RISC-V: disallow x0 with certain macro-insns

While for some of the macro insns using x0 is kind of okay, as they
would merely resolve to a sequence of hint insns (and hence not cause
misbehavior at runtime), several of them have the degenerate AUIPC
followed by a load, store, or branch using other than the designated
symbol as address and hence causing runtime issues. Refuse to assemble
those, leveraging that the matching function so far wasn't really used
for macro insns: NULL is now allowed, indicating a match (which imo is
preferable over converting match_never() to match_always()), while
other matching functions now (also) used for macro insns need to avoid
calling match_opcode().

Note that for LA the restriction is slightly too strict: In non-PIC mode
using x0 would be okay-ish as per above (as it's just LLA there). Yet
libopcodes doesn't know what mode gas is presently assembling for, so we
want to err on the safe side.

Acked-by: Palmer Dabbelt <palmer@rivosinc.com>

4 files changed, 54 insertions, 48 deletions

diff --git a/gas/NEWS b/gas/NEWS
index 53b8759..643f0e6 100644
--- a/gas/NEWS
+++ b/gas/NEWS
@@ -1,5 +1,8 @@
 -*- text -*-
 
+* On RISC-V macro instructions expanding to AUIPC and a load, store, or branch
+  no longer accept x0 as an intermediate and/or destination register.
+
 * Add support for Reliability, Availability and Serviceability extension v2
   (RASv2) for AArch64.
 
diff --git a/gas/config/tc-riscv.c b/gas/config/tc-riscv.c
index af9a34a..3222bd1 100644
--- a/gas/config/tc-riscv.c
+++ b/gas/config/tc-riscv.c
@@ -2531,11 +2531,11 @@ riscv_ip (char *str, struct riscv_cl_insn *ip, expressionS *imm_expr,
 	  switch (*oparg)
 	    {
 	    case '\0': /* End of args.  */
+	      if (insn->match_func && !insn->match_func (insn, ip->insn_opcode))
+		break;
+
 	      if (insn->pinfo != INSN_MACRO)
 		{
-		  if (!insn->match_func (insn, ip->insn_opcode))
-		    break;
-
 		  /* For .insn, insn->match and insn->mask are 0.  */
 		  if (riscv_insn_length ((insn->match == 0 && insn->mask == 0)
 					 ? ip->insn_opcode
diff --git a/opcodes/riscv-dis.c b/opcodes/riscv-dis.c
index 2d7c154..6fa9855 100644
--- a/opcodes/riscv-dis.c
+++ b/opcodes/riscv-dis.c
@@ -787,6 +787,9 @@ riscv_disassemble_insn (bfd_vma memaddr,
 
       for (; op->name; op++)
 	{
+	  /* Ignore macro insns.  */
+	  if (op->pinfo == INSN_MACRO)
+	    continue;
 	  /* Does the opcode match?  */
 	  if (! (op->match_func) (op, word))
 	    continue;
diff --git a/opcodes/riscv-opc.c b/opcodes/riscv-opc.c
index fcba499..39196e7 100644
--- a/opcodes/riscv-opc.c
+++ b/opcodes/riscv-opc.c
@@ -164,13 +164,6 @@ match_opcode (const struct riscv_opcode *op, insn_t insn)
 }
 
 static int
-match_never (const struct riscv_opcode *op ATTRIBUTE_UNUSED,
-	     insn_t insn ATTRIBUTE_UNUSED)
-{
-  return 0;
-}
-
-static int
 match_rs1_eq_rs2 (const struct riscv_opcode *op, insn_t insn)
 {
   int rs1 = (insn & MASK_RS1) >> OP_SH_RS1;
@@ -181,7 +174,14 @@ match_rs1_eq_rs2 (const struct riscv_opcode *op, insn_t insn)
 static int
 match_rd_nonzero (const struct riscv_opcode *op, insn_t insn)
 {
-  return match_opcode (op, insn) && ((insn & MASK_RD) != 0);
+  return (op->pinfo == INSN_MACRO || match_opcode (op, insn))
+	 && ((insn & MASK_RD) != 0);
+}
+
+static int
+match_rs1_nonzero (const struct riscv_opcode *op ATTRIBUTE_UNUSED, insn_t insn)
+{
+  return (insn & MASK_RS1) != 0;
 }
 
