RISC-V: Fix disassembly of c.addi4spn, c.addi16sp, c.lui when imm=0

These are all invalid instructions, so they should not disassemble.

opcodes/ChangeLog

2017-10-24  Andrew Waterman  <andrew@sifive.com>

        * riscv-opc.c (match_c_addi16sp) : New function.
        (match_c_addi4spn): New function.
        (match_c_lui): Don't allow 0-immediate encodings.
        (riscv_opcodes) <addi>: Use the above functions.
        <add>: Likewise.
        <c.addi4spn>: Likewise.
        <c.addi16sp>: Likewise.

gas/ChangeLog

2017-10-24  Andrew Waterman  <andrew@sifive.com>

        * testsuite/gas/riscv/c-addi16sp-fail.d: New test.
        testsuite/gas/riscv/c-addi16sp-fail.l: Likewise.
        testsuite/gas/riscv/c-addi16sp-fail.s: Likewise.
        testsuite/gas/riscv/c-addi4spn-fail.d: Likewise.
        testsuite/gas/riscv/c-addi4spn-fail.l: Likewise.
        testsuite/gas/riscv/c-addi4spn-fail.s: Likewise.
        testsuite/gas/riscv/riscv.exp: Add new tests.

10 files changed, 59 insertions, 7 deletions

diff --git a/gas/ChangeLog b/gas/ChangeLog
index a0f36f0..833e41c 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,5 +1,15 @@
 2017-10-24  Andrew Waterman  <andrew@sifive.com>
 
+	* testsuite/gas/riscv/c-addi16sp-fail.d: New test.
+	testsuite/gas/riscv/c-addi16sp-fail.l: Likewise.
+	testsuite/gas/riscv/c-addi16sp-fail.s: Likewise.
+	testsuite/gas/riscv/c-addi4spn-fail.d: Likewise.
+	testsuite/gas/riscv/c-addi4spn-fail.l: Likewise.
+	testsuite/gas/riscv/c-addi4spn-fail.s: Likewise.
+	testsuite/gas/riscv/riscv.exp: Add new tests.
+
+2017-10-24  Andrew Waterman  <andrew@sifive.com>
+
 	* testsuite/gas/riscv/c-lui-fail.d: New testcase.
 	gas/testsuite/gas/riscv/c-lui-fail.l: Likewise.
 	gas/testsuite/gas/riscv/c-lui-fail.s: Likewise.
diff --git a/gas/testsuite/gas/riscv/c-addi16sp-fail.d b/gas/testsuite/gas/riscv/c-addi16sp-fail.d
new file mode 100644
index 0000000..cc20923
--- /dev/null
+++ b/gas/testsuite/gas/riscv/c-addi16sp-fail.d
@@ -0,0 +1,3 @@
+#as: -march=rv32ic
+#source: c-addi16sp-fail.s
+#error-output: c-addi16sp-fail.l
diff --git a/gas/testsuite/gas/riscv/c-addi16sp-fail.l b/gas/testsuite/gas/riscv/c-addi16sp-fail.l
new file mode 100644
index 0000000..15f91fd
--- /dev/null
+++ b/gas/testsuite/gas/riscv/c-addi16sp-fail.l
@@ -0,0 +1,2 @@
+.*: Assembler messages:
+.*: Error: illegal operands `c.addi16sp x1,0'
diff --git a/gas/testsuite/gas/riscv/c-addi16sp-fail.s b/gas/testsuite/gas/riscv/c-addi16sp-fail.s
new file mode 100644
index 0000000..c0d3918
--- /dev/null
+++ b/gas/testsuite/gas/riscv/c-addi16sp-fail.s
@@ -0,0 +1,2 @@
+target:
+	c.addi16sp x1, 0
diff --git a/gas/testsuite/gas/riscv/c-addi4spn-fail.d b/gas/testsuite/gas/riscv/c-addi4spn-fail.d
new file mode 100644
index 0000000..b3c0af4
--- /dev/null
+++ b/gas/testsuite/gas/riscv/c-addi4spn-fail.d
@@ -0,0 +1,3 @@
+#as: -march=rv32ic
+#source: c-addi4spn-fail.s
+#error-output: c-addi4spn-fail.l
diff --git a/gas/testsuite/gas/riscv/c-addi4spn-fail.l b/gas/testsuite/gas/riscv/c-addi4spn-fail.l
new file mode 100644
index 0000000..2a8a593
--- /dev/null
+++ b/gas/testsuite/gas/riscv/c-addi4spn-fail.l
@@ -0,0 +1,2 @@
+.*: Assembler messages:
+.*: Error: illegal operands `c.addi4spn x1,0'
diff --git a/gas/testsuite/gas/riscv/c-addi4spn-fail.s b/gas/testsuite/gas/riscv/c-addi4spn-fail.s
new file mode 100644
index 0000000..6963beb
--- /dev/null
+++ b/gas/testsuite/gas/riscv/c-addi4spn-fail.s
@@ -0,0 +1,2 @@
+target:
+	c.addi4spn x1, 0
diff --git a/gas/testsuite/gas/riscv/riscv.exp b/gas/testsuite/gas/riscv/riscv.exp
index f411335..b2eaec1 100644
--- a/gas/testsuite/gas/riscv/riscv.exp
+++ b/gas/testsuite/gas/riscv/riscv.exp
@@ -22,4 +22,6 @@ if [istarget riscv*-*-*] {
     run_dump_test "t_insns"
     run_dump_test "fmv.x"
     run_dump_test "c-lui-fail"
+    run_dump_test "c-addi4spn-fail"
+    run_dump_test "c-addi16sp-fail"
 }
diff --git a/opcodes/ChangeLog b/opcodes/ChangeLog
index e47ede5..89ab194 100644
--- a/opcodes/ChangeLog
+++ b/opcodes/ChangeLog
@@ -1,3 +1,13 @@
+2017-10-24  Andrew Waterman  <andrew@sifive.com>
+
+	* riscv-opc.c (match_c_addi16sp) : New function.
+	(match_c_addi4spn): New function.
+	(match_c_lui): Don't allow 0-immediate encodings.
+	(riscv_opcodes) <addi>: Use the above functions.
+	<add>: Likewise.
+	<c.addi4spn>: Likewise.
+	<c.addi16sp>: Likewise.
+
 2017-10-23  Igor Tsimbalist  <igor.v.tsimbalist@intel.com>
 
