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/Target/X86/X86TargetMachine.cpp b/lib/Target/X86/X86TargetMachine.cpp
new file mode 100644
index 0000000..4d4bd3f
--- /dev/null
+++ b/lib/Target/X86/X86TargetMachine.cpp
@@ -0,0 +1,190 @@
+//===-- X86TargetMachine.cpp - Define TargetMachine for the X86 -----------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the X86 specific subclass of TargetMachine.
+//
+//===----------------------------------------------------------------------===//
+
+#include "X86TargetAsmInfo.h"
+#include "X86TargetMachine.h"
+#include "X86.h"
+#include "llvm/Module.h"
+#include "llvm/PassManager.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/Passes.h"
+#include "llvm/Target/TargetOptions.h"
+#include "llvm/Target/TargetMachineRegistry.h"
+#include "llvm/Transforms/Scalar.h"
+using namespace llvm;
+
+/// X86TargetMachineModule - Note that this is used on hosts that cannot link
+/// in a library unless there are references into the library.  In particular,
+/// it seems that it is not possible to get things to work on Win32 without
+/// this.  Though it is unused, do not remove it.
+extern "C" int X86TargetMachineModule;
+int X86TargetMachineModule = 0;
+
+namespace {
+  // Register the target.
+  RegisterTarget<X86_32TargetMachine>
+  X("x86",    "  32-bit X86: Pentium-Pro and above");
+  RegisterTarget<X86_64TargetMachine>
+  Y("x86-64", "  64-bit X86: EM64T and AMD64");
+}
+
+const TargetAsmInfo *X86TargetMachine::createTargetAsmInfo() const {
+  return new X86TargetAsmInfo(*this);
+}
+
+unsigned X86_32TargetMachine::getJITMatchQuality() {
+#if defined(i386) || defined(__i386__) || defined(__x86__) || defined(_M_IX86)
+  return 10;
+#endif
+  return 0;
+}
+
+unsigned X86_64TargetMachine::getJITMatchQuality() {
+#if defined(__x86_64__)
+  return 10;
+#endif
+  return 0;
+}
+
+unsigned X86_32TargetMachine::getModuleMatchQuality(const Module &M) {
+  // We strongly match "i[3-9]86-*".
+  std::string TT = M.getTargetTriple();
+  if (TT.size() >= 5 && TT[0] == 'i' && TT[2] == '8' && TT[3] == '6' &&
+      TT[4] == '-' && TT[1] - '3' < 6)
+    return 20;
+  // If the target triple is something non-X86, we don't match.
+  if (!TT.empty()) return 0;
+
+  if (M.getEndianness()  == Module::LittleEndian &&
+      M.getPointerSize() == Module::Pointer32)
+    return 10;                                   // Weak match
+  else if (M.getEndianness() != Module::AnyEndianness ||
+           M.getPointerSize() != Module::AnyPointerSize)
+    return 0;                                    // Match for some other target
+
+  return getJITMatchQuality()/2;
+}
+
+unsigned X86_64TargetMachine::getModuleMatchQuality(const Module &M) {
+  // We strongly match "x86_64-*".
+  std::string TT = M.getTargetTriple();
+  if (TT.size() >= 7 && TT[0] == 'x' && TT[1] == '8' && TT[2] == '6' &&
+      TT[3] == '_' && TT[4] == '6' && TT[5] == '4' && TT[6] == '-')
+    return 20;
+
+  // We strongly match "amd64-*".
+  if (TT.size() >= 6 && TT[0] == 'a' && TT[1] == 'm' && TT[2] == 'd' &&
+      TT[3] == '6' && TT[4] == '4' && TT[5] == '-')
+    return 20;
+  
+  // If the target triple is something non-X86-64, we don't match.
