From 4fc6339f04958150c538bf97bf721f58e0084ffb Mon Sep 17 00:00:00 2001
From: lemon <lsof@mailbox.org>
Date: Thu, 23 Oct 2025 19:30:45 +0200
Subject: ir bugfixes

---
 ir/cfg.c      |  5 ++++-
 ir/ir.c       | 21 ++++++++++++++++++++-
 ir/ir.h       |  1 +
 ir/regalloc.c |  4 ++--
 4 files changed, 27 insertions(+), 4 deletions(-)

diff --git a/ir/cfg.c b/ir/cfg.c
index d9aa409..df428d1 100644
--- a/ir/cfg.c
+++ b/ir/cfg.c
@@ -24,8 +24,11 @@ sortrpo(struct function *fn)
    fn->entry->id = 0;
    porec(&rpo, fn->entry);
    ndead = rpo - rpobuf;
-   for (struct block *blk = fn->entry; ndead > 0; blk = blk->lnext) {
+   for (struct block *blk = fn->entry->lprev, *next; ndead > 0; blk = next) {
+      next = blk->lprev;
       if (!wasvisited(blk)) {
+         for (int i = 0; i < blk->npred; ++i)
+            assert(!wasvisited(blkpred(blk, i)));
          blk->lnext = blk->lprev = NULL;
          freeblk(fn, blk);
          --ndead;
diff --git a/ir/ir.c b/ir/ir.c
index 967870f..586b9b8 100644
--- a/ir/ir.c
+++ b/ir/ir.c
@@ -228,7 +228,7 @@ delpred(struct block *blk, struct block *p)
          return;
       }
    }
-   assert(0&&"blk not in p");
+   //assert(0&&"blk not in p");
 }
 
 struct block *
@@ -245,6 +245,25 @@ freeblk(struct function *fn, struct block *blk)
 {
    if (blk->npred > 1)
       xbfree(blk->_pred);
+
+   for (int i = 0; i < blk->phi.n; ++i) {
+      int ui = blk->phi.p[i];
+      union ref *r = phitab.p[instrtab[ui].l.i];
+      for (int j = 0; j < blk->npred; ++j) {
+         deluse(blk, ui, *r);
+      }
+   }
+   for (int i = 0; i < blk->ins.n; ++i) {
+      int ui = blk->ins.p[i];
+      struct instr *ins = &instrtab[ui];
+      if (ins->l.t == RTMP) deluse(blk, ui, ins->l);
+      if (ins->r.t == RTMP) deluse(blk, ui, ins->r);
+   }
+   for (int i = 0; i < 2; ++i) {
+      if (blk->jmp.arg[i].t == RTMP) deluse(blk, USERJUMP, blk->jmp.arg[i]);
+   }
+   if (blk->s1) delpred(blk->s1, blk);
+   if (blk->s2) delpred(blk->s2, blk);
    vfree(&blk->phi);
    vfree(&blk->ins);
    if (blk->lnext) blk->lnext->lprev = blk->lprev;
diff --git a/ir/ir.h b/ir/ir.h
index 2c8a55d..a49432d 100644
--- a/ir/ir.h
+++ b/ir/ir.h
@@ -236,6 +236,7 @@ void adduse(struct block *ublk, int ui, union ref r);
 union ref insertinstr(struct block *, int idx, struct instr);
 union ref insertphi(struct block *, enum irclass cls);
 void replcuses(union ref from, union ref to);
+bool deluse(struct block *ublk, int ui, union ref r);
 void deluses(int ins);
 void delinstr(struct block *, int idx);
 void delphi(struct block *, int idx);
diff --git a/ir/regalloc.c b/ir/regalloc.c
index f73a3d1..ca84eb7 100644
--- a/ir/regalloc.c
+++ b/ir/regalloc.c
@@ -1031,12 +1031,12 @@ devirt(struct rega *ra, struct block *blk)
          } else {
             bool dosave = 0;
             int reg = kisint(insrescls(*ins)) ? mctarg->gprscratch : mctarg->fprscratch;
-            assert(nspill < 2);
             if (nspill > 0) {
                for (reg = kisflt(cls) ? mctarg->fpr0 : mctarg->gpr0;; ++reg) {
                   for (int j = 0; j < nargref; ++j)
-                     if (argref[j]->t == RREG && argref[j]->i == reg) continue;
+                     if (argref[j]->t == RREG && argref[j]->i == reg) goto NotThis;
                   break;
+               NotThis:;
                }
                /* if not the designated scratch register, we need to save+restore */
                if ((dosave = rstest(fn->regusage, reg) || rstest(mctarg->rcallee, reg))) {
-- 
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