Ryujinx/ARMeilleure/CodeGen/Optimizations/BlockPlacement.cs
FICTURE7 fbf40424f4
Add an early TailMerge pass (#2721)
* Add an early `TailMerge` pass

Some translations can have a lot of guest calls and since for each guest
call there is a call guard which may return. This can produce a lot of
epilogue code for returns. This pass merges the epilogue into a single
block.

```
Using filter 'hcq'.
Using metric 'code size'.

Total diff: -1648111 (-7.19 %) (bytes):
  Base: 22913847
  Diff: 21265736

Improved: 4567, regressed: 14, unchanged: 144
```

* Set PTC version

* Address feedback

* Handle `void` returning functions

* Actually handle `void` returning functions

* Fix `RegisterToLocal` logging
2021-10-18 19:51:22 -03:00

72 lines
2.3 KiB
C#

using ARMeilleure.IntermediateRepresentation;
using ARMeilleure.Translation;
using System.Diagnostics;
using static ARMeilleure.IntermediateRepresentation.Operand.Factory;
namespace ARMeilleure.CodeGen.Optimizations
{
static class BlockPlacement
{
public static void RunPass(ControlFlowGraph cfg)
{
bool update = false;
BasicBlock block;
BasicBlock nextBlock;
BasicBlock lastBlock = cfg.Blocks.Last;
// Move cold blocks at the end of the list, so that they are emitted away from hot code.
for (block = cfg.Blocks.First; block != null; block = nextBlock)
{
nextBlock = block.ListNext;
if (block.Frequency == BasicBlockFrequency.Cold)
{
cfg.Blocks.Remove(block);
cfg.Blocks.AddLast(block);
}
if (block == lastBlock)
{
break;
}
}
for (block = cfg.Blocks.First; block != null; block = nextBlock)
{
nextBlock = block.ListNext;
if (block.SuccessorsCount == 2)
{
Operation branchOp = block.Operations.Last;
Debug.Assert(branchOp.Instruction == Instruction.BranchIf);
BasicBlock falseSucc = block.GetSuccessor(0);
BasicBlock trueSucc = block.GetSuccessor(1);
// If true successor is next block in list, invert the condition. We avoid extra branching by
// making the true side the fallthrough (i.e, convert it to the false side).
if (trueSucc == block.ListNext)
{
Comparison comp = (Comparison)branchOp.GetSource(2).AsInt32();
Comparison compInv = comp.Invert();
branchOp.SetSource(2, Const((int)compInv));
block.SetSuccessor(0, trueSucc);
block.SetSuccessor(1, falseSucc);
update = true;
}
}
}
if (update)
{
cfg.Update();
}
}
}
}