[PATCH v2 13/14] tcg/riscv: Implement vector roti/v/x shi ops

LIU Zhiwei posted 14 patches 2 months, 3 weeks ago
There is a newer version of this series
[PATCH v2 13/14] tcg/riscv: Implement vector roti/v/x shi ops
Posted by LIU Zhiwei 2 months, 3 weeks ago
From: TANG Tiancheng <tangtiancheng.ttc@alibaba-inc.com>

Signed-off-by: TANG Tiancheng <tangtiancheng.ttc@alibaba-inc.com>
Reviewed-by: Liu Zhiwei <zhiwei_liu@linux.alibaba.com>
---
 tcg/riscv/tcg-target.c.inc | 98 +++++++++++++++++++++++++++++++++++++-
 tcg/riscv/tcg-target.h     |  8 ++--
 tcg/riscv/tcg-target.opc.h |  3 ++
 3 files changed, 104 insertions(+), 5 deletions(-)

diff --git a/tcg/riscv/tcg-target.c.inc b/tcg/riscv/tcg-target.c.inc
index 31e161c5bc..6560d3381a 100644
--- a/tcg/riscv/tcg-target.c.inc
+++ b/tcg/riscv/tcg-target.c.inc
@@ -358,10 +358,13 @@ typedef enum {
     OPC_VMSGT_VX = 0x7c000057 | V_OPIVX,
 
     OPC_VSLL_VV = 0x94000057 | V_OPIVV,
+    OPC_VSLL_VI = 0x94000057 | V_OPIVI,
     OPC_VSLL_VX = 0x94000057 | V_OPIVX,
     OPC_VSRL_VV = 0xa0000057 | V_OPIVV,
+    OPC_VSRL_VI = 0xa0000057 | V_OPIVI,
     OPC_VSRL_VX = 0xa0000057 | V_OPIVX,
     OPC_VSRA_VV = 0xa4000057 | V_OPIVV,
+    OPC_VSRA_VI = 0xa4000057 | V_OPIVI,
     OPC_VSRA_VX = 0xa4000057 | V_OPIVX,
 
     OPC_VMV_V_V = 0x5e000057 | V_OPIVV,
@@ -2477,6 +2480,18 @@ static void tcg_out_vec_op(TCGContext *s, TCGOpcode opc,
         riscv_set_vec_config_vl_vece(s, type, vece);
         tcg_out_opc_vv(s, OPC_VSRA_VV, a0, a1, a2, true);
         break;
+    case INDEX_op_rvv_shli_vec:
+        riscv_set_vec_config_vl_vece(s, type, vece);
+        tcg_out_opc_vi(s, OPC_VSLL_VI, a0, a1, a2, true);
+        break;
+    case INDEX_op_rvv_shri_vec:
+        riscv_set_vec_config_vl_vece(s, type, vece);
+        tcg_out_opc_vi(s, OPC_VSRL_VI, a0, a1, a2, true);
+        break;
+    case INDEX_op_rvv_sari_vec:
+        riscv_set_vec_config_vl_vece(s, type, vece);
+        tcg_out_opc_vi(s, OPC_VSRA_VI, a0, a1, a2, true);
+        break;
     case INDEX_op_rvv_cmp_vx:
         riscv_set_vec_config_vl_vece(s, type, vece);
         tcg_out_cmp_vec_vx(s, a2, a0, a1);
@@ -2561,7 +2576,8 @@ void tcg_expand_vec_op(TCGOpcode opc, TCGType type, unsigned vece,
                        TCGArg a0, ...)
 {
     va_list va;
-    TCGv_vec v0, v1;
+    TCGv_vec v0, v1, v2, t1;
+    TCGv_i32 t2;
     TCGArg a2, a3;
 
