[Qemu-devel] [PULL 21/34] target/riscv: Remove manual decoding from gen_load()

[Palmer Dabbelt <palmer@sifive.com>]

From: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>

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

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Signed-off-by: Peer Adelt <peer.adelt@hni.uni-paderborn.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
---
 target/riscv/insn_trans/trans_rvi.inc.c | 35 +++++++++++++++----------
 target/riscv/translate.c                |  6 +++--
 2 files changed, 25 insertions(+), 16 deletions(-)

diff --git a/target/riscv/insn_trans/trans_rvi.inc.c b/target/riscv/insn_trans/trans_rvi.inc.c
index ae4b0a2bcb78..cc361ed4d151 100644
--- a/target/riscv/insn_trans/trans_rvi.inc.c
+++ b/target/riscv/insn_trans/trans_rvi.inc.c
@@ -129,34 +129,43 @@ static bool trans_bgeu(DisasContext *ctx, arg_bgeu *a)
     return gen_branch(ctx, a, TCG_COND_GEU);
 }
 
-static bool trans_lb(DisasContext *ctx, arg_lb *a)
+static bool gen_load(DisasContext *ctx, arg_lb *a, TCGMemOp memop)
 {
-    gen_load(ctx, OPC_RISC_LB, a->rd, a->rs1, a->imm);
+    TCGv t0 = tcg_temp_new();
+    TCGv t1 = tcg_temp_new();
+    gen_get_gpr(t0, a->rs1);
+    tcg_gen_addi_tl(t0, t0, a->imm);
+
+    tcg_gen_qemu_ld_tl(t1, t0, ctx->mem_idx, memop);
+    gen_set_gpr(a->rd, t1);
+    tcg_temp_free(t0);
+    tcg_temp_free(t1);
     return true;
 }
 
+static bool trans_lb(DisasContext *ctx, arg_lb *a)
+{
+    return gen_load(ctx, a, MO_SB);
+}
+
 static bool trans_lh(DisasContext *ctx, arg_lh *a)
 {
-    gen_load(ctx, OPC_RISC_LH, a->rd, a->rs1, a->imm);
-    return true;
+    return gen_load(ctx, a, MO_TESW);
 }
 
 static bool trans_lw(DisasContext *ctx, arg_lw *a)
 {
-    gen_load(ctx, OPC_RISC_LW, a->rd, a->rs1, a->imm);
-    return true;
+    return gen_load(ctx, a, MO_TESL);
 }
 
 static bool trans_lbu(DisasContext *ctx, arg_lbu *a)
 {
-    gen_load(ctx, OPC_RISC_LBU, a->rd, a->rs1, a->imm);
-    return true;
+    return gen_load(ctx, a, MO_UB);
 }
 
 static bool trans_lhu(DisasContext *ctx, arg_lhu *a)
 {
-    gen_load(ctx, OPC_RISC_LHU, a->rd, a->rs1, a->imm);
-    return true;
+    return gen_load(ctx, a, MO_TEUW);
 }
 
 static bool trans_sb(DisasContext *ctx, arg_sb *a)
@@ -180,14 +189,12 @@ static bool trans_sw(DisasContext *ctx, arg_sw *a)
 #ifdef TARGET_RISCV64
 static bool trans_lwu(DisasContext *ctx, arg_lwu *a)
 {
-    gen_load(ctx, OPC_RISC_LWU, a->rd, a->rs1, a->imm);
-    return true;
+    return gen_load(ctx, a, MO_TEUL);
 }
 
 static bool trans_ld(DisasContext *ctx, arg_ld *a)
 {
-    gen_load(ctx, OPC_RISC_LD, a->rd, a->rs1, a->imm);
-    return true;
+    return gen_load(ctx, a, MO_TEQ);
 }
 
 static bool trans_sd(DisasContext *ctx, arg_sd *a)
diff --git a/target/riscv/translate.c b/target/riscv/translate.c
index a3d5cdbad82d..99d6d3b4ae91 100644
--- a/target/riscv/translate.c
+++ b/target/riscv/translate.c
@@ -531,7 +531,8 @@ static void gen_jal(DisasContext *ctx, int rd, target_ulong imm)
     ctx->base.is_jmp = DISAS_NORETURN;
 }
 
-static void gen_load(DisasContext *ctx, uint32_t opc, int rd, int rs1,
+#ifdef TARGET_RISCV64
+static void gen_load_c(DisasContext *ctx, uint32_t opc, int rd, int rs1,
         target_long imm)
 {
     TCGv t0 = tcg_temp_new();
@@ -550,6 +551,7 @@ static void gen_load(DisasContext *ctx, uint32_t opc, int rd, int rs1,
     tcg_temp_free(t0);
     tcg_temp_free(t1);
 }
+#endif
 
 static void gen_store(DisasContext *ctx, uint32_t opc, int rs1, int rs2,
         target_long imm)
@@ -723,7 +725,7 @@ static void decode_RV32_64C0(DisasContext *ctx)
     case 3:
 #if defined(TARGET_RISCV64)
         /* C.LD(RV64/128) -> ld rd', offset[7:3](rs1')*/
-        gen_load(ctx, OPC_RISC_LD, rd_rs2, rs1s,
+        gen_load_c(ctx, OPC_RISC_LD, rd_rs2, rs1s,
                  GET_C_LD_IMM(ctx->opcode));
 #else
         /* C.FLW (RV32) -> flw rd', offset[6:2](rs1')*/
-- 
2.18.1