backend: fix regalloc to work with more complex dataflow

basically an allocation map at the beginning (in) and end (out) of each
block is kept and after the first allocation pass another pass is ran to
resolve allocation conflicts between each edge, plus another pass to
finish lowering phi functions.
also introduced `regset` and plenty of other miscellaneous fixes

1 files changed, 6 insertions, 5 deletions

diff --git a/irdump.c b/irdump.c
index 9eda415..3d95843 100644
--- a/irdump.c
+++ b/irdump.c
@@ -80,10 +80,9 @@ dumpref(enum op o, union ref ref)
          efmt("??");
       break;
    case RTMP:
+      efmt("%%%d", ref.i);
       if (instrtab[ref.i].reg)
-         efmt("%s", mctarg->rnames[instrtab[ref.i].reg - 1]);
-      else
-         efmt("%%%d", ref.i);
+         efmt("(%s)", mctarg->rnames[instrtab[ref.i].reg-1]);
       break;
    case RREG:
       efmt("%s", mctarg->rnames[ref.i]);
@@ -168,7 +167,7 @@ dumpinst(const struct instr *ins)
       if (ins->reg) {
          if (cls)
             efmt("%s ", clsname[cls]);
-         efmt("%s = ", mctarg->rnames[ins->reg - 1]);
+         efmt("(%%%d)%s = ", ins - instrtab, mctarg->rnames[ins->reg - 1]);
       } else if (cls) {
          efmt("%s %%%d", clsname[cls], ins - instrtab);
          efmt(" = ");
@@ -198,7 +197,9 @@ dumpblk(struct function *fn, struct block *blk)
       struct instr *phi = &instrtab[blk->phi.p[i]];
       union ref *refs = phitab.p[phi->l.i];
       assert(phi->op == Ophi);
-      efmt("    %s %%%d = phi ", clsname[phi->cls], blk->phi.p[i]);
+      efmt("    %s ", clsname[phi->cls]);
+      if (!phi->reg) efmt("%%%d = phi ", blk->phi.p[i]);
+      else efmt("(%%%d)%s = phi ", phi - instrtab, mctarg->rnames[phi->reg-1]);
       for (int i = 0; i < blk->npred; ++i) {
          if (i) efmt(", ");
          efmt("@%d ", blkpred(blk, i)->id);