Interpreter: optimize NaN checks

NaNs always propagate, so we can get away with only checking for NaN inputs in the rare case that the result is NaN (as already done in Jit64::HandleNaNs()).
dolphin-emu · Jun 10, 2015 · d3e6520 · d3e6520
1 parent 9b8eb55
commit d3e6520
Showing 1 changed file with 14 additions and 12 deletions.
diff --git a/Source/Core/Core/PowerPC/Interpreter/Interpreter_FPUtils.h b/Source/Core/Core/PowerPC/Interpreter/Interpreter_FPUtils.h
@@ -83,11 +83,11 @@ inline double Force25Bit(double d)
 
 inline double NI_mul(double a, double b)
 {
-	if (a != a) return a;
-	if (b != b) return b;
 	double t = a * b;
 	if (t != t)
 	{
+		if (a != a) return a;
+		if (b != b) return b;
 		SetFPException(FPSCR_VXIMZ);
 		return PPC_NAN;
 	}
@@ -96,11 +96,11 @@ inline double NI_mul(double a, double b)
 
 inline double NI_add(double a, double b)
 {
-	if (a != a) return a;
-	if (b != b) return b;
 	double t = a + b;
 	if (t != t)
 	{
+		if (a != a) return a;
+		if (b != b) return b;
 		SetFPException(FPSCR_VXISI);
 		return PPC_NAN;
 	}
@@ -109,11 +109,11 @@ inline double NI_add(double a, double b)
 
 inline double NI_sub(double a, double b)
 {
-	if (a != a) return a;
-	if (b != b) return b;
 	double t = a - b;
 	if (t != t)
 	{
+		if (a != a) return a;
+		if (b != b) return b;
 		SetFPException(FPSCR_VXISI);
 		return PPC_NAN;
 	}
@@ -122,18 +122,19 @@ inline double NI_sub(double a, double b)
 
 inline double NI_madd(double a, double c, double b, bool negate = false)
 {
-	if (a != a) return a;
-	if (b != b) return b;
-	if (c != c) return c;
 	double t = a * c;
 	if (t != t)
 	{
+		if (a != a) return a;
+		if (b != b) return b;
+		if (c != c) return c;
 		SetFPException(FPSCR_VXIMZ);
 		return PPC_NAN;
 	}
 	t = t + b;
 	if (t != t)
 	{
+		if (b != b) return b;
 		SetFPException(FPSCR_VXISI);
 		return PPC_NAN;
 	}
@@ -142,19 +143,20 @@ inline double NI_madd(double a, double c, double b, bool negate = false)
 
 inline double NI_msub(double a, double c, double b, bool negate = false)
 {
-	if (a != a) return a;
-	if (b != b) return b;
-	if (c != c) return c;
 	double t = a * c;
 	if (t != t)
 	{
+		if (a != a) return a;
+		if (b != b) return b;
+		if (c != c) return c;
 		SetFPException(FPSCR_VXIMZ);
 		return PPC_NAN;
 	}
 
 	t = t - b;
 	if (t != t)
 	{
+		if (b != b) return b;
 		SetFPException(FPSCR_VXISI);
 		return PPC_NAN;
 	}