REFACTOR: move sources to src/

1 files changed, 46 insertions, 0 deletions

diff --git a/src/ir_ssa.c b/src/ir_ssa.c
new file mode 100644
index 0000000..6598fba
--- /dev/null
+++ b/src/ir_ssa.c
@@ -0,0 +1,46 @@
+#include "ir.h"
+
+void
+copyopt(struct function *fn)
+{
+   struct block *blk = fn->entry;
+
+   FREQUIRE(FNUSE);
+   do {
+      for (int i = 0; i < blk->phi.n; ++i) {
+         /* simplify same-arg phi */
+         int phi = blk->phi.p[i];
+         union ref *arg = phitab.p[instrtab[phi].l.i];
+         for (int j = 1; j < blk->npred; ++j) {
+            if (arg[j].bits != arg->bits) goto Next;
+         }
+         /* being conservative here because phis could have circular dependencies? */
+         if (arg->t != RTMP || instrtab[arg->i].op != Ophi) {
+            replcuses(mkref(RTMP, phi), *arg);
+            delphi(blk, i--);
+         }
+      Next:;
+      }
+      for (int i = 0; i < blk->ins.n; ++i) {
+         union ref var = mkref(RTMP, blk->ins.p[i]);
+         struct instr *ins = &instrtab[var.i];
+         enum irclass k;
+
+         if (ins->op == Ocopy) {
+            union ref arg = ins->l;
+            if (arg.t == RTMP) k = insrescls(instrtab[arg.i]);
+            else if (arg.t == RICON) k = cls2siz[ins->cls] == 4 ? KI32 : KI64;
+            else if (arg.t == RXCON) k = isnumcon(arg) ? concls(arg) : KPTR;
+            else continue;
+            if (ins->cls != k) continue;
+
+            replcuses(var, arg);
+            *ins = mkinstr(Onop,0,);
+            deluses(var.i);
+         }
+      }
+      delnops(blk);
+   } while ((blk = blk->lnext) != fn->entry);
+}
+
+/* vim:set ts=3 sw=3 expandtab: */