Commit 4e69284b authored by Urvang Joshi's avatar Urvang Joshi

Rewrite some loops to avoid -Wunsafe-loop-optimizations warnings.

For example, loops of the form:
"for (i = 0; i < 1 + max_value; ++i) ..." or
"for (i = 0; i <= max_value; ++i) ..." are possibly infinite loops,
theoretically speaking (even if practically, they aren't).
So, compiler cannot optimize those loops.

When possible, I rewrote such loops to be finite even theoretically.

Change-Id: Ied47a24833b689c0ec011f8645cf1c01856f7c59
parent d55aaa81
......@@ -68,24 +68,25 @@ static void scale1d_2t1_i(const unsigned char *source, int source_step,
unsigned int source_scale, unsigned int source_length,
unsigned char *dest, int dest_step,
unsigned int dest_scale, unsigned int dest_length) {
unsigned int i, j;
unsigned int temp;
int source_pitch = source_step;
const unsigned int source_pitch = source_step;
const unsigned char *const dest_end = dest + dest_length * dest_step;
(void)source_length;
(void)source_scale;
(void)dest_scale;
source_step *= 2;
dest[0] = source[0];
for (i = dest_step, j = source_step; i < dest_length * dest_step;
i += dest_step, j += source_step) {
temp = 8;
temp += 3 * source[j - source_pitch];
temp += 10 * source[j];
temp += 3 * source[j + source_pitch];
temp >>= 4;
dest[i] = (char)(temp);
source_step *= 2; // Every other row.
dest[0] = source[0]; // Special case: 1st pixel.
source += source_step;
dest += dest_step;
while (dest < dest_end) {
const unsigned int a = 3 * source[-source_pitch];
const unsigned int b = 10 * source[0];
const unsigned int c = 3 * source[source_pitch];
*dest = (unsigned char)((8 + a + b + c) >> 4);
source += source_step;
dest += dest_step;
}
}
......@@ -119,17 +120,18 @@ static void scale1d_2t1_ps(const unsigned char *source, int source_step,
unsigned int source_length, unsigned char *dest,
int dest_step, unsigned int dest_scale,
unsigned int dest_length) {
unsigned int i, j;
const unsigned char *const dest_end = dest + dest_length * dest_step;
(void)source_length;
(void)source_scale;
(void)dest_scale;
source_step *= 2;
j = 0;
source_step *= 2; // Every other row.
for (i = 0; i < dest_length * dest_step; i += dest_step, j += source_step)
dest[i] = source[j];
while (dest < dest_end) {
*dest = *source;
source += source_step;
dest += dest_step;
}
}
/****************************************************************************
*
......@@ -159,12 +161,12 @@ static void scale1d_c(const unsigned char *source, int source_step,
unsigned int source_scale, unsigned int source_length,
unsigned char *dest, int dest_step,
unsigned int dest_scale, unsigned int dest_length) {
unsigned int i;
unsigned int round_value = dest_scale / 2;
const unsigned char *const dest_end = dest + dest_length * dest_step;
const unsigned int round_value = dest_scale / 2;
unsigned int left_modifier = dest_scale;
unsigned int right_modifier = 0;
unsigned char left_pixel = *source;
unsigned char right_pixel = *(source + source_step);
unsigned char left_pixel = source[0];
unsigned char right_pixel = source[source_step];
(void)source_length;
......@@ -173,18 +175,18 @@ static void scale1d_c(const unsigned char *source, int source_step,
/* assert ( (source_length - 1) * dest_scale >= (dest_length - 1) *
* source_scale);*/
for (i = 0; i < dest_length * dest_step; i += dest_step) {
dest[i] = (char)((left_modifier * left_pixel +
right_modifier * right_pixel + round_value) /
dest_scale);
while (dest < dest_end) {
*dest = (unsigned char)((left_modifier * left_pixel +
right_modifier * right_pixel + round_value) /
