RISC-V: PR33216, Fixed gcc testcases failed for commit 28520d7

I made a stupid mistake in the commit 28520d7, allow to assemble slli/srli/srai
with 0 immediate to hint c.slli/c.srli/c.srai.  These hints will be regared as
illegal instruction for gdb and qemu, so at least I got following gcc testcases
failed,

                === g++: Unexpected fails for rv64gc lp64d medlow ===
FAIL: c-c++-common/torture/builtin-arith-overflow-17.c   -O0  execution test
FAIL: c-c++-common/torture/builtin-arith-overflow-6.c   -O0  execution test
FAIL: c-c++-common/torture/builtin-arith-overflow-p-17.c   -O0  execution test
FAIL: c-c++-common/torture/builtin-arith-overflow-p-6.c   -O0  execution test

                === gfortran: Unexpected fails for rv64gc lp64d medlow ===
FAIL: gfortran.dg/leadz_trailz_2.f90   -O0  execution test

                === gcc: Unexpected fails for rv64gc lp64d medlow ===
FAIL: c-c++-common/torture/builtin-arith-overflow-17.c   -O0  execution test
FAIL: c-c++-common/torture/builtin-arith-overflow-6.c   -O0  execution test
FAIL: c-c++-common/torture/builtin-arith-overflow-p-17.c   -O0  execution test
FAIL: c-c++-common/torture/builtin-arith-overflow-p-6.c   -O0  execution test

So we should just allow c.slli/c.srli/c.srai with zero immediate as hints, but
don't allow slli/srli/srai with zero immediate.

gas/
	PR 33216
	* testsuite/gas/riscv/c-zero-imm.d: Only allow c.slli/c.srli/c.srai
	with zero immediate as hints, but don't allow slli/srli/srai with
	zero immediate.
	* testsuite/gas/riscv/c-zero-imm.s: Likewise.
opcodes/
	PR 33216
	* riscv-opc.c (match_slli_as_c_slli): Added back.
	(match_srxi_as_c_srxi): Likewise.
	(riscv_opcodes): Only allow c.slli/c.srli/c.srai with zero immediate
	as hints, but don't allow slli/srli/srai with zero immediate.

3 files changed, 40 insertions, 16 deletions

diff --git a/gas/testsuite/gas/riscv/c-zero-imm.d b/gas/testsuite/gas/riscv/c-zero-imm.d
index 56274df..c3bab3a 100644
--- a/gas/testsuite/gas/riscv/c-zero-imm.d
+++ b/gas/testsuite/gas/riscv/c-zero-imm.d
@@ -14,10 +14,13 @@ Disassembly of section .text:
 [ 	]+8:[ 	]+0001[ 	]+nop
 [ 	]+a:[ 	]+873a[ 	]+mv[ 	]+a4,a4
 [ 	]+c:[ 	]+0781[ 	]+addi[ 	]+a5,a5,0
-[ 	]+e:[ 	]+0502[ 	]+slli[ 	]+a0,a0,0x0
-[ 	]+10:[ 	]+8181[ 	]+srli[ 	]+a1,a1,0x0
-[ 	]+12:[ 	]+8601[ 	]+srai[ 	]+a2,a2,0x0
-[ 	]+14:[ 	]+0682[ 	]+slli[ 	]+a3,a3,0x0
-[ 	]+16:[ 	]+8301[ 	]+srli[ 	]+a4,a4,0x0
-[ 	]+18:[ 	]+8781[ 	]+srai[ 	]+a5,a5,0x0
+[ 	]+e:[ 	]+00051513[ 	]+slli[ 	]+a0,a0,0x0
+[ 	]+12:[ 	]+0005d593[ 	]+srli[ 	]+a1,a1,0x0
+[ 	]+16:[ 	]+40065613[ 	]+srai[ 	]+a2,a2,0x0
+[ 	]+1a:[ 	]+0502[ 	]+c.slli[ 	]+a0,0x0
+[ 	]+1c:[ 	]+8181[ 	]+c.srli[ 	]+a1,0x0
+[ 	]+1e:[ 	]+8601[ 	]+c.srai[ 	]+a2,0x0
+[ 	]+20:[ 	]+0682[ 	]+c.slli[ 	]+a3,0x0
+[ 	]+22:[ 	]+8301[ 	]+c.srli[ 	]+a4,0x0
+[ 	]+24:[ 	]+8781[ 	]+c.srai[ 	]+a5,0x0
 #...
diff --git a/gas/testsuite/gas/riscv/c-zero-imm.s b/gas/testsuite/gas/riscv/c-zero-imm.s
index be7c820..54269cf 100644
--- a/gas/testsuite/gas/riscv/c-zero-imm.s
+++ b/gas/testsuite/gas/riscv/c-zero-imm.s
@@ -9,11 +9,15 @@
 	addi a4,a4,0
 	# These are hints.
 	c.addi a5,0
-	# Allow these compress to hints.
+	# Don't let these compress to hints
 	slli a0, a0, 0
 	srli a1, a1, 0
 	srai a2, a2, 0
 	# These are hints.
+	c.slli a0, 0
+	c.srli a1, 0
+	c.srai a2, 0
+	# These are also hints.
 	c.slli64 a3
 	c.srli64 a4
 	c.srai64 a5
diff --git a/opcodes/riscv-opc.c b/opcodes/riscv-opc.c
index b34fffe..e6fe5e9 100644
--- a/opcodes/riscv-opc.c
+++ b/opcodes/riscv-opc.c
@@ -313,6 +313,14 @@ match_c_addi4spn (const struct riscv_opcode *op, insn_t insn)
   return match_opcode (op, insn) && EXTRACT_CIWTYPE_ADDI4SPN_IMM (insn) != 0;
 }
 
