From 1777d0c6c555fb20177b3a60b40eef265c2b842a Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Tue, 5 May 2009 18:52:19 +0000
Subject: [PATCH] Add basic support for code generation of addrspace(257) -> FS
 relative on x86.  Patch by Zoltan Varga!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70992 91177308-0d34-0410-b5e6-96231b3b80d8
---
 docs/CodeGenerator.html         | 10 ++++++----
 lib/Target/X86/X86Instr64bit.td |  5 +++++
 lib/Target/X86/X86InstrInfo.td  | 12 ++++++++++++
 test/CodeGen/X86/movfs.ll       |  8 ++++++++
 4 files changed, 31 insertions(+), 4 deletions(-)
 create mode 100644 test/CodeGen/X86/movfs.ll

diff --git a/docs/CodeGenerator.html b/docs/CodeGenerator.html
index b4edbd73564..e620c1782e9 100644
--- a/docs/CodeGenerator.html
+++ b/docs/CodeGenerator.html
@@ -1844,11 +1844,13 @@ OperandTy: VirtReg, | VirtReg, UnsImm, VirtReg,   SignExtImm
    segment.  LLVM address space 0 is the default address space, which includes
    the stack, and any unqualified memory accesses in a program.  Address spaces
    1-255 are currently reserved for user-defined code.  The GS-segment is
-   represented by address space 256.  Other x86 segments have yet to be
-   allocated address space numbers.</p>
+   represented by address space 256, while the FS-segment is represented by 
+   address space 257. Other x86 segments have yet to be allocated address space
+   numbers.</p>
 
-<p>Some operating systems use the GS-segment to implement TLS, so care should be
-   taken when reading and writing to address space 256 on these platforms.</p>
+<p>Some operating systems use the FS/GS-segment to implement TLS, so care 
+   should be taken when reading and writing to address space 256/257 on these
+   platforms.</p>
 
 </div>
 
diff --git a/lib/Target/X86/X86Instr64bit.td b/lib/Target/X86/X86Instr64bit.td
index 715eb006e52..77847e474d0 100644
--- a/lib/Target/X86/X86Instr64bit.td
+++ b/lib/Target/X86/X86Instr64bit.td
@@ -1326,6 +1326,11 @@ def MOV64GSrm : RI<0x8B, MRMSrcMem, (outs GR64:$dst), (ins i64mem:$src),
                  "movq\t%gs:$src, $dst",
                  [(set GR64:$dst, (gsload addr:$src))]>, SegGS;
 
+let AddedComplexity = 5 in
+def MOV64FSrm : RI<0x8B, MRMSrcMem, (outs GR64:$dst), (ins i64mem:$src),
+                 "movq\t%fs:$src, $dst",
+                 [(set GR64:$dst, (fsload addr:$src))]>, SegFS;
+
 //===----------------------------------------------------------------------===//
 // Atomic Instructions
 //===----------------------------------------------------------------------===//
diff --git a/lib/Target/X86/X86InstrInfo.td b/lib/Target/X86/X86InstrInfo.td
index 33e0a3d67d2..0d3b6857e68 100644
--- a/lib/Target/X86/X86InstrInfo.td
+++ b/lib/Target/X86/X86InstrInfo.td
@@ -345,6 +345,13 @@ def gsload : PatFrag<(ops node:$ptr), (load node:$ptr), [{
   return false;
 }]>;
 
+def fsload : PatFrag<(ops node:$ptr), (load node:$ptr), [{
+  if (const Value *Src = cast<LoadSDNode>(N)->getSrcValue())
+    if (const PointerType *PT = dyn_cast<PointerType>(Src->getType()))
+      return PT->getAddressSpace() == 257;
+  return false;
+}]>;
+
 def loadi8  : PatFrag<(ops node:$ptr), (i8  (load node:$ptr)), [{
   if (const Value *Src = cast<LoadSDNode>(N)->getSrcValue())
     if (const PointerType *PT = dyn_cast<PointerType>(Src->getType()))
@@ -3004,6 +3011,11 @@ def GS_MOV32rm : I<0x8B, MRMSrcMem, (outs GR32:$dst), (ins i32mem:$src),
                    "movl\t%gs:$src, $dst",
                    [(set GR32:$dst, (gsload addr:$src))]>, SegGS;
 
+let AddedComplexity = 5 in
+def FS_MOV32rm : I<0x8B, MRMSrcMem, (outs GR32:$dst), (ins i32mem:$src),
+                   "movl\t%fs:$src, $dst",
+                   [(set GR32:$dst, (fsload addr:$src))]>, SegFS;
+
 //===----------------------------------------------------------------------===//
 // DWARF Pseudo Instructions
 //
diff --git a/test/CodeGen/X86/movfs.ll b/test/CodeGen/X86/movfs.ll
new file mode 100644
index 00000000000..af102d49569
--- /dev/null
+++ b/test/CodeGen/X86/movfs.ll
@@ -0,0 +1,8 @@
+; RUN: llvm-as < %s | llc -march=x86 | grep fs
+
+define i32 @foo() nounwind readonly {
+entry:
+	%tmp = load i32* addrspace(257)* getelementptr (i32* addrspace(257)* inttoptr (i32 72 to i32* addrspace(257)*), i32 31)		; <i32*> [#uses=1]
+	%tmp1 = load i32* %tmp		; <i32> [#uses=1]
+	ret i32 %tmp1
+}