first runnable test program

+ tests/pointer_literal.ek compiles down to very simple assembly that
  tasm can assemble and triscv run with correct results. Whopee

+ Did notice that void return functions should still have implicit return statements added

1 files changed, 96 insertions, 0 deletions

diff --git a/src/asm.c b/src/asm.c
new file mode 100644
index 0000000..4102265
--- /dev/null
+++ b/src/asm.c
@@ -0,0 +1,96 @@
+#include <ek/ops.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+
+/* I guess using the zero register might be okay in some scenarios, but for now
+ * I'll just keep it an illegal register */
+#define ASSERT_REG(x) {assert(x->kind == LOC_REG); assert(x->reg > 0 && x->reg < 81);}
+#define ASSERT_MEM(x) {assert(x->kind == LOC_MEM); assert(x->reg > 0 && x->reg < 81);}
+
+static int print_comment(struct op *op, FILE *f)
+{
+	fprintf(f, "/* %s */\n", op->string);
+	return 0;
+}
+
+static int print_label(struct op *op, FILE *f)
+{
+	fprintf(f, "%s:\n", op->string);
+	return 0;
+}
+
+static int print_li(struct op *op, FILE *f)
+{
+	struct loc *o = &op->outputs;
+	assert(o->next == NULL);
+	/* unsure if this will always hold, but for now */
+	ASSERT_REG(o);
+
+	fprintf(f, "li x%zd, %lld\n", o->reg, op->constant);
+	return 0;
+}
+
+static int print_mv(struct op *op, FILE *f)
+{
+	struct loc *i = &op->inputs;
+	struct loc *o = &op->outputs;
+	assert(i->next == NULL);
+	assert(o->next == NULL);
+	ASSERT_REG(i);
+	ASSERT_REG(o);
+
+	fprintf(f, "mv x%zd, x%zd\n", o->reg, i->reg);
+	return 0;
+}
+
+static int print_stt(struct op *op, FILE *f)
+{
+	struct loc *i = &op->inputs;
+	struct loc *o = &op->outputs;
+	assert(i->next == NULL);
+	assert(o->next == NULL);
+	ASSERT_REG(i);
+	ASSERT_MEM(o);
+
+	fprintf(f, "st t, x%zd, %lld(x%zd)\n", i->reg, o->off, o->reg);
+	return 0;
+}
+
+static int print_op(struct op *op, FILE *f)
+{
+	int ret = 0;
+	switch (op->opcode) {
+	case OP_COMMENT: ret = print_comment(op, f); break;
+	case OP_LABEL: ret = print_label(op, f); break;
+	case OP_LI: ret = print_li(op, f); break;
+	case OP_MV: ret = print_mv(op, f); break;
+	case OP_STT: ret = print_stt(op, f); break;
+	default: abort();
+	}
+
+	return ret;
+}
+
+int print_asm(struct ops *ops, const char *output)
+{
+	FILE *f = fopen(output, "w");
+
+	/* main should probably be mangled here as well */
+	fprintf(f, "jal x0, main\n");
+	int ret = 0;
+	struct op *op = ops->base;
+	while (op) {
+		if ((ret = print_op(op, f)))
+			break;
+
+		op = op->next;
+	}
+
+	/* tell simulator to turn off (very much temp) */
+	fprintf(f, "li x1, 3\n");
+	fprintf(f, "csrrw mpower, x0, x1\n");
+
+	fclose(f);
+	return ret;
+}