Ryujinx/Ryujinx.Graphics.Shader/Translation/Dominance.cs
gdkchan 49f970d5bd
Implement CAL and RET shader instructions (#1618)
* Add support for CAL and RET shader instructions

* Remove unused stuff

* Fix a bug that could cause the wrong values to be passed to a function

* Avoid repopulating function id dictionary every time

* PR feedback

* Fix vertex shader A/B merge
2020-10-25 17:00:44 -03:00

95 lines
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3 KiB
C#

using Ryujinx.Graphics.Shader.IntermediateRepresentation;
using System.Collections.Generic;
namespace Ryujinx.Graphics.Shader.Translation
{
static class Dominance
{
// Those methods are an implementation of the algorithms on "A Simple, Fast Dominance Algorithm".
// https://www.cs.rice.edu/~keith/EMBED/dom.pdf
public static void FindDominators(ControlFlowGraph cfg)
{
BasicBlock Intersect(BasicBlock block1, BasicBlock block2)
{
while (block1 != block2)
{
while (cfg.PostOrderMap[block1.Index] < cfg.PostOrderMap[block2.Index])
{
block1 = block1.ImmediateDominator;
}
while (cfg.PostOrderMap[block2.Index] < cfg.PostOrderMap[block1.Index])
{
block2 = block2.ImmediateDominator;
}
}
return block1;
}
cfg.Blocks[0].ImmediateDominator = cfg.Blocks[0];
bool modified;
do
{
modified = false;
for (int blkIndex = cfg.PostOrderBlocks.Length - 2; blkIndex >= 0; blkIndex--)
{
BasicBlock block = cfg.PostOrderBlocks[blkIndex];
BasicBlock newIDom = null;
foreach (BasicBlock predecessor in block.Predecessors)
{
if (predecessor.ImmediateDominator != null)
{
if (newIDom != null)
{
newIDom = Intersect(predecessor, newIDom);
}
else
{
newIDom = predecessor;
}
}
}
if (block.ImmediateDominator != newIDom)
{
block.ImmediateDominator = newIDom;
modified = true;
}
}
}
while (modified);
}
public static void FindDominanceFrontiers(BasicBlock[] blocks)
{
for (int blkIndex = 0; blkIndex < blocks.Length; blkIndex++)
{
BasicBlock block = blocks[blkIndex];
if (block.Predecessors.Count < 2)
{
continue;
}
for (int pBlkIndex = 0; pBlkIndex < block.Predecessors.Count; pBlkIndex++)
{
BasicBlock current = block.Predecessors[pBlkIndex];
while (current != block.ImmediateDominator)
{
current.DominanceFrontiers.Add(block);
current = current.ImmediateDominator;
}
}
}
}
}
}