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64 lines
No EOL
1.8 KiB
C#
64 lines
No EOL
1.8 KiB
C#
using Ryujinx.Graphics.Shader.IntermediateRepresentation;
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using System;
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namespace Ryujinx.Graphics.Shader.Translation.Optimizations
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{
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static class BranchElimination
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{
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public static bool RunPass(BasicBlock block)
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{
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if (block.HasBranch && IsRedundantBranch((Operation)block.GetLastOp(), Next(block)))
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{
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block.Branch = null;
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return true;
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}
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return false;
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}
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private static bool IsRedundantBranch(Operation current, BasicBlock nextBlock)
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{
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// Here we check that:
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// - The current block ends with a branch.
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// - The next block only contains a branch.
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// - The branch on the next block is unconditional.
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// - Both branches are jumping to the same location.
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// In this case, the branch on the current block can be removed,
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// as the next block is going to jump to the same place anyway.
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if (nextBlock == null)
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{
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return false;
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}
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if (!(nextBlock.Operations.First?.Value is Operation next))
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{
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return false;
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}
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if (next.Inst != Instruction.Branch)
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{
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return false;
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}
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return current.Dest == next.Dest;
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}
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private static BasicBlock Next(BasicBlock block)
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{
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block = block.Next;
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while (block != null && block.Operations.Count == 0)
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{
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if (block.HasBranch)
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{
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throw new InvalidOperationException("Found a bogus empty block that \"ends with a branch\".");
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}
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block = block.Next;
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}
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return block;
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}
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}
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} |