     va_start(va, a0);
@@ -2589,6 +2605,69 @@ void tcg_expand_vec_op(TCGOpcode opc, TCGType type, unsigned vece,
             }
         }
         break;
+    case INDEX_op_shli_vec:
+        if (a2 > 31) {
+            tcg_gen_shls_vec(vece, v0, v1, tcg_constant_i32(a2));
+        } else {
+            vec_gen_3(INDEX_op_rvv_shli_vec, type, vece, tcgv_vec_arg(v0),
+                      tcgv_vec_arg(v1), a2);
+        }
+        break;
+    case INDEX_op_shri_vec:
+        if (a2 > 31) {
+            tcg_gen_shrs_vec(vece, v0, v1, tcg_constant_i32(a2));
+        } else {
+            vec_gen_3(INDEX_op_rvv_shri_vec, type, vece, tcgv_vec_arg(v0),
+                      tcgv_vec_arg(v1), a2);
+        }
+        break;
+    case INDEX_op_sari_vec:
+        if (a2 > 31) {
+            tcg_gen_sars_vec(vece, v0, v1, tcg_constant_i32(a2));
+        } else {
+            vec_gen_3(INDEX_op_rvv_sari_vec, type, vece, tcgv_vec_arg(v0),
+                      tcgv_vec_arg(v1), a2);
+        }
+        break;
+    case INDEX_op_rotli_vec:
+        t1 = tcg_temp_new_vec(type);
+        tcg_gen_shli_vec(vece, t1, v1, a2);
+        tcg_gen_shri_vec(vece, v0, v1, (8 << vece) - a2);
+        tcg_gen_or_vec(vece, v0, v0, t1);
+        tcg_temp_free_vec(t1);
+        break;
+    case INDEX_op_rotls_vec:
+        t1 = tcg_temp_new_vec(type);
+        t2 = tcg_temp_new_i32();
+        tcg_gen_neg_i32(t2, temp_tcgv_i32(arg_temp(a2)));
+        tcg_gen_shrs_vec(vece, v0, v1, t2);
+        tcg_gen_shls_vec(vece, t1, v1, temp_tcgv_i32(arg_temp(a2)));
+        tcg_gen_or_vec(vece, v0, v0, t1);
+        tcg_temp_free_vec(t1);
+        tcg_temp_free_i32(t2);
+        break;
+    case INDEX_op_rotlv_vec:
+        v2 = temp_tcgv_vec(arg_temp(a2));
+        t1 = tcg_temp_new_vec(type);
+        tcg_gen_neg_vec(vece, t1, v2);
+        vec_gen_3(INDEX_op_shrv_vec, type, vece, tcgv_vec_arg(t1),
+                  tcgv_vec_arg(v1), tcgv_vec_arg(t1));
+        vec_gen_3(INDEX_op_shlv_vec, type, vece, tcgv_vec_arg(v0),
+                  tcgv_vec_arg(v1), tcgv_vec_arg(v2));
+        tcg_gen_or_vec(vece, v0, v0, t1);
+        tcg_temp_free_vec(t1);
+        break;
+    case INDEX_op_rotrv_vec:
+        v2 = temp_tcgv_vec(arg_temp(a2));
+        t1 = tcg_temp_new_vec(type);
+        tcg_gen_neg_vec(vece, t1, v2);
+        vec_gen_3(INDEX_op_shlv_vec, type, vece, tcgv_vec_arg(t1),
+                  tcgv_vec_arg(v1), tcgv_vec_arg(t1));
+        vec_gen_3(INDEX_op_shrv_vec, type, vece, tcgv_vec_arg(v0),
+                  tcgv_vec_arg(v1), tcgv_vec_arg(v2));
+        tcg_gen_or_vec(vece, v0, v0, t1);
+        tcg_temp_free_vec(t1);
+        break;
     default:
         g_assert_not_reached();
     }
@@ -2622,6 +2701,13 @@ int tcg_can_emit_vec_op(TCGOpcode opc, TCGType type, unsigned vece)
     case INDEX_op_sarv_vec:
         return 1;
     case INDEX_op_cmp_vec:
+    case INDEX_op_shri_vec:
+    case INDEX_op_shli_vec:
+    case INDEX_op_sari_vec:
+    case INDEX_op_rotls_vec:
+    case INDEX_op_rotlv_vec:
+    case INDEX_op_rotrv_vec:
+    case INDEX_op_rotli_vec:
         return -1;
     default:
         return 0;
@@ -2775,6 +2861,13 @@ static TCGConstraintSetIndex tcg_target_op_def(TCGOpcode op)
         return C_O1_I1(v, r);
     case INDEX_op_neg_vec:
     case INDEX_op_not_vec:
+    case INDEX_op_rotli_vec:
+    case INDEX_op_shli_vec:
+    case INDEX_op_shri_vec:
+    case INDEX_op_sari_vec:
+    case INDEX_op_rvv_shli_vec:
+    case INDEX_op_rvv_shri_vec:
+    case INDEX_op_rvv_sari_vec:
         return C_O1_I1(v, v);
     case INDEX_op_add_vec:
     case INDEX_op_sub_vec:
