diff mbox series

[v2,06/29] target/riscv: Convert RVXI fence insns to decodetree

Message ID 20181020071451.27808-7-kbastian@mail.uni-paderborn.de
State New
Headers show
Series target/riscv: Convert to decodetree | expand

Commit Message

Bastian Koppelmann Oct. 20, 2018, 7:14 a.m. UTC
Signed-off-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Signed-off-by: Peer Adelt <peer.adelt@hni.uni-paderborn.de>
---
v1 -> v2:
    - simplified fence/fence_i as suggested by Richard

 target/riscv/insn32.decode              |  6 ++++++
 target/riscv/insn_trans/trans_rvi.inc.c | 20 ++++++++++++++++++++
 target/riscv/translate.c                | 14 --------------
 3 files changed, 26 insertions(+), 14 deletions(-)

Comments

Richard Henderson Oct. 21, 2018, 2:05 p.m. UTC | #1
On 10/20/18 8:14 AM, Bastian Koppelmann wrote:
> Signed-off-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
> Signed-off-by: Peer Adelt <peer.adelt@hni.uni-paderborn.de>
> ---
> v1 -> v2:
>     - simplified fence/fence_i as suggested by Richard
> 
>  target/riscv/insn32.decode              |  6 ++++++
>  target/riscv/insn_trans/trans_rvi.inc.c | 20 ++++++++++++++++++++
>  target/riscv/translate.c                | 14 --------------
>  3 files changed, 26 insertions(+), 14 deletions(-)
> 
> diff --git a/target/riscv/insn32.decode b/target/riscv/insn32.decode
> index cb7622e223..00e30dbc71 100644
> --- a/target/riscv/insn32.decode
> +++ b/target/riscv/insn32.decode
> @@ -24,6 +24,9 @@
>  %sh6    20:6
>  %sh5    20:5
>  
> +%pred   24:4
> +%succ   20:4

Unused.

> +static bool trans_fence(DisasContext *ctx, arg_fence *a, uint32_t insn)
> +{
> +#ifndef CONFIG_USER_ONLY
> +    /* FENCE is a full memory barrier. */
> +    tcg_gen_mb(TCG_MO_ALL | TCG_BAR_SC);
> +#endif
> +    return true;
> +}
> +static bool trans_fence_i(DisasContext *ctx, arg_fence_i *a, uint32_t insn)

Spacing.

> +{
> +#ifndef CONFIG_USER_ONLY
> +    /* FENCE_I is a no-op in QEMU,
> +     * however we need to end the translation block */
> +    tcg_gen_movi_tl(cpu_pc, ctx->pc_succ_insn);
> +    tcg_gen_exit_tb(NULL, 0);
> +    ctx->base.is_jmp = DISAS_NORETURN;
> +#endif
> +    return true;
> +}

I will note that both of these should apply to user-only as well...

> -    case OPC_RISC_FENCE:
> -#ifndef CONFIG_USER_ONLY
> -        if (ctx->opcode & 0x1000) {
> -            /* FENCE_I is a no-op in QEMU,
> -             * however we need to end the translation block */
> -            tcg_gen_movi_tl(cpu_pc, ctx->pc_succ_insn);
> -            tcg_gen_exit_tb(NULL, 0);
> -            ctx->base.is_jmp = DISAS_NORETURN;
> -        } else {
> -            /* FENCE is a full memory barrier. */
> -            tcg_gen_mb(TCG_MO_ALL | TCG_BAR_SC);
> -        }
> -#endif

... even though you're simply copying the bug.

I mentioned this twice during initial review of risc-v, but it seems to have
been missed during commit.

Also note that one can do better than TCG_MO_ALL by actually using the
pred/succ bits to select TCG_MO_{LD,ST}_{LD,ST}.