+  if (!TT.empty()) return 0;
+
+  if (M.getEndianness()  == Module::LittleEndian &&
+      M.getPointerSize() == Module::Pointer64)
+    return 10;                                   // Weak match
+  else if (M.getEndianness() != Module::AnyEndianness ||
+           M.getPointerSize() != Module::AnyPointerSize)
+    return 0;                                    // Match for some other target
+
+  return getJITMatchQuality()/2;
+}
+
+X86_32TargetMachine::X86_32TargetMachine(const Module &M, const std::string &FS) 
+  : X86TargetMachine(M, FS, false) {
+}
+
+
+X86_64TargetMachine::X86_64TargetMachine(const Module &M, const std::string &FS)
+  : X86TargetMachine(M, FS, true) {
+}
+
+/// X86TargetMachine ctor - Create an ILP32 architecture model
+///
+X86TargetMachine::X86TargetMachine(const Module &M, const std::string &FS,
+                                   bool is64Bit)
+  : Subtarget(M, FS, is64Bit),
+    DataLayout(Subtarget.is64Bit() ?
+               std::string("e-p:64:64-f64:32:64-i64:32:64") :
+               std::string("e-p:32:32-f64:32:64-i64:32:64")),
+    FrameInfo(TargetFrameInfo::StackGrowsDown,
+              Subtarget.getStackAlignment(), Subtarget.is64Bit() ? -8 : -4),
+    InstrInfo(*this), JITInfo(*this), TLInfo(*this) {
+  if (getRelocationModel() == Reloc::Default)
+    if (Subtarget.isTargetDarwin() || Subtarget.isTargetCygMing())
+      setRelocationModel(Reloc::DynamicNoPIC);
+    else
+      setRelocationModel(Reloc::Static);
+  if (Subtarget.is64Bit()) {
+    // No DynamicNoPIC support under X86-64.
+    if (getRelocationModel() == Reloc::DynamicNoPIC)
+      setRelocationModel(Reloc::PIC_);
+    // Default X86-64 code model is small.
+    if (getCodeModel() == CodeModel::Default)
+      setCodeModel(CodeModel::Small);
+  }
+
+  if (Subtarget.isTargetCygMing())
+    Subtarget.setPICStyle(PICStyle::WinPIC);
+  else if (Subtarget.isTargetDarwin())
+    if (Subtarget.is64Bit())
+      Subtarget.setPICStyle(PICStyle::RIPRel);
+    else
+      Subtarget.setPICStyle(PICStyle::Stub);
+  else if (Subtarget.isTargetELF())
+    if (Subtarget.is64Bit())
+      Subtarget.setPICStyle(PICStyle::RIPRel);
+    else
+      Subtarget.setPICStyle(PICStyle::GOT);
+}
+
+//===----------------------------------------------------------------------===//
+// Pass Pipeline Configuration
+//===----------------------------------------------------------------------===//
+
+bool X86TargetMachine::addInstSelector(FunctionPassManager &PM, bool Fast) {
+  // Install an instruction selector.
+  PM.add(createX86ISelDag(*this, Fast));
+  return false;
+}
+
+bool X86TargetMachine::addPostRegAlloc(FunctionPassManager &PM, bool Fast) {
+  PM.add(createX86FloatingPointStackifierPass());
+  return true;  // -print-machineinstr should print after this.
+}
+
+bool X86TargetMachine::addAssemblyEmitter(FunctionPassManager &PM, bool Fast, 
+                                          std::ostream &Out) {
+  PM.add(createX86CodePrinterPass(Out, *this));
+  return false;
+}
+
+bool X86TargetMachine::addCodeEmitter(FunctionPassManager &PM, bool Fast,
+                                      MachineCodeEmitter &MCE) {
+  // FIXME: Move this to TargetJITInfo!
+  setRelocationModel(Reloc::Static);
+  Subtarget.setPICStyle(PICStyle::None);
+  
+  // JIT cannot ensure globals are placed in the lower 4G of address.
+  if (Subtarget.is64Bit())
+    setCodeModel(CodeModel::Large);
+
+  PM.add(createX86CodeEmitterPass(*this, MCE));
+  return false;
+}
+
+bool X86TargetMachine::addSimpleCodeEmitter(FunctionPassManager &PM, bool Fast,
+                                            MachineCodeEmitter &MCE) {
+  PM.add(createX86CodeEmitterPass(*this, MCE));
+  return false;
+}