Move DataLayout back to the TargetMachine from TargetSubtargetInfo

derived classes.

Since global data alignment, layout, and mangling is often based on the
DataLayout, move it to the TargetMachine. This ensures that global
data is going to be layed out and mangled consistently if the subtarget
changes on a per function basis. Prior to this all targets(*) have
had subtarget dependent code moved out and onto the TargetMachine.

*One target hasn't been migrated as part of this change: R600. The
R600 port has, as a subtarget feature, the size of pointers and
this affects global data layout. I've currently hacked in a FIXME
to enable progress, but the port needs to be updated to either pass
the 64-bitness to the TargetMachine, or fix the DataLayout to
avoid subtarget dependent features.

llvm-svn: 227113

1 files changed, 41 insertions, 0 deletions

diff --git a/llvm/lib/Target/X86/X86TargetMachine.cpp b/llvm/lib/Target/X86/X86TargetMachine.cpp
index 5e6aa7d3dbf..11f6fd17ec6 100644
--- a/llvm/lib/Target/X86/X86TargetMachine.cpp
+++ b/llvm/lib/Target/X86/X86TargetMachine.cpp
@@ -47,6 +47,46 @@ static std::unique_ptr<TargetLoweringObjectFile> createTLOF(const Triple &TT) {
   llvm_unreachable("unknown subtarget type");
 }
 
+static std::string computeDataLayout(const Triple &TT) {
+  // X86 is little endian
+  std::string Ret = "e";
+
+  Ret += DataLayout::getManglingComponent(TT);
+  // X86 and x32 have 32 bit pointers.
+  if ((TT.isArch64Bit() &&
+       (TT.getEnvironment() == Triple::GNUX32 || TT.isOSNaCl())) ||
+      !TT.isArch64Bit())
+    Ret += "-p:32:32";
+
+  // Some ABIs align 64 bit integers and doubles to 64 bits, others to 32.
+  if (TT.isArch64Bit() || TT.isOSWindows() || TT.isOSNaCl())
+    Ret += "-i64:64";
+  else
+    Ret += "-f64:32:64";
+
+  // Some ABIs align long double to 128 bits, others to 32.
+  if (TT.isOSNaCl())
+    ; // No f80
+  else if (TT.isArch64Bit() || TT.isOSDarwin())
+    Ret += "-f80:128";
+  else
+    Ret += "-f80:32";
+
+  // The registers can hold 8, 16, 32 or, in x86-64, 64 bits.
+  if (TT.isArch64Bit())
+    Ret += "-n8:16:32:64";
+  else
+    Ret += "-n8:16:32";
+
+  // The stack is aligned to 32 bits on some ABIs and 128 bits on others.
+  if (!TT.isArch64Bit() && TT.isOSWindows())
+    Ret += "-S32";
+  else
+    Ret += "-S128";
+
+  return Ret;
+}
+
 /// X86TargetMachine ctor - Create an X86 target.
 ///
 X86TargetMachine::X86TargetMachine(const Target &T, StringRef TT, StringRef CPU,
@@ -55,6 +95,7 @@ X86TargetMachine::X86TargetMachine(const Target &T, StringRef TT, StringRef CPU,
                                    CodeGenOpt::Level OL)
     : LLVMTargetMachine(T, TT, CPU, FS, Options, RM, CM, OL),
       TLOF(createTLOF(Triple(getTargetTriple()))),
+      DL(computeDataLayout(Triple(TT))),
       Subtarget(TT, CPU, FS, *this, Options.StackAlignmentOverride) {
   // default to hard float ABI
   if (Options.FloatABIType == FloatABI::Default)