[PATCH] RISC-V: XTheadMemPair: Remove register restrictions for store-pair

Christoph Muellner posted 1 patch 1 year, 2 months ago
Patches applied successfully (tree, apply log)
git fetch https://github.com/patchew-project/qemu tags/patchew/20230220095612.1529031-1-christoph.muellner@vrull.eu
Maintainers: Christoph Muellner <christoph.muellner@vrull.eu>, LIU Zhiwei <zhiwei_liu@linux.alibaba.com>, Palmer Dabbelt <palmer@dabbelt.com>, Alistair Francis <alistair.francis@wdc.com>, Bin Meng <bin.meng@windriver.com>
target/riscv/insn_trans/trans_xthead.c.inc | 4 ----
1 file changed, 4 deletions(-)
[PATCH] RISC-V: XTheadMemPair: Remove register restrictions for store-pair
Posted by Christoph Muellner 1 year, 2 months ago
From: Christoph Müllner <christoph.muellner@vrull.eu>

The XTheadMemPair does not define any restrictions for store-pair
instructions (th.sdd or th.swd). However, the current code enforces
the restrictions that are required for load-pair instructions.
Let's fix this by removing this code.

Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
---
 target/riscv/insn_trans/trans_xthead.c.inc | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/target/riscv/insn_trans/trans_xthead.c.inc b/target/riscv/insn_trans/trans_xthead.c.inc
index be87c34f56..cf1731b08d 100644
--- a/target/riscv/insn_trans/trans_xthead.c.inc
+++ b/target/riscv/insn_trans/trans_xthead.c.inc
@@ -980,10 +980,6 @@ static bool trans_th_lwud(DisasContext *ctx, arg_th_pair *a)
 static bool gen_storepair_tl(DisasContext *ctx, arg_th_pair *a, MemOp memop,
                              int shamt)
 {
-    if (a->rs == a->rd1 || a->rs == a->rd2 || a->rd1 == a->rd2) {
-        return false;
-    }
-
     TCGv data1 = get_gpr(ctx, a->rd1, EXT_NONE);
     TCGv data2 = get_gpr(ctx, a->rd2, EXT_NONE);
     TCGv addr1 = tcg_temp_new();
-- 
2.39.2


Re: [PATCH] RISC-V: XTheadMemPair: Remove register restrictions for store-pair
Posted by Palmer Dabbelt 1 year, 1 month ago
On Mon, 20 Feb 2023 01:56:12 PST (-0800), christoph.muellner@vrull.eu wrote:
> From: Christoph Müllner <christoph.muellner@vrull.eu>
>
> The XTheadMemPair does not define any restrictions for store-pair
> instructions (th.sdd or th.swd). However, the current code enforces
> the restrictions that are required for load-pair instructions.
> Let's fix this by removing this code.
>
> Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
> ---
>  target/riscv/insn_trans/trans_xthead.c.inc | 4 ----
>  1 file changed, 4 deletions(-)
>
> diff --git a/target/riscv/insn_trans/trans_xthead.c.inc b/target/riscv/insn_trans/trans_xthead.c.inc
> index be87c34f56..cf1731b08d 100644
> --- a/target/riscv/insn_trans/trans_xthead.c.inc
> +++ b/target/riscv/insn_trans/trans_xthead.c.inc
> @@ -980,10 +980,6 @@ static bool trans_th_lwud(DisasContext *ctx, arg_th_pair *a)
>  static bool gen_storepair_tl(DisasContext *ctx, arg_th_pair *a, MemOp memop,
>                               int shamt)
>  {
> -    if (a->rs == a->rd1 || a->rs == a->rd2 || a->rd1 == a->rd2) {
> -        return false;
> -    }
> -
>      TCGv data1 = get_gpr(ctx, a->rd1, EXT_NONE);
>      TCGv data2 = get_gpr(ctx, a->rd2, EXT_NONE);
>      TCGv addr1 = tcg_temp_new();

Thanks, this is queued in riscv-to-apply.next .

Re: [PATCH] RISC-V: XTheadMemPair: Remove register restrictions for store-pair
Posted by LIU Zhiwei 1 year, 2 months ago
On 2023/2/20 17:56, Christoph Muellner wrote:
> From: Christoph Müllner <christoph.muellner@vrull.eu>
>
> The XTheadMemPair does not define any restrictions for store-pair
> instructions (th.sdd or th.swd). However, the current code enforces
> the restrictions that are required for load-pair instructions.
> Let's fix this by removing this code.
>
> Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
> ---
>   target/riscv/insn_trans/trans_xthead.c.inc | 4 ----
>   1 file changed, 4 deletions(-)
>
> diff --git a/target/riscv/insn_trans/trans_xthead.c.inc b/target/riscv/insn_trans/trans_xthead.c.inc
> index be87c34f56..cf1731b08d 100644
> --- a/target/riscv/insn_trans/trans_xthead.c.inc
> +++ b/target/riscv/insn_trans/trans_xthead.c.inc
> @@ -980,10 +980,6 @@ static bool trans_th_lwud(DisasContext *ctx, arg_th_pair *a)
>   static bool gen_storepair_tl(DisasContext *ctx, arg_th_pair *a, MemOp memop,
>                                int shamt)
>   {
> -    if (a->rs == a->rd1 || a->rs == a->rd2 || a->rd1 == a->rd2) {
> -        return false;
> -    }
> -

Reviewed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>

Zhiwei

>       TCGv data1 = get_gpr(ctx, a->rd1, EXT_NONE);
>       TCGv data2 = get_gpr(ctx, a->rd2, EXT_NONE);
>       TCGv addr1 = tcg_temp_new();