Re: [PATCH v4 06/36] tcg: Introduce tcg_target_call_oarg_reg

[Alex Bennée]

Richard Henderson <richard.henderson@linaro.org> writes:

> Replace the flat array tcg_target_call_oarg_regs[] with
> a function call including the TCGCallReturnKind.
>
> Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  tcg/tcg.c                        |  9 ++++++---
>  tcg/aarch64/tcg-target.c.inc     | 10 +++++++---
>  tcg/arm/tcg-target.c.inc         | 10 +++++++---
>  tcg/i386/tcg-target.c.inc        | 16 ++++++++++------
>  tcg/loongarch64/tcg-target.c.inc | 10 ++++++----
>  tcg/mips/tcg-target.c.inc        | 10 ++++++----
>  tcg/ppc/tcg-target.c.inc         | 10 ++++++----
>  tcg/riscv/tcg-target.c.inc       | 10 ++++++----
>  tcg/s390x/tcg-target.c.inc       |  9 ++++++---
>  tcg/sparc64/tcg-target.c.inc     | 12 ++++++------
>  tcg/tci/tcg-target.c.inc         | 12 ++++++------
>  11 files changed, 72 insertions(+), 46 deletions(-)
>
> diff --git a/tcg/tcg.c b/tcg/tcg.c
> index 93d1331f93..092cdaf422 100644
> --- a/tcg/tcg.c
> +++ b/tcg/tcg.c
> @@ -148,6 +148,7 @@ static bool tcg_out_sti(TCGContext *s, TCGType type, 
> TCGArg val,
>                          TCGReg base, intptr_t ofs);
>  static void tcg_out_call(TCGContext *s, const tcg_insn_unit *target,
>                           const TCGHelperInfo *info);
> +static TCGReg tcg_target_call_oarg_reg(TCGCallReturnKind kind, int slot);
>  static bool tcg_target_const_match(int64_t val, TCGType type, int ct);
>  #ifdef TCG_TARGET_NEED_LDST_LABELS
>  static int tcg_out_ldst_finalize(TCGContext *s);
> @@ -719,14 +720,16 @@ static void init_call_layout(TCGHelperInfo *info)
>      case dh_typecode_s64:
>          info->nr_out = 64 / TCG_TARGET_REG_BITS;
>          info->out_kind = TCG_CALL_RET_NORMAL;
> -        assert(info->nr_out <= ARRAY_SIZE(tcg_target_call_oarg_regs));
> +        /* Query the last register now to trigger any assert early. */
> +        tcg_target_call_oarg_reg(info->out_kind, info->nr_out - 1);
>          break;
>      case dh_typecode_i128:
>          info->nr_out = 128 / TCG_TARGET_REG_BITS;
>          info->out_kind = TCG_CALL_RET_NORMAL; /* TODO */
>          switch (/* TODO */ TCG_CALL_RET_NORMAL) {
>          case TCG_CALL_RET_NORMAL:
> -            assert(info->nr_out <= ARRAY_SIZE(tcg_target_call_oarg_regs));
> +            /* Query the last register now to trigger any assert early. */
> +            tcg_target_call_oarg_reg(info->out_kind, info->nr_out - 1);
>              break;
>          case TCG_CALL_RET_BY_REF:
>              /*
> @@ -4563,7 +4566,7 @@ static void tcg_reg_alloc_call(TCGContext *s, TCGOp *op)
>      case TCG_CALL_RET_NORMAL:
>          for (i = 0; i < nb_oargs; i++) {
>              TCGTemp *ts = arg_temp(op->args[i]);
> -            TCGReg reg = tcg_target_call_oarg_regs[i];
> +            TCGReg reg = tcg_target_call_oarg_reg(TCG_CALL_RET_NORMAL, i);
>  
>              /* ENV should not be modified.  */
>              tcg_debug_assert(!temp_readonly(ts));
> diff --git a/tcg/aarch64/tcg-target.c.inc b/tcg/aarch64/tcg-target.c.inc
> index 2279a14c11..dfe569dd8c 100644
> --- a/tcg/aarch64/tcg-target.c.inc
> +++ b/tcg/aarch64/tcg-target.c.inc
> @@ -63,9 +63,13 @@ static const int tcg_target_call_iarg_regs[8] = {
>      TCG_REG_X0, TCG_REG_X1, TCG_REG_X2, TCG_REG_X3,
>      TCG_REG_X4, TCG_REG_X5, TCG_REG_X6, TCG_REG_X7
>  };
> -static const int tcg_target_call_oarg_regs[1] = {
> -    TCG_REG_X0
> -};
> +
> +static TCGReg tcg_target_call_oarg_reg(TCGCallReturnKind kind, int slot)
> +{
> +    tcg_debug_assert(kind == TCG_CALL_RET_NORMAL);
> +    tcg_debug_assert(slot >= 0 && slot <= 1);
> +    return TCG_REG_X0 + slot;
> +}
>  
>  #define TCG_REG_TMP TCG_REG_X30
>  #define TCG_VEC_TMP TCG_REG_V31
> diff --git a/tcg/arm/tcg-target.c.inc b/tcg/arm/tcg-target.c.inc
> index 8b24481d8c..4e1d06dcd8 100644
> --- a/tcg/arm/tcg-target.c.inc
> +++ b/tcg/arm/tcg-target.c.inc
> @@ -79,9 +79,13 @@ static const int tcg_target_reg_alloc_order[] = {
>  static const int tcg_target_call_iarg_regs[4] = {
>      TCG_REG_R0, TCG_REG_R1, TCG_REG_R2, TCG_REG_R3
>  };
> -static const int tcg_target_call_oarg_regs[2] = {
> -    TCG_REG_R0, TCG_REG_R1
> -};
> +
> +static TCGReg tcg_target_call_oarg_reg(TCGCallReturnKind kind, int slot)
> +{
> +    tcg_debug_assert(kind == TCG_CALL_RET_NORMAL);
> +    tcg_debug_assert(slot >= 0 && slot <= 3);
> +    return TCG_REG_R0 + slot;
> +}

