[PATCH v2 22/52] disas/riscv: Handle aliases of csrrw during decode

[Richard Henderson]

Reviewed-by: Alistair Francis <alistair.fran...@wdc.com>
Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
---
 disas/riscv.c | 22 +++++++++-------------
 1 file changed, 9 insertions(+), 13 deletions(-)

diff --git a/disas/riscv.c b/disas/riscv.c
index bde1cc6e62..e464b8b075 100644
--- a/disas/riscv.c
+++ b/disas/riscv.c
@@ -1081,9 +1081,6 @@ static const rvc_constraint rvcc_frrm[] = { 
rvc_rs1_eq_x0, rvc_csr_eq_0x002,
                                             rvc_end };
 static const rvc_constraint rvcc_frflags[] = { rvc_rs1_eq_x0, rvc_csr_eq_0x001,
                                                rvc_end };
-static const rvc_constraint rvcc_fscsr[] = { rvc_csr_eq_0x003, rvc_end };
-static const rvc_constraint rvcc_fsrm[] = { rvc_csr_eq_0x002, rvc_end };
-static const rvc_constraint rvcc_fsflags[] = { rvc_csr_eq_0x001, 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 };
 
@@ -1166,14 +1163,6 @@ static const rv_comp_data rvcp_subw[] = {
     { rv_op_illegal, NULL }
 };
 
-static const rv_comp_data rvcp_csrrw[] = {
-    { rv_op_fscsr, rvcc_fscsr },
-    { rv_op_fsrm, rvcc_fsrm },
-    { rv_op_fsflags, rvcc_fsflags },
-    { rv_op_illegal, NULL }
-};
-
-
 static const rv_comp_data rvcp_csrrs[] = {
     { rv_op_rdcycle, rvcc_rdcycle },
     { rv_op_rdtime, rvcc_rdtime },
@@ -1761,7 +1750,7 @@ static const rv_opcode_data rvi_opcode_data[] = {
     { "sfence.vm", rv_codec_r, rv_fmt_rs1 },
     { "sfence.vma", rv_codec_r, rv_fmt_rs1_rs2 },
     { "wfi", rv_codec_none, rv_fmt_none },
-    { "csrrw", rv_codec_i_csr, rv_fmt_rd_csr_rs1, rvcp_csrrw },
+    { "csrrw", rv_codec_i_csr, rv_fmt_rd_csr_rs1 },
     { "csrrs", rv_codec_i_csr, rv_fmt_rd_csr_rs1, rvcp_csrrs },
     { "csrrc", rv_codec_i_csr, rv_fmt_rd_csr_rs1 },
     { "csrrwi", rv_codec_i_csr, rv_fmt_rd_csr_zimm, rvcp_csrrwi },
@@ -4443,7 +4432,14 @@ static void decode_inst_opcode(rv_decode *dec, rv_isa 
isa)
                     break;
                 }
                 break;
-            case 1: op = rv_op_csrrw; break;
+            case 1:
+                switch (operand_csr12(inst)) {
+                case 1: op = rv_op_fsflags; break;
+                case 2: op = rv_op_fsrm; break;
+                case 3: op = rv_op_fscsr; break;
+                default: op = rv_op_csrrw; break;
+                }
+                break;
             case 2: op = rv_op_csrrs; break;
             case 3: op = rv_op_csrrc; break;
             case 4:
-- 
2.43.0