 static int
@@ -378,10 +378,10 @@ const struct riscv_opcode riscv_opcodes[] =
 {"jal",        32, INSN_CLASS_C, "Ca",        MATCH_C_JAL, MASK_C_JAL, match_opcode, INSN_ALIAS|INSN_JSR },
 {"jal",         0, INSN_CLASS_I, "a",         MATCH_JAL|(X_RA << OP_SH_RD), MASK_JAL|MASK_RD, match_opcode, INSN_ALIAS|INSN_JSR },
 {"jal",         0, INSN_CLASS_I, "d,a",       MATCH_JAL, MASK_JAL, match_opcode, INSN_JSR },
-{"call",        0, INSN_CLASS_I, "d,c",       (X_T1 << OP_SH_RS1), (int) M_CALL, match_never, INSN_MACRO },
-{"call",        0, INSN_CLASS_I, "c",         (X_RA << OP_SH_RS1)|(X_RA << OP_SH_RD), (int) M_CALL, match_never, INSN_MACRO },
-{"tail",        0, INSN_CLASS_I, "c",         (X_T1 << OP_SH_RS1), (int) M_CALL, match_never, INSN_MACRO },
-{"jump",        0, INSN_CLASS_I, "c,s",       0, (int) M_CALL, match_never, INSN_MACRO },
+{"call",        0, INSN_CLASS_I, "d,c",       (X_T1 << OP_SH_RS1), (int) M_CALL, NULL, INSN_MACRO },
+{"call",        0, INSN_CLASS_I, "c",         (X_RA << OP_SH_RS1)|(X_RA << OP_SH_RD), (int) M_CALL, NULL, INSN_MACRO },
+{"tail",        0, INSN_CLASS_I, "c",         (X_T1 << OP_SH_RS1), (int) M_CALL, NULL, INSN_MACRO },
+{"jump",        0, INSN_CLASS_I, "c,s",       0, (int) M_CALL, match_rs1_nonzero, INSN_MACRO },
 {"nop",         0, INSN_CLASS_C, "",          MATCH_C_ADDI, 0xffff, match_opcode, INSN_ALIAS },
 {"nop",         0, INSN_CLASS_I, "",          MATCH_ADDI, MASK_ADDI|MASK_RD|MASK_RS1|MASK_IMM, match_opcode, INSN_ALIAS },
 {"lui",         0, INSN_CLASS_C, "d,Cu",      MATCH_C_LUI, MASK_C_LUI, match_c_lui, INSN_ALIAS },
@@ -389,7 +389,7 @@ const struct riscv_opcode riscv_opcodes[] =
 {"li",          0, INSN_CLASS_C, "d,Cv",      MATCH_C_LUI, MASK_C_LUI, match_c_lui, INSN_ALIAS },
 {"li",          0, INSN_CLASS_C, "d,Co",      MATCH_C_LI, MASK_C_LI, match_rd_nonzero, INSN_ALIAS },
 {"li",          0, INSN_CLASS_I, "d,j",       MATCH_ADDI, MASK_ADDI|MASK_RS1, match_opcode, INSN_ALIAS }, /* addi  */
-{"li",          0, INSN_CLASS_I, "d,I",       0, (int) M_LI,  match_never, INSN_MACRO },
+{"li",          0, INSN_CLASS_I, "d,I",       0, (int) M_LI,  NULL, INSN_MACRO },
 {"mv",          0, INSN_CLASS_C, "d,CV",      MATCH_C_MV, MASK_C_MV, match_c_add, INSN_ALIAS },
 {"mv",          0, INSN_CLASS_I, "d,s",       MATCH_ADDI, MASK_ADDI|MASK_IMM, match_opcode, INSN_ALIAS },
 {"move",        0, INSN_CLASS_C, "d,CV",      MATCH_C_MV, MASK_C_MV, match_c_add, INSN_ALIAS },
@@ -440,11 +440,11 @@ const struct riscv_opcode riscv_opcodes[] =
 {"add",         0, INSN_CLASS_I, "d,s,t",     MATCH_ADD, MASK_ADD, match_opcode, 0 },
 {"add",         0, INSN_CLASS_I, "d,s,t,1",   MATCH_ADD, MASK_ADD, match_opcode, 0 },