So this is now returning allocations of TCG_REG_R0 to TCG_REG_R3? Do we
have to take care to get things right if slot is ever bigger w.r.t.
tcg_target_reg_alloc_order?

>  
>  #define TCG_REG_TMP  TCG_REG_R12
>  #define TCG_VEC_TMP  TCG_REG_Q15
> diff --git a/tcg/i386/tcg-target.c.inc b/tcg/i386/tcg-target.c.inc
> index 6a021dda8b..ab6881a4f3 100644
> --- a/tcg/i386/tcg-target.c.inc
> +++ b/tcg/i386/tcg-target.c.inc
> @@ -109,12 +109,16 @@ static const int tcg_target_call_iarg_regs[] = {
>  #endif
>  };
>  
> -static const int tcg_target_call_oarg_regs[] = {
> -    TCG_REG_EAX,
> -#if TCG_TARGET_REG_BITS == 32
> -    TCG_REG_EDX
> -#endif
> -};
> +static TCGReg tcg_target_call_oarg_reg(TCGCallReturnKind kind, int slot)
> +{
> +    switch (kind) {
> +    case TCG_CALL_RET_NORMAL:
> +        tcg_debug_assert(slot >= 0 && slot <= 1);
> +        return slot ? TCG_REG_EDX : TCG_REG_EAX;
> +    default:
> +        g_assert_not_reached();
> +    }
> +}
>  
>  /* Constants we accept.  */
>  #define TCG_CT_CONST_S32 0x100
> diff --git a/tcg/loongarch64/tcg-target.c.inc 
> b/tcg/loongarch64/tcg-target.c.inc
> index 54b1dcd911..f6b0ed00bb 100644
> --- a/tcg/loongarch64/tcg-target.c.inc
> +++ b/tcg/loongarch64/tcg-target.c.inc
> @@ -114,10 +114,12 @@ static const int tcg_target_call_iarg_regs[] = {
>      TCG_REG_A7,
>  };
>  
> -static const int tcg_target_call_oarg_regs[] = {
> -    TCG_REG_A0,
> -    TCG_REG_A1,
> -};
> +static TCGReg tcg_target_call_oarg_reg(TCGCallReturnKind kind, int slot)
> +{
> +    tcg_debug_assert(kind == TCG_CALL_RET_NORMAL);
> +    tcg_debug_assert(slot >= 0 && slot <= 1);
> +    return TCG_REG_A0 + slot;
> +}
>  
>  #ifndef CONFIG_SOFTMMU
>  #define USE_GUEST_BASE     (guest_base != 0)
> diff --git a/tcg/mips/tcg-target.c.inc b/tcg/mips/tcg-target.c.inc
> index 22b5463f0f..92883176c6 100644
> --- a/tcg/mips/tcg-target.c.inc
> +++ b/tcg/mips/tcg-target.c.inc
> @@ -136,10 +136,12 @@ static const TCGReg tcg_target_call_iarg_regs[] = {
>  #endif
>  };
>  
> -static const TCGReg tcg_target_call_oarg_regs[2] = {
> -    TCG_REG_V0,
> -    TCG_REG_V1
> -};
> +static TCGReg tcg_target_call_oarg_reg(TCGCallReturnKind kind, int slot)
> +{
> +    tcg_debug_assert(kind == TCG_CALL_RET_NORMAL);
> +    tcg_debug_assert(slot >= 0 && slot <= 1);
> +    return TCG_REG_V0 + slot;
> +}
>  
>  static const tcg_insn_unit *tb_ret_addr;
>  static const tcg_insn_unit *bswap32_addr;
> diff --git a/tcg/ppc/tcg-target.c.inc b/tcg/ppc/tcg-target.c.inc
> index bf3812eb8d..d31e6c3de4 100644
> --- a/tcg/ppc/tcg-target.c.inc
> +++ b/tcg/ppc/tcg-target.c.inc
> @@ -186,10 +186,12 @@ static const int tcg_target_call_iarg_regs[] = {
>      TCG_REG_R10
>  };
>  
> -static const int tcg_target_call_oarg_regs[] = {
> -    TCG_REG_R3,
> -    TCG_REG_R4
> -};
> +static TCGReg tcg_target_call_oarg_reg(TCGCallReturnKind kind, int slot)
> +{
> +    tcg_debug_assert(kind == TCG_CALL_RET_NORMAL);
> +    tcg_debug_assert(slot >= 0 && slot <= 1);
> +    return TCG_REG_R3 + slot;
> +}
>  
>  static const int tcg_target_callee_save_regs[] = {
