ALL: Remove obsolete register keyword

The register keyword was deprecated from the C++11 standard,
<http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4193.html#809>,
and removed from the C++17 standard,
<http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4340>, so
cannot exist in a well-formed C++17 program.

It has never done anything in GCC
<https://gcc.gnu.org/ml/gcc/2010-05/msg00113.html>
and because of the way it is specified in the standard, it is “as
meaningful as whitespace”
<http://www.drdobbs.com/keywords-that-arent-or-comments-by-anoth/184403859>.

The one remaining use of the register keyword is in the DS backend,
where it is used to create a local register variable using the
non-standard GCC Extended Asm feature.

Closes gh-1079.

6 files changed, 18 insertions, 19 deletions

diff --git a/graphics/VectorRendererSpec.cpp b/graphics/VectorRendererSpec.cpp
index 7d3cdff7c7..028f62101a 100644
--- a/graphics/VectorRendererSpec.cpp
+++ b/graphics/VectorRendererSpec.cpp
@@ -52,7 +52,7 @@ inline frac_t fp_sqroot(uint32 x) {
 	// decreasing values. By feeding it the sqrt of the previous old x, as well
 	// as the old x, it should be possible to compute the correct sqrt with far
 	// fewer than 23 iterations.
-	register uint32 root, remHI, remLO, testDIV, count;
+	uint32 root, remHI, remLO, testDIV, count;
 
 	root = 0;
 	remHI = 0;
@@ -443,10 +443,10 @@ namespace Graphics {
  */
 template<typename PixelType>
 void colorFill(PixelType *first, PixelType *last, PixelType color) {
-	register int count = (last - first);
+	int count = (last - first);
 	if (!count)
 		return;
-	register int n = (count + 7) >> 3;
+	int n = (count + 7) >> 3;
 	switch (count % 8) {
 	case 0: do {
 				*first++ = color;	// fall through
@@ -466,26 +466,26 @@ void colorFillClip(PixelType *first, PixelType *last, PixelType color, int realX
 	if (realY < clippingArea.top || realY >= clippingArea.bottom)
 		return;
 
-	register int count = (last - first);
+	int count = (last - first);
 
 	if (realX > clippingArea.right || realX + count < clippingArea.left)
 		return;
 
 	if (realX < clippingArea.left) {
-		register int diff = (clippingArea.left - realX);
+		int diff = (clippingArea.left - realX);
 		realX += diff;
 		count -= diff;
 	}
 
 	if (clippingArea.right <= realX + count) {
-		register int diff = (realX + count - clippingArea.right);
+		int diff = (realX + count - clippingArea.right);
 		count -= diff;
 	}
 
 	if (!count)
 		return;
 
-	register int n = (count + 7) >> 3;
+	int n = (count + 7) >> 3;
 	switch (count % 8) {
 	case 0: do {
 		*first++ = color;	// fall through
diff --git a/graphics/scaler/2xsai.cpp b/graphics/scaler/2xsai.cpp
index 757c1cf8de..4389d52745 100644
--- a/graphics/scaler/2xsai.cpp
+++ b/graphics/scaler/2xsai.cpp
@@ -92,7 +92,7 @@ void Super2xSaITemplate(const uint8 *srcPtr, uint32 srcPitch, uint8 *dstPtr, uin
 			} else if (color5 == color3 && color2 != color6) {
 				product2b = product1b = color5;
 			} else if (color5 == color3 && color2 == color6) {
-				register int r = 0;
+				int r = 0;
 
 				r += GetResult(color6, color5, color1, colorA1);
 				r += GetResult(color6, color5, color4, colorB1);
@@ -227,7 +227,7 @@ void SuperEagleTemplate(const uint8 *srcPtr, uint32 srcPitch, uint8 *dstPtr, uin
 						product2a = interpolate_1_1(color2, color3);
 					}
 				} else {
-					register int r = 0;
+					int r = 0;
 
 					r += GetResult(color6, color5, color1, colorA1);
 					r += GetResult(color6, color5, color4, colorB1);
@@ -282,8 +282,7 @@ void _2xSaITemplate(const uint8 *srcPtr, uint32 srcPitch, uint8 *dstPtr, uint32
 
 		for (int i = 0; i < width; ++i) {
 
-			register unsigned colorA, colorB;
-			unsigned colorC, colorD,
+			unsigned colorA, colorB, colorC, colorD,
 				colorE, colorF, colorG, colorH, colorI, colorJ, colorK, colorL, colorM, colorN, colorO;
 			unsigned product, product1, product2;
 
