mirror of
https://github.com/Ryujinx/Ryujinx.git
synced 2024-08-17 14:18:44 +02:00
64 lines
1.8 KiB
C#
64 lines
1.8 KiB
C#
using Ryujinx.Graphics.Shader.IntermediateRepresentation;
|
|
using System;
|
|
|
|
namespace Ryujinx.Graphics.Shader.Translation.Optimizations
|
|
{
|
|
static class BranchElimination
|
|
{
|
|
public static bool RunPass(BasicBlock block)
|
|
{
|
|
if (block.HasBranch && IsRedundantBranch((Operation)block.GetLastOp(), Next(block)))
|
|
{
|
|
block.Branch = null;
|
|
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
private static bool IsRedundantBranch(Operation current, BasicBlock nextBlock)
|
|
{
|
|
// Here we check that:
|
|
// - The current block ends with a branch.
|
|
// - The next block only contains a branch.
|
|
// - The branch on the next block is unconditional.
|
|
// - Both branches are jumping to the same location.
|
|
// In this case, the branch on the current block can be removed,
|
|
// as the next block is going to jump to the same place anyway.
|
|
if (nextBlock == null)
|
|
{
|
|
return false;
|
|
}
|
|
|
|
if (!(nextBlock.Operations.First?.Value is Operation next))
|
|
{
|
|
return false;
|
|
}
|
|
|
|
if (next.Inst != Instruction.Branch)
|
|
{
|
|
return false;
|
|
}
|
|
|
|
return current.Dest == next.Dest;
|
|
}
|
|
|
|
private static BasicBlock Next(BasicBlock block)
|
|
{
|
|
block = block.Next;
|
|
|
|
while (block != null && block.Operations.Count == 0)
|
|
{
|
|
if (block.HasBranch)
|
|
{
|
|
throw new InvalidOperationException("Found a bogus empty block that \"ends with a branch\".");
|
|
}
|
|
|
|
block = block.Next;
|
|
}
|
|
|
|
return block;
|
|
}
|
|
}
|
|
} |