[PATCH v2 24/52] disas/riscv: Handle aliases of csrrwi during decode

[Richard Henderson]

Reviewed-by: Alistair Francis <alistair.fran...@wdc.com>
Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
---
 disas/riscv.h |  2 --
 disas/riscv.c | 28 ++++++++--------------------
 2 files changed, 8 insertions(+), 22 deletions(-)

diff --git a/disas/riscv.h b/disas/riscv.h
index d8c5acd969..3bbcbf10fb 100644
--- a/disas/riscv.h
+++ b/disas/riscv.h
@@ -84,8 +84,6 @@ typedef enum {
     rvc_imm_eq_zero,
     rvc_imm_eq_n1,
     rvc_imm_eq_p1,
-    rvc_csr_eq_0x001,
-    rvc_csr_eq_0x002,
 } rvc_constraint;
 
 typedef enum {
diff --git a/disas/riscv.c b/disas/riscv.c
index 9ec79baf4d..d3cbfb86ac 100644
--- a/disas/riscv.c
+++ b/disas/riscv.c
@@ -1063,8 +1063,6 @@ static const rvc_constraint rvcc_ret[] = { rvc_rd_eq_x0, 
rvc_rs1_eq_ra,
                                            rvc_end };
 static const rvc_constraint rvcc_jr[] = { rvc_rd_eq_x0, rvc_imm_eq_zero,
                                           rvc_end };
-static const rvc_constraint rvcc_fsrmi[] = { rvc_csr_eq_0x002, rvc_end };
-static const rvc_constraint rvcc_fsflagsi[] = { rvc_csr_eq_0x001, rvc_end };
 
 /* pseudo-instruction metadata */
 
@@ -1145,12 +1143,6 @@ static const rv_comp_data rvcp_subw[] = {
     { rv_op_illegal, NULL }
 };
 
-static const rv_comp_data rvcp_csrrwi[] = {
-    { rv_op_fsrmi, rvcc_fsrmi },
-    { rv_op_fsflagsi, rvcc_fsflagsi },
-    { rv_op_illegal, NULL }
-};
-
 static const rv_comp_data rvcp_fsgnj_s[] = {
     { rv_op_fmv_s, rvcc_fmv_s },
     { rv_op_illegal, NULL }
@@ -1722,7 +1714,7 @@ static const rv_opcode_data rvi_opcode_data[] = {
     { "csrrw", rv_codec_i_csr, rv_fmt_rd_csr_rs1 },
     { "csrrs", rv_codec_i_csr, rv_fmt_rd_csr_rs1 },
     { "csrrc", rv_codec_i_csr, rv_fmt_rd_csr_rs1 },
-    { "csrrwi", rv_codec_i_csr, rv_fmt_rd_csr_zimm, rvcp_csrrwi },
+    { "csrrwi", rv_codec_i_csr, rv_fmt_rd_csr_zimm },
     { "csrrsi", rv_codec_i_csr, rv_fmt_rd_csr_zimm },
     { "csrrci", rv_codec_i_csr, rv_fmt_rd_csr_zimm },
     { "flw", rv_codec_i, rv_fmt_frd_offset_rs1 },
@@ -4469,7 +4461,13 @@ static void decode_inst_opcode(rv_decode *dec, rv_isa 
isa)
                     }
                 }
                 break;
-            case 5: op = rv_op_csrrwi; break;
+            case 5:
+                switch (operand_csr12(inst)) {
+                case 1: op = rv_op_fsflagsi; break;
+                case 2: op = rv_op_fsrmi; break;
+                default: op = rv_op_csrrwi; break;
+                }
+                break;
             case 6: op = rv_op_csrrsi; break;
             case 7: op = rv_op_csrrci; break;
             }
@@ -4991,16 +4989,6 @@ static bool check_constraints(rv_decode *dec, const 
rvc_constraint *c)
                 return false;
             }
             break;
-        case rvc_csr_eq_0x001:
-            if (!(imm == 0x001)) {
-                return false;
-            }
-            break;
-        case rvc_csr_eq_0x002:
-            if (!(imm == 0x002)) {
-                return false;
-            }
-            break;
         default: break;
         }
         c++;
-- 
2.43.0