[PATCH v2 25/52] disas/riscv: Break pseudo loop for jal and jalr

[Richard Henderson]

These were clearly intending to simplify
        jal     ra, foo
to
        jal     foo
and similarly for jalr, but the pseudo expansion looped
back to the original jal/jalr with the full format.

Add new opcode expansions dropping the implied ra.

Reviewed-by: Alistair Francis <alistair.fran...@wdc.com>
Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
---
 disas/riscv.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/disas/riscv.c b/disas/riscv.c
index d3cbfb86ac..fe503b6cae 100644
--- a/disas/riscv.c
+++ b/disas/riscv.c
@@ -326,6 +326,8 @@ typedef enum {
     rv_op_bgez = 295,
     rv_op_bltz = 296,
     rv_op_bgtz = 297,
+    rv_op_jal_ra = 298,
+    rv_op_jalr_ra = 299,
     rv_op_j = 302,
     rv_op_ret = 303,
     rv_op_jr = 304,
@@ -1029,9 +1031,9 @@ static const char rv_fli_name_const[32][9] =
 
 /* pseudo-instruction constraints */
 
-static const rvc_constraint rvcc_jal[] = { rvc_rd_eq_ra, rvc_end };
-static const rvc_constraint rvcc_jalr[] = { rvc_rd_eq_ra, rvc_imm_eq_zero,
-                                            rvc_end };
+static const rvc_constraint rvcc_jal_ra[] = { rvc_rd_eq_ra, rvc_end };
+static const rvc_constraint rvcc_jalr_ra[] = { rvc_rd_eq_ra, rvc_imm_eq_zero,
+                                               rvc_end };
 static const rvc_constraint rvcc_nop[] = { rvc_rd_eq_x0, rvc_rs1_eq_x0,
                                            rvc_imm_eq_zero, rvc_end };
 static const rvc_constraint rvcc_mv[] = { rvc_imm_eq_zero, rvc_end };
@@ -1068,14 +1070,14 @@ static const rvc_constraint rvcc_jr[] = { rvc_rd_eq_x0, 
rvc_imm_eq_zero,
 
 static const rv_comp_data rvcp_jal[] = {
     { rv_op_j, rvcc_j },
-    { rv_op_jal, rvcc_jal },
+    { rv_op_jal_ra, rvcc_jal_ra },
     { rv_op_illegal, NULL }
 };
 
 static const rv_comp_data rvcp_jalr[] = {
     { rv_op_ret, rvcc_ret },
     { rv_op_jr, rvcc_jr },
-    { rv_op_jalr, rvcc_jalr },
+    { rv_op_jalr_ra, rvcc_jalr_ra },
     { rv_op_illegal, NULL }
 };
 
@@ -1884,8 +1886,8 @@ static const rv_opcode_data rvi_opcode_data[] = {
     { "bgez", rv_codec_sb, rv_fmt_rs1_offset },
     { "bltz", rv_codec_sb, rv_fmt_rs1_offset },
     { "bgtz", rv_codec_sb, rv_fmt_rs2_offset },
-    { },
-    { },
+    { "jal", rv_codec_none, rv_fmt_offset }, /* rv_op_jal_ra */
+    { "jalr", rv_codec_none, rv_fmt_rs1 }, /* rv_op_jalr_ra */
     { },
     { },
     { "j", rv_codec_uj, rv_fmt_offset },
-- 
2.43.0