From b6afdd647ce394dc7e1281cc42c05b6981cd62b2 Mon Sep 17 00:00:00 2001
From: lemon <lsof@mailbox.org>
Date: Sun, 19 Oct 2025 11:07:07 +0200
Subject: codegen bugfixes

---
 ir/abi0.c     |  9 +++++++++
 ir/regalloc.c | 10 +++++++---
 2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/ir/abi0.c b/ir/abi0.c
index 82d10a5..9e30ab7 100644
--- a/ir/abi0.c
+++ b/ir/abi0.c
@@ -249,6 +249,7 @@ abi0_call(struct function *fn, struct instr *ins, struct block *blk, int *curi)
          }
          for (int i = 0; i < nret; ++i) {
             struct instr store = {0};
+            int iref;
             /* XXX this can generate unaligned stores */
             switch (call->abiret[i].ty.cls) {
             default: assert(0);
@@ -264,6 +265,14 @@ abi0_call(struct function *fn, struct instr *ins, struct block *blk, int *curi)
             }
             store.r = r[i];
             insertinstr(blk, ++*curi, store);
+            iref = retmem.i;
+            if (instrnuse[iref] > 1) {
+               /* make store the first use */
+               struct use tmp = instruse[iref][instrnuse[iref - 1]];
+               for (int i = instrnuse[iref] - 1; i > 0; --i)
+                  instruse[iref][i] = instruse[iref][i-1];
+               instruse[iref][0] = tmp;
+            }
          }
       }
    }
diff --git a/ir/regalloc.c b/ir/regalloc.c
index 64dcfac..1e23a8a 100644
--- a/ir/regalloc.c
+++ b/ir/regalloc.c
@@ -1026,7 +1026,8 @@ devirt(struct rega *ra, struct block *blk)
                   insertinstr(blk, ++curi, mkinstr(store, 0, .r = mkref(RREG, reg))).i,
                   alloc->a*8);
          }
-      } else if (!ins->reg && insrescls(*ins) && ins->op != Omove && !ins->keep) {
+      }
+      if (!ins->reg && insrescls(*ins) && ins->op != Omove && !ins->keep) {
          /* dead */
       Nop:
         ins->op = Onop;
@@ -1036,12 +1037,15 @@ devirt(struct rega *ra, struct block *blk)
       } else if (ins->op == Ocopy && ins->l.t == RREG && ins->reg-1 == ins->l.i) {
          /* r1 = copy r2  /  r1=r2 */
          goto Nop;
-      } else if (ins->inplace && ins->l.t == RREG && ins->reg && ins->reg-1 != ins->l.i) {
+      } else if (ins->op != Onop) {
+         allnops = 0;
+      }
+      if (ins->inplace && ins->l.t == RREG && ins->reg && ins->reg-1 != ins->l.i) {
          /* fixup in-place (two-address) instructions */
          allnops = 0;
          insertinstr(blk, curi++, mkmove(ins->cls, ins->reg-1, ins->l.i));
          ins->l.i = ins->reg-1;
-      } else if (ins->op != Onop) allnops = 0;
+      }
    }
 
    return allnops;
-- 
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