@@ -2793,10 +2886,13 @@ static TCGConstraintSetIndex tcg_target_op_def(TCGOpcode op)
     case INDEX_op_shlv_vec:
     case INDEX_op_shrv_vec:
     case INDEX_op_sarv_vec:
+    case INDEX_op_rotlv_vec:
+    case INDEX_op_rotrv_vec:
         return C_O1_I2(v, v, v);
     case INDEX_op_shls_vec:
     case INDEX_op_shrs_vec:
     case INDEX_op_sars_vec:
+    case INDEX_op_rotls_vec:
         return C_O1_I2(v, v, r);
     case INDEX_op_rvv_merge_vec:
         return C_O1_I2(v, v, vK);
diff --git a/tcg/riscv/tcg-target.h b/tcg/riscv/tcg-target.h
index 41c6c446e8..eb5129a976 100644
--- a/tcg/riscv/tcg-target.h
+++ b/tcg/riscv/tcg-target.h
@@ -154,10 +154,10 @@ typedef enum {
 #define TCG_TARGET_HAS_not_vec          1
 #define TCG_TARGET_HAS_neg_vec          1
 #define TCG_TARGET_HAS_abs_vec          0
-#define TCG_TARGET_HAS_roti_vec         0
-#define TCG_TARGET_HAS_rots_vec         0
-#define TCG_TARGET_HAS_rotv_vec         0
-#define TCG_TARGET_HAS_shi_vec          0
+#define TCG_TARGET_HAS_roti_vec         -1
+#define TCG_TARGET_HAS_rots_vec         -1
+#define TCG_TARGET_HAS_rotv_vec         -1
+#define TCG_TARGET_HAS_shi_vec          -1
 #define TCG_TARGET_HAS_shs_vec          1
 #define TCG_TARGET_HAS_shv_vec          1
 #define TCG_TARGET_HAS_mul_vec          1
diff --git a/tcg/riscv/tcg-target.opc.h b/tcg/riscv/tcg-target.opc.h
index 8eb0daf0a7..9f31286025 100644
--- a/tcg/riscv/tcg-target.opc.h
+++ b/tcg/riscv/tcg-target.opc.h
@@ -15,3 +15,6 @@ DEF(rvv_cmp_vi, 0, 1, 2, IMPLVEC)
 DEF(rvv_cmp_vx, 0, 2, 1, IMPLVEC)
 DEF(rvv_cmp_vv, 0, 2, 1, IMPLVEC)
 DEF(rvv_merge_vec, 1, 2, 0, IMPLVEC)
+DEF(rvv_shli_vec, 1, 1, 1, IMPLVEC)
+DEF(rvv_shri_vec, 1, 1, 1, IMPLVEC)
+DEF(rvv_sari_vec, 1, 1, 1, IMPLVEC)
-- 
2.43.0
Re: [PATCH v2 13/14] tcg/riscv: Implement vector roti/v/x shi ops
Posted by Richard Henderson 2 months, 3 weeks ago
On 8/29/24 23:16, LIU Zhiwei wrote:
> @@ -2589,6 +2605,69 @@ void tcg_expand_vec_op(TCGOpcode opc, TCGType type, unsigned vece,
>               }
>           }
>           break;
> +    case INDEX_op_shli_vec:
> +        if (a2 > 31) {
> +            tcg_gen_shls_vec(vece, v0, v1, tcg_constant_i32(a2));
> +        } else {
> +            vec_gen_3(INDEX_op_rvv_shli_vec, type, vece, tcgv_vec_arg(v0),
> +                      tcgv_vec_arg(v1), a2);
> +        }
> +        break;
> +    case INDEX_op_shri_vec:
> +        if (a2 > 31) {
> +            tcg_gen_shrs_vec(vece, v0, v1, tcg_constant_i32(a2));
> +        } else {
> +            vec_gen_3(INDEX_op_rvv_shri_vec, type, vece, tcgv_vec_arg(v0),
> +                      tcgv_vec_arg(v1), a2);
> +        }
> +        break;
> +    case INDEX_op_sari_vec:
> +        if (a2 > 31) {
> +            tcg_gen_sars_vec(vece, v0, v1, tcg_constant_i32(a2));
> +        } else {
> +            vec_gen_3(INDEX_op_rvv_sari_vec, type, vece, tcgv_vec_arg(v0),
> +                      tcgv_vec_arg(v1), a2);
> +        }
> +        break;
> +    case INDEX_op_rotli_vec:
> +        t1 = tcg_temp_new_vec(type);
> +        tcg_gen_shli_vec(vece, t1, v1, a2);
> +        tcg_gen_shri_vec(vece, v0, v1, (8 << vece) - a2);
> +        tcg_gen_or_vec(vece, v0, v0, t1);
> +        tcg_temp_free_vec(t1);
> +        break;
> +    case INDEX_op_rotls_vec:
> +        t1 = tcg_temp_new_vec(type);
> +        t2 = tcg_temp_new_i32();
> +        tcg_gen_neg_i32(t2, temp_tcgv_i32(arg_temp(a2)));
> +        tcg_gen_shrs_vec(vece, v0, v1, t2);
> +        tcg_gen_shls_vec(vece, t1, v1, temp_tcgv_i32(arg_temp(a2)));
> +        tcg_gen_or_vec(vece, v0, v0, t1);
> +        tcg_temp_free_vec(t1);
> +        tcg_temp_free_i32(t2);
> +        break;

