx oi,
>      label->datahi_reg = datahi;
>      label->addrlo_reg = addrlo;
>      label->addrhi_reg = addrhi;
> -    label->raddr = raddr;
> +    /* TODO: Cast goes away when all hosts converted */
> +    label->raddr = (void *)tcg_splitwx_to_rx(raddr);
>      label->label_ptr[0] = label_ptr[0];
>  }
>
> @@ -1012,7 +1016,7 @@ static bool tcg_out_qemu_ld_slow_path(TCGContext *s, 
> TCGLabelQemuLdst *l)
>      }
>
>      /* resolve label address */
> -    if (!reloc_sbimm12(l->label_ptr[0], s->code_ptr)) {
> +    if (!reloc_sbimm12(l->label_ptr[0], tcg_splitwx_to_rx(s->code_ptr))) {
>          return false;
>      }
>
> @@ -1046,7 +1050,7 @@ static bool tcg_out_qemu_st_slow_path(TCGContext *s, 
> TCGLabelQemuLdst *l)
>      }
>
>      /* resolve label address */
> -    if (!reloc_sbimm12(l->label_ptr[0], s->code_ptr)) {
> +    if (!reloc_sbimm12(l->label_ptr[0], tcg_splitwx_to_rx(s->code_ptr))) {
>          return false;
>      }
>
> @@ -1232,7 +1236,7 @@ static void tcg_out_qemu_st(TCGContext *s, const TCGArg 
> *args, bool is_64)
>  #endif
>  }
>
> -static tcg_insn_unit *tb_ret_addr;
> +static const tcg_insn_unit *tb_ret_addr;
>
>  static void tcg_out_op(TCGContext *s, TCGOpcode opc,
>                         const TCGArg *args, const int *const_args)
> @@ -1780,11 +1784,12 @@ static void tcg_target_qemu_prologue(TCGContext *s)
>      tcg_out_opc_imm(s, OPC_JALR, TCG_REG_ZERO, tcg_target_call_iarg_regs[1], 
> 0);
>
>      /* Return path for goto_ptr. Set return value to 0 */
> -    tcg_code_gen_epilogue = s->code_ptr;
> +    /* TODO: Cast goes away when all hosts converted */
> +    tcg_code_gen_epilogue = (void *)tcg_splitwx_to_rx(s->code_ptr);
>      tcg_out_mov(s, TCG_TYPE_REG, TCG_REG_A0, TCG_REG_ZERO);
>
>      /* TB epilogue */
> -    tb_ret_addr = s->code_ptr;
> +    tb_ret_addr = tcg_splitwx_to_rx(s->code_ptr);
>      for (i = 0; i < ARRAY_SIZE(tcg_target_callee_save_regs); i++) {
>          tcg_out_ld(s, TCG_TYPE_REG, tcg_target_callee_save_regs[i],
>                     TCG_REG_SP, SAVE_OFS + i * REG_SIZE);
> --
> 2.25.1
>
>