int main(int argc, char **argv) {
int i, j;
Halide::Func black;
Halide::Func white;
Halide::Var x, y;
black(x, y) = 0;
white(x, y) = 254;
Halide::Image<int32_t> output1 = black.realize(800, 600);
Halide::Image<int32_t> output2 = white.realize(800, 600);
// Save the output for inspection. It should look like a bright parrot.
save(output1, "input1.png");
save(output2, "input2.png");
//Check to see everything is copacetic
for( i = 0; i < 800; i ++ )
{
for( j = 0; j < 600; j ++ )
if (output2(i, j) != 254 || output1(i, j) != 0)
{
printf("Failure! Failed at (%d, %d)\n", i, j);
return 1;
}
}
printf("Success!\n");
return 0;
}
void prog01()
{
Halide::Var x;
Halide::Func init_cond;
init_cond(x) = 1.0f*x;
Halide::Image<float_t> input, output;
input=init_cond.realize(NX);
Halide::ImageParam inPar(Halide::Float(32), 1, "inPar");
Halide::Func cell;
cell(x)=inPar(x)+1;
{
std::vector<Halide::Argument> arg_vect;
arg_vect.push_back(Halide::Argument("inPar", true, Halide::Int(32)));
cell.compile_to_bitcode("stencil-fusion-01.bc", arg_vect, "blur");
}
for (int t =0; t < 100000; ++t) {
inPar.set(input);
output = cell.realize(NX);
swap(output,input);
}
for (int i = 0; i < NX; ++i)
cout << input(i) << " ";
cout << endl;
}
inline void _autotune_timing_stub(Halide::Func& func) {
func.compile_jit();
// TODO: this assumes scalar/non-Tuple outputs - should generalize to a Realization
Halide::Type out_type = func.output_types()[0];
buffer_t out_size_buf;
{
// Use the Buffer constructor as a helper to set up the buffer_t,
// but then throw away its allocation which we don't really want.
Halide::Buffer bufinit(out_type, AUTOTUNE_N);
out_size_buf = *bufinit.raw_buffer();
out_size_buf.host = NULL;
}
Halide::Buffer out_size(out_type, &out_size_buf);
assert(out_size.host_ptr() == NULL); // make sure we don't have an allocation
func.infer_input_bounds(out_size);
// allocate the real output using the inferred mins + extents
Halide::Buffer output( out_type,
out_size.extent(0),
out_size.extent(1),
out_size.extent(2),
out_size.extent(3),
NULL,
"output" );
output.set_min( out_size.min(0),
out_size.min(1),
out_size.min(2),
out_size.min(3) );
// re-run input inference on enlarged output buffer
func.unbind_image_params(); // TODO: iterate to convergence
func.infer_input_bounds(output);
timeval t1, t2;
double rv = 0;
const unsigned int timeout = AUTOTUNE_LIMIT;
alarm(timeout);
for (int i = 0; i < AUTOTUNE_TRIALS; i++) {
gettimeofday(&t1, NULL);
func.realize(output);
gettimeofday(&t2, NULL);
alarm(0); // disable alarm
double t = (t2.tv_sec - t1.tv_sec) + (t2.tv_usec - t1.tv_usec)/1000000.0;
if(i == 0 || t < rv)
rv = t;
}
printf("{\"time\": %.10f}\n", rv);
exit(0);
}
inline void _autotune_timing_stub(Halide::Func& func) {
func.compile_jit();
func.infer_input_bounds(1024,1024);
timeval t1, t2;
double rv = 0;
for (int i = 0; i < 3; i++) {
gettimeofday(&t1, NULL);
func.realize(1024,1024);
gettimeofday(&t2, NULL);
double t = (t2.tv_sec - t1.tv_sec) + (t2.tv_usec - t1.tv_usec)/1000000.0;
if(i == 0 || t < rv)
rv = t;
}
printf("{\"time\": %.10f}\n", rv);
exit(0);
}
void NamedWindow::showImage2D(Halide::Image<uint8_t> im)
{
static Halide::Func convert("convertToMat2D");
static Halide::ImageParam ip(Halide::UInt(8), 2);
static Halide::Var x, y;