I'm trying to work out how much benefit there is here of expanding these early, as opposed 
to simply using TCG_REG_TMP0 when the immediate doesn't fit, or for rotls_vec negation.

> +    case INDEX_op_rotlv_vec:
> +        v2 = temp_tcgv_vec(arg_temp(a2));
> +        t1 = tcg_temp_new_vec(type);
> +        tcg_gen_neg_vec(vece, t1, v2);
> +        vec_gen_3(INDEX_op_shrv_vec, type, vece, tcgv_vec_arg(t1),
> +                  tcgv_vec_arg(v1), tcgv_vec_arg(t1));
> +        vec_gen_3(INDEX_op_shlv_vec, type, vece, tcgv_vec_arg(v0),
> +                  tcgv_vec_arg(v1), tcgv_vec_arg(v2));
> +        tcg_gen_or_vec(vece, v0, v0, t1);
> +        tcg_temp_free_vec(t1);
> +        break;
> +    case INDEX_op_rotrv_vec:
> +        v2 = temp_tcgv_vec(arg_temp(a2));
> +        t1 = tcg_temp_new_vec(type);
> +        tcg_gen_neg_vec(vece, t1, v2);
> +        vec_gen_3(INDEX_op_shlv_vec, type, vece, tcgv_vec_arg(t1),
> +                  tcgv_vec_arg(v1), tcgv_vec_arg(t1));
> +        vec_gen_3(INDEX_op_shrv_vec, type, vece, tcgv_vec_arg(v0),
> +                  tcgv_vec_arg(v1), tcgv_vec_arg(v2));
> +        tcg_gen_or_vec(vece, v0, v0, t1);
> +        tcg_temp_free_vec(t1);
> +        break;

And here we can use TCG_REG_V0 as the temporary, both for negation and shift intermediate.

