Fix up -fstack-protector on linux to use the segment
registers.  Split out testcases per architecture and os
now.

Patch from Nelson Elhage.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107640 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 423a076..8a0a04e 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -1189,6 +1189,27 @@
   return F->hasFnAttr(Attribute::OptimizeForSize) ? 0 : 4;
 }
 
+bool X86TargetLowering::getStackCookieLocation(unsigned &AddressSpace,
+                                               unsigned &Offset) const {
+  if (!Subtarget->isTargetLinux())
+    return false;
+
+  if (Subtarget->is64Bit()) {
+    // %fs:0x28, unless we're using a Kernel code model, in which case it's %gs:
+    Offset = 0x28;
+    if (getTargetMachine().getCodeModel() == CodeModel::Kernel)
+      AddressSpace = 256;
+    else
+      AddressSpace = 257;
+  } else {
+    // %gs:0x14 on i386
+    Offset = 0x14;
+    AddressSpace = 256;
+  }
+  return true;
+}
+
+
 //===----------------------------------------------------------------------===//
 //               Return Value Calling Convention Implementation
 //===----------------------------------------------------------------------===//
diff --git a/lib/Target/X86/X86ISelLowering.h b/lib/Target/X86/X86ISelLowering.h
index a7de0b1..82cef27 100644
--- a/lib/Target/X86/X86ISelLowering.h
+++ b/lib/Target/X86/X86ISelLowering.h
@@ -593,6 +593,12 @@
     /// getFunctionAlignment - Return the Log2 alignment of this function.
     virtual unsigned getFunctionAlignment(const Function *F) const;
 
+    /// getStackCookieLocation - Return true if the target stores stack
+    /// protector cookies at a fixed offset in some non-standard address
+    /// space, and populates the address space and offset as
+    /// appropriate.
+    virtual bool getStackCookieLocation(unsigned &AddressSpace, unsigned &Offset) const;
+
   private:
     /// Subtarget - Keep a pointer to the X86Subtarget around so that we can
     /// make the right decision when generating code for different targets.