 	* i386-init.h: Regenerate
diff --git a/opcodes/riscv-opc.c b/opcodes/riscv-opc.c
index 27b4b9f..84cdea8 100644
--- a/opcodes/riscv-opc.c
+++ b/opcodes/riscv-opc.c
@@ -114,9 +114,25 @@ match_c_add (const struct riscv_opcode *op, insn_t insn)
 }
 
 static int
+match_c_addi16sp (const struct riscv_opcode *op, insn_t insn)
+{
+  return (match_opcode (op, insn)
+	  && (((insn & MASK_RD) >> OP_SH_RD) == 2)
+	  && EXTRACT_RVC_ADDI16SP_IMM (insn) != 0);
+}
+
+static int
 match_c_lui (const struct riscv_opcode *op, insn_t insn)
 {
-  return match_rd_nonzero (op, insn) && (((insn & MASK_RD) >> OP_SH_RD) != 2);
+  return (match_rd_nonzero (op, insn)
+	  && (((insn & MASK_RD) >> OP_SH_RD) != 2)
+	  && EXTRACT_RVC_LUI_IMM (insn) != 0);
+}
+
+static int
+match_c_addi4spn (const struct riscv_opcode *op, insn_t insn)
+{
+  return match_opcode (op, insn) && EXTRACT_RVC_ADDI4SPN_IMM (insn) != 0;
 }
 
