target/riscv: Remove manual decoding from gen_store()

With decodetree we don't need to convert RISC-V opcodes into to MemOps
as the old gen_store() did.

Backports commit bce8a342a1f0919479d18ec812b100136daa746b from qemu

qemu/target/riscv/insn_trans/trans_rvi.inc.c

@@ -175,22 +175,35 @@ static bool trans_lhu(DisasContext *ctx, arg_lhu *a)
     return gen_load(ctx, a, MO_TEUW);
 }
 
+static bool gen_store(DisasContext *ctx, arg_sb *a, TCGMemOp memop)
+{
+    TCGContext *tcg_ctx = ctx->uc->tcg_ctx;
+
+    TCGv t0 = tcg_temp_new(tcg_ctx);
+    TCGv dat = tcg_temp_new(tcg_ctx);
+    gen_get_gpr(ctx, t0, a->rs1);
+    tcg_gen_addi_tl(tcg_ctx, t0, t0, a->imm);
+    gen_get_gpr(ctx, dat, a->rs2);
+
+    tcg_gen_qemu_st_tl(ctx->uc, dat, t0, ctx->mem_idx, memop);
+    tcg_temp_free(tcg_ctx, t0);
+    tcg_temp_free(tcg_ctx, dat);
+    return true;
+}
+
 static bool trans_sb(DisasContext *ctx, arg_sb *a)
 {
-    gen_store(ctx, OPC_RISC_SB, a->rs1, a->rs2, a->imm);
+    return gen_store(ctx, a, MO_SB);
-    return true;
 }
 
 static bool trans_sh(DisasContext *ctx, arg_sh *a)
 {
-    gen_store(ctx, OPC_RISC_SH, a->rs1, a->rs2, a->imm);
+    return gen_store(ctx, a, MO_TESW);
-    return true;
 }
 
 static bool trans_sw(DisasContext *ctx, arg_sw *a)
 {
-    gen_store(ctx, OPC_RISC_SW, a->rs1, a->rs2, a->imm);
+    return gen_store(ctx, a, MO_TESL);
-    return true;
 }
 
 #ifdef TARGET_RISCV64
@@ -206,8 +219,7 @@ static bool trans_ld(DisasContext *ctx, arg_ld *a)
 
 static bool trans_sd(DisasContext *ctx, arg_sd *a)
 {
-    gen_store(ctx, OPC_RISC_SD, a->rs1, a->rs2, a->imm);
+    return gen_store(ctx, a, MO_TEQ);
-    return true;
 }
 #endif
 

qemu/target/riscv/translate.c

@@ -57,6 +57,7 @@ typedef struct DisasContext {
     struct uc_struct *uc;
 } DisasContext;
 
+#ifdef TARGET_RISCV64
 /* convert riscv funct3 to qemu memop for load/store */
 static const int tcg_memop_lookup[8] = {
     [0 ... 7] = -1,
@@ -70,6 +71,7 @@ static const int tcg_memop_lookup[8] = {
     [6] = MO_TEUL,
 #endif
 };
+#endif
 
 #ifdef TARGET_RISCV64
 #define CASE_OP_32_64(X) case X: case glue(X, W)
@@ -568,9 +570,8 @@ static void gen_load_c(DisasContext *ctx, uint32_t opc, int rd, int rs1,
     tcg_temp_free(tcg_ctx, t0);
     tcg_temp_free(tcg_ctx, t1);
 }
-#endif
 
-static void gen_store(DisasContext *ctx, uint32_t opc, int rs1, int rs2,
+static void gen_store_c(DisasContext *ctx, uint32_t opc, int rs1, int rs2,
         target_long imm)
 {
     TCGContext *tcg_ctx = ctx->uc->tcg_ctx;
@@ -590,6 +591,7 @@ static void gen_store(DisasContext *ctx, uint32_t opc, int rs1, int rs2,
     tcg_temp_free(tcg_ctx, t0);
     tcg_temp_free(tcg_ctx, dat);
 }
+#endif
 
 #ifndef CONFIG_USER_ONLY
 /* The states of mstatus_fs are:
@@ -760,7 +762,7 @@ static void decode_RV32_64C0(DisasContext *ctx)
     case 7:
 #if defined(TARGET_RISCV64)
         /* C.SD (RV64/128) -> sd rs2', offset[7:3](rs1')*/
-        gen_store(ctx, OPC_RISC_SD, rs1s, rd_rs2,
+        gen_store_c(ctx, OPC_RISC_SD, rs1s, rd_rs2,
                   GET_C_LD_IMM(ctx->opcode));
 #else
         /* C.FSW (RV32) -> fsw rs2', offset[6:2](rs1')*/