oasm: Introduce AND mnemonic

Implement mnemonic for the AND instruction:

--
and x1, #7   ! x1 = x1 & 7
--

Signed-off-by: Ian Moffett <ian@osmora.org>

4 files changed, 67 insertions, 1 deletions

diff --git a/usr.bin/oasm/emit.c b/usr.bin/oasm/emit.c
index 6b17eab..ea14cce 100644
--- a/usr.bin/oasm/emit.c
+++ b/usr.bin/oasm/emit.c
@@ -377,6 +377,60 @@ emit_encode_nop(struct emit_state *state, struct oasm_token *tok)
     return TAILQ_NEXT(tok, link);
 }
 
+/*
+ * Encode a bitwise instruction:
+ *
+ * and r, r/imm
+ * or r, r/imm
+ * xor r, r/imm
+ */
+static struct oasm_token *
+emit_encode_bitw(struct emit_state *state, struct oasm_token *tok)
+{
+    inst_t curinst;
+    imm_t imm;
+    reg_t rd;
+    uint8_t opcode = OSMX64_AND;
+    char *inst_str = "and";
+
+    /* Next token should be a register */
+    tok = TAILQ_NEXT(tok, link);
+    if (tok == NULL) {
+        oasm_err("[emit error]: expected register for '%s'\n", inst_str);
+        return NULL;
+    }
+    if (!tok_is_xreg(tok->type)) {
+        oasm_err("[emit error]: bad register for '%s'\n", inst_str);
+        return NULL;
+    }
+
+    rd = ir_to_reg(tok->type);
+    tok = TAILQ_NEXT(tok, link);
+    if (tok == NULL) {
+        oasm_err("[emit error]: missing operand in '%s'\n", inst_str);
+        return NULL;
+    }
+
+    /*
+     * Check that the next token is an immediate
+     * value.
+     *
+     * TODO: Allow a register operand to be passed
+     *       to these instructions.
+     */
+    if (tok->type != TT_IMM) {
+        oasm_err("[emit error]: expected <imm> for '%s'\n", inst_str);
+        return NULL;
+    }
+
+    imm = tok->imm;
+    curinst.opcode = opcode;
+    curinst.rd = rd;
+    curinst.imm = imm;
+    emit_bytes(state, &curinst, sizeof(curinst));
+    return TAILQ_NEXT(tok, link);
+}
+
 int
 emit_osmx64(struct emit_state *state, struct oasm_token *tp)
 {
@@ -464,6 +518,9 @@ emit_process(struct oasm_state *oasm, struct emit_state *emit)
         case TT_DIV:
             curtok = emit_encode_arith(emit, curtok);
             break;
+        case TT_AND:
+            curtok = emit_encode_bitw(emit, curtok);
+            break;
         case TT_BR:
             curtok = emit_encode_br(emit, curtok);
             break;
diff --git a/usr.bin/oasm/include/oasm/lex.h b/usr.bin/oasm/include/oasm/lex.h
index 873f6b9..69e98ff 100644
--- a/usr.bin/oasm/include/oasm/lex.h
+++ b/usr.bin/oasm/include/oasm/lex.h
@@ -103,6 +103,7 @@ typedef enum {
     TT_MROW,        /* 'mrow' */
     TT_MROD,        /* 'mrod' */
     TT_MROQ,        /* 'mroq' */
+    TT_AND,         /* 'and' */
 
     /* Register ops */
     TT_MOV,         /* 'mov' */
diff --git a/usr.bin/oasm/lex.c b/usr.bin/oasm/lex.c
index fea9dc3..220cdb4 100644
--- a/usr.bin/oasm/lex.c
+++ b/usr.bin/oasm/lex.c
@@ -54,6 +54,7 @@ static char putback = '\0';
 #define S_IMN_MROW "mrow"
 #define S_IMN_MROD "mrod"
 #define S_IMN_MROQ "mroq"
+#define S_IMN_AND  "and"
 
 /* Instruction length */
 #define OSMX64_INST_LEN 4
@@ -242,6 +243,8 @@ token_bitw_mro(char *p)
         return TT_MROD;
     } else if (strcmp(p, S_IMN_MROQ) == 0) {
         return TT_MROQ;
+    } else if (strcmp(p, S_IMN_AND) == 0) {
+        return TT_AND;
     }
 
     return TT_UNKNOWN;
diff --git a/usr.bin/oasm/parse.c b/usr.bin/oasm/parse.c
index c81b498..523058b 100644
--- a/usr.bin/oasm/parse.c
+++ b/usr.bin/oasm/parse.c
@@ -58,7 +58,7 @@ static const char *tokstr[] = {
     [ TT_MROW ] = "mrow",
     [ TT_MROD ] = "mrod",
     [ TT_MROQ ] = "mroq",
-
+    [ TT_AND  ] = "and",
 
     /* X<n> registers */
     [ TT_X0 ]  = "x0",
@@ -124,6 +124,7 @@ parse_reg(struct oasm_state *state, struct oasm_token *tok)
     case TT_MUL:
     case TT_DIV:
     case TT_BR:
+    case TT_AND:
         state->last = tok->type;
         break;
     default:
@@ -166,6 +167,10 @@ parse_tok(struct oasm_state *state, struct oasm_token *tok)
         state->last = tok->type;
         label_enter(tok->raw, state->pip);
         break;
+    case TT_AND:
+        state->last = tok->type;
+        emit_osmx64(&emit_state, tok);
+        break;
     case TT_HLT:
         state->last = tok->type;
         emit_osmx64(&emit_state, tok);