 {"add",         0, INSN_CLASS_I, "d,s,j",     MATCH_ADDI, MASK_ADDI, match_opcode, INSN_ALIAS },
-{"la",          0, INSN_CLASS_I, "d,B",       0, (int) M_LA, match_never, INSN_MACRO },
-{"lla",         0, INSN_CLASS_I, "d,B",       0, (int) M_LLA, match_never, INSN_MACRO },
-{"lga",         0, INSN_CLASS_I, "d,B",       0, (int) M_LGA, match_never, INSN_MACRO },
-{"la.tls.gd",   0, INSN_CLASS_I, "d,A",       0, (int) M_LA_TLS_GD, match_never, INSN_MACRO },
-{"la.tls.ie",   0, INSN_CLASS_I, "d,A",       0, (int) M_LA_TLS_IE, match_never, INSN_MACRO },
+{"la",          0, INSN_CLASS_I, "d,B",       0, (int) M_LA, match_rd_nonzero, INSN_MACRO },
+{"lla",         0, INSN_CLASS_I, "d,B",       0, (int) M_LLA, NULL, INSN_MACRO },
+{"lga",         0, INSN_CLASS_I, "d,B",       0, (int) M_LGA, match_rd_nonzero, INSN_MACRO },
+{"la.tls.gd",   0, INSN_CLASS_I, "d,A",       0, (int) M_LA_TLS_GD, NULL, INSN_MACRO },
+{"la.tls.ie",   0, INSN_CLASS_I, "d,A",       0, (int) M_LA_TLS_IE, match_rd_nonzero, INSN_MACRO },
 {"neg",         0, INSN_CLASS_I, "d,t",       MATCH_SUB, MASK_SUB|MASK_RS1, match_opcode, INSN_ALIAS }, /* sub 0  */
 {"slli",        0, INSN_CLASS_C, "d,CU,C>",   MATCH_C_SLLI, MASK_C_SLLI, match_slli_as_c_slli, INSN_ALIAS },
 {"slli",        0, INSN_CLASS_I, "d,s,>",     MATCH_SLLI, MASK_SLLI, match_opcode, 0 },
@@ -464,20 +464,20 @@ const struct riscv_opcode riscv_opcodes[] =
 {"sub",         0, INSN_CLASS_C, "Cs,Cw,Ct",  MATCH_C_SUB, MASK_C_SUB, match_opcode, INSN_ALIAS },
 {"sub",         0, INSN_CLASS_I, "d,s,t",     MATCH_SUB, MASK_SUB, match_opcode, 0 },
 {"lb",          0, INSN_CLASS_I, "d,o(s)",    MATCH_LB, MASK_LB, match_opcode, INSN_DREF|INSN_1_BYTE },
-{"lb",          0, INSN_CLASS_I, "d,A",       0, (int) M_Lx, match_never, INSN_MACRO },
+{"lb",          0, INSN_CLASS_I, "d,A",       0, (int) M_Lx, match_rd_nonzero, INSN_MACRO },
 {"lbu",         0, INSN_CLASS_ZCB, "Ct,Wcb(Cs)", MATCH_C_LBU, MASK_C_LBU, match_opcode, INSN_ALIAS|INSN_DREF|INSN_1_BYTE },
 {"lbu",         0, INSN_CLASS_I, "d,o(s)",    MATCH_LBU, MASK_LBU, match_opcode, INSN_DREF|INSN_1_BYTE },
-{"lbu",         0, INSN_CLASS_I, "d,A",       0, (int) M_Lx, match_never, INSN_MACRO },
+{"lbu",         0, INSN_CLASS_I, "d,A",       0, (int) M_Lx, match_rd_nonzero, INSN_MACRO },
 {"lh",          0, INSN_CLASS_ZCB, "Ct,Wch(Cs)", MATCH_C_LH, MASK_C_LH, match_opcode, INSN_ALIAS|INSN_DREF|INSN_2_BYTE },
 {"lh",          0, INSN_CLASS_I, "d,o(s)",    MATCH_LH, MASK_LH, match_opcode, INSN_DREF|INSN_2_BYTE },
-{"lh",          0, INSN_CLASS_I, "d,A",       0, (int) M_Lx, match_never, INSN_MACRO },