@@ -347,7 +346,7 @@ void _2xSaITemplate(const uint8 *srcPtr, uint32 srcPitch, uint8 *dstPtr, uint32
 					product1 = colorA;
 					product2 = colorA;
 				} else {
-					register int r = 0;
+					int r = 0;
 
 					product1 = interpolate_1_1(colorA, colorC);
 					product = interpolate_1_1(colorA, colorB);
diff --git a/graphics/scaler/hq2x.cpp b/graphics/scaler/hq2x.cpp
index 74ceebd611..7efbef305c 100644
--- a/graphics/scaler/hq2x.cpp
+++ b/graphics/scaler/hq2x.cpp
@@ -103,7 +103,7 @@ extern "C" uint32   *RGBtoYUV;
  */
 template<typename ColorMask>
 static void HQ2x_implementation(const uint8 *srcPtr, uint32 srcPitch, uint8 *dstPtr, uint32 dstPitch, int width, int height) {
-	register int w1, w2, w3, w4, w5, w6, w7, w8, w9;
+	int w1, w2, w3, w4, w5, w6, w7, w8, w9;
 
 	const uint32 nextlineSrc = srcPitch / sizeof(uint16);
 	const uint16 *p = (const uint16 *)srcPtr;
diff --git a/graphics/scaler/hq3x.cpp b/graphics/scaler/hq3x.cpp
index f6c86b3017..8ef82aea3d 100644
--- a/graphics/scaler/hq3x.cpp
+++ b/graphics/scaler/hq3x.cpp
@@ -106,7 +106,7 @@ extern "C" uint32   *RGBtoYUV;
  */
 template<typename ColorMask>
 static void HQ3x_implementation(const uint8 *srcPtr, uint32 srcPitch, uint8 *dstPtr, uint32 dstPitch, int width, int height) {
-	register int  w1, w2, w3, w4, w5, w6, w7, w8, w9;
+	int  w1, w2, w3, w4, w5, w6, w7, w8, w9;
 
 	const uint32 nextlineSrc = srcPitch / sizeof(uint16);
 	const uint16 *p = (const uint16 *)srcPtr;
diff --git a/graphics/scaler/intern.h b/graphics/scaler/intern.h
index 0f3f874675..eddc3c7f3d 100644
--- a/graphics/scaler/intern.h
+++ b/graphics/scaler/intern.h
@@ -46,8 +46,8 @@ static inline uint32 interpolate32_1_1(uint32 p1, uint32 p2) {
  */
 template<typename ColorMask>
 static inline uint32 interpolate32_3_1(uint32 p1, uint32 p2) {
-	register uint32 x = ((p1 & ColorMask::qhighBits) >> 2) * 3 + ((p2 & ColorMask::qhighBits) >> 2);
-	register uint32 y = ((p1 & ColorMask::qlowBits) * 3 + (p2 & ColorMask::qlowBits)) >> 2;
+	uint32 x = ((p1 & ColorMask::qhighBits) >> 2) * 3 + ((p2 & ColorMask::qhighBits) >> 2);
+	uint32 y = ((p1 & ColorMask::qlowBits) * 3 + (p2 & ColorMask::qlowBits)) >> 2;
 
 	y &= ColorMask::qlowBits;
 	return x + y;
diff --git a/graphics/yuv_to_rgb.cpp b/graphics/yuv_to_rgb.cpp
index 2a485fa664..f4429cb607 100644
--- a/graphics/yuv_to_rgb.cpp
+++ b/graphics/yuv_to_rgb.cpp
@@ -207,7 +207,7 @@ void convertYUV444ToRGB(byte *dstPtr, int dstPitch, const YUVToRGBLookup *lookup
 
 	for (int h = 0; h < yHeight; h++) {
 		for (int w = 0; w < yWidth; w++) {
-			register const uint32 *L;
+			const uint32 *L;
 
 			int16 cr_r  = Cr_r_tab[*vSrc];
 			int16 crb_g = Cr_g_tab[*vSrc] + Cb_g_tab[*uSrc];
@@ -256,7 +256,7 @@ void convertYUV420ToRGB(byte *dstPtr, int dstPitch, const YUVToRGBLookup *lookup
 
 	for (int h = 0; h < halfHeight; h++) {
 		for (int w = 0; w < halfWidth; w++) {
-			register const uint32 *L;
+			const uint32 *L;
 
 			int16 cr_r  = Cr_r_tab[*vSrc];
 			int16 crb_g = Cr_g_tab[*vSrc] + Cb_g_tab[*uSrc];
@@ -346,7 +346,7 @@ void convertYUV410ToRGB(byte *dstPtr, int dstPitch, const YUVToRGBLookup *lookup
 			// Declare some variables for the following macros
 			byte u, v;
 			int16 cr_r, crb_g, cb_b;
-			register const uint32 *L;
+			const uint32 *L;
 
 			READ_QUAD(uSrc, u);
 			READ_QUAD(vSrc, v);