dest_scale);
right_modifier += source_scale;
while (right_modifier > dest_scale) {
right_modifier -= dest_scale;
source += source_step;
left_pixel = *source;
right_pixel = *(source + source_step);
left_pixel = source[0];
right_pixel = source[source_step];
}
left_modifier = dest_scale - right_modifier;
......@@ -236,11 +238,10 @@ static void Scale2D(
unsigned int dest_width, unsigned int dest_height, unsigned char *temp_area,
unsigned char temp_area_height, unsigned int hscale, unsigned int hratio,
unsigned int vscale, unsigned int vratio, unsigned int interlaced) {
/*unsigned*/
int i, j, k;
int bands;
int dest_band_height;
int source_band_height;
unsigned int i, j, k;
unsigned int bands;
unsigned int dest_band_height;
unsigned int source_band_height;
typedef void (*Scale1D)(const unsigned char *source, int source_step,
unsigned int source_scale, unsigned int source_length,
......@@ -331,7 +332,7 @@ static void Scale2D(
if (ratio_scalable) {
if (source_height == dest_height) {
/* for each band of the image */
for (k = 0; k < (int)dest_height; k++) {
for (k = 0; k < dest_height; ++k) {
horiz_line_scale(source, source_width, dest, dest_width);
source += source_pitch;
dest += dest_pitch;
......@@ -346,14 +347,13 @@ static void Scale2D(
horiz_line_scale(source, source_width, temp_area, dest_width);
}
for (k = 0;
k < (int)(dest_height + dest_band_height - 1) / dest_band_height;
k++) {
for (k = 0; k < (dest_height + dest_band_height - 1) / dest_band_height;
++k) {
/* scale one band horizontally */
for (i = 0; i < source_band_height; i++) {
for (i = 0; i < source_band_height; ++i) {
/* Trap case where we could read off the base of the source buffer */
line_src = (unsigned char *)source + i * source_pitch;
line_src = source + i * source_pitch;
if (line_src < source_base) line_src = source_base;
......@@ -388,7 +388,7 @@ static void Scale2D(
if (source_height == dest_height) {
/* for each band of the image */
for (k = 0; k < (int)dest_height; k++) {
for (k = 0; k < dest_height; ++k) {
Scale1Dh(source, 1, hscale, source_width + 1, dest, 1, hratio,
dest_width);
source += source_pitch;
......@@ -414,10 +414,10 @@ static void Scale2D(
/* for each band of the image */
bands = (dest_height + dest_band_height - 1) / dest_band_height;
for (k = 0; k < bands; k++) {
for (k = 0; k < bands; ++k) {
/* scale one band horizontally */
for (i = 1; i < source_band_height + 1; i++) {
if (k * source_band_height + i < (int)source_height) {
for (i = 1; i < source_band_height + 1; ++i) {
if (k * source_band_height + i < source_height) {
Scale1Dh(source + i * source_pitch, 1, hscale, source_width + 1,
temp_area + i * dest_pitch, 1, hratio, dest_width);
} else { /* Duplicate the last row */
......@@ -428,7 +428,7 @@ static void Scale2D(
}
/* scale one band vertically */
for (j = 0; j < (int)dest_width; j++) {
for (j = 0; j < dest_width; ++j) {
Scale1Dv(&temp_area[j], dest_pitch, vscale, source_band_height + 1,
&dest[j], dest_pitch, vratio, dest_band_height);
}
......@@ -487,12 +487,12 @@ void aom_scale_frame(YV12_BUFFER_CONFIG *src, YV12_BUFFER_CONFIG *dst,
temp_area, temp_height, hscale, hratio, vscale, vratio, interlaced);
if (dw < (int)dst->y_width)
for (i = 0; i < dh; i++)
for (i = 0; i < dh; ++i)
memset(dst->y_buffer + i * dst->y_stride + dw - 1,
dst->y_buffer[i * dst->y_stride + dw - 2], dst->y_width - dw + 1);
if (dh < (int)dst->y_height)
for (i = dh - 1; i < (int)dst->y_height; i++)
for (i = dh - 1; i < (int)dst->y_height; ++i)
memcpy(dst->y_buffer + i * dst->y_stride,
