From bd955caf35876f15a94d2445ff3e8861941ead48 Mon Sep 17 00:00:00 2001
From: "yoli@rim.com" <yoli@rim.com@268f45cc-cd09-0410-ab3c-d52691b4dbfc>
Date: Tue, 20 Nov 2012 16:32:32 +0000
Subject: [PATCH] [CherryPick] [ARMv7] Neither linkCall() nor linkPointer()
 should flush code.

[Title] [ARMv7] Neither linkCall() nor linkPointer() should flush code.
[Issue#] N/A
[Problem] Speed up for SunSpider benchmark
[Cause] N/A
[Solution] N/A
[CherryPicker] Han HoJong<hojong.han@samsung.com>

Change-Id: Id3a6b1e74fcbbb86a578b3f07a025cef66f45ffc
---
 Source/JavaScriptCore/ChangeLog                  | 25 ++++++++++++++++++++++++
 Source/JavaScriptCore/assembler/ARMv7Assembler.h | 23 +++++++++++-----------
 2 files changed, 37 insertions(+), 11 deletions(-)

diff --git a/Source/JavaScriptCore/ChangeLog b/Source/JavaScriptCore/ChangeLog
index 57d0620..8e76043 100644
--- a/Source/JavaScriptCore/ChangeLog
+++ b/Source/JavaScriptCore/ChangeLog
@@ -1,3 +1,28 @@
+2012-11-20  Yong Li  <yoli@rim.com>
+
+        [ARMv7] Neither linkCall() nor linkPointer() should flush code.
+        https://bugs.webkit.org/show_bug.cgi?id=99213
+
+        Reviewed by George Staikos.
+
+        LinkBuffer doesn't need to flush code during linking. It will
+        eventually flush the whole executable. Fixing this gives >%5
+        sunspider boost (on QNX).
+
+        Also make replaceWithLoad() and replaceWithAddressComputation() flush
+        only when necessary.
+
+        * assembler/ARMv7Assembler.h:
+        (JSC::ARMv7Assembler::linkCall):
+        (JSC::ARMv7Assembler::linkPointer):
+        (JSC::ARMv7Assembler::relinkCall):
+        (JSC::ARMv7Assembler::repatchInt32):
+        (JSC::ARMv7Assembler::repatchPointer):
+        (JSC::ARMv7Assembler::replaceWithLoad): Flush only after it did write.
+        (JSC::ARMv7Assembler::replaceWithAddressComputation): Flush only after it did write.
+        (JSC::ARMv7Assembler::setInt32):
+        (JSC::ARMv7Assembler::setPointer):
+
 2012-08-30  Byungwoo Lee  <bw80.lee@samsung.com>
 
         Build warning : -Wsign-compare on DFGByteCodeParser.cpp.
diff --git a/Source/JavaScriptCore/assembler/ARMv7Assembler.h b/Source/JavaScriptCore/assembler/ARMv7Assembler.h
index f81fde5..6e7a1c1 100644
--- a/Source/JavaScriptCore/assembler/ARMv7Assembler.h
+++ b/Source/JavaScriptCore/assembler/ARMv7Assembler.h
@@ -2061,12 +2061,12 @@ public:
         ASSERT(from.isSet());
         ASSERT(reinterpret_cast<intptr_t>(to) & 1);
 
-        setPointer(reinterpret_cast<uint16_t*>(reinterpret_cast<intptr_t>(code) + from.m_offset) - 1, to);
+        setPointer(reinterpret_cast<uint16_t*>(reinterpret_cast<intptr_t>(code) + from.m_offset) - 1, to, false);
     }
 
     static void linkPointer(void* code, AssemblerLabel where, void* value)
     {
-        setPointer(reinterpret_cast<char*>(code) + where.m_offset, value);
+        setPointer(reinterpret_cast<char*>(code) + where.m_offset, value, false);
     }
 
     static void relinkJump(void* from, void* to)
@@ -2084,7 +2084,7 @@ public:
         ASSERT(!(reinterpret_cast<intptr_t>(from) & 1));
         ASSERT(reinterpret_cast<intptr_t>(to) & 1);
 
-        setPointer(reinterpret_cast<uint16_t*>(from) - 1, to);
+        setPointer(reinterpret_cast<uint16_t*>(from) - 1, to, true);
     }
     
     static void* readCallTarget(void* from)
@@ -2096,7 +2096,7 @@ public:
     {
         ASSERT(!(reinterpret_cast<intptr_t>(where) & 1));
         
-        setInt32(where, value);
+        setInt32(where, value, true);
     }
     
     static void repatchCompact(void* where, int32_t offset)
@@ -2123,7 +2123,7 @@ public:
     {
         ASSERT(!(reinterpret_cast<intptr_t>(where) & 1));
         
-        setPointer(where, value);
+        setPointer(where, value, true);
     }
 
     static void* readPointer(void* where)
@@ -2168,11 +2168,11 @@ public:
             ptr[0] |= OP_LDR_imm_T3;
             ptr[1] |= (ptr[1] & 0x0F00) << 4;
             ptr[1] &= 0xF0FF;
+            cacheFlush(ptr, sizeof(uint16_t) * 2);
             break;
         default:
             ASSERT_NOT_REACHED();
         }
-        cacheFlush(ptr, sizeof(uint16_t) * 2);
     }
 
     static void replaceWithAddressComputation(void* instructionStart)
@@ -2186,13 +2186,13 @@ public:
             ptr[0] |= OP_ADD_imm_T3;
             ptr[1] |= (ptr[1] & 0xF000) >> 4;
             ptr[1] &= 0x0FFF;
+            cacheFlush(ptr, sizeof(uint16_t) * 2);
             break;
         case OP_ADD_imm_T3:
             break;
         default:
             ASSERT_NOT_REACHED();
         }
-        cacheFlush(ptr, sizeof(uint16_t) * 2);
     }
 
     unsigned debugOffset() { return m_formatter.debugOffset(); }
@@ -2313,7 +2313,7 @@ private:
         return VFPOperand(op);
     }
 
-    static void setInt32(void* code, uint32_t value)
+    static void setInt32(void* code, uint32_t value, bool flush)
     {
         uint16_t* location = reinterpret_cast<uint16_t*>(code);
         ASSERT(isMOV_imm_T3(location - 4) && isMOVT(location - 2));
@@ -2325,7 +2325,8 @@ private:
         location[-2] = twoWordOp5i6Imm4Reg4EncodedImmFirst(OP_MOVT, hi16);
         location[-1] = twoWordOp5i6Imm4Reg4EncodedImmSecond((location[-1] >> 8) & 0xf, hi16);
 
-        cacheFlush(location - 4, 4 * sizeof(uint16_t));
+        if (flush)
+            cacheFlush(location - 4, 4 * sizeof(uint16_t));
     }
     
     static int32_t readInt32(void* code)
@@ -2356,9 +2357,9 @@ private:
         cacheFlush(location, sizeof(uint16_t));
     }
 
-    static void setPointer(void* code, void* value)
+    static void setPointer(void* code, void* value, bool flush)
     {
-        setInt32(code, reinterpret_cast<uint32_t>(value));
+        setInt32(code, reinterpret_cast<uint32_t>(value), flush);
     }
 
     static bool isB(void* address)
-- 
2.7.4