+{"lh",          0, INSN_CLASS_I, "d,A",       0, (int) M_Lx, match_rd_nonzero, INSN_MACRO },
 {"lhu",         0, INSN_CLASS_ZCB, "Ct,Wch(Cs)", MATCH_C_LHU, MASK_C_LHU, match_opcode, INSN_ALIAS|INSN_DREF|INSN_2_BYTE },
 {"lhu",         0, INSN_CLASS_I, "d,o(s)",    MATCH_LHU, MASK_LHU, match_opcode, INSN_DREF|INSN_2_BYTE },
-{"lhu",         0, INSN_CLASS_I, "d,A",       0, (int) M_Lx, match_never, INSN_MACRO },
+{"lhu",         0, INSN_CLASS_I, "d,A",       0, (int) M_Lx, match_rd_nonzero, INSN_MACRO },
 {"lw",          0, INSN_CLASS_C, "d,Cm(Cc)",  MATCH_C_LWSP, MASK_C_LWSP, match_rd_nonzero, INSN_ALIAS|INSN_DREF|INSN_4_BYTE },
 {"lw",          0, INSN_CLASS_C, "Ct,Ck(Cs)", MATCH_C_LW, MASK_C_LW, match_opcode, INSN_ALIAS|INSN_DREF|INSN_4_BYTE },
 {"lw",          0, INSN_CLASS_I, "d,o(s)",    MATCH_LW, MASK_LW, match_opcode, INSN_DREF|INSN_4_BYTE },
-{"lw",          0, INSN_CLASS_I, "d,A",       0, (int) M_Lx, match_never, INSN_MACRO },
+{"lw",          0, INSN_CLASS_I, "d,A",       0, (int) M_Lx, match_rd_nonzero, INSN_MACRO },
 {"not",         0, INSN_CLASS_ZCB,  "Cs,Cw",  MATCH_C_NOT, MASK_C_NOT, match_opcode, INSN_ALIAS },
 {"not",         0, INSN_CLASS_I, "d,s",       MATCH_XORI|MASK_IMM, MASK_XORI|MASK_IMM, match_opcode, INSN_ALIAS },
 {"ori",         0, INSN_CLASS_I, "d,s,j",     MATCH_ORI, MASK_ORI, match_opcode, 0 },
@@ -500,14 +500,14 @@ const struct riscv_opcode riscv_opcodes[] =
 {"sgtu",        0, INSN_CLASS_I, "d,t,s",     MATCH_SLTU, MASK_SLTU, match_opcode, INSN_ALIAS },
 {"sb",          0, INSN_CLASS_ZCB, "Ct,Wcb(Cs)", MATCH_C_SB, MASK_C_SB, match_opcode, INSN_DREF|INSN_1_BYTE|INSN_ALIAS },
 {"sb",          0, INSN_CLASS_I, "t,q(s)",    MATCH_SB, MASK_SB, match_opcode, INSN_DREF|INSN_1_BYTE },
-{"sb",          0, INSN_CLASS_I, "t,A,s",     0, (int) M_Sx_FSx, match_never, INSN_MACRO },
+{"sb",          0, INSN_CLASS_I, "t,A,s",     0, (int) M_Sx_FSx, match_rs1_nonzero, INSN_MACRO },
 {"sh",          0, INSN_CLASS_ZCB, "Ct,Wch(Cs)", MATCH_C_SH, MASK_C_SH, match_opcode, INSN_DREF|INSN_2_BYTE|INSN_ALIAS },
 {"sh",          0, INSN_CLASS_I, "t,q(s)",    MATCH_SH, MASK_SH, match_opcode, INSN_DREF|INSN_2_BYTE },
-{"sh",          0, INSN_CLASS_I, "t,A,s",     0, (int) M_Sx_FSx, match_never, INSN_MACRO },
+{"sh",          0, INSN_CLASS_I, "t,A,s",     0, (int) M_Sx_FSx, match_rs1_nonzero, INSN_MACRO },
 {"sw",          0, INSN_CLASS_C, "CV,CM(Cc)", MATCH_C_SWSP, MASK_C_SWSP, match_opcode, INSN_ALIAS|INSN_DREF|INSN_4_BYTE },
 {"sw",          0, INSN_CLASS_C, "Ct,Ck(Cs)", MATCH_C_SW, MASK_C_SW, match_opcode, INSN_ALIAS|INSN_DREF|INSN_4_BYTE },
 {"sw",          0, INSN_CLASS_I, "t,q(s)",    MATCH_SW, MASK_SW, match_opcode, INSN_DREF|INSN_4_BYTE },