+/* This requires a non-zero rd, and a non-zero shift.  */
+
+static int
+match_slli_as_c_slli (const struct riscv_opcode *op, insn_t insn)
+{
+  return match_rd_nonzero (op, insn) && EXTRACT_CITYPE_IMM (insn) != 0;
+}
+
 /* This requires a zero shift.  A zero rd is a hint, so is allowed.  */
 
 static int
@@ -321,6 +329,15 @@ match_c_slli64 (const struct riscv_opcode *op, insn_t insn)
   return match_opcode (op, insn) && EXTRACT_CITYPE_IMM (insn) == 0;
 }
 
+/* This is used for both srli and srai.  This requires a non-zero shift.
+   A zero rd is not possible.  */
+
+static int
+match_srxi_as_c_srxi (const struct riscv_opcode *op, insn_t insn)
+{
+  return match_opcode (op, insn) && EXTRACT_CITYPE_IMM (insn) != 0;
+}
+
 static int
 match_vs1_eq_vs2 (const struct riscv_opcode *op,
 		  insn_t insn)
@@ -552,19 +569,19 @@ const struct riscv_opcode riscv_opcodes[] =
 {"mips.ehb", 0, INSN_CLASS_XMIPSEXECTL, "", MATCH_MIPS_EHB, MASK_MIPS_EHB, match_opcode, 0 },
 {"mips.ihb", 0, INSN_CLASS_XMIPSEXECTL, "", MATCH_MIPS_IHB, MASK_MIPS_IHB, match_opcode, 0 },
 {"mips.pause", 0, INSN_CLASS_XMIPSEXECTL, "", MATCH_MIPS_PAUSE, MASK_MIPS_PAUSE, match_opcode, 0 },
-{"slli",        0, INSN_CLASS_ZCA, "d,CU,C>",   MATCH_C_SLLI, MASK_C_SLLI, match_rd_nonzero, INSN_ALIAS },
+{"slli",        0, INSN_CLASS_ZCA, "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 },
-{"sll",         0, INSN_CLASS_ZCA, "d,CU,C>",   MATCH_C_SLLI, MASK_C_SLLI, match_rd_nonzero, INSN_ALIAS },
+{"sll",         0, INSN_CLASS_ZCA, "d,CU,C>",   MATCH_C_SLLI, MASK_C_SLLI, match_slli_as_c_slli, INSN_ALIAS },
 {"sll",         0, INSN_CLASS_I, "d,s,t",     MATCH_SLL, MASK_SLL, match_opcode, 0 },
 {"sll",         0, INSN_CLASS_I, "d,s,>",     MATCH_SLLI, MASK_SLLI, match_opcode, INSN_ALIAS },
-{"srli",        0, INSN_CLASS_ZCA, "Cs,Cw,C>",  MATCH_C_SRLI, MASK_C_SRLI, match_rd_nonzero, INSN_ALIAS },
+{"srli",        0, INSN_CLASS_ZCA, "Cs,Cw,C>",  MATCH_C_SRLI, MASK_C_SRLI, match_srxi_as_c_srxi, INSN_ALIAS },
 {"srli",        0, INSN_CLASS_I, "d,s,>",     MATCH_SRLI, MASK_SRLI, match_opcode, 0 },
-{"srl",         0, INSN_CLASS_ZCA, "Cs,Cw,C>",  MATCH_C_SRLI, MASK_C_SRLI, match_rd_nonzero, INSN_ALIAS },
+{"srl",         0, INSN_CLASS_ZCA, "Cs,Cw,C>",  MATCH_C_SRLI, MASK_C_SRLI, match_srxi_as_c_srxi, INSN_ALIAS },
 {"srl",         0, INSN_CLASS_I, "d,s,t",     MATCH_SRL, MASK_SRL, match_opcode, 0 },
 {"srl",         0, INSN_CLASS_I, "d,s,>",     MATCH_SRLI, MASK_SRLI, match_opcode, INSN_ALIAS },