 const struct riscv_opcode riscv_opcodes[] =
@@ -188,15 +204,15 @@ const struct riscv_opcode riscv_opcodes[] =
 {"bnez",      "C",   "Cs,Cp",  MATCH_C_BNEZ, MASK_C_BNEZ, match_opcode, INSN_ALIAS },
 {"bnez",      "I",   "s,p",  MATCH_BNE, MASK_BNE | MASK_RS2, match_opcode, INSN_ALIAS },
 {"bne",       "I",   "s,t,p",  MATCH_BNE, MASK_BNE, match_opcode, 0 },
-{"addi",      "C",   "Ct,Cc,CK", MATCH_C_ADDI4SPN, MASK_C_ADDI4SPN, match_opcode, INSN_ALIAS },
+{"addi",      "C",   "Ct,Cc,CK", MATCH_C_ADDI4SPN, MASK_C_ADDI4SPN, match_c_addi4spn, INSN_ALIAS },
 {"addi",      "C",   "d,CU,Cj",  MATCH_C_ADDI, MASK_C_ADDI, match_rd_nonzero, INSN_ALIAS },
-{"addi",      "C",   "Cc,Cc,CL", MATCH_C_ADDI16SP, MASK_C_ADDI16SP, match_opcode, INSN_ALIAS },
+{"addi",      "C",   "Cc,Cc,CL", MATCH_C_ADDI16SP, MASK_C_ADDI16SP, match_c_addi16sp, INSN_ALIAS },
 {"addi",      "I",   "d,s,j",  MATCH_ADDI, MASK_ADDI, match_opcode, 0 },
 {"add",       "C",   "d,CU,CV",  MATCH_C_ADD, MASK_C_ADD, match_c_add, INSN_ALIAS },
 {"add",       "C",   "d,CV,CU",  MATCH_C_ADD, MASK_C_ADD, match_c_add, INSN_ALIAS },
 {"add",       "C",   "d,CU,Cj",  MATCH_C_ADDI, MASK_C_ADDI, match_rd_nonzero, INSN_ALIAS },
-{"add",       "C",   "Ct,Cc,CK", MATCH_C_ADDI4SPN, MASK_C_ADDI4SPN, match_opcode, INSN_ALIAS },
-{"add",       "C",   "Cc,Cc,CL", MATCH_C_ADDI16SP, MASK_C_ADDI16SP, match_opcode, INSN_ALIAS },
+{"add",       "C",   "Ct,Cc,CK", MATCH_C_ADDI4SPN, MASK_C_ADDI4SPN, match_c_addi4spn, INSN_ALIAS },
+{"add",       "C",   "Cc,Cc,CL", MATCH_C_ADDI16SP, MASK_C_ADDI16SP, match_c_addi16sp, INSN_ALIAS },
 {"add",       "I",   "d,s,t",  MATCH_ADD, MASK_ADD, match_opcode, 0 },
 {"add",       "I",   "d,s,t,0",MATCH_ADD, MASK_ADD, match_opcode, 0 },
 {"add",       "I",   "d,s,j",  MATCH_ADDI, MASK_ADDI, match_opcode, INSN_ALIAS },
@@ -628,8 +644,8 @@ const struct riscv_opcode riscv_opcodes[] =
 {"c.mv",      "C",   "d,CV",  MATCH_C_MV, MASK_C_MV, match_c_add, 0 },
 {"c.lui",     "C",   "d,Cu",  MATCH_C_LUI, MASK_C_LUI, match_c_lui, 0 },
 {"c.li",      "C",   "d,Co",  MATCH_C_LI, MASK_C_LI, match_rd_nonzero, 0 },
-{"c.addi4spn","C",   "Ct,Cc,CK", MATCH_C_ADDI4SPN, MASK_C_ADDI4SPN, match_opcode, 0 },
-{"c.addi16sp","C",   "Cc,CL", MATCH_C_ADDI16SP, MASK_C_ADDI16SP, match_opcode, 0 },
+{"c.addi4spn","C",   "Ct,Cc,CK", MATCH_C_ADDI4SPN, MASK_C_ADDI4SPN, match_c_addi4spn, 0 },
+{"c.addi16sp","C",   "Cc,CL", MATCH_C_ADDI16SP, MASK_C_ADDI16SP, match_c_addi16sp, 0 },
 {"c.addi",    "C",   "d,Cj",  MATCH_C_ADDI, MASK_C_ADDI, match_opcode, 0 },
 {"c.add",     "C",   "d,CV",  MATCH_C_ADD, MASK_C_ADD, match_c_add, 0 },
 {"c.sub",     "C",   "Cs,Ct",  MATCH_C_SUB, MASK_C_SUB, match_opcode, 0 },