dst->y_buffer + (dh - 2) * dst->y_stride, dst->y_width + 1);
......@@ -502,13 +502,13 @@ void aom_scale_frame(YV12_BUFFER_CONFIG *src, YV12_BUFFER_CONFIG *dst,
vratio, interlaced);
if (dw / 2 < (int)dst->uv_width)
for (i = 0; i < dst->uv_height; i++)
for (i = 0; i < dst->uv_height; ++i)
memset(dst->u_buffer + i * dst->uv_stride + dw / 2 - 1,
dst->u_buffer[i * dst->uv_stride + dw / 2 - 2],
dst->uv_width - dw / 2 + 1);
if (dh / 2 < (int)dst->uv_height)
for (i = dh / 2 - 1; i < (int)dst->y_height / 2; i++)
for (i = dh / 2 - 1; i < (int)dst->y_height / 2; ++i)
memcpy(dst->u_buffer + i * dst->uv_stride,
dst->u_buffer + (dh / 2 - 2) * dst->uv_stride, dst->uv_width);
......@@ -518,13 +518,13 @@ void aom_scale_frame(YV12_BUFFER_CONFIG *src, YV12_BUFFER_CONFIG *dst,
vratio, interlaced);
if (dw / 2 < (int)dst->uv_width)
for (i = 0; i < dst->uv_height; i++)
for (i = 0; i < dst->uv_height; ++i)
memset(dst->v_buffer + i * dst->uv_stride + dw / 2 - 1,
dst->v_buffer[i * dst->uv_stride + dw / 2 - 2],
dst->uv_width - dw / 2 + 1);
if (dh / 2 < (int)dst->uv_height)
for (i = dh / 2 - 1; i < (int)dst->y_height / 2; i++)
for (i = dh / 2 - 1; i < (int)dst->y_height / 2; ++i)
memcpy(dst->v_buffer + i * dst->uv_stride,
dst->v_buffer + (dh / 2 - 2) * dst->uv_stride, dst->uv_width);
}
......@@ -39,27 +39,23 @@ void aom_horizontal_line_5_4_scale_c(const unsigned char *source,
unsigned int source_width,
unsigned char *dest,
unsigned int dest_width) {
unsigned i;
unsigned int a, b, c, d, e;
unsigned char *des = dest;
const unsigned char *src = source;
const unsigned char *const source_end = source + source_width;
(void)dest_width;
for (i = 0; i < source_width; i += 5) {
a = src[0];
b = src[1];
c = src[2];
d = src[3];
e = src[4];
while (source < source_end) {
const unsigned int a = source[0];
const unsigned int b = source[1];
const unsigned int c = source[2];
const unsigned int d = source[3];
const unsigned int e = source[4];
des[0] = (unsigned char)a;
des[1] = (unsigned char)((b * 192 + c * 64 + 128) >> 8);
des[2] = (unsigned char)((c * 128 + d * 128 + 128) >> 8);
des[3] = (unsigned char)((d * 64 + e * 192 + 128) >> 8);
dest[0] = (unsigned char)a;
dest[1] = (unsigned char)((b * 192 + c * 64 + 128) >> 8);
dest[2] = (unsigned char)((c * 128 + d * 128 + 128) >> 8);
dest[3] = (unsigned char)((d * 64 + e * 192 + 128) >> 8);
src += 5;
des += 4;
source += 5;
dest += 4;
}
}
......@@ -67,25 +63,21 @@ void aom_vertical_band_5_4_scale_c(unsigned char *source,
unsigned int src_pitch, unsigned char *dest,
unsigned int dest_pitch,
unsigned int dest_width) {
unsigned int i;
unsigned int a, b, c, d, e;
unsigned char *des = dest;
unsigned char *src = source;
for (i = 0; i < dest_width; i++) {
a = src[0 * src_pitch];
b = src[1 * src_pitch];
c = src[2 * src_pitch];
d = src[3 * src_pitch];
e = src[4 * src_pitch];
des[0 * dest_pitch] = (unsigned char)a;
des[1 * dest_pitch] = (unsigned char)((b * 192 + c * 64 + 128) >> 8);
des[2 * dest_pitch] = (unsigned char)((c * 128 + d * 128 + 128) >> 8);
des[3 * dest_pitch] = (unsigned char)((d * 64 + e * 192 + 128) >> 8);
src++;
des++;
const unsigned char *const dest_end = dest + dest_width;
while (dest < dest_end) {
const unsigned int a = source[0 * src_pitch];
const unsigned int b = source[1 * src_pitch];
const unsigned int c = source[2 * src_pitch];
const unsigned int d = source[3 * src_pitch];
const unsigned int e = source[4 * src_pitch];
dest[0 * dest_pitch] = (unsigned char)a;
dest[1 * dest_pitch] = (unsigned char)((b * 192 + c * 64 + 128) >> 8);
dest[2 * dest_pitch] = (unsigned char)((c * 128 + d * 128 + 128) >> 8);