-{"srai",        0, INSN_CLASS_ZCA, "Cs,Cw,C>",  MATCH_C_SRAI, MASK_C_SRAI, match_rd_nonzero, INSN_ALIAS },
+{"srai",        0, INSN_CLASS_ZCA, "Cs,Cw,C>",  MATCH_C_SRAI, MASK_C_SRAI, match_srxi_as_c_srxi, INSN_ALIAS },
 {"srai",        0, INSN_CLASS_I, "d,s,>",     MATCH_SRAI, MASK_SRAI, match_opcode, 0 },
-{"sra",         0, INSN_CLASS_ZCA, "Cs,Cw,C>",  MATCH_C_SRAI, MASK_C_SRAI, match_rd_nonzero, INSN_ALIAS },
+{"sra",         0, INSN_CLASS_ZCA, "Cs,Cw,C>",  MATCH_C_SRAI, MASK_C_SRAI, match_srxi_as_c_srxi, INSN_ALIAS },
 {"sra",         0, INSN_CLASS_I, "d,s,t",     MATCH_SRA, MASK_SRA, match_opcode, 0 },
 {"sra",         0, INSN_CLASS_I, "d,s,>",     MATCH_SRAI, MASK_SRAI, match_opcode, INSN_ALIAS },
 {"sub",         0, INSN_CLASS_ZCA, "Cs,Cw,Ct",  MATCH_C_SUB, MASK_C_SUB, match_opcode, INSN_ALIAS },
@@ -1174,12 +1191,12 @@ const struct riscv_opcode riscv_opcodes[] =
 {"c.and",      0, INSN_CLASS_ZCA,   "Cs,Ct",     MATCH_C_AND, MASK_C_AND, match_opcode, 0 },
 {"c.or",       0, INSN_CLASS_ZCA,   "Cs,Ct",     MATCH_C_OR, MASK_C_OR, match_opcode, 0 },
 {"c.xor",      0, INSN_CLASS_ZCA,   "Cs,Ct",     MATCH_C_XOR, MASK_C_XOR, match_opcode, 0 },
-{"c.slli64",   0, INSN_CLASS_ZCA,   "d",         MATCH_C_SLLI64, MASK_C_SLLI64, match_c_slli64, INSN_ALIAS },
-{"c.srli64",   0, INSN_CLASS_ZCA,   "Cs",        MATCH_C_SRLI64, MASK_C_SRLI64, match_c_slli64, INSN_ALIAS },
-{"c.srai64",   0, INSN_CLASS_ZCA,   "Cs",        MATCH_C_SRAI64, MASK_C_SRAI64, match_c_slli64, INSN_ALIAS },
 {"c.slli",     0, INSN_CLASS_ZCA,   "d,C>",      MATCH_C_SLLI, MASK_C_SLLI, match_opcode, 0 },
 {"c.srli",     0, INSN_CLASS_ZCA,   "Cs,C>",     MATCH_C_SRLI, MASK_C_SRLI, match_opcode, 0 },
 {"c.srai",     0, INSN_CLASS_ZCA,   "Cs,C>",     MATCH_C_SRAI, MASK_C_SRAI, match_opcode, 0 },
+{"c.slli64",   0, INSN_CLASS_ZCA,   "d",         MATCH_C_SLLI64, MASK_C_SLLI64, match_c_slli64, INSN_ALIAS }, /* Deprecated.  */
+{"c.srli64",   0, INSN_CLASS_ZCA,   "Cs",        MATCH_C_SRLI64, MASK_C_SRLI64, match_c_slli64, INSN_ALIAS }, /* Deprecated.  */
+{"c.srai64",   0, INSN_CLASS_ZCA,   "Cs",        MATCH_C_SRAI64, MASK_C_SRAI64, match_c_slli64, INSN_ALIAS }, /* Deprecated.  */
 {"c.andi",     0, INSN_CLASS_ZCA,   "Cs,Co",     MATCH_C_ANDI, MASK_C_ANDI, match_opcode, 0 },
 {"c.addiw",   64, INSN_CLASS_ZCA,   "d,Co",      MATCH_C_ADDIW, MASK_C_ADDIW, match_rd_nonzero, 0 },
 {"c.addw",    64, INSN_CLASS_ZCA,   "Cs,Ct",     MATCH_C_ADDW, MASK_C_ADDW, match_opcode, 0 },