[Qemu-devel] [PATCH v5 26/35] target/riscv: Remove shift and slt insn manual decoding

[Bastian Koppelmann]

Reviewed-by: Richard Henderson <address@hidden>
Signed-off-by: Bastian Koppelmann <address@hidden>
Signed-off-by: Peer Adelt <address@hidden>
---
v4 -> v5:
    - removed rs2 == 0 special cases in sraw/srlw

 target/riscv/insn_trans/trans_rvi.inc.c | 93 +++++++++++++++++--------
 target/riscv/translate.c                | 59 +++++-----------
 2 files changed, 81 insertions(+), 71 deletions(-)

diff --git a/target/riscv/insn_trans/trans_rvi.inc.c 
b/target/riscv/insn_trans/trans_rvi.inc.c
index f52182e9f4..3badb70b1d 100644
--- a/target/riscv/insn_trans/trans_rvi.inc.c
+++ b/target/riscv/insn_trans/trans_rvi.inc.c
@@ -220,30 +220,25 @@ static bool trans_addi(DisasContext *ctx, arg_addi *a)
     return gen_arith_imm(ctx, a, &tcg_gen_add_tl);
 }
 
-static bool trans_slti(DisasContext *ctx, arg_slti *a)
+static void gen_slt(TCGv ret, TCGv s1, TCGv s2)
 {
-    TCGv source1;
-    source1 = tcg_temp_new();
-    gen_get_gpr(source1, a->rs1);
+    tcg_gen_setcond_tl(TCG_COND_LT, ret, s1, s2);
+}
+
+static void gen_sltu(TCGv ret, TCGv s1, TCGv s2)
+{
+    tcg_gen_setcond_tl(TCG_COND_LTU, ret, s1, s2);
+}
 
-    tcg_gen_setcondi_tl(TCG_COND_LT, source1, source1, a->imm);
 
-    gen_set_gpr(a->rd, source1);
-    tcg_temp_free(source1);
-    return true;
+static bool trans_slti(DisasContext *ctx, arg_slti *a)
+{
+    return gen_arith_imm(ctx, a, &gen_slt);
 }
 
 static bool trans_sltiu(DisasContext *ctx, arg_sltiu *a)
 {
-    TCGv source1;
-    source1 = tcg_temp_new();
-    gen_get_gpr(source1, a->rs1);
-
-    tcg_gen_setcondi_tl(TCG_COND_LTU, source1, source1, a->imm);
-
-    gen_set_gpr(a->rd, source1);
-    tcg_temp_free(source1);
-    return true;
+    return gen_arith_imm(ctx, a, &gen_sltu);
 }
 
 static bool trans_xori(DisasContext *ctx, arg_xori *a)
@@ -322,20 +317,17 @@ static bool trans_sub(DisasContext *ctx, arg_sub *a)
 
 static bool trans_sll(DisasContext *ctx, arg_sll *a)
 {
-    gen_arith(ctx, OPC_RISC_SLL, a->rd, a->rs1, a->rs2);
-    return true;
+    return gen_shift(ctx, a, &tcg_gen_shl_tl);
 }
 
 static bool trans_slt(DisasContext *ctx, arg_slt *a)
 {
-    gen_arith(ctx, OPC_RISC_SLT, a->rd, a->rs1, a->rs2);
-    return true;
+    return trans_arith(ctx, a, &gen_slt);
 }
 
 static bool trans_sltu(DisasContext *ctx, arg_sltu *a)
 {
-    gen_arith(ctx, OPC_RISC_SLTU, a->rd, a->rs1, a->rs2);
-    return true;
+    return trans_arith(ctx, a, &gen_sltu);
 }
 
 static bool trans_xor(DisasContext *ctx, arg_xor *a)
@@ -345,14 +337,12 @@ static bool trans_xor(DisasContext *ctx, arg_xor *a)
 
 static bool trans_srl(DisasContext *ctx, arg_srl *a)
 {
-    gen_arith(ctx, OPC_RISC_SRL, a->rd, a->rs1, a->rs2);
-    return true;
+    return gen_shift(ctx, a, &tcg_gen_shr_tl);
 }
 
 static bool trans_sra(DisasContext *ctx, arg_sra *a)
 {
-    gen_arith(ctx, OPC_RISC_SRA, a->rd, a->rs1, a->rs2);
-    return true;
+    return gen_shift(ctx, a, &tcg_gen_sar_tl);
 }
 
 static bool trans_or(DisasContext *ctx, arg_or *a)
@@ -419,19 +409,62 @@ static bool trans_subw(DisasContext *ctx, arg_subw *a)
 
 static bool trans_sllw(DisasContext *ctx, arg_sllw *a)
 {
-    gen_arith(ctx, OPC_RISC_SLLW, a->rd, a->rs1, a->rs2);
+    TCGv source1 = tcg_temp_new();
+    TCGv source2 = tcg_temp_new();
+
+    gen_get_gpr(source1, a->rs1);
+    gen_get_gpr(source2, a->rs2);
+
+    tcg_gen_andi_tl(source2, source2, 0x1F);
+    tcg_gen_shl_tl(source1, source1, source2);
+
+    tcg_gen_ext32s_tl(source1, source1);
+    gen_set_gpr(a->rd, source1);
+    tcg_temp_free(source1);
+    tcg_temp_free(source2);
     return true;
 }
 
