From c79f41d114801486304dc705708ac39a65c308f6 Mon Sep 17 00:00:00 2001
From: skidau <skidau@gmail.com>
Date: Sun, 28 Nov 2010 13:06:52 +0000
Subject: [PATCH] LLE JIT: Speed up the dispatcher by removing the compiled
 block check.  Initialised the blocks with a stub which calls the compiler.

git-svn-id: https://dolphin-emu.googlecode.com/svn/trunk@6490 8ced0084-cf51-0410-be5f-012b33b47a6e
---
 Source/Core/DSPCore/Src/DSPEmitter.cpp | 47 ++++++++++++++------------
 Source/Core/DSPCore/Src/DSPEmitter.h   |  2 +-
 2 files changed, 27 insertions(+), 22 deletions(-)

diff --git a/Source/Core/DSPCore/Src/DSPEmitter.cpp b/Source/Core/DSPCore/Src/DSPEmitter.cpp
index ec41305f9e..3f714e5fcc 100644
--- a/Source/Core/DSPCore/Src/DSPEmitter.cpp
+++ b/Source/Core/DSPCore/Src/DSPEmitter.cpp
@@ -30,6 +30,8 @@
 
 using namespace Gen;
 
+const u8 *stubEntryPoint;
+
 DSPEmitter::DSPEmitter() : storeIndex(-1), storeIndex2(-1)
 {
 	m_compiledCode = NULL;
@@ -39,18 +41,19 @@ DSPEmitter::DSPEmitter() : storeIndex(-1), storeIndex2(-1)
 	blocks = new CompiledCode[MAX_BLOCKS];
 	blockSize = new u16[0x10000];
 	
-	//clear all of the block references
-	for(int i = 0x0000; i < MAX_BLOCKS; i++)
-	{
-		blocks[i] = NULL;
-		blockSize[i] = 0;
-	}
-
 	compileSR = 0;
 	compileSR |= SR_INT_ENABLE;
 	compileSR |= SR_EXT_INT_ENABLE;
 
 	CompileDispatcher();
+	stubEntryPoint = CompileStub();
+
+	//clear all of the block references
+	for(int i = 0x0000; i < MAX_BLOCKS; i++)
+	{
+		blocks[i] = (CompiledCode)stubEntryPoint;
+		blockSize[i] = 0;
+	}
 }
 
 DSPEmitter::~DSPEmitter() 
@@ -64,12 +67,11 @@ void DSPEmitter::ClearIRAM() {
 	// ClearCodeSpace();
 	for(int i = 0x0000; i < 0x1000; i++)
 	{
-		blocks[i] = NULL;
+		blocks[i] = (CompiledCode)stubEntryPoint;
 		blockSize[i] = 0;
 	}
 }
 
-
 // Must go out of block if exception is detected
 void DSPEmitter::checkExceptions(u32 retval) {
 	// Check for interrupts and exceptions
@@ -296,6 +298,20 @@ void DSPEmitter::Compile(int start_addr)
 	RET();
 }
 
+const u8 *DSPEmitter::CompileStub()
+{
+	const u8 *entryPoint = AlignCode16();
+	ABI_PushAllCalleeSavedRegsAndAdjustStack();
+	//	ABI_AlignStack(0);
+	CALL((void *)CompileCurrent);
+	//	ABI_RestoreStack(0);
+	ABI_PopAllCalleeSavedRegsAndAdjustStack();
+	//MOVZX(32, 16, ECX, M(&g_dsp.pc));
+	XOR(32, R(EAX), R(EAX)); // Return 0 cycles executed
+	RET();
+	return entryPoint;
+}
+
 void DSPEmitter::CompileDispatcher()
 {
 	enterDispatcher = AlignCode16();
@@ -305,11 +321,9 @@ void DSPEmitter::CompileDispatcher()
 #ifdef _M_IX86
 	MOV(32, R(ESI), M(&cyclesLeft));
 	MOV(32, R(EBX), Imm32((u32)blocks));
-	MOV(32, R(EDI), Imm32((u32)blockSize));
 #else
 	MOV(32, R(ESI), M(&cyclesLeft));
 	MOV(64, R(RBX), Imm64((u64)blocks));
-	MOV(64, R(RDI), Imm64((u64)blockSize));
 #endif
 
 	const u8 *dispatcherLoop = GetCodePtr();
@@ -318,16 +332,7 @@ void DSPEmitter::CompileDispatcher()
 	TEST(8, M(&g_dsp.cr), Imm8(CR_HALT));
 	FixupBranch halt = J_CC(CC_NE);
 
-	// Check if block has been compiled (blockSize > 0)
 	MOVZX(32, 16, ECX, M(&g_dsp.pc));
-	MOVZX(32, 16, EAX, MComplex(RDI, ECX, SCALE_2, 0));
-	TEST(16, R(AX), R(AX));
-
-	// Compile block if needed
-	FixupBranch found = J_CC(CC_NE);
-	CALL((void *)CompileCurrent);
-	MOVZX(32, 16, ECX, M(&g_dsp.pc));
-	SetJumpTarget(found);
 
 	// Execute block. Cycles executed returned in EAX.
 #ifdef _M_IX86
@@ -338,7 +343,7 @@ void DSPEmitter::CompileDispatcher()
 
 	// Decrement cyclesLeft
 	SUB(32, R(ESI), R(EAX));
-	
+
 	J_CC(CC_A, dispatcherLoop);
 	
 	// DSP gave up the remaining cycles.
diff --git a/Source/Core/DSPCore/Src/DSPEmitter.h b/Source/Core/DSPCore/Src/DSPEmitter.h
index 17de54bd69..7020a5fd26 100644
--- a/Source/Core/DSPCore/Src/DSPEmitter.h
+++ b/Source/Core/DSPCore/Src/DSPEmitter.h
@@ -41,7 +41,7 @@ public:
 	void ClearIRAM();
 
 	void CompileDispatcher();
-
+	const u8 *CompileStub();
 	void Compile(int start_addr);
 
 	int STACKALIGN RunForCycles(int cycles);