[Qemu-devel] [PATCH 24/28] target/riscv: Remove shift and slt insn manual decoding

[Bastian Koppelmann <kbastian@mail.uni-paderborn.de>]

Signed-off-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Signed-off-by: Peer Adelt <peer.adelt@hni.uni-paderborn.de>
---
 target/riscv/insn_trans/trans_rvi.inc.c | 79 +++++++++++++++++++++----
 target/riscv/translate.c                | 59 ++++++------------
 2 files changed, 86 insertions(+), 52 deletions(-)

diff --git a/target/riscv/insn_trans/trans_rvi.inc.c b/target/riscv/insn_trans/trans_rvi.inc.c
index cb0c6263bd..b84a2e018b 100644
--- a/target/riscv/insn_trans/trans_rvi.inc.c
+++ b/target/riscv/insn_trans/trans_rvi.inc.c
@@ -333,19 +333,39 @@ static bool trans_sub(DisasContext *ctx, arg_sub *a, uint32_t insn)
 
 static bool trans_sll(DisasContext *ctx, arg_sll *a, uint32_t insn)
 {
-    gen_arith(ctx, OPC_RISC_SLL, a->rd, a->rs1, a->rs2);
-    return true;
+
+    return trans_shift(ctx, a, &tcg_gen_shl_tl);
 }
 
 static bool trans_slt(DisasContext *ctx, arg_slt *a, uint32_t insn)
 {
-    gen_arith(ctx, OPC_RISC_SLT, 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_setcond_tl(TCG_COND_LT, source1, source1, source2);
+
+    gen_set_gpr(a->rd, source1);
+    tcg_temp_free(source1);
+    tcg_temp_free(source2);
     return true;
 }
 
 static bool trans_sltu(DisasContext *ctx, arg_sltu *a, uint32_t insn)
 {
-    gen_arith(ctx, OPC_RISC_SLTU, 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_setcond_tl(TCG_COND_LTU, source1, source1, source2);
+
+    gen_set_gpr(a->rd, source1);
+    tcg_temp_free(source1);
+    tcg_temp_free(source2);
     return true;
 }
 
@@ -354,16 +374,15 @@ static bool trans_xor(DisasContext *ctx, arg_xor *a, uint32_t insn)
     return trans_arith(ctx, a, &tcg_gen_xor_tl);
 }
 
+
 static bool trans_srl(DisasContext *ctx, arg_srl *a, uint32_t insn)
 {
-    gen_arith(ctx, OPC_RISC_SRL, a->rd, a->rs1, a->rs2);
-    return true;
+    return trans_shift(ctx, a, &tcg_gen_shr_tl);
 }
 
 static bool trans_sra(DisasContext *ctx, arg_sra *a, uint32_t insn)
 {
-    gen_arith(ctx, OPC_RISC_SRA, a->rd, a->rs1, a->rs2);
-    return true;
+    return trans_shift(ctx, a, &tcg_gen_sar_tl);
 }
 
 static bool trans_or(DisasContext *ctx, arg_or *a, uint32_t insn)
@@ -449,7 +468,18 @@ static bool trans_sllw(DisasContext *ctx, arg_sllw *a, uint32_t insn)
     gen_exception_illegal(ctx);
     return true;
 #endif
-    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);
+
+    gen_set_gpr(a->rd, source1);
+    tcg_temp_free(source1);
+    tcg_temp_free(source2);
     return true;
 }
 
@@ -459,7 +489,20 @@ static bool trans_srlw(DisasContext *ctx, arg_srlw *a, uint32_t insn)
     gen_exception_illegal(ctx);
     return true;
 #endif
-    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);
+
+    gen_set_gpr(a->rd, source1);
+    tcg_temp_free(source1);
+    tcg_temp_free(source2);
     return true;
 }
 
@@ -469,7 +512,21 @@ static bool trans_sraw(DisasContext *ctx, arg_sraw *a, uint32_t insn)
     gen_exception_illegal(ctx);
     return true;
 #endif
-    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;
 }
 
diff --git a/target/riscv/translate.c b/target/riscv/translate.c
index 92aa4641b0..047f64c6f2 100644
--- a/target/riscv/translate.c
+++ b/target/riscv/translate.c
@@ -175,47 +175,6 @@ 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;
@@ -476,6 +435,24 @@ static bool trans_arith(DisasContext *ctx, arg_arith *a,
     return true;
 }
 
+static bool trans_shift(DisasContext *ctx, arg_arith *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"
-- 
2.19.1