Add segmented stack support for DragonFlyBSD.

Patch by Michael Neumann.

llvm-svn: 224936

2 files changed, 12 insertions, 3 deletions

diff --git a/llvm/lib/Target/X86/X86FrameLowering.cpp b/llvm/lib/Target/X86/X86FrameLowering.cpp
index cf738f41cbd..c408fddf890 100644
--- a/llvm/lib/Target/X86/X86FrameLowering.cpp
+++ b/llvm/lib/Target/X86/X86FrameLowering.cpp
@@ -1476,8 +1476,9 @@ X86FrameLowering::adjustForSegmentedStacks(MachineFunction &MF) const {
 
   if (MF.getFunction()->isVarArg())
     report_fatal_error("Segmented stacks do not support vararg functions.");
-  if (!STI.isTargetLinux() && !STI.isTargetDarwin() &&
-      !STI.isTargetWin32() && !STI.isTargetWin64() && !STI.isTargetFreeBSD())
+  if (!STI.isTargetLinux() && !STI.isTargetDarwin() && !STI.isTargetWin32() &&
+      !STI.isTargetWin64() && !STI.isTargetFreeBSD() &&
+      !STI.isTargetDragonFly())
     report_fatal_error("Segmented stacks not supported on this platform.");
 
   // Eventually StackSize will be calculated by a link-time pass; which will
@@ -1531,6 +1532,9 @@ X86FrameLowering::adjustForSegmentedStacks(MachineFunction &MF) const {
     } else if (STI.isTargetFreeBSD()) {
       TlsReg = X86::FS;
       TlsOffset = 0x18;
+    } else if (STI.isTargetDragonFly()) {
+      TlsReg = X86::FS;
+      TlsOffset = 0x20; // use tls_tcb.tcb_segstack
     } else {
       report_fatal_error("Segmented