It's not necessary to do rounding for alloca operations when the requested
alignment is equal to the stack alignment.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40004 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/LLVMTargetMachine.cpp b/lib/CodeGen/LLVMTargetMachine.cpp
new file mode 100644
index 0000000..b72704b
--- /dev/null
+++ b/lib/CodeGen/LLVMTargetMachine.cpp
@@ -0,0 +1,205 @@
+//===-- LLVMTargetMachine.cpp - Implement the LLVMTargetMachine class -----===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by Chris Lattner and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the LLVMTargetMachine class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/PassManager.h"
+#include "llvm/Pass.h"
+#include "llvm/Assembly/PrintModulePass.h"
+#include "llvm/Analysis/LoopPass.h"
+#include "llvm/CodeGen/Passes.h"
+#include "llvm/Target/TargetOptions.h"
+#include "llvm/Transforms/Scalar.h"
+#include "llvm/Support/CommandLine.h"
+using namespace llvm;
+
+static cl::opt<bool> PrintLSR("print-lsr-output", cl::Hidden,
+    cl::desc("Print LLVM IR produced by the loop-reduce pass"));
+static cl::opt<bool> PrintISelInput("print-isel-input", cl::Hidden,
+    cl::desc("Print LLVM IR input to isel pass"));
+
+FileModel::Model
+LLVMTargetMachine::addPassesToEmitFile(FunctionPassManager &PM,
+                                       std::ostream &Out,
+                                       CodeGenFileType FileType,
+                                       bool Fast) {
+  // Standard LLVM-Level Passes.
+  
+  // Run loop strength reduction before anything else.
+  if (!Fast) {
+    PM.add(createLoopStrengthReducePass(getTargetLowering()));
+    if (PrintLSR)
+      PM.add(new PrintFunctionPass("\n\n*** Code after LSR *** \n", &cerr));
+  }
+  
+  // FIXME: Implement efficient support for garbage collection intrinsics.
+  PM.add(createLowerGCPass());
+
+  if (!ExceptionHandling)
+    PM.add(createLowerInvokePass(getTargetLowering()));
+
+  // Make sure that no unreachable blocks are instruction selected.
+  PM.add(createUnreachableBlockEliminationPass());
+
+  if (!Fast)
+    PM.add(createCodeGenPreparePass(getTargetLowering()));
+
+  if (PrintISelInput)
+    PM.add(new PrintFunctionPass("\n\n*** Final LLVM Code input to ISel *** \n",
+                                 &cerr));
+  
+  // Ask the target for an isel.
+  if (addInstSelector(PM, Fast))
+    return FileModel::Error;
+
+  // Print the instruction selected machine code...
+  if (PrintMachineCode)
+    PM.add(createMachineFunctionPrinterPass(cerr));
+  
+  // Perform register allocation to convert to a concrete x86 representation
+  PM.add(createRegisterAllocator());
+  
+  if (PrintMachineCode)
+    PM.add(createMachineFunctionPrinterPass(cerr));
+
+  // Run post-ra passes.
+  if (addPostRegAlloc(PM, Fast) && PrintMachineCode)
+    PM.add(createMachineFunctionPrinterPass(cerr));
+
+  // Insert prolog/epilog code.  Eliminate abstract frame index references...
+  PM.add(createPrologEpilogCodeInserter());
+  
+  // Second pass scheduler.
+  if (!Fast)
+    PM.add(createPostRAScheduler());
+
+  // Branch folding must be run after regalloc and prolog/epilog insertion.
+  if (!Fast)
+    PM.add(createBranchFoldingPass(getEnableTailMergeDefault()));
+    
+  // Fold redundant debug labels.
