Subject: [PATCH] [CodeGen] Add pass to combine interleaved loads.

This patch defines an interleaved-load-combine pass. The pass searches
for ShuffleVector instructions that represent interleaved loads. Matches are
converted such that they will be captured by the InterleavedAccessPass.

The pass extends LLVMs capabilities to use target specific instruction
selection of interleaved load patterns (e.g.: ld4 on Aarch64
architectures).

Differential Revision: https://reviews.llvm.org/D52653

llvm-svn: 347208

llvm/include/llvm/CodeGen/Passes.h

@@ -379,6 +379,11 @@ namespace llvm {
   ///
   FunctionPass *createInterleavedAccessPass();
 
+  /// InterleavedLoadCombines Pass - This pass identifies interleaved loads and
+  /// combines them into wide loads detectable by InterleavedAccessPass
+  ///
+  FunctionPass *createInterleavedLoadCombinePass();
+
   /// LowerEmuTLS - This pass generates __emutls_[vt].xyz variables for all
   /// TLS variables for the emulated TLS model.
   ///

llvm/include/llvm/InitializePasses.h

@@ -182,6 +182,7 @@ void initializeInstrProfilingLegacyPassPass(PassRegistry&);
 void initializeInstructionCombiningPassPass(PassRegistry&);
 void initializeInstructionSelectPass(PassRegistry&);
 void initializeInterleavedAccessPass(PassRegistry&);
+void initializeInterleavedLoadCombinePass(PassRegistry &);
 void initializeInternalizeLegacyPassPass(PassRegistry&);
 void initializeIntervalPartitionPass(PassRegistry&);
 void initializeJumpThreadingPass(PassRegistry&);

llvm/lib/CodeGen/CMakeLists.txt

@@ -39,6 +39,7 @@ add_llvm_library(LLVMCodeGen
   InlineSpiller.cpp
   InterferenceCache.cpp
   InterleavedAccessPass.cpp
+  InterleavedLoadCombinePass.cpp
   IntrinsicLowering.cpp
   LatencyPriorityQueue.cpp
   LazyMachineBlockFrequencyInfo.cpp

llvm/lib/CodeGen/CodeGen.cpp

@@ -42,6 +42,7 @@ void llvm::initializeCodeGen(PassRegistry &Registry) {
   initializeIfConverterPass(Registry);
   initializeImplicitNullChecksPass(Registry);
   initializeIndirectBrExpandPassPass(Registry);
+  initializeInterleavedLoadCombinePass(Registry);
   initializeInterleavedAccessPass(Registry);
   initializeLiveDebugValuesPass(Registry);
   initializeLiveDebugVariablesPass(Registry);