-{"sw",          0, INSN_CLASS_I, "t,A,s",     0, (int) M_Sx_FSx, match_never, INSN_MACRO },
+{"sw",          0, INSN_CLASS_I, "t,A,s",     0, (int) M_Sx_FSx, match_rs1_nonzero, INSN_MACRO },
 {"fence",       0, INSN_CLASS_I, "",          MATCH_FENCE|MASK_PRED|MASK_SUCC, MASK_FENCE|MASK_RD|MASK_RS1|MASK_IMM, match_opcode, INSN_ALIAS },
 {"fence",       0, INSN_CLASS_I, "P,Q",       MATCH_FENCE, MASK_FENCE|MASK_RD|MASK_RS1|(MASK_IMM & ~MASK_PRED & ~MASK_SUCC), match_opcode, 0 },
 {"fence.i",     0, INSN_CLASS_ZIFENCEI, "",   MATCH_FENCE_I, MASK_FENCE|MASK_RD|MASK_RS1|MASK_IMM, match_opcode, 0 },
@@ -526,15 +526,15 @@ const struct riscv_opcode riscv_opcodes[] =
 {"xor",         0, INSN_CLASS_C, "Cs,Ct,Cw",  MATCH_C_XOR, MASK_C_XOR, match_opcode, INSN_ALIAS },
 {"xor",         0, INSN_CLASS_I, "d,s,t",     MATCH_XOR, MASK_XOR, match_opcode, 0 },
 {"lwu",        64, INSN_CLASS_I, "d,o(s)",    MATCH_LWU, MASK_LWU, match_opcode, INSN_DREF|INSN_4_BYTE },
-{"lwu",        64, INSN_CLASS_I, "d,A",       0, (int) M_Lx, match_never, INSN_MACRO },
+{"lwu",        64, INSN_CLASS_I, "d,A",       0, (int) M_Lx, match_rd_nonzero, INSN_MACRO },
 {"ld",         64, INSN_CLASS_C, "d,Cn(Cc)",  MATCH_C_LDSP, MASK_C_LDSP, match_rd_nonzero, INSN_ALIAS|INSN_DREF|INSN_8_BYTE },
 {"ld",         64, INSN_CLASS_C, "Ct,Cl(Cs)", MATCH_C_LD, MASK_C_LD, match_opcode, INSN_ALIAS|INSN_DREF|INSN_8_BYTE },
 {"ld",         64, INSN_CLASS_I, "d,o(s)",    MATCH_LD, MASK_LD, match_opcode, INSN_DREF|INSN_8_BYTE },
-{"ld",         64, INSN_CLASS_I, "d,A",       0, (int) M_Lx, match_never, INSN_MACRO },
+{"ld",         64, INSN_CLASS_I, "d,A",       0, (int) M_Lx, match_rd_nonzero, INSN_MACRO },
 {"sd",         64, INSN_CLASS_C, "CV,CN(Cc)", MATCH_C_SDSP, MASK_C_SDSP, match_opcode, INSN_ALIAS|INSN_DREF|INSN_8_BYTE },
 {"sd",         64, INSN_CLASS_C, "Ct,Cl(Cs)", MATCH_C_SD, MASK_C_SD, match_opcode, INSN_ALIAS|INSN_DREF|INSN_8_BYTE },
 {"sd",         64, INSN_CLASS_I, "t,q(s)",    MATCH_SD, MASK_SD, match_opcode, INSN_DREF|INSN_8_BYTE },
-{"sd",         64, INSN_CLASS_I, "t,A,s",     0, (int) M_Sx_FSx, match_never, INSN_MACRO },
+{"sd",         64, INSN_CLASS_I, "t,A,s",     0, (int) M_Sx_FSx, match_rs1_nonzero, INSN_MACRO },
 {"sext.w",     64, INSN_CLASS_C, "d,CU",      MATCH_C_ADDIW, MASK_C_ADDIW|MASK_RVC_IMM, match_rd_nonzero, INSN_ALIAS },
 {"sext.w",     64, INSN_CLASS_I, "d,s",       MATCH_ADDIW, MASK_ADDIW|MASK_IMM, match_opcode, INSN_ALIAS },
 {"addiw",      64, INSN_CLASS_C, "d,CU,Co",   MATCH_C_ADDIW, MASK_C_ADDIW, match_rd_nonzero, INSN_ALIAS },
@@ -665,9 +665,9 @@ const struct riscv_opcode riscv_opcodes[] =
 
