[PATCH] D19582: [X86] Add support for llvm.thread.pointer

[Marcin Kościelnicki via llvm-commits]

koriakin created this revision.
koriakin added reviewers: nadav, bruno.
koriakin added a subscriber: llvm-commits.
koriakin set the repository for this revision to rL LLVM.

This will be used for __builtin_thread_pointer in clang.

Repository:
  rL LLVM

http://reviews.llvm.org/D19582

Files:
  lib/Target/X86/X86ISelLowering.cpp
  test/CodeGen/X86/thread-pointer.ll

Index: test/CodeGen/X86/thread-pointer.ll
===================================================================
--- /dev/null
+++ test/CodeGen/X86/thread-pointer.ll
@@ -0,0 +1,12 @@
+; RUN: llc < %s -mtriple=i386-unknown-linux | FileCheck %s --check-prefix=CHECK-32
+; RUN: llc < %s -mtriple=x86_64-unknown-linux | FileCheck %s --check-prefix=CHECK-64
+
+; Function Attrs: nounwind readnone
+declare i8* @llvm.thread.pointer() #1
+
+define i8* @thread_pointer() {
+; CHECK-32: movl %gs:0, %eax
+; CHECK-64: movq %fs:0, %rax
+  %1 = tail call i8* @llvm.thread.pointer()
+  ret i8* %1
+}
Index: lib/Target/X86/X86ISelLowering.cpp
===================================================================
--- lib/Target/X86/X86ISelLowering.cpp
+++ lib/Target/X86/X86ISelLowering.cpp
@@ -17818,6 +17818,17 @@
       Reg = RegInfo->getPtrSizedFrameRegister(MF);
     return DAG.getCopyFromReg(DAG.getEntryNode(), dl, Reg, VT);
   }
+
+  case Intrinsic::thread_pointer: {
+    const TargetLowering &TLI = DAG.getTargetLoweringInfo();
+    EVT PtrVT = TLI.getPointerTy(DAG.getDataLayout());
+    // Get the Thread Pointer, which is %gs:0 (32-bit) or %fs:0 (64-bit).
+    Value *Ptr = Constant::getNullValue(
+        Type::getInt8PtrTy(*DAG.getContext(), Subtarget.is64Bit() ? 257 : 256));
+    return DAG.getLoad(PtrVT, dl, DAG.getEntryNode(),
+                       DAG.getIntPtrConstant(0, dl),
+                       MachinePointerInfo(Ptr), false, false, false, 0);
+  }
   }
 }
 


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D19582.55168.patch
Type: text/x-patch
Size: 1473 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20160427/023865f4/attachment.bin>