if (!convert.defined())
{
convert(x, y) = ip(x, y);
convert.vectorize(x, 4).parallel(y, 4);
}
ip.set(im);
cv::Mat mat(im.height(), im.width(), CV_8UC1, cv::Scalar(0));
convert.realize(Halide::Buffer(Halide::UInt(8), im.width(), im.height(), 0, 0, mat.data));
cv::imshow(name, mat);
}
void NamedWindow::showImage3D(Halide::Image<float> im)
{
static Halide::Func convert("convertToMat3D");
static Halide::ImageParam ip(Halide::Float(32), 3);
static Halide::Var x, y, c;
if (!convert.defined())
{
convert(c, x, y) = Halide::cast<uint8_t>(ip(x, y, 2 - c) * 255);
convert.vectorize(x, 4).parallel(y, 4);
}
ip.set(im);
cv::Mat mat(im.height(), im.width(), CV_8UC3, cv::Scalar(0));
convert.realize(Halide::Buffer(Halide::UInt(8), im.channels(), im.width(), im.height(), 0, mat.data));
cv::imshow(name, mat);
}
inline void _autotune_timing_stub(Halide::Func& func) {
func.compile_jit();
func.infer_input_bounds(AUTOTUNE_N);
timeval t1, t2;
double rv = 0;
const unsigned int timeout = AUTOTUNE_LIMIT;
alarm(timeout);
for (int i = 0; i < AUTOTUNE_TRIALS; i++) {
gettimeofday(&t1, NULL);
func.realize(AUTOTUNE_N);
gettimeofday(&t2, NULL);
alarm(0); // disable alarm
double t = (t2.tv_sec - t1.tv_sec) + (t2.tv_usec - t1.tv_usec)/1000000.0;
if(i == 0 || t < rv)
rv = t;
}
printf("{\"time\": %.10f}\n", rv);
exit(0);
}
int main(int argc, char **argv) {
// This program defines a single-stage imaging pipeline that
// brightens an image.
// First we'll load the input image we wish to brighten.
Halide::Image<uint8_t> input = load<uint8_t>("../apps/images/rgb.png");
// Next we define our Func object that represents our one pipeline
// stage.
Halide::Func brighter;
// Our Func will have three arguments, representing the position
// in the image and the color channel. Halide treats color
// channels as an extra dimension of the image.
Halide::Var x, y, c;
// Normally we'd probably write the whole function definition on
// one line. Here we'll break it apart so we can explain what
// we're doing at every step.
// For each pixel of the input image.
Halide::Expr value = input(x, y, c);
// Cast it to a floating point value.
value = Halide::cast<float>(value);
// Multiply it by 1.5 to brighten it. Halide represents real
// numbers as floats, not doubles, so we stick an 'f' on the end
// of our constant.
value = value * 1.5f;
// Clamp it to be less than 255, so we don't get overflow when we
// cast it back to an 8-bit unsigned int.
value = Halide::min(value, 255.0f);
// Cast it back to an 8-bit unsigned integer.
value = Halide::cast<uint8_t>(value);
// Define the function.
brighter(x, y, c) = value;
// The equivalent one-liner to all of the above is:
//
// brighter(x, y, c) = Halide::cast<uint8_t>(min(input(x, y, c) * 1.5f, 255));
//
// In the shorter version:
// - I skipped the cast to float, because multiplying by 1.5f does
// that automatically.
// - I also used integer constants in clamp, because they get cast
// to match the type of the first argument.
// - I left the Halide:: off clamp. It's unnecessary due to Koenig
// lookup.
// Remember. All we've done so far is build a representation of a
// Halide program in memory. We haven't actually processed any
// pixels yet. We haven't even compiled that Halide program yet.
