SPIRV-Cross/shaders/frag/inside-loop-dominated-variable-preservation.frag

#version 310 es
precision mediump float;
layout(location = 0) out vec4 FragColor;

void main()
{
	float v;
	bool written = false;
	for (int j = 0; j < 10; j++)
	{
		for (int i = 0; i < 4; i++)
		{
			float w = 0.0;
			if (written)
				w += v;
			else
				v = 20.0;

			v += float(i);
			written = true;
		}
	}
	FragColor = vec4(1.0);
}
Deal with case where a variable is dominated by inner part of a loop. There is a risk that we try to preserve a loop variable through multiple iterations, even though the dominating block is inside a loop. Fix this by analyzing if a block starts off by writing to a variable. In that case, there cannot be any preservation going on. If we don't, pretend the loop header is reading the variable, which moves the variable to an appropriate scope. 2019-06-06 09:10:39 +00:00			`#version 310 es`
			`precision mediump float;`
			`layout(location = 0) out vec4 FragColor;`

			`void main()`
			`{`
			`float v;`
			`bool written = false;`
Deal with nested loops. Actually need to hoist out variable to outermost loop. 2019-06-06 12:37:02 +00:00			`for (int j = 0; j < 10; j++)`
Deal with case where a variable is dominated by inner part of a loop. There is a risk that we try to preserve a loop variable through multiple iterations, even though the dominating block is inside a loop. Fix this by analyzing if a block starts off by writing to a variable. In that case, there cannot be any preservation going on. If we don't, pretend the loop header is reading the variable, which moves the variable to an appropriate scope. 2019-06-06 09:10:39 +00:00			`{`
Deal with nested loops. Actually need to hoist out variable to outermost loop. 2019-06-06 12:37:02 +00:00			`for (int i = 0; i < 4; i++)`
			`{`
			`float w = 0.0;`
			`if (written)`
			`w += v;`
			`else`
			`v = 20.0;`
Deal with case where a variable is dominated by inner part of a loop. There is a risk that we try to preserve a loop variable through multiple iterations, even though the dominating block is inside a loop. Fix this by analyzing if a block starts off by writing to a variable. In that case, there cannot be any preservation going on. If we don't, pretend the loop header is reading the variable, which moves the variable to an appropriate scope. 2019-06-06 09:10:39 +00:00
Deal with nested loops. Actually need to hoist out variable to outermost loop. 2019-06-06 12:37:02 +00:00			`v += float(i);`
			`written = true;`
			`}`
Deal with case where a variable is dominated by inner part of a loop. There is a risk that we try to preserve a loop variable through multiple iterations, even though the dominating block is inside a loop. Fix this by analyzing if a block starts off by writing to a variable. In that case, there cannot be any preservation going on. If we don't, pretend the loop header is reading the variable, which moves the variable to an appropriate scope. 2019-06-06 09:10:39 +00:00			`}`
			`FragColor = vec4(1.0);`
			`}`