From 3f2221dfb9ab33b7ac44bbf822a78753a0357d25 Mon Sep 17 00:00:00 2001
From: lemon <lsof@mailbox.org>
Date: Wed, 21 Jun 2023 23:52:23 +0200
Subject: mem2reg: implement ssa construction; this breaks regalloc right now

---
 ssa.c | 79 ++++++++++---------------------------------------------------------
 1 file changed, 11 insertions(+), 68 deletions(-)

(limited to 'ssa.c')

diff --git a/ssa.c b/ssa.c
index 46e0741..a2abf7b 100644
--- a/ssa.c
+++ b/ssa.c
@@ -1,89 +1,32 @@
+#include "common.h"
 #include "ir.h"
-#include <stdint.h>
 
-struct uses *
-ssauses(struct function *fn)
+void
+filluses(struct function *fn)
 {
    extern int ninstr;
-   struct uses *uses = xcalloc(ninstr * sizeof *uses);
-   vec_of(struct use) *vuse = xcalloc(ninstr * sizeof *vuse), useacc = {0};
    struct block *blk = fn->entry;
 
-   #define USE(r, isjmp, x) do {                       \
-      struct use u0, u = {isjmp, {x}};                 \
-      if ((r).t == RTMP) {                             \
-         if (vuse[(r).i].n == 0){                      \
-            memcpy(&vuse[(r).i].p, &u, sizeof u);      \
-            ++vuse[(r).i].n;                           \
-         } else {                                      \
-            if (vuse[(r).i].n == 1) {                  \
-               memcpy(&u0, &vuse[(r).i].p, sizeof u0); \
-               vuse[(r).i].n = 0;                      \
-               vuse[(r).i].p = 0;                      \
-               vpush(&vuse[(r).i], u0);                \
-            }                                          \
-            vpush(&vuse[(r).i], u);                    \
-         }                                             \
-      }                                                \
-   } while (0)
+   for (int i = 0; i < ninstr; ++i)
+      deluses(i);
 
    do {
       for (int i = 0; i < blk->phi.n; ++i) {
          int ins = blk->phi.p[i];
          union ref *phi = phitab.p[instrtab[ins].l.i];
-         for (int i = 0; i < blk->npred; ++i) {
-            USE(phi[i], 0, ins);
-         }
+         for (int i = 0; i < blk->npred; ++i)
+            adduse(blk, ins, phi[i]);
       }
       for (int i = 0; i < blk->ins.n; ++i) {
          int ins = blk->ins.p[i];
          assert(instrtab[ins].l.t != RMORE);
          if (instrtab[ins].op != Ocall) assert(instrtab[ins].l.t != RMORE);
-         USE(instrtab[ins].l, 0, ins);
-         USE(instrtab[ins].r, 0, ins);
+         adduse(blk, ins, instrtab[ins].l);
+         adduse(blk, ins, instrtab[ins].r);
       }
-      USE(blk->jmp.arg[0], 1, blk->id);
-      USE(blk->jmp.arg[1], 1, blk->id);
+      adduse(blk, USERJUMP, blk->jmp.arg[0]);
+      adduse(blk, USERJUMP, blk->jmp.arg[1]);
    } while ((blk = blk->lnext) != fn->entry);
-   for (int i = 0; i < ninstr; ++i) {
-      int nuse = uses[i].nuse = vuse[i].n;
-      if (!nuse) continue;
-      if (nuse == 1) {
-         uses[i].use = uses[i]._use0;
-         memcpy(uses[i].use, &vuse[i].p, sizeof *uses[i].use);
-      } else if (nuse < arraylength(uses[i]._use0)) {
-         uses[i].use = uses[i]._use0;
-         memcpy(uses[i].use, vuse[i].p, nuse * sizeof(struct use));
-         vfree(&vuse[i]);
-      } else {
-         intptr_t o;
-         o = useacc.n;
-         memcpy(&uses[i].use, &o, sizeof o);
-         vpushn(&useacc, vuse[i].p, nuse);
-         vfree(&vuse[i]);
-      }
-   }
-   for (int i = 0; i < ninstr; ++i) {
-      if (uses[i].use != uses[i]._use0) {
-         intptr_t o;
-         memcpy(&o, &uses[i].use, sizeof o);
-         uses[i].use = useacc.p + o;
-      }
-   }
-   free(vuse);
-   return uses;
-}
-
-void
-freeuses(struct uses *u, int n)
-{
-   for (int i = 0; i < n; ++i) {
-      if (u[i].use != u[i]._use0) {
-         free(u[i].use);
-         break;
-      }
-   }
-   free(u);
 }
 
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