// So now we'll realize the Func. The size of the output image
// should match the size of the input image. If we just wanted to
// brighten a portion of the input image we could request a
// smaller size. If we request a larger size Halide will throw an
// error at runtime telling us we're trying to read out of bounds
// on the input image.
Halide::Image<uint8_t> output = brighter.realize(input.width(), input.height(), input.channels());
// Save the output for inspection. It should look like a bright parrot.
save(output, "brighter.png");
printf("Success!\n");
return 0;
}
void func_realize3(h::Func &that, h::Buffer dst, const h::Target &target = h::Target())
{
that.realize(dst, target);
return;
}
void func_realize2(h::Func &that, h::Realization dst, const h::Target &target = h::Target())
{
that.realize(dst, target);
return;
}
h::Realization func_realize1(h::Func &that, int x_size=0, int y_size=0, int z_size=0, int w_size=0,
const h::Target &target = h::Target())
{
return that.realize(x_size, y_size, z_size, w_size, target);
}
h::Realization func_realize0(h::Func &that, std::vector<int32_t> sizes, const h::Target &target = h::Target())
{
return that.realize(sizes, target);
}
int main(int argc, char **argv) {
// This program defines a single-stage imaging pipeline that
// outputs a grayscale diagonal gradient.
// A 'Func' object represents a pipeline stage. It's a pure
// function that defines what value each pixel should have. You
// can think of it as a computed image.
Halide::Func gradient;
// Var objects are names to use as variables in the definition of
// a Func. They have no meaning by themselves.
Halide::Var x, y;
// We typically use Vars named 'x' and 'y' to correspond to the x
// and y axes of an image, and we write them in that order. If
// you're used to thinking of images as having rows and columns,
// then x is the column index, and y is the row index.
// Funcs are defined at any integer coordinate of its variables as
// an Expr in terms of those variables and other functions.
// Here, we'll define an Expr which has the value x + y. Vars have
// appropriate operator overloading so that expressions like
// 'x + y' become 'Expr' objects.
Halide::Expr e = x + y;
// Now we'll add a definition for the Func object. At pixel x, y,
// the image will have the value of the Expr e. On the left hand
// side we have the Func we're defining and some Vars. On the right
// hand side we have some Expr object that uses those same Vars.
gradient(x, y) = e;
// This is the same as writing:
//
// gradient(x, y) = x + y;
//
// which is the more common form, but we are showing the
// intermediate Expr here for completeness.
// That line of code defined the Func, but it didn't actually
// compute the output image yet. At this stage it's just Funcs,
// Exprs, and Vars in memory, representing the structure of our
// imaging pipeline. We're meta-programming. This C++ program is
// constructing a Halide program in memory. Actually computing
// pixel data comes next.
// Now we 'realize' the Func, which JIT compiles some code that
// implements the pipeline we've defined, and then runs it. We
// also need to tell Halide the domain over which to evaluate the
// Func, which determines the range of x and y above, and the
// resolution of the output image. Halide.h also provides a basic
// templatized Image type we can use. We'll make an 800 x 600
// image.
Halide::Image<int32_t> output = gradient.realize(800, 600);
// Halide does type inference for you. Var objects represent
// 32-bit integers, so the Expr object 'x + y' also represents a
// 32-bit integer, and so 'gradient' defines a 32-bit image, and
// so we got a 32-bit signed integer image out when we call
// 'realize'. Halide types and type-casting rules are equivalent
// to C.
// Let's check everything worked, and we got the output we were
// expecting:
for (int j = 0; j < output.height(); j++) {
for (int i = 0; i < output.width(); i++) {
// We can access a pixel of an Image object using similar
// syntax to defining and using functions.
if (output(i, j) != i + j) {
printf("Something went wrong!\n"
"Pixel %d, %d was supposed to be %d, but instead it's %d\n",
i, j, i+j, output(i, j));
return -1;
}
}
}
// Everything worked! We defined a Func, then called 'realize' on
// it to generate and run machine code that produced an Image.
printf("Success!\n");
return 0;
}
