From 1603bbb5f44f3046667dabdbcb60cb09b970f979 Mon Sep 17 00:00:00 2001
From: nitsuja <nitsuja-@hotmail.com>
Date: Sat, 7 Jan 2012 22:19:45 -0800
Subject: [PATCH] fixed and reenabled and slightly optimized the JIT version of
 fcmpo/fcmpu.

---
 Source/Core/Core/Src/PowerPC/Jit64/Jit.cpp    |  2 +-
 .../Src/PowerPC/Jit64/Jit_FloatingPoint.cpp   | 63 ++++++++++++-------
 2 files changed, 43 insertions(+), 22 deletions(-)

diff --git a/Source/Core/Core/Src/PowerPC/Jit64/Jit.cpp b/Source/Core/Core/Src/PowerPC/Jit64/Jit.cpp
index 0d31893b53..2a2f3c36b0 100644
--- a/Source/Core/Core/Src/PowerPC/Jit64/Jit.cpp
+++ b/Source/Core/Core/Src/PowerPC/Jit64/Jit.cpp
@@ -193,7 +193,7 @@ void Jit64::Init()
 	jo.enableFastMem = false;
 #endif
 	jo.assumeFPLoadFromMem = Core::g_CoreStartupParameter.bUseFastMem;
-	jo.fpAccurateFcmp = true; // Fallback to Interpreter
+	jo.fpAccurateFcmp = Core::g_CoreStartupParameter.bEnableFPRF;
 	jo.optimizeGatherPipe = true;
 	jo.fastInterrupts = false;
 	jo.accurateSinglePrecision = true;
diff --git a/Source/Core/Core/Src/PowerPC/Jit64/Jit_FloatingPoint.cpp b/Source/Core/Core/Src/PowerPC/Jit64/Jit_FloatingPoint.cpp
index a325e3a150..5fcd2f9e29 100644
--- a/Source/Core/Core/Src/PowerPC/Jit64/Jit_FloatingPoint.cpp
+++ b/Source/Core/Core/Src/PowerPC/Jit64/Jit_FloatingPoint.cpp
@@ -229,8 +229,6 @@ void Jit64::fmrx(UGeckoInstruction inst)
  
 void Jit64::fcmpx(UGeckoInstruction inst)
 {
-	// TODO : This still causes crashes in Nights, and broken graphics
-	// in Paper Mario, Super Paper Mario as well as SoulCalibur 2 prolly others too.. :(
 	INSTRUCTION_START
 	JITDISABLE(FloatingPoint)
 	if (jo.fpAccurateFcmp) {
@@ -243,36 +241,59 @@ void Jit64::fcmpx(UGeckoInstruction inst)
 	int crf	= inst.CRFD;
 
 	fpr.Lock(a,b);
-	if (a != b) fpr.BindToRegister(a, true);
+	fpr.BindToRegister(b, true);
 
 	// Are we masking sNaN invalid floating point exceptions? If not this could crash if we don't handle the exception?
-	UCOMISD(fpr.R(a).GetSimpleReg(), fpr.R(b));
+	UCOMISD(fpr.R(b).GetSimpleReg(), fpr.R(a));
 
-	FixupBranch pNaN	 = J_CC(CC_P);
-	FixupBranch pLesser  = J_CC(CC_B);
-	FixupBranch pGreater = J_CC(CC_A);
+	FixupBranch pNaN, pLesser, pGreater;
+	FixupBranch continue1, continue2, continue3;
+
+	if (a != b)
+	{
+		// if B > A, goto Lesser's jump target
+		pLesser  = J_CC(CC_A);
+	}
+
+	// if (B != B) or (A != A), goto NaN's jump target
+	pNaN    	 = J_CC(CC_P);
+
+	if (a != b)
+	{
+		// if B < A, goto Greater's jump target
+		// JB can't precede the NaN check because it doesn't test ZF
+		pGreater = J_CC(CC_B);
+	}
 
 	// Equal
 	MOV(8, M(&PowerPC::ppcState.cr_fast[crf]), Imm8(0x2));
-	FixupBranch continue1 = J();
-	
-	// Greater Than
-	SetJumpTarget(pGreater);
-	MOV(8, M(&PowerPC::ppcState.cr_fast[crf]), Imm8(0x4));
-	FixupBranch continue2 = J();
-	
-	// Less Than
-	SetJumpTarget(pLesser);
-	MOV(8, M(&PowerPC::ppcState.cr_fast[crf]), Imm8(0x8));
-	FixupBranch continue3 = J();
-	
+	continue1 = J();
+
 	// NAN
 	SetJumpTarget(pNaN);
 	MOV(8, M(&PowerPC::ppcState.cr_fast[crf]), Imm8(0x1));
+
+	if (a != b)
+	{
+		continue2 = J();
+
+		// Greater Than
+		SetJumpTarget(pGreater);
+		MOV(8, M(&PowerPC::ppcState.cr_fast[crf]), Imm8(0x4));
+		continue3 = J();
+	
+		// Less Than
+		SetJumpTarget(pLesser);
+		MOV(8, M(&PowerPC::ppcState.cr_fast[crf]), Imm8(0x8));
+	}
 	
 	SetJumpTarget(continue1);
-	SetJumpTarget(continue2);
-	SetJumpTarget(continue3);
+	if (a != b)
+	{
+		SetJumpTarget(continue2);
+		SetJumpTarget(continue3);
+	}
+
 	fpr.UnlockAll();
 }