dest[3 * dest_pitch] = (unsigned char)((d * 64 + e * 192 + 128) >> 8);
++source;
++dest;
}
}
......@@ -114,26 +106,21 @@ void aom_horizontal_line_5_3_scale_c(const unsigned char *source,
unsigned int source_width,
unsigned char *dest,
unsigned int dest_width) {
unsigned int i;
unsigned int a, b, c, d, e;
unsigned char *des = dest;
const unsigned char *src = source;
const unsigned char *const source_end = source + source_width;
(void)dest_width;
for (i = 0; i < source_width; i += 5) {
a = src[0];
b = src[1];
c = src[2];
d = src[3];
e = src[4];
des[0] = (unsigned char)a;
des[1] = (unsigned char)((b * 85 + c * 171 + 128) >> 8);
des[2] = (unsigned char)((d * 171 + e * 85 + 128) >> 8);
src += 5;
des += 3;
while (source < source_end) {
const unsigned int a = source[0];
const unsigned int b = source[1];
const unsigned int c = source[2];
const unsigned int d = source[3];
const unsigned int e = source[4];
dest[0] = (unsigned char)a;
dest[1] = (unsigned char)((b * 85 + c * 171 + 128) >> 8);
dest[2] = (unsigned char)((d * 171 + e * 85 + 128) >> 8);
source += 5;
dest += 3;
}
}
......@@ -141,24 +128,20 @@ void aom_vertical_band_5_3_scale_c(unsigned char *source,
unsigned int src_pitch, unsigned char *dest,
unsigned int dest_pitch,
unsigned int dest_width) {
unsigned int i;
unsigned int a, b, c, d, e;
unsigned char *des = dest;
unsigned char *src = source;
for (i = 0; i < dest_width; i++) {
a = src[0 * src_pitch];
b = src[1 * src_pitch];
c = src[2 * src_pitch];
d = src[3 * src_pitch];
e = src[4 * src_pitch];
des[0 * dest_pitch] = (unsigned char)a;
des[1 * dest_pitch] = (unsigned char)((b * 85 + c * 171 + 128) >> 8);
des[2 * dest_pitch] = (unsigned char)((d * 171 + e * 85 + 128) >> 8);
src++;
des++;
const unsigned char *const dest_end = dest + dest_width;
while (dest < dest_end) {
const unsigned int a = source[0 * src_pitch];
const unsigned int b = source[1 * src_pitch];
const unsigned int c = source[2 * src_pitch];
const unsigned int d = source[3 * src_pitch];
const unsigned int e = source[4 * src_pitch];
dest[0 * dest_pitch] = (unsigned char)a;
dest[1 * dest_pitch] = (unsigned char)((b * 85 + c * 171 + 128) >> 8);
dest[2 * dest_pitch] = (unsigned char)((d * 171 + e * 85 + 128) >> 8);
++source;
++dest;
}
}
......@@ -186,18 +169,12 @@ void aom_horizontal_line_2_1_scale_c(const unsigned char *source,
unsigned int source_width,
unsigned char *dest,
unsigned int dest_width) {
unsigned int i;
unsigned int a;
unsigned char *des = dest;
const unsigned char *src = source;
const unsigned char *const source_end = source + source_width;
(void)dest_width;
for (i = 0; i < source_width; i += 2) {
a = src[0];
des[0] = (unsigned char)(a);
src += 2;
des += 1;
while (source < source_end) {
dest[0] = source[0];
source += 2;
++dest;
}
}
......@@ -215,18 +192,14 @@ void aom_vertical_band_2_1_scale_i_c(unsigned char *source,
unsigned char *dest,
unsigned int dest_pitch,
unsigned int dest_width) {
int i;
int temp;
int width = dest_width;
const unsigned char *const dest_end = dest + dest_width;
(void)dest_pitch;
for (i = 0; i < width; i++) {
temp = 8;
temp += source[i - (int)src_pitch] * 3;
temp += source[i] * 10;
temp += source[i + src_pitch] * 3;
temp >>= 4;
dest[i] = (unsigned char)(temp);
while (dest < dest_end) {
const unsigned int a = source[-src_pitch] * 3;
const unsigned int b = source[0] * 10;
const unsigned int c = source[src_pitch] * 3;
dest[0] = (unsigned char)((8 + a + b + c) >> 4);
++source;
++dest;
}
}
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