     vrsub_vi  V0, a2, 0
     vshlv_vv  V0, a1, V0
     vshrv_vv  a0, a1, a2
     vor_vv    a0, a0, V0


r~
Re: [PATCH v2 13/14] tcg/riscv: Implement vector roti/v/x shi ops
Posted by LIU Zhiwei 2 months, 2 weeks ago
On 2024/9/3 23:15, Richard Henderson wrote:
> On 8/29/24 23:16, LIU Zhiwei wrote:
>> @@ -2589,6 +2605,69 @@ void tcg_expand_vec_op(TCGOpcode opc, TCGType 
>> type, unsigned vece,
>>               }
>>           }
>>           break;
>> +    case INDEX_op_shli_vec:
>> +        if (a2 > 31) {
>> +            tcg_gen_shls_vec(vece, v0, v1, tcg_constant_i32(a2));
>> +        } else {
>> +            vec_gen_3(INDEX_op_rvv_shli_vec, type, vece, 
>> tcgv_vec_arg(v0),
>> +                      tcgv_vec_arg(v1), a2);
>> +        }
>> +        break;
>> +    case INDEX_op_shri_vec:
>> +        if (a2 > 31) {
>> +            tcg_gen_shrs_vec(vece, v0, v1, tcg_constant_i32(a2));
>> +        } else {
>> +            vec_gen_3(INDEX_op_rvv_shri_vec, type, vece, 
>> tcgv_vec_arg(v0),
>> +                      tcgv_vec_arg(v1), a2);
>> +        }
>> +        break;
>> +    case INDEX_op_sari_vec:
>> +        if (a2 > 31) {
>> +            tcg_gen_sars_vec(vece, v0, v1, tcg_constant_i32(a2));
>> +        } else {
>> +            vec_gen_3(INDEX_op_rvv_sari_vec, type, vece, 
>> tcgv_vec_arg(v0),
>> +                      tcgv_vec_arg(v1), a2);
>> +        }
>> +        break;
>> +    case INDEX_op_rotli_vec:
>> +        t1 = tcg_temp_new_vec(type);
>> +        tcg_gen_shli_vec(vece, t1, v1, a2);
>> +        tcg_gen_shri_vec(vece, v0, v1, (8 << vece) - a2);
>> +        tcg_gen_or_vec(vece, v0, v0, t1);
>> +        tcg_temp_free_vec(t1);
>> +        break;
>> +    case INDEX_op_rotls_vec:
>> +        t1 = tcg_temp_new_vec(type);
>> +        t2 = tcg_temp_new_i32();
>> +        tcg_gen_neg_i32(t2, temp_tcgv_i32(arg_temp(a2)));
>> +        tcg_gen_shrs_vec(vece, v0, v1, t2);
>> +        tcg_gen_shls_vec(vece, t1, v1, temp_tcgv_i32(arg_temp(a2)));
>> +        tcg_gen_or_vec(vece, v0, v0, t1);
>> +        tcg_temp_free_vec(t1);
>> +        tcg_temp_free_i32(t2);
>> +        break;
>
> I'm trying to work out how much benefit there is here of expanding 
> these early, as opposed to simply using TCG_REG_TMP0 when the 
> immediate doesn't fit,

We find for rotli,  it just copied code from the implementation of 
INDEX_op_shli_vec and INDEX_op_shri_vec if we don't expand it.

   case INDEX_op_rotli_vec:
         if (a2 > 31) {
             tcg_out_opc_imm(s, OPC_ADDI, TCG_REG_TMP0, TCG_REG_ZERO, a2);
             tcg_out_opc_vx(s, OPC_VSLL_VX, TCG_REG_V0, a1, TCG_REG_TMP0, true);
         } else {
             tcg_out_opc_vi(s, OPC_VSLL_VI, TCG_REG_V0, a1, a2, true);
         }

         if ((8 << vece) - a2) > 31) {
             tcg_out_opc_imm(s, OPC_ADDI, TCG_REG_TMP0, TCG_REG_ZERO, 8 << vece) - a2);
             tcg_out_opc_vx(s, OPC_VSRL_VX, a0, a1, TCG_REG_TMP0, true);
         } else {
             tcg_out_opc_vi(s, OPC_VSRL_VI, a0, a1, 8 << vece) - a2, true);
         }
         tcg_out_opc_vv(s, OPC_VOR_VV, a0, a0, TCG_REG_V0, true);
         break;

Thus, I prefer to expand it early, at least for rotli_vec.

