Improve memory read/write

sysprog21 · Apr 6, 2023 · 8d6908f · 8d6908f
1 parent 66300d0
commit 8d6908f
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Showing 3 changed files with 48 additions and 25 deletions.
diff --git a/src/io.c b/src/io.c
@@ -85,37 +85,21 @@ uint32_t memory_ifetch(memory_t *m, uint32_t addr)
 uint32_t memory_read_w(memory_t *m, uint32_t addr)
 {
     const uint32_t addr_lo = addr & mask_lo;
-    if (addr_lo <= 0xfffc) { /* test if this is within one chunk */
-        chunk_t *c;
-        if ((c = m->chunks[addr >> 16]))
-            return *(const uint32_t *) (c->data + addr_lo);
-        return 0U;
-    }
-    uint32_t dst = 0;
-    memory_read(m, (uint8_t *) &dst, addr, 4);
-    return dst;
+    chunk_t *c = m->chunks[addr >> 16];
+    return *(const uint32_t *) (c->data + addr_lo);
 }
 
 uint16_t memory_read_s(memory_t *m, uint32_t addr)
 {
     const uint32_t addr_lo = addr & mask_lo;
-    if (addr_lo <= 0xfffe) { /* test if this is within one chunk */
-        chunk_t *c;
-        if ((c = m->chunks[addr >> 16]))
-            return *(const uint16_t *) (c->data + addr_lo);
-        return 0U;
-    }
-    uint16_t dst = 0;
-    memory_read(m, (uint8_t *) &dst, addr, 2);
-    return dst;
+    chunk_t *c = m->chunks[addr >> 16];
+    return *(const uint16_t *) (c->data + addr_lo);
 }
 
 uint8_t memory_read_b(memory_t *m, uint32_t addr)
 {
-    chunk_t *c;
-    if ((c = m->chunks[addr >> 16]))
-        return *(c->data + (addr & 0xffff));
-    return 0U;
+    chunk_t *c = m->chunks[addr >> 16];
+    return c->data[addr & mask_lo];
 }
 
 void memory_write(memory_t *m, uint32_t addr, const uint8_t *src, uint32_t size)
@@ -125,14 +109,46 @@ void memory_write(memory_t *m, uint32_t addr, const uint8_t *src, uint32_t size)
         uint32_t x = p >> 16;
         chunk_t *c = m->chunks[x];
         if (!c) {
-            c = malloc(sizeof(chunk_t));
-            memset(c->data, 0, sizeof(c->data));
+            c = calloc(1, sizeof(chunk_t));
             m->chunks[x] = c;
         }
         c->data[p & 0xffff] = src[i];
     }
 }
 
+void memory_write_w(memory_t *m, uint32_t addr, const uint8_t *src)
+{
+    const uint32_t addr_lo = addr & mask_lo, addr_hi = addr >> 16;
+    chunk_t *c = m->chunks[addr_hi];
+    if (unlikely(!c)) {
+        c = calloc(1, sizeof(chunk_t));
+        m->chunks[addr_hi] = c;
+    }
+    *(uint32_t *) (c->data + addr_lo) = *(const uint32_t *) src;
+}
+
+void memory_write_s(memory_t *m, uint32_t addr, const uint8_t *src)
+{
+    const uint32_t addr_lo = addr & mask_lo, addr_hi = addr >> 16;
+    chunk_t *c = m->chunks[addr_hi];
+    if (unlikely(!c)) {
+        c = calloc(1, sizeof(chunk_t));
+        m->chunks[addr_hi] = c;
+    }
+    *(uint16_t *) (c->data + addr_lo) = *(const uint16_t *) src;
+}
+
+void memory_write_b(memory_t *m, uint32_t addr, const uint8_t *src)
+{
+    const uint32_t addr_lo = addr & mask_lo, addr_hi = addr >> 16;
+    chunk_t *c = m->chunks[addr_hi];
+    if (unlikely(!c)) {
+        c = calloc(1, sizeof(chunk_t));
+        m->chunks[addr_hi] = c;
+    }
+    c->data[addr_lo] = src[0];
+}
+
 void memory_fill(memory_t *m, uint32_t addr, uint32_t size, uint8_t val)
 {
     for (uint32_t i = 0; i < size; ++i) {

diff --git a/src/io.h b/src/io.h
@@ -43,4 +43,11 @@ void memory_write(memory_t *m,
                   uint32_t addr,
                   const uint8_t *src,
                   uint32_t size);
+
+void memory_write_w(memory_t *m, uint32_t addr, const uint8_t *src);
+
+void memory_write_s(memory_t *m, uint32_t addr, const uint8_t *src);
+
+void memory_write_b(memory_t *m, uint32_t addr, const uint8_t *src);
+
 void memory_fill(memory_t *m, uint32_t addr, uint32_t size, uint8_t val);
diff --git a/src/main.c b/src/main.c
@@ -34,7 +34,7 @@ static const char *opt_prog_name = "a.out";
     {                                                                        \
         state_t *s = rv_userdata(rv);                                        \
         IIF(RW)                                                              \
-        (memory_write(s->mem, addr, (uint8_t *) &data, sizeof(data)),        \
+        (memory_##op(s->mem, addr, (uint8_t *) &data),                       \
          return memory_##op(s->mem, addr));                                  \
     }