+  PM.add(createDebugLabelFoldingPass());
+  
+  if (PrintMachineCode)  // Print the register-allocated code
+    PM.add(createMachineFunctionPrinterPass(cerr));
+
+  if (addPreEmitPass(PM, Fast) && PrintMachineCode)
+    PM.add(createMachineFunctionPrinterPass(cerr));
+
+  switch (FileType) {
+  default:
+    break;
+  case TargetMachine::AssemblyFile:
+    if (addAssemblyEmitter(PM, Fast, Out))
+      return FileModel::Error;
+    return FileModel::AsmFile;
+  case TargetMachine::ObjectFile:
+    if (getMachOWriterInfo())
+      return FileModel::MachOFile;
+    else if (getELFWriterInfo())
+      return FileModel::ElfFile;
+  }
+
+  return FileModel::Error;
+}
+ 
+/// addPassesToEmitFileFinish - If the passes to emit the specified file had to
+/// be split up (e.g., to add an object writer pass), this method can be used to
+/// finish up adding passes to emit the file, if necessary.
+bool LLVMTargetMachine::addPassesToEmitFileFinish(FunctionPassManager &PM,
+                                                  MachineCodeEmitter *MCE,
+                                                  bool Fast) {
+  if (MCE)
+    addSimpleCodeEmitter(PM, Fast, *MCE);
+
+  // Delete machine code for this function
+  PM.add(createMachineCodeDeleter());
+
+  return false; // success!
+}
+
+/// addPassesToEmitMachineCode - Add passes to the specified pass manager to
+/// get machine code emitted.  This uses a MachineCodeEmitter object to handle
+/// actually outputting the machine code and resolving things like the address
+/// of functions.  This method should returns true if machine code emission is
+/// not supported.
+///
+bool LLVMTargetMachine::addPassesToEmitMachineCode(FunctionPassManager &PM,
+                                                   MachineCodeEmitter &MCE,
+                                                   bool Fast) {
+  // Standard LLVM-Level Passes.
+  
+  // Run loop strength reduction before anything else.
+  if (!Fast) {
+    PM.add(createLoopStrengthReducePass(getTargetLowering()));
+    if (PrintLSR)
+      PM.add(new PrintFunctionPass("\n\n*** Code after LSR *** \n", &cerr));
+  }
+  
+  // FIXME: Implement efficient support for garbage collection intrinsics.
+  PM.add(createLowerGCPass());
+  
+  // FIXME: Implement the invoke/unwind instructions!
+  PM.add(createLowerInvokePass(getTargetLowering()));
+  
+  // Make sure that no unreachable blocks are instruction selected.
+  PM.add(createUnreachableBlockEliminationPass());
+
+  if (!Fast)
+    PM.add(createCodeGenPreparePass(getTargetLowering()));
+
+  if (PrintISelInput)
+    PM.add(new PrintFunctionPass("\n\n*** Final LLVM Code input to ISel *** \n",
+                                 &cerr));
+
+  // Ask the target for an isel.
+  if (addInstSelector(PM, Fast))
+    return true;
+
+  // Print the instruction selected machine code...
+  if (PrintMachineCode)
+    PM.add(createMachineFunctionPrinterPass(cerr));
+  
+  // Perform register allocation to convert to a concrete x86 representation
+  PM.add(createRegisterAllocator());
+  
+  if (PrintMachineCode)
+    PM.add(createMachineFunctionPrinterPass(cerr));
+
+  // Run post-ra passes.
+  if (addPostRegAlloc(PM, Fast) && PrintMachineCode)
+    PM.add(createMachineFunctionPrinterPass(cerr));
+
+  // Insert prolog/epilog code.  Eliminate abstract frame index references...
+  PM.add(createPrologEpilogCodeInserter());
+  
+  if (PrintMachineCode)  // Print the register-allocated code
+    PM.add(createMachineFunctionPrinterPass(cerr));
+  
+  // Second pass scheduler.
+  if (!Fast)
+    PM.add(createPostRAScheduler());
+
+  // Branch folding must be run after regalloc and prolog/epilog insertion.
+  if (!Fast)
+    PM.add(createBranchFoldingPass(getEnableTailMergeDefault()));
+  
+  if (addPreEmitPass(PM, Fast) && PrintMachineCode)
+    PM.add(createMachineFunctionPrinterPass(cerr));
+
+  addCodeEmitter(PM, Fast, MCE);
+  
+  // Delete machine code for this function
+  PM.add(createMachineCodeDeleter());
+  
+  return false; // success!
+}