Thanks,
Zhiwei

> or for rotls_vec negation.
>
>> +    case INDEX_op_rotlv_vec:
>> +        v2 = temp_tcgv_vec(arg_temp(a2));
>> +        t1 = tcg_temp_new_vec(type);
>> +        tcg_gen_neg_vec(vece, t1, v2);
>> +        vec_gen_3(INDEX_op_shrv_vec, type, vece, tcgv_vec_arg(t1),
>> +                  tcgv_vec_arg(v1), tcgv_vec_arg(t1));
>> +        vec_gen_3(INDEX_op_shlv_vec, type, vece, tcgv_vec_arg(v0),
>> +                  tcgv_vec_arg(v1), tcgv_vec_arg(v2));
>> +        tcg_gen_or_vec(vece, v0, v0, t1);
>> +        tcg_temp_free_vec(t1);
>> +        break;
>> +    case INDEX_op_rotrv_vec:
>> +        v2 = temp_tcgv_vec(arg_temp(a2));
>> +        t1 = tcg_temp_new_vec(type);
>> +        tcg_gen_neg_vec(vece, t1, v2);
>> +        vec_gen_3(INDEX_op_shlv_vec, type, vece, tcgv_vec_arg(t1),
>> +                  tcgv_vec_arg(v1), tcgv_vec_arg(t1));
>> +        vec_gen_3(INDEX_op_shrv_vec, type, vece, tcgv_vec_arg(v0),
>> +                  tcgv_vec_arg(v1), tcgv_vec_arg(v2));
>> +        tcg_gen_or_vec(vece, v0, v0, t1);
>> +        tcg_temp_free_vec(t1);
>> +        break;
>
> And here we can use TCG_REG_V0 as the temporary, both for negation and 
> shift intermediate.
>
>     vrsub_vi  V0, a2, 0
>     vshlv_vv  V0, a1, V0
>     vshrv_vv  a0, a1, a2
>     vor_vv    a0, a0, V0
>
>
> r~
Re: [PATCH v2 13/14] tcg/riscv: Implement vector roti/v/x shi ops
Posted by Richard Henderson 2 months, 2 weeks ago
On 9/4/24 08:25, LIU Zhiwei wrote:
>> I'm trying to work out how much benefit there is here of expanding these early, as 
>> opposed to simply using TCG_REG_TMP0 when the immediate doesn't fit,
> 
> We find for rotli,  it just copied code from the implementation of INDEX_op_shli_vec and 
> INDEX_op_shri_vec if we don't expand it.
> 
>    case INDEX_op_rotli_vec:
>          if (a2 > 31) {
>              tcg_out_opc_imm(s, OPC_ADDI, TCG_REG_TMP0, TCG_REG_ZERO, a2);
>              tcg_out_opc_vx(s, OPC_VSLL_VX, TCG_REG_V0, a1, TCG_REG_TMP0, true);
>          } else {
>              tcg_out_opc_vi(s, OPC_VSLL_VI, TCG_REG_V0, a1, a2, true);
>          }
> 
>          if ((8 << vece) - a2) > 31) {
>              tcg_out_opc_imm(s, OPC_ADDI, TCG_REG_TMP0, TCG_REG_ZERO, 8 << vece) - a2);
>              tcg_out_opc_vx(s, OPC_VSRL_VX, a0, a1, TCG_REG_TMP0, true);
>          } else {
>              tcg_out_opc_vi(s, OPC_VSRL_VI, a0, a1, 8 << vece) - a2, true);
>          }
>          tcg_out_opc_vv(s, OPC_VOR_VV, a0, a0, TCG_REG_V0, true);
>          break;
> 
> Thus, I prefer to expand it early, at least for rotli_vec.

