Revert "[X86] Support AMX fast register allocation"

This reverts commit 3b8ec86.

Revert "[X86] Refine AMX fast register allocation"

This reverts commit c3f95e9.

This pass breaks using LLVM in a multi-threaded environment by
introducing global state.

Author: d0k

llvm/include/llvm/CodeGen/Passes.h

@@ -501,9 +501,6 @@ namespace llvm {
   /// or split the data to two <128 x i32>.
   FunctionPass *createX86LowerAMXTypePass();
 
-  /// The pass insert tile config intrinsics for AMX fast register allocation.
-  FunctionPass *createX86PreAMXConfigPass();
-
   /// The pass transforms amx intrinsics to scalar operation if the function has
   /// optnone attribute or it is O0.
   FunctionPass *createX86LowerAMXIntrinsicsPass();

llvm/include/llvm/CodeGen/TargetPassConfig.h

@@ -406,10 +406,6 @@ class TargetPassConfig : public ImmutablePass {
     return false;
   }
 
-  /// addPostFastRegAllocRewrite - Add passes to the optimized register
-  /// allocation pipeline after fast register allocation is complete.
-  virtual bool addPostFastRegAllocRewrite() { return false; }
-
   /// Add passes to be run immediately after virtual registers are rewritten
   /// to physical registers.
   virtual void addPostRewrite() { }

llvm/lib/CodeGen/TargetPassConfig.cpp

@@ -1316,10 +1316,6 @@ bool TargetPassConfig::addRegAssignAndRewriteFast() {
     report_fatal_error("Must use fast (default) register allocator for unoptimized regalloc.");
 
   addPass(createRegAllocPass(false));
-
-  // Allow targets to change the register assignments after
-  // fast register allocation.
-  addPostFastRegAllocRewrite();
   return true;
 }
 

llvm/lib/Target/X86/CMakeLists.txt

@@ -34,10 +34,8 @@ set(sources
   X86DiscriminateMemOps.cpp
   X86LowerTileCopy.cpp
   X86LowerAMXType.cpp
-  X86PreAMXConfig.cpp
   X86LowerAMXIntrinsics.cpp
   X86TileConfig.cpp
-  X86FastTileConfig.cpp
   X86PreTileConfig.cpp
   X86ExpandPseudo.cpp
   X86FastISel.cpp

llvm/lib/Target/X86/X86.h

@@ -79,9 +79,6 @@ FunctionPass *createX86WinAllocaExpander();
 /// Return a pass that config the tile registers.
 FunctionPass *createX86TileConfigPass();
 
-/// Return a pass that config the tile registers after fast reg allocation.
-FunctionPass *createX86FastTileConfigPass();
-
 /// Return a pass that insert pseudo tile config instruction.
 FunctionPass *createX86PreTileConfigPass();
 
@@ -175,10 +172,8 @@ void initializeX86PartialReductionPass(PassRegistry &);
 void initializeX86SpeculativeLoadHardeningPassPass(PassRegistry &);
 void initializeX86SpeculativeExecutionSideEffectSuppressionPass(PassRegistry &);
 void initializeX86PreTileConfigPass(PassRegistry &);
-void initializeX86FastTileConfigPass(PassRegistry &);
 void initializeX86TileConfigPass(PassRegistry &);
 void initializeX86LowerAMXTypeLegacyPassPass(PassRegistry &);
-void initializeX86PreAMXConfigPassPass(PassRegistry &);
 void initializeX86LowerTileCopyPass(PassRegistry &);
 void initializeX86LowerAMXIntrinsicsLegacyPassPass(PassRegistry &);