 static bool trans_srlw(DisasContext *ctx, arg_srlw *a)
 {
-    gen_arith(ctx, OPC_RISC_SRLW, a->rd, a->rs1, a->rs2);
+    TCGv source1 = tcg_temp_new();
+    TCGv source2 = tcg_temp_new();
+
+    gen_get_gpr(source1, a->rs1);
+    gen_get_gpr(source2, a->rs2);
+
+    /* clear upper 32 */
+    tcg_gen_ext32u_tl(source1, source1);
+    tcg_gen_andi_tl(source2, source2, 0x1F);
+    tcg_gen_shr_tl(source1, source1, source2);
+
+    tcg_gen_ext32s_tl(source1, source1);
+    gen_set_gpr(a->rd, source1);
+    tcg_temp_free(source1);
+    tcg_temp_free(source2);
     return true;
 }
 
 static bool trans_sraw(DisasContext *ctx, arg_sraw *a)
 {
-    gen_arith(ctx, OPC_RISC_SRAW, a->rd, a->rs1, a->rs2);
+    TCGv source1 = tcg_temp_new();
+    TCGv source2 = tcg_temp_new();
+
+    gen_get_gpr(source1, a->rs1);
+    gen_get_gpr(source2, a->rs2);
+
+    /*
+     * first, trick to get it to act like working on 32 bits (get rid of
+     * upper 32, sign extend to fill space)
+     */
+    tcg_gen_ext32s_tl(source1, source1);
+    tcg_gen_andi_tl(source2, source2, 0x1F);
+    tcg_gen_sar_tl(source1, source1, source2);
+
+    gen_set_gpr(a->rd, source1);
+    tcg_temp_free(source1);
+    tcg_temp_free(source2);
+
     return true;
 }
 #endif
diff --git a/target/riscv/translate.c b/target/riscv/translate.c
index f691cbcd80..442c7d26a3 100644
--- a/target/riscv/translate.c
+++ b/target/riscv/translate.c
@@ -192,47 +192,6 @@ static void gen_arith(DisasContext *ctx, uint32_t opc, int 
rd, int rs1,
     gen_get_gpr(source2, rs2);
 
     switch (opc) {
-#if defined(TARGET_RISCV64)
-    case OPC_RISC_SLLW:
-        tcg_gen_andi_tl(source2, source2, 0x1F);
-        tcg_gen_shl_tl(source1, source1, source2);
-        break;
-#endif
-    case OPC_RISC_SLL:
-        tcg_gen_andi_tl(source2, source2, TARGET_LONG_BITS - 1);
-        tcg_gen_shl_tl(source1, source1, source2);
-        break;
-    case OPC_RISC_SLT:
-        tcg_gen_setcond_tl(TCG_COND_LT, source1, source1, source2);
-        break;
-    case OPC_RISC_SLTU:
-        tcg_gen_setcond_tl(TCG_COND_LTU, source1, source1, source2);
-        break;
-#if defined(TARGET_RISCV64)
-    case OPC_RISC_SRLW:
-        /* clear upper 32 */
-        tcg_gen_ext32u_tl(source1, source1);
-        tcg_gen_andi_tl(source2, source2, 0x1F);
-        tcg_gen_shr_tl(source1, source1, source2);
-        break;
-#endif
-    case OPC_RISC_SRL:
-        tcg_gen_andi_tl(source2, source2, TARGET_LONG_BITS - 1);
-        tcg_gen_shr_tl(source1, source1, source2);
-        break;
-#if defined(TARGET_RISCV64)
-    case OPC_RISC_SRAW:
-        /* first, trick to get it to act like working on 32 bits (get rid of
-        upper 32, sign extend to fill space) */
-        tcg_gen_ext32s_tl(source1, source1);
-        tcg_gen_andi_tl(source2, source2, 0x1F);
-        tcg_gen_sar_tl(source1, source1, source2);
-        break;
-#endif
-    case OPC_RISC_SRA:
-        tcg_gen_andi_tl(source2, source2, TARGET_LONG_BITS - 1);
-        tcg_gen_sar_tl(source1, source1, source2);
-        break;
     CASE_OP_32_64(OPC_RISC_MUL):
         tcg_gen_mul_tl(source1, source1, source2);
         break;
@@ -653,6 +612,24 @@ static bool trans_arith(DisasContext *ctx, arg_r *a,
     return true;
 }
 
+static bool gen_shift(DisasContext *ctx, arg_r *a,
+                        void(*func)(TCGv, TCGv, TCGv))
+{
+    TCGv source1 = tcg_temp_new();
+    TCGv source2 = tcg_temp_new();
+
+    gen_get_gpr(source1, a->rs1);
+    gen_get_gpr(source2, a->rs2);
+
+    tcg_gen_andi_tl(source2, source2, TARGET_LONG_BITS - 1);
+    (*func)(source1, source1, source2);
+
+    gen_set_gpr(a->rd, source1);
+    tcg_temp_free(source1);
+    tcg_temp_free(source2);
+    return true;
+}
+
 /* Include insn module translation function */
 #include "insn_trans/trans_rvi.inc.c"
 #include "insn_trans/trans_rvm.inc.c"
-- 
2.20.1