>  #ifdef _CALL_DARWIN
> diff --git a/tcg/riscv/tcg-target.c.inc b/tcg/riscv/tcg-target.c.inc
> index b961972b9f..7cfd35e753 100644
> --- a/tcg/riscv/tcg-target.c.inc
> +++ b/tcg/riscv/tcg-target.c.inc
> @@ -113,10 +113,12 @@ static const int tcg_target_call_iarg_regs[] = {
>      TCG_REG_A7,
>  };
>  
> -static const int tcg_target_call_oarg_regs[] = {
> -    TCG_REG_A0,
> -    TCG_REG_A1,
> -};
> +static TCGReg tcg_target_call_oarg_reg(TCGCallReturnKind kind, int slot)
> +{
> +    tcg_debug_assert(kind == TCG_CALL_RET_NORMAL);
> +    tcg_debug_assert(slot >= 0 && slot <= 1);
> +    return TCG_REG_A0 + slot;
> +}
>  
>  #define TCG_CT_CONST_ZERO  0x100
>  #define TCG_CT_CONST_S12   0x200
> diff --git a/tcg/s390x/tcg-target.c.inc b/tcg/s390x/tcg-target.c.inc
> index d65cd79899..cebf180777 100644
> --- a/tcg/s390x/tcg-target.c.inc
> +++ b/tcg/s390x/tcg-target.c.inc
> @@ -390,9 +390,12 @@ static const int tcg_target_call_iarg_regs[] = {
>      TCG_REG_R6,
>  };
>  
> -static const int tcg_target_call_oarg_regs[] = {
> -    TCG_REG_R2,
> -};
> +static TCGReg tcg_target_call_oarg_reg(TCGCallReturnKind kind, int slot)
> +{
> +    tcg_debug_assert(kind == TCG_CALL_RET_NORMAL);
> +    tcg_debug_assert(slot == 0);
> +    return TCG_REG_R2;
> +}
>  
>  #define S390_CC_EQ      8
>  #define S390_CC_LT      4
> diff --git a/tcg/sparc64/tcg-target.c.inc b/tcg/sparc64/tcg-target.c.inc
> index f6a8a8e605..9b5afb8248 100644
> --- a/tcg/sparc64/tcg-target.c.inc
> +++ b/tcg/sparc64/tcg-target.c.inc
> @@ -133,12 +133,12 @@ static const int tcg_target_call_iarg_regs[6] = {
>      TCG_REG_O5,
>  };
>  
> -static const int tcg_target_call_oarg_regs[] = {
> -    TCG_REG_O0,
> -    TCG_REG_O1,
> -    TCG_REG_O2,
> -    TCG_REG_O3,
> -};
> +static TCGReg tcg_target_call_oarg_reg(TCGCallReturnKind kind, int slot)
> +{
> +    tcg_debug_assert(kind == TCG_CALL_RET_NORMAL);
> +    tcg_debug_assert(slot >= 0 && slot <= 3);
> +    return TCG_REG_O0 + slot;
> +}
>  
>  #define INSN_OP(x)  ((x) << 30)
>  #define INSN_OP2(x) ((x) << 22)
> diff --git a/tcg/tci/tcg-target.c.inc b/tcg/tci/tcg-target.c.inc
> index 633345d74b..cd53cb6b6b 100644
> --- a/tcg/tci/tcg-target.c.inc
> +++ b/tcg/tci/tcg-target.c.inc
> @@ -200,12 +200,12 @@ static const int tcg_target_reg_alloc_order[] = {
>  /* No call arguments via registers.  All will be stored on the "stack". */
>  static const int tcg_target_call_iarg_regs[] = { };
>  
> -static const int tcg_target_call_oarg_regs[] = {
> -    TCG_REG_R0,
> -#if TCG_TARGET_REG_BITS == 32
> -    TCG_REG_R1
> -#endif
> -};
> +static TCGReg tcg_target_call_oarg_reg(TCGCallReturnKind kind, int slot)
> +{
> +    tcg_debug_assert(kind == TCG_CALL_RET_NORMAL);
> +    tcg_debug_assert(slot >= 0 && slot < 64 / TCG_TARGET_REG_BITS);
> +    return TCG_REG_R0 + slot;
> +}
>  
>  #ifdef CONFIG_DEBUG_TCG
>  static const char *const tcg_target_reg_names[TCG_TARGET_NB_REGS] = {

Otherwise:

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

-- 
Alex Bennée
Virtualisation Tech Lead @ Linaro