From cb82618f3bf5a9f06e41765ed55a495fde4a0bb7 Mon Sep 17 00:00:00 2001
From: Thomas Neumann <neumann@in.tum.de>
Date: Sat, 27 Jul 2024 18:53:40 +0200
Subject: [PATCH] simplify jump generation in auto-grow mode

All jumps are performed relative to the current position, and the
encoding is computed based upon jmpAddr - codeOffset. Which means
that the encoding is unaffected by the absolute position of the
code in memory. Thus, it is not necessary to treat the auto-grow
mode differently, the encoding can always be computed eagerly.
---
 xbyak_aarch64/xbyak_aarch64_code_array.h | 19 -------------------
 xbyak_aarch64/xbyak_aarch64_label.h      |  6 +-----
 2 files changed, 1 insertion(+), 24 deletions(-)

diff --git a/xbyak_aarch64/xbyak_aarch64_code_array.h b/xbyak_aarch64/xbyak_aarch64_code_array.h
index 8acaf80..215ea94 100644
--- a/xbyak_aarch64/xbyak_aarch64_code_array.h
+++ b/xbyak_aarch64/xbyak_aarch64_code_array.h
@@ -100,19 +100,6 @@ class CodeArray {
   void operator=(const CodeArray &);
   bool isAllocType() const { return type_ == ALLOC_BUF || type_ == AUTO_GROW; }
 
-  // type of partially applied function for encoding
-  typedef std::function<uint32_t(int64_t)> EncFunc;
-
-  struct AddrInfo {
-    size_t codeOffset; // position to write
-    size_t jmpAddr;    // value to write
-    EncFunc encFunc;   // encoding function
-    AddrInfo(size_t _codeOffset, size_t _jmpAddr, EncFunc encFunc) : codeOffset(_codeOffset), jmpAddr(_jmpAddr), encFunc(encFunc) {}
-    uint32_t getVal() const { return encFunc((int64_t)(jmpAddr - codeOffset) * CSIZE); }
-  };
-
-  typedef std::list<AddrInfo> AddrInfoList;
-  AddrInfoList addrInfoList_;
   const Type type_;
 #ifdef XBYAK_USE_MMAP_ALLOCATOR
   MmapAllocator defaultAllocator_;
@@ -149,10 +136,6 @@ class CodeArray {
   void calcJmpAddress() {
     if (isCalledCalcJmpAddress_)
       return;
-    for (AddrInfoList::const_iterator i = addrInfoList_.begin(), ie = addrInfoList_.end(); i != ie; ++i) {
-      uint32_t disp = i->getVal();
-      rewrite(i->codeOffset, disp);
-    }
     isCalledCalcJmpAddress_ = true;
   }
 
@@ -193,7 +176,6 @@ class CodeArray {
   bool setProtectModeRW(bool throwException = true) { return setProtectMode(PROTECT_RW, throwException); }
   void resetSize() {
     size_ = 0;
-    addrInfoList_.clear();
     isCalledCalcJmpAddress_ = false;
   }
   void clearCodeArray() {
@@ -241,7 +223,6 @@ class CodeArray {
     uint32_t *const data = top_ + offset;
     *data = disp;
   }
-  void save(size_t offset, size_t jmpAddr, const EncFunc &encFunc) { addrInfoList_.push_back(AddrInfo(offset, jmpAddr, encFunc)); }
   bool isAutoGrow() const { return type_ == AUTO_GROW; }
   bool isCalledCalcJmpAddress() const { return isCalledCalcJmpAddress_; }
   /**
diff --git a/xbyak_aarch64/xbyak_aarch64_label.h b/xbyak_aarch64/xbyak_aarch64_label.h
index 1c88c83..5855b6d 100644
--- a/xbyak_aarch64/xbyak_aarch64_label.h
+++ b/xbyak_aarch64/xbyak_aarch64_label.h
@@ -88,11 +88,7 @@ class LabelManager {
       const size_t offset = jmp->endOfJmp;
       int64_t labelOffset = (addrOffset - offset) * CSIZE;
       uint32_t disp = jmp->encFunc(labelOffset);
-      if (base_->isAutoGrow()) {
-        base_->save(offset, addrOffset, jmp->encFunc);
-      } else {
-        base_->rewrite(offset, disp);
-      }
+      base_->rewrite(offset, disp);
       undefList.erase(itr);
     }
   }