[RFC PATCH 04/13] target/riscv: Support UXL32 for slit/sltiu

[LIU Zhiwei]

For slitu, the imm is sign-extend before unsigned compare. Thus we
should only use the LSB 32 bits of the imm for UXL32.

Signed-off-by: LIU Zhiwei <zhiwei_...@c-sky.com>
---
 target/riscv/insn_trans/trans_rvi.c.inc |  8 ++---
 target/riscv/translate.c                | 44 +++++++++++++++++++++++++
 2 files changed, 48 insertions(+), 4 deletions(-)

diff --git a/target/riscv/insn_trans/trans_rvi.c.inc 
b/target/riscv/insn_trans/trans_rvi.c.inc
index 6823a6b3e0..6201c07795 100644
--- a/target/riscv/insn_trans/trans_rvi.c.inc
+++ b/target/riscv/insn_trans/trans_rvi.c.inc
@@ -276,12 +276,12 @@ static void gen_sltu(TCGv ret, TCGv s1, TCGv s2)
 
 static bool trans_slti(DisasContext *ctx, arg_slti *a)
 {
-    return gen_arith_imm_tl(ctx, a, &gen_slt);
+    return gen_arith_simm_tl(ctx, a, &gen_slt);
 }
 
 static bool trans_sltiu(DisasContext *ctx, arg_sltiu *a)
 {
-    return gen_arith_imm_tl(ctx, a, &gen_sltu);
+    return gen_arith_uimm_tl(ctx, a, &gen_sltu);
 }
 
 static bool trans_xori(DisasContext *ctx, arg_xori *a)
@@ -328,12 +328,12 @@ static bool trans_sll(DisasContext *ctx, arg_sll *a)
 
 static bool trans_slt(DisasContext *ctx, arg_slt *a)
 {
-    return gen_arith(ctx, a, &gen_slt);
+    return gen_arith_s(ctx, a, &gen_slt);
 }
 
 static bool trans_sltu(DisasContext *ctx, arg_sltu *a)
 {
-    return gen_arith(ctx, a, &gen_sltu);
+    return gen_arith_u(ctx, a, &gen_sltu);
 }
 
 static bool trans_xor(DisasContext *ctx, arg_xor *a)
diff --git a/target/riscv/translate.c b/target/riscv/translate.c
index d334a9db86..912e5f1061 100644
--- a/target/riscv/translate.c
+++ b/target/riscv/translate.c
@@ -494,6 +494,28 @@ static bool gen_arith_imm_tl(DisasContext *ctx, arg_i *a,
     return true;
 }
 
+static bool gen_arith_simm_tl(DisasContext *ctx, arg_i *a,
+                              void (*func)(TCGv, TCGv, TCGv))
+{
+    TCGv dest = gpr_dst(ctx, a->rd);
+    TCGv src1 = gpr_src_s(ctx, a->rs1);
+    TCGv src2 = tcg_constant_tl(a->imm);
+
+    (*func)(dest, src1, src2);
+    return true;
+}
+
+static bool gen_arith_uimm_tl(DisasContext *ctx, arg_i *a,
+                              void (*func)(TCGv, TCGv, TCGv))
+{
+    TCGv dest = gpr_dst(ctx, a->rd);
+    TCGv src1 = gpr_src_u(ctx, a->rs1);
+    TCGv src2 = tcg_constant_tl(ctx->uxl32 ? a->imm & UINT32_MAX : a->imm);
+
+    (*func)(dest, src1, src2);
+    return true;
+}
+
 static void gen_addw(TCGv ret, TCGv arg1, TCGv arg2)
 {
     tcg_gen_add_tl(ret, arg1, arg2);
@@ -779,6 +801,28 @@ static bool gen_arith(DisasContext *ctx, arg_r *a,
     return true;
 }
 
+static bool gen_arith_u(DisasContext *ctx, arg_r *a,
+                        void(*func)(TCGv, TCGv, TCGv))
+{
+    TCGv dest = gpr_dst(ctx, a->rd);
+    TCGv src1 = gpr_src_u(ctx, a->rs1);
+    TCGv src2 = gpr_src_u(ctx, a->rs2);
+
+    (*func)(dest, src1, src2);
+    return true;
+}
+
+static bool gen_arith_s(DisasContext *ctx, arg_r *a,
+                        void(*func)(TCGv, TCGv, TCGv))
+{
+    TCGv dest = gpr_dst(ctx, a->rd);
+    TCGv src1 = gpr_src_s(ctx, a->rs1);
+    TCGv src2 = gpr_src_s(ctx, a->rs2);
+
+    (*func)(dest, src1, src2);
+    return true;
+}
+
 static bool gen_shift(DisasContext *ctx, arg_r *a,
                         void(*func)(TCGv, TCGv, TCGv))
 {
-- 
2.17.1