Reduce contiguous memory space requirement in 32-bit mode slightly. Could help some people who get the error message.

git-svn-id: https://dolphin-emu.googlecode.com/svn/trunk@6 8ced0084-cf51-0410-be5f-012b33b47a6e

Source/Core/Common/Src/MemArena.cpp

@@ -104,7 +104,8 @@ u64 MemArena::Find4GBBase()
 {
 #ifdef _M_X64
 #ifdef _WIN32
-	u8* base = (u8*)VirtualAlloc(0, 0x100000000, MEM_RESERVE, PAGE_READWRITE);
+	// The highest thing in any 1GB section of memory space is the locked cache. We only need to fit it.
+	u8* base = (u8*)VirtualAlloc(0, 0xE1000000, MEM_RESERVE, PAGE_READWRITE);
 	VirtualFree(base, 0, MEM_RELEASE);
 	return((u64)base);
 

Source/Core/Core/Src/HW/Memmap.cpp

@@ -470,7 +470,10 @@ bool Init()
 	// Do a poor mans version - just grab 1GB, possibly discontiguous, and use &0x3FFFFFFF as the mask whenever it is accessed.
 	base = (u8*)MemArena::Find4GBBase();
 	if (!base) {
-		PanicAlert("Failed to grab 1 GB of contiguous memory!");
+		PanicAlert("Failed to grab 1 GB of contiguous memory!\nDo you have an antivirus program or any other program\n"
+			       "that injects itself into every process, consuming address space?\nOr simply a bad graphics driver?\n\n"
+				   "Dolphin will handle this better in the future by falling back to slow memory emulation.\n"
+				   "For now, sorry, but it won't work. Try the 64-bit build if you can.");
 	}
 	position = 0;
 	m_pPhysicalRAM        = (u8*)g_arena.CreateViewAt(position, RAM_SIZE, base + (0x00000000 & MEMVIEW32_MASK));

Source/Core/Core/Src/PowerPC/Jit64/Jit_LoadStore.cpp

@@ -569,6 +569,7 @@ namespace Jit64
 				MOV(16, R(EAX), MComplex(RBX, gpr.R(inst.RA).GetSimpleReg(), 1, offset));
 				MOV(32, M(&temp64), R(EAX));
 				MOVD_xmm(XMM0, M(&temp64));
+				// SSE4 optimization opportunity here.
 				PXOR(XMM1, R(XMM1));
 				PUNPCKLBW(XMM0, R(XMM1));
 				PUNPCKLWD(XMM0, R(XMM1));