1 files changed, 134 insertions, 0 deletions
diff --git a/src/prc1/cgen/qbe/from.c b/src/prc1/cgen/qbe/from.c
new file mode 100644
index 0000000..40b2724
--- /dev/null
+++ b/src/prc1/cgen/qbe/from.c
@@ -0,0 +1,134 @@
+#include "from.h"
+#include "stmt.h"
+#include "cgen.h"
+#include "qbe.h"
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+static int loadvar(const struct from_it *st, struct cgen *c)
+{
+    const struct stentry *e = st->u.e;
+    size_t sz = e->t->sz;
+    const char *tmp = cgen_tmp(sz);
+
+    printf("%%%s =%s load%s ", tmp, cgen_sz(sz), cgen_load(e->t));
+    cgen_printvar(c->fn, e);
+    putchar('\n');
+    return 0;
+}
+
+/* TODO: de-duplicate function */
+static unsigned long long tonum(const char *s)
+{
+    unsigned long long v;
+    char *end;
+
+    errno = 0;
+    v = strtoull(s, &end, 0);
+
+    if (*s == '-' || errno || *end)
+        return strtoll(s, NULL, 0);
+
+    return v;
+}
+
+static int loadval(const struct from *fr, struct cgen *c)
+{
+    const struct stentry *dst = fr->var;
+    const struct from_it *st = &fr->start;
+    unsigned long long v = tonum(st->u.tk->s);
+
+    printf("store%s %llu, ", cgen_sz(dst->t->sz), v);
+    cgen_printvar(c->fn, dst);
+    putchar('\n');
+    return 0;
+}
+
+static int endvar(const struct from *fr, struct cgen *c)
+{
+    fprintf(stderr, "%s: TODO\n", __func__);
+    return -1;
+}
+
+static int endval(const struct from *fr, struct cgen *c)
+{
+    const struct stentry *src = fr->var;
+    size_t sz = src->t->sz;
+    const char *tmp = cgen_tmp(sz);
+    const struct from_it *end = &fr->end;
+    const struct tk *tk = end->u.tk;
+    int neg = *tk->s == '-';
+    size_t bl = fr->block_i;
+
+    printf("%%%s =%s load%s ", tmp, cgen_sz(sz), cgen_load(src->t));
+    cgen_printvar(c->fn, src);
+    putchar('\n');
+    printf("%%%s =%s c", tmp, cgen_sz(sz));
+    fputs(neg ? "sge" : "uge", stdout);
+    printf("%s ", cgen_sz(sz));
+    printf("%%%s, %s\n", tmp, tk->s);
+    printf("jnz %%%s, @__end%zu, @__blockbody%zu\n", tmp, bl, bl);
+    printf("@__blockbody%zu\n", bl);
+    return 0;
+}
+
+static int from_var(const struct from *fr, struct cgen *c)
+{
+    const struct from_it *st = &fr->start;
+
+    switch (st->type)
+    {
+    case FR_VAR:
+        if (loadvar(st, c))
+            return -1;
+        break;
+
+    case FR_VAL:
+        if (loadval(fr, c))
+            return -1;
+        break;
+    }
+
+    printf("@__block%zu\n", fr->block_i);
+
+    switch (fr->end.type)
+    {
+    case FR_VAR:
+        if (endvar(fr, c))
+            return -1;
+        break;
+
+    case FR_VAL:
+        if (endval(fr, c))
+            return -1;
+        break;
+    }
+
+    return 0;
+}
+
+int from_end(const struct stmt *s, struct cgen *c)
+{
+    const struct from *fr = &s->u.from;
+    const struct stentry *src = fr->var;
+    const struct type *t = src->t;
+    size_t sz = t->sz;
+    const char *tmp = cgen_tmp(sz);
+    const struct fn *fn = c->fn;
+
+    printf("%%%s =%s load%s ", tmp, cgen_sz(sz), cgen_load(t));
+    cgen_printvar(fn, src);
+    putchar('\n');
+    printf("%%%s =%s add %%%s, 1\n", tmp, cgen_sz(sz), tmp);
+    printf("store%s %%%s, ", cgen_sz(sz), tmp);
+    cgen_printvar(fn, src);
+    putchar('\n');
+    printf("jmp @__block%zu\n", fr->block_i);
+    return 0;
+}
+
+int qbe_from(const struct from *fr, struct cgen *c)
+{
+    return from_var(fr, c);
+}