static void tcg_out_vshifti(TCGContext *s, RISCVInsn op_vi, RISCVInsn op_vx,
                             TCGReg dst, TCGReg src, unsigned imm)
{
     if (imm < 32) {
         tcg_out_opc_vi(s, op_vi, dst, src, imm);
     } else {
         tcg_out_movi(s, TCG_TYPE_I32, TCG_REG_TMP0, imm);
         tcg_out_opc_vx(s, op_vx, dst, src, TCG_REG_TMP0);
     }
}


     case INDEX_op_shli_vec:
         set_vconfig_vl_sew(s, type, vece);
         tcg_out_vshifti(s, OPC_VSLL_VI, OPC_VSLL_VX, a0, a1, a2);
         break;

     case INDEX_op_rotli_vec:
         set_vconfig_vl_sew(s, type, vece);
         tcg_out_vshifti(s, OPC_VSLL_VI, OPC_VSLL_VX, TCG_REG_V0, a1, a2);
         a2 = -a2 & ((8 << vece) - 1);
         tcg_out_vshifti(s, OPC_VSRL_VI, OPC_VSRL_VX, a0, a1, a2);
         tcg_out_opc_vv(s, OPC_VOR_VV, a0, a0, TCG_REG_V0);
         break;

r~

Re: [PATCH v2 13/14] tcg/riscv: Implement vector roti/v/x shi ops
Posted by LIU Zhiwei 2 months, 2 weeks ago
On 2024/9/5 3:05, Richard Henderson wrote:
> On 9/4/24 08:25, LIU Zhiwei wrote:
>>> I'm trying to work out how much benefit there is here of expanding 
>>> these early, as opposed to simply using TCG_REG_TMP0 when the 
>>> immediate doesn't fit,
>>
>> We find for rotli,  it just copied code from the implementation of 
>> INDEX_op_shli_vec and INDEX_op_shri_vec if we don't expand it.
>>
>>    case INDEX_op_rotli_vec:
>>          if (a2 > 31) {
>>              tcg_out_opc_imm(s, OPC_ADDI, TCG_REG_TMP0, TCG_REG_ZERO, 
>> a2);
>>              tcg_out_opc_vx(s, OPC_VSLL_VX, TCG_REG_V0, a1, 
>> TCG_REG_TMP0, true);
>>          } else {
>>              tcg_out_opc_vi(s, OPC_VSLL_VI, TCG_REG_V0, a1, a2, true);
>>          }
>>
>>          if ((8 << vece) - a2) > 31) {
>>              tcg_out_opc_imm(s, OPC_ADDI, TCG_REG_TMP0, TCG_REG_ZERO, 
>> 8 << vece) - a2);
>>              tcg_out_opc_vx(s, OPC_VSRL_VX, a0, a1, TCG_REG_TMP0, true);
>>          } else {
>>              tcg_out_opc_vi(s, OPC_VSRL_VI, a0, a1, 8 << vece) - a2, 
>> true);
>>          }
>>          tcg_out_opc_vv(s, OPC_VOR_VV, a0, a0, TCG_REG_V0, true);
>>          break;
>>
>> Thus, I prefer to expand it early, at least for rotli_vec.
>
> static void tcg_out_vshifti(TCGContext *s, RISCVInsn op_vi, RISCVInsn 
> op_vx,
>                             TCGReg dst, TCGReg src, unsigned imm)
> {
>     if (imm < 32) {
>         tcg_out_opc_vi(s, op_vi, dst, src, imm);
>     } else {
>         tcg_out_movi(s, TCG_TYPE_I32, TCG_REG_TMP0, imm);
>         tcg_out_opc_vx(s, op_vx, dst, src, TCG_REG_TMP0);
>     }
> }
>
>
Thanks for the guide.
> case INDEX_op_shli_vec:
>         set_vconfig_vl_sew(s, type, vece);
>         tcg_out_vshifti(s, OPC_VSLL_VI, OPC_VSLL_VX, a0, a1, a2);
>         break;
>
>     case INDEX_op_rotli_vec:
>         set_vconfig_vl_sew(s, type, vece);
>         tcg_out_vshifti(s, OPC_VSLL_VI, OPC_VSLL_VX, TCG_REG_V0, a1, a2);
>         a2 = -a2 & ((8 << vece) - 1);
>         tcg_out_vshifti(s, OPC_VSRL_VI, OPC_VSRL_VX, a0, a1, a2);
>         tcg_out_opc_vv(s, OPC_VOR_VV, a0, a0, TCG_REG_V0);
>         break;

OK. We will take this way.

Thanks,
Zhiwei

>
> r~