From ff03a2f7b16ee43a591e0747621862c9ef75f41d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Karel=20Ko=C4=8D=C3=AD?= <cynerd@email.cz>
Date: Thu, 5 Apr 2018 11:41:50 +0200
Subject: Use whole words in memory

---
 qtmips_machine/memory.h | 36 ++++++++++++++++--------------------
 1 file changed, 16 insertions(+), 20 deletions(-)

(limited to 'qtmips_machine/memory.h')

diff --git a/qtmips_machine/memory.h b/qtmips_machine/memory.h
index 525ca56..8dea63c 100644
--- a/qtmips_machine/memory.h
+++ b/qtmips_machine/memory.h
@@ -11,6 +11,7 @@ namespace machine {
 class MemoryAccess : public QObject {
     Q_OBJECT
 public:
+    // Note: hword and word methods are throwing away lowest bits so unaligned access is ignored without error.
     void write_byte(std::uint32_t offset, std::uint8_t value);
     void write_hword(std::uint32_t offset, std::uint16_t value);
     void write_word(std::uint32_t offset, std::uint32_t value);
@@ -30,12 +31,12 @@ public:
     void write_ctl(enum AccessControl ctl, std::uint32_t offset, std::uint32_t value);
     std::uint32_t read_ctl(enum AccessControl ctl, std::uint32_t offset) const;
 
-signals:
-    void byte_change(std::uint32_t address, std::uint32_t value);
-
 protected:
-    virtual void wbyte(std::uint32_t offset, std::uint8_t value) = 0;
-    virtual std::uint8_t rbyte(std::uint32_t offset) const = 0;
+    virtual void wword(std::uint32_t offset, std::uint32_t value) = 0;
+    virtual std::uint32_t rword(std::uint32_t offset) const = 0;
+
+private:
+    static int sh_nth(std::uint32_t offset);
 };
 
 class MemorySection : public MemoryAccess {
@@ -44,30 +45,25 @@ public:
     MemorySection(const MemorySection&);
     ~MemorySection();
 
-    void wbyte(std::uint32_t offset, std::uint8_t value);
-    std::uint8_t rbyte(std::uint32_t offset) const;
+    void wword(std::uint32_t offset, std::uint32_t value);
+    std::uint32_t rword(std::uint32_t offset) const;
     void merge(MemorySection&);
 
     std::uint32_t length() const;
-    const std::uint8_t* data() const;
+    const std::uint32_t* data() const;
 
     bool operator==(const MemorySection&) const;
     bool operator!=(const MemorySection&) const;
 
 private:
     std::uint32_t len;
-    std::uint8_t *dt;
+    std::uint32_t *dt;
 };
 
-//////////////////////////////////////////////////////////////////////////////
-/// Some optimalization options
-// How big memory sections will be (2^8=256)
-#define MEMORY_SECTION_BITS 8
-// How deep memory lookup tree will be
-#define MEMORY_TREE_H 4
-//////////////////////////////////////////////////////////////////////////////
-
-union MemoryTree;
+union MemoryTree {
+    union MemoryTree *mt;
+    MemorySection *sec;
+};
 
 class Memory : public MemoryAccess {
     Q_OBJECT
@@ -79,8 +75,8 @@ public:
     void reset(const Memory&);
 
     MemorySection *get_section(std::uint32_t address, bool create) const; // returns section containing given address
-    void wbyte(std::uint32_t address, std::uint8_t value);
-    std::uint8_t rbyte(std::uint32_t address) const;
+    void wword(std::uint32_t address, std::uint32_t value);
+    std::uint32_t rword(std::uint32_t address) const;
 
     bool operator==(const Memory&) const;
     bool operator!=(const Memory&) const;
-- 
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