That said, no new bugs with this patch, so
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>


r~
diff mbox series

Patch

diff --git a/target/riscv/insn32.decode b/target/riscv/insn32.decode
index cb7622e223..00e30dbc71 100644
--- a/target/riscv/insn32.decode
+++ b/target/riscv/insn32.decode
@@ -24,6 +24,9 @@ 
 %sh6    20:6
 %sh5    20:5
 
+%pred   24:4
+%succ   20:4
+
 # immediates:
 %imm_i    20:s12
 %imm_s    25:s7 7:5
@@ -36,6 +39,7 @@ 
 &shift     shamt rs1 rd
 
 # Formats 32:
+
 @r       .......   ..... ..... ... ..... .......                   %rs2 %rs1 %rd
 @i       ............    ..... ... ..... .......         imm=%imm_i     %rs1 %rd
 @b       .......   ..... ..... ... ..... ....... &branch imm=%imm_b %rs2 %rs1
@@ -84,6 +88,8 @@  srl      0000000 .....    ..... 101 ..... 0110011 @r
 sra      0100000 .....    ..... 101 ..... 0110011 @r
 or       0000000 .....    ..... 110 ..... 0110011 @r
 and      0000000 .....    ..... 111 ..... 0110011 @r
+fence    ---- pred:4 succ:4 ----- 000 ----- 0001111
+fence_i  ---- ----   ----   ----- 001 ----- 0001111
 
 # *** RV64I Base Instruction Set (in addition to RV32I) ***
 lwu      ............   ..... 110 ..... 0000011 @i
diff --git a/target/riscv/insn_trans/trans_rvi.inc.c b/target/riscv/insn_trans/trans_rvi.inc.c
index e5a67e64cb..14164a952d 100644
--- a/target/riscv/insn_trans/trans_rvi.inc.c
+++ b/target/riscv/insn_trans/trans_rvi.inc.c
@@ -341,3 +341,23 @@  static bool trans_sraw(DisasContext *ctx, arg_sraw *a, uint32_t insn)
     gen_arith(ctx, OPC_RISC_SRAW, a->rd, a->rs1, a->rs2);
     return true;
 }
+
+static bool trans_fence(DisasContext *ctx, arg_fence *a, uint32_t insn)
+{
+#ifndef CONFIG_USER_ONLY
+    /* FENCE is a full memory barrier. */
+    tcg_gen_mb(TCG_MO_ALL | TCG_BAR_SC);
+#endif
+    return true;
+}
+static bool trans_fence_i(DisasContext *ctx, arg_fence_i *a, uint32_t insn)
+{
+#ifndef CONFIG_USER_ONLY
+    /* FENCE_I is a no-op in QEMU,
+     * however we need to end the translation block */
+    tcg_gen_movi_tl(cpu_pc, ctx->pc_succ_insn);
+    tcg_gen_exit_tb(NULL, 0);
+    ctx->base.is_jmp = DISAS_NORETURN;
+#endif
+    return true;
+}
diff --git a/target/riscv/translate.c b/target/riscv/translate.c
index 3e296a2627..f2567117b9 100644
--- a/target/riscv/translate.c
+++ b/target/riscv/translate.c
@@ -1740,20 +1740,6 @@  static void decode_RV32_64G(CPURISCVState *env, DisasContext *ctx)
         gen_fp_arith(ctx, MASK_OP_FP_ARITH(ctx->opcode), rd, rs1, rs2,
                      GET_RM(ctx->opcode));
         break;
-    case OPC_RISC_FENCE:
-#ifndef CONFIG_USER_ONLY
-        if (ctx->opcode & 0x1000) {
-            /* FENCE_I is a no-op in QEMU,
-             * however we need to end the translation block */
-            tcg_gen_movi_tl(cpu_pc, ctx->pc_succ_insn);
-            tcg_gen_exit_tb(NULL, 0);
-            ctx->base.is_jmp = DISAS_NORETURN;
-        } else {
-            /* FENCE is a full memory barrier. */
-            tcg_gen_mb(TCG_MO_ALL | TCG_BAR_SC);
-        }
-#endif
-        break;
     case OPC_RISC_SYSTEM:
         gen_system(env, ctx, MASK_OP_SYSTEM(ctx->opcode), rd, rs1,
                    (ctx->opcode & 0xFFF00000) >> 20);