 /* Half-precision floating-point instruction subset.  */
 {"flh",        0, INSN_CLASS_ZFHMIN,   "D,o(s)",    MATCH_FLH, MASK_FLH, match_opcode, INSN_DREF|INSN_2_BYTE },
-{"flh",        0, INSN_CLASS_ZFHMIN,   "D,A,s",     0, (int) M_FLx, match_never, INSN_MACRO },
+{"flh",        0, INSN_CLASS_ZFHMIN,   "D,A,s",     0, (int) M_FLx, match_rs1_nonzero, INSN_MACRO },
 {"fsh",        0, INSN_CLASS_ZFHMIN,   "T,q(s)",    MATCH_FSH, MASK_FSH, match_opcode, INSN_DREF|INSN_2_BYTE },
-{"fsh",        0, INSN_CLASS_ZFHMIN,   "T,A,s",     0, (int) M_Sx_FSx, match_never, INSN_MACRO },
+{"fsh",        0, INSN_CLASS_ZFHMIN,   "T,A,s",     0, (int) M_Sx_FSx, match_rs1_nonzero, INSN_MACRO },
 {"fmv.x.h",    0, INSN_CLASS_ZFHMIN,   "d,S",       MATCH_FMV_X_H, MASK_FMV_X_H, match_opcode, 0 },
 {"fmv.h.x",    0, INSN_CLASS_ZFHMIN,   "D,s",       MATCH_FMV_H_X, MASK_FMV_H_X, match_opcode, 0 },
 {"fmv.h",      0, INSN_CLASS_ZFH_INX,   "D,U",       MATCH_FSGNJ_H, MASK_FSGNJ_H, match_rs1_eq_rs2, INSN_ALIAS },
@@ -748,11 +748,11 @@ const struct riscv_opcode riscv_opcodes[] =
 {"flw",       32, INSN_CLASS_F_AND_C, "D,Cm(Cc)",  MATCH_C_FLWSP, MASK_C_FLWSP, match_opcode, INSN_ALIAS|INSN_DREF|INSN_4_BYTE },
 {"flw",       32, INSN_CLASS_F_AND_C, "CD,Ck(Cs)", MATCH_C_FLW, MASK_C_FLW, match_opcode, INSN_ALIAS|INSN_DREF|INSN_4_BYTE },
 {"flw",        0, INSN_CLASS_F,   "D,o(s)",    MATCH_FLW, MASK_FLW, match_opcode, INSN_DREF|INSN_4_BYTE },
-{"flw",        0, INSN_CLASS_F,   "D,A,s",     0, (int) M_FLx, match_never, INSN_MACRO },
+{"flw",        0, INSN_CLASS_F,   "D,A,s",     0, (int) M_FLx, match_rs1_nonzero, INSN_MACRO },
 {"fsw",       32, INSN_CLASS_F_AND_C, "CT,CM(Cc)", MATCH_C_FSWSP, MASK_C_FSWSP, match_opcode, INSN_ALIAS|INSN_DREF|INSN_4_BYTE },
 {"fsw",       32, INSN_CLASS_F_AND_C, "CD,Ck(Cs)", MATCH_C_FSW, MASK_C_FSW, match_opcode, INSN_ALIAS|INSN_DREF|INSN_4_BYTE },
 {"fsw",        0, INSN_CLASS_F,   "T,q(s)",    MATCH_FSW, MASK_FSW, match_opcode, INSN_DREF|INSN_4_BYTE },
-{"fsw",        0, INSN_CLASS_F,   "T,A,s",     0, (int) M_Sx_FSx, match_never, INSN_MACRO },
+{"fsw",        0, INSN_CLASS_F,   "T,A,s",     0, (int) M_Sx_FSx, match_rs1_nonzero, INSN_MACRO },
 {"fmv.x.w",    0, INSN_CLASS_F,   "d,S",       MATCH_FMV_X_S, MASK_FMV_X_S, match_opcode, 0 },
 {"fmv.w.x",    0, INSN_CLASS_F,   "D,s",       MATCH_FMV_S_X, MASK_FMV_S_X, match_opcode, 0 },
 {"fmv.x.s",    0, INSN_CLASS_F,   "d,S",       MATCH_FMV_X_S, MASK_FMV_X_S, match_opcode, 0 },
@@ -810,11 +810,11 @@ const struct riscv_opcode riscv_opcodes[] =
 {"fld",        0, INSN_CLASS_D_AND_C, "D,Cn(Cc)",  MATCH_C_FLDSP, MASK_C_FLDSP, match_opcode, INSN_ALIAS|INSN_DREF|INSN_8_BYTE },
 {"fld",        0, INSN_CLASS_D_AND_C, "CD,Cl(Cs)", MATCH_C_FLD, MASK_C_FLD, match_opcode, INSN_ALIAS|INSN_DREF|INSN_8_BYTE },
 {"fld",        0, INSN_CLASS_D,   "D,o(s)",    MATCH_FLD, MASK_FLD, match_opcode, INSN_DREF|INSN_8_BYTE },
-{"fld",        0, INSN_CLASS_D,   "D,A,s",     0, (int) M_FLx, match_never, INSN_MACRO },
+{"fld",        0, INSN_CLASS_D,   "D,A,s",     0, (int) M_FLx, match_rs1_nonzero, INSN_MACRO },
 {"fsd",        0, INSN_CLASS_D_AND_C, "CT,CN(Cc)", MATCH_C_FSDSP, MASK_C_FSDSP, match_opcode, INSN_ALIAS|INSN_DREF|INSN_8_BYTE },
 {"fsd",        0, INSN_CLASS_D_AND_C, "CD,Cl(Cs)", MATCH_C_FSD, MASK_C_FSD, match_opcode, INSN_ALIAS|INSN_DREF|INSN_8_BYTE },
 {"fsd",        0, INSN_CLASS_D,   "T,q(s)",    MATCH_FSD, MASK_FSD, match_opcode, INSN_DREF|INSN_8_BYTE },
-{"fsd",        0, INSN_CLASS_D,   "T,A,s",     0, (int) M_Sx_FSx, match_never, INSN_MACRO },
+{"fsd",        0, INSN_CLASS_D,   "T,A,s",     0, (int) M_Sx_FSx, match_rs1_nonzero, INSN_MACRO },
 {"fmv.d",      0, INSN_CLASS_D_INX,   "D,U",       MATCH_FSGNJ_D, MASK_FSGNJ_D, match_rs1_eq_rs2, INSN_ALIAS },
 {"fneg.d",     0, INSN_CLASS_D_INX,   "D,U",       MATCH_FSGNJN_D, MASK_FSGNJN_D, match_rs1_eq_rs2, INSN_ALIAS },
 {"fabs.d",     0, INSN_CLASS_D_INX,   "D,U",       MATCH_FSGNJX_D, MASK_FSGNJX_D, match_rs1_eq_rs2, INSN_ALIAS },
@@ -869,9 +869,9 @@ const struct riscv_opcode riscv_opcodes[] =
 
