Imported WebKit commit e89504fa9195b2063b2530961d4b73dd08de3242 (http://svn.webkit.org/repository/webkit/trunk@135485)

Change-Id: I03774e5ac79721c13ffa30d152537a74d0b12e66
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>

1 files changed, 71 insertions, 7 deletions

diff --git a/Source/JavaScriptCore/assembler/X86Assembler.h b/Source/JavaScriptCore/assembler/X86Assembler.h
index ecb178e88..25ff6f0a5 100644
--- a/Source/JavaScriptCore/assembler/X86Assembler.h
+++ b/Source/JavaScriptCore/assembler/X86Assembler.h
@@ -1475,6 +1475,12 @@ public:
         return m_formatter.immediateRel32();
     }
 
+    AssemblerLabel jnp()
+    {
+        m_formatter.twoByteOp(jccRel32(ConditionNP));
+        return m_formatter.immediateRel32();
+    }
+
     AssemblerLabel jp()
     {
         m_formatter.twoByteOp(jccRel32(ConditionP));
@@ -1877,6 +1883,61 @@ public:
         return 5;
     }
     
+#if CPU(X86_64)
+    static void revertJumpTo_movq_i64r(void* instructionStart, int64_t imm, RegisterID dst)
+    {
+        const int rexBytes = 1;
+        const int opcodeBytes = 1;
+        ASSERT(rexBytes + opcodeBytes <= maxJumpReplacementSize());
+        uint8_t* ptr = reinterpret_cast<uint8_t*>(instructionStart);
+        ptr[0] = PRE_REX | (1 << 3) | (dst >> 3);
+        ptr[1] = OP_MOV_EAXIv | (dst & 7);
+        
+        union {
+            uint64_t asWord;
+            uint8_t asBytes[8];
+        } u;
+        u.asWord = imm;
+        for (unsigned i = rexBytes + opcodeBytes; i < static_cast<unsigned>(maxJumpReplacementSize()); ++i)
+            ptr[i] = u.asBytes[i - rexBytes - opcodeBytes];
+    }
+#endif
+    
+    static void revertJumpTo_cmpl_ir_force32(void* instructionStart, int32_t imm, RegisterID dst)
+    {
+        const int opcodeBytes = 1;
+        const int modRMBytes = 1;
+        ASSERT(opcodeBytes + modRMBytes <= maxJumpReplacementSize());
+        uint8_t* ptr = reinterpret_cast<uint8_t*>(instructionStart);
+        ptr[0] = OP_GROUP1_EvIz;
+        ptr[1] = (X86InstructionFormatter::ModRmRegister << 6) | (GROUP1_OP_CMP << 3) | dst;
+        union {
+            uint32_t asWord;
+            uint8_t asBytes[4];
+        } u;
+        u.asWord = imm;
+        for (unsigned i = opcodeBytes + modRMBytes; i < static_cast<unsigned>(maxJumpReplacementSize()); ++i)
+            ptr[i] = u.asBytes[i - opcodeBytes - modRMBytes];
+    }
+    
+    static void revertJumpTo_cmpl_im_force32(void* instructionStart, int32_t imm, int offset, RegisterID dst)
+    {
+        ASSERT_UNUSED(offset, !offset);
+        const int opcodeBytes = 1;
+        const int modRMBytes = 1;
+        ASSERT(opcodeBytes + modRMBytes <= maxJumpReplacementSize());
+        uint8_t* ptr = reinterpret_cast<uint8_t*>(instructionStart);
+        ptr[0] = OP_GROUP1_EvIz;
+        ptr[1] = (X86InstructionFormatter::ModRmMemoryNoDisp << 6) | (GROUP1_OP_CMP << 3) | dst;
+        union {
+            uint32_t asWord;
+            uint8_t asBytes[4];
+        } u;
+        u.asWord = imm;
+        for (unsigned i = opcodeBytes + modRMBytes; i < static_cast<unsigned>(maxJumpReplacementSize()); ++i)
+            ptr[i] = u.asBytes[i - opcodeBytes - modRMBytes];
+    }
+    
     static void replaceWithLoad(void* instructionStart)
     {
         uint8_t* ptr = reinterpret_cast<uint8_t*>(instructionStart);
@@ -1976,6 +2037,13 @@ private:
 
     public:
 
+        enum ModRmMode {
+            ModRmMemoryNoDisp,
+            ModRmMemoryDisp8,
+            ModRmMemoryDisp32,
+            ModRmRegister,
+        };
+
         // Legacy prefix bytes:
         //
         // These are emmitted prior to the instruction.
@@ -2314,6 +2382,9 @@ private:
         // Format a REX prefix byte.
         inline void emitRex(bool w, int r, int x, int b)
         {
+            ASSERT(r >= 0);
+            ASSERT(x >= 0);
+            ASSERT(b >= 0);
             m_buffer.putByteUnchecked(PRE_REX | ((int)w << 3) | ((r>>3)<<2) | ((x>>3)<<1) | (b>>3));
         }
 
@@ -2343,13 +2414,6 @@ private:
         inline void emitRexIfNeeded(int, int, int) {}
 #endif
 
-        enum ModRmMode {
-            ModRmMemoryNoDisp,
-            ModRmMemoryDisp8,
-            ModRmMemoryDisp32,
-            ModRmRegister,
-        };
-
         void putModRm(ModRmMode mode, int reg, RegisterID rm)
         {
             m_buffer.putByteUnchecked((mode << 6) | ((reg & 7) << 3) | (rm & 7));