From e3f50e6d67e5e4010384ab6b63fad530e6c368a8 Mon Sep 17 00:00:00 2001
From: Joel Dice <joel.dice@gmail.com>
Date: Mon, 29 Dec 2014 11:04:27 -0700
Subject: [PATCH] fix ARM64 OffsetPromise::value

I must have done a search-and-replace from 4 to TargetBytesPerWord
earlier, but in this case it should have been the instruction size
(4), not the word size.
---
 src/codegen/target/arm/assembler.cpp |  2 ++
 src/codegen/target/arm/fixup.cpp     | 10 ++++++++--
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/src/codegen/target/arm/assembler.cpp b/src/codegen/target/arm/assembler.cpp
index 1ff070bcea..d34f9992f1 100644
--- a/src/codegen/target/arm/assembler.cpp
+++ b/src/codegen/target/arm/assembler.cpp
@@ -981,6 +981,8 @@ class MyAssembler : public Assembler {
 
         bool jump = needJump(b);
         if (jump) {
+          expect(&con, TargetBytesPerWord == 4);
+
           write4(dst + dstOffset,
                  isa::b((poolSize + TargetBytesPerWord - 8) >> 2));
         }
diff --git a/src/codegen/target/arm/fixup.cpp b/src/codegen/target/arm/fixup.cpp
index 7f5c0ff277..2e32813cbb 100644
--- a/src/codegen/target/arm/fixup.cpp
+++ b/src/codegen/target/arm/fixup.cpp
@@ -12,6 +12,12 @@
 #include "fixup.h"
 #include "block.h"
 
+namespace {
+
+const unsigned InstructionSize = 4;
+
+} // namespace
+
 namespace avian {
 namespace codegen {
 namespace arm {
@@ -39,7 +45,7 @@ int64_t OffsetPromise::value()
 
   unsigned o = offset - block->offset;
   return block->start
-         + padding(block, forTrace ? o - vm::TargetBytesPerWord : o) + o;
+         + padding(block, forTrace ? o - InstructionSize : o) + o;
 }
 
 Promise* offsetPromise(Context* con, bool forTrace)
@@ -115,7 +121,7 @@ void* updateOffset(vm::System* s, uint8_t* instruction, int64_t value)
 
   *p = (v & mask) | ((~mask) & *p);
 
-  return instruction + 4;
+  return instruction + InstructionSize;
 }
 
 ConstantPoolEntry::ConstantPoolEntry(Context* con,