 /* Quad-precision floating-point instruction subset.  */
 {"flq",        0, INSN_CLASS_Q,   "D,o(s)",    MATCH_FLQ, MASK_FLQ, match_opcode, INSN_DREF|INSN_16_BYTE },
-{"flq",        0, INSN_CLASS_Q,   "D,A,s",     0, (int) M_FLx, match_never, INSN_MACRO },
+{"flq",        0, INSN_CLASS_Q,   "D,A,s",     0, (int) M_FLx, match_rs1_nonzero, INSN_MACRO },
 {"fsq",        0, INSN_CLASS_Q,   "T,q(s)",    MATCH_FSQ, MASK_FSQ, match_opcode, INSN_DREF|INSN_16_BYTE },
-{"fsq",        0, INSN_CLASS_Q,   "T,A,s",     0, (int) M_Sx_FSx, match_never, INSN_MACRO },
+{"fsq",        0, INSN_CLASS_Q,   "T,A,s",     0, (int) M_Sx_FSx, match_rs1_nonzero, INSN_MACRO },
 {"fmv.q",      0, INSN_CLASS_Q_INX,   "D,U",       MATCH_FSGNJ_Q, MASK_FSGNJ_Q, match_rs1_eq_rs2, INSN_ALIAS },
 {"fneg.q",     0, INSN_CLASS_Q_INX,   "D,U",       MATCH_FSGNJN_Q, MASK_FSGNJN_Q, match_rs1_eq_rs2, INSN_ALIAS },
 {"fabs.q",     0, INSN_CLASS_Q_INX,   "D,U",       MATCH_FSGNJX_Q, MASK_FSGNJX_Q, match_rs1_eq_rs2, INSN_ALIAS },
@@ -1041,14 +1041,14 @@ const struct riscv_opcode riscv_opcodes[] =
 {"maxu",       0, INSN_CLASS_ZBB,  "d,s,t", MATCH_MAXU, MASK_MAXU, match_opcode, 0 },
 {"sext.b",     0, INSN_CLASS_ZCB_AND_ZBB,  "Cs,Cw", MATCH_C_SEXT_B, MASK_C_SEXT_B, match_opcode, INSN_ALIAS },
 {"sext.b",     0, INSN_CLASS_ZBB,  "d,s",   MATCH_SEXT_B, MASK_SEXT_B, match_opcode, 0 },
-{"sext.b",     0, INSN_CLASS_I,         "d,s",   0, (int) M_SEXTB, match_never, INSN_MACRO },
+{"sext.b",     0, INSN_CLASS_I,         "d,s",   0, (int) M_SEXTB, NULL, INSN_MACRO },
 {"sext.h",     0, INSN_CLASS_ZCB_AND_ZBB,  "Cs,Cw", MATCH_C_SEXT_H, MASK_C_SEXT_H, match_opcode, INSN_ALIAS },
 {"sext.h",     0, INSN_CLASS_ZBB,  "d,s",   MATCH_SEXT_H, MASK_SEXT_H, match_opcode, 0 },
-{"sext.h",     0, INSN_CLASS_I,         "d,s",   0, (int) M_SEXTH, match_never, INSN_MACRO },
+{"sext.h",     0, INSN_CLASS_I,         "d,s",   0, (int) M_SEXTH, NULL, INSN_MACRO },
 {"zext.h",     0, INSN_CLASS_ZCB_AND_ZBB,  "Cs,Cw", MATCH_C_ZEXT_H, MASK_C_ZEXT_H, match_opcode, INSN_ALIAS },
 {"zext.h",    32, INSN_CLASS_ZBB,  "d,s",   MATCH_PACK, MASK_PACK | MASK_RS2, match_opcode, 0 },
 {"zext.h",    64, INSN_CLASS_ZBB,  "d,s",   MATCH_PACKW, MASK_PACKW | MASK_RS2, match_opcode, 0 },
-{"zext.h",     0, INSN_CLASS_I,         "d,s",   0, (int) M_ZEXTH, match_never, INSN_MACRO },
+{"zext.h",     0, INSN_CLASS_I,         "d,s",   0, (int) M_ZEXTH, NULL, INSN_MACRO },
 {"orc.b",      0, INSN_CLASS_ZBB,  "d,s",   MATCH_GORCI | MATCH_SHAMT_ORC_B, MASK_GORCI | MASK_SHAMT, match_opcode, 0 },
 {"clzw",      64, INSN_CLASS_ZBB,  "d,s",   MATCH_CLZW, MASK_CLZW, match_opcode, 0 },
 {"ctzw",      64, INSN_CLASS_ZBB,  "d,s",   MATCH_CTZW, MASK_CTZW, match_opcode, 0 },
@@ -1083,7 +1083,7 @@ const struct riscv_opcode riscv_opcodes[] =
 {"sh3add.uw", 64, INSN_CLASS_ZBA,  "d,s,t", MATCH_SH3ADD_UW, MASK_SH3ADD_UW, match_opcode, 0 },
 {"zext.w",    64, INSN_CLASS_ZCB_AND_ZBA,  "Cs,Cw", MATCH_C_ZEXT_W, MASK_C_ZEXT_W, match_opcode, INSN_ALIAS },
 {"zext.w",    64, INSN_CLASS_ZBA,  "d,s",   MATCH_ADD_UW, MASK_ADD_UW | MASK_RS2, match_opcode, INSN_ALIAS },
-{"zext.w",    64, INSN_CLASS_I, "d,s",       0, (int) M_ZEXTW, match_never, INSN_MACRO },
+{"zext.w",    64, INSN_CLASS_I, "d,s",       0, (int) M_ZEXTW, NULL, INSN_MACRO },
 {"add.uw",    64, INSN_CLASS_ZBA,  "d,s,t", MATCH_ADD_UW, MASK_ADD_UW, match_opcode, 0 },
 {"slli.uw",   64, INSN_CLASS_ZBA,  "d,s,>", MATCH_SLLI_UW, MASK_SLLI_UW, match_opcode, 0 },
 
@@ -1620,10 +1620,10 @@ const struct riscv_opcode riscv_opcodes[] =
 {"vmsgeu.vi",  0, INSN_CLASS_V,  "Vd,Vu,0Vm", MATCH_VMSEQVV, MASK_VMSEQVV, match_vs1_eq_vs2, INSN_ALIAS },
 {"vmsgeu.vi",  0, INSN_CLASS_V,  "Vd,Vt,VkVm", MATCH_VMSGTUVI, MASK_VMSGTUVI, match_opcode, INSN_ALIAS },
 
-{"vmsge.vx",   0, INSN_CLASS_V, "Vd,Vt,sVm", 0, (int) M_VMSGE, match_never, INSN_MACRO },
-{"vmsge.vx",   0, INSN_CLASS_V, "Vd,Vt,s,VM,VT", 0, (int) M_VMSGE, match_never, INSN_MACRO },
-{"vmsgeu.vx",  0, INSN_CLASS_V, "Vd,Vt,sVm", 1, (int) M_VMSGE, match_never, INSN_MACRO },
-{"vmsgeu.vx",  0, INSN_CLASS_V, "Vd,Vt,s,VM,VT", 1, (int) M_VMSGE, match_never, INSN_MACRO },
+{"vmsge.vx",   0, INSN_CLASS_V, "Vd,Vt,sVm", 0, (int) M_VMSGE, NULL, INSN_MACRO },
+{"vmsge.vx",   0, INSN_CLASS_V, "Vd,Vt,s,VM,VT", 0, (int) M_VMSGE, NULL, INSN_MACRO },
+{"vmsgeu.vx",  0, INSN_CLASS_V, "Vd,Vt,sVm", 1, (int) M_VMSGE, NULL, INSN_MACRO },
+{"vmsgeu.vx",  0, INSN_CLASS_V, "Vd,Vt,s,VM,VT", 1, (int) M_VMSGE, NULL, INSN_MACRO },
 
 {"vminu.vv",   0, INSN_CLASS_V,  "Vd,Vt,VsVm", MATCH_VMINUVV, MASK_VMINUVV, match_opcode, 0},
 {"vminu.vx",   0, INSN_CLASS_V,  "Vd,Vt,sVm", MATCH_VMINUVX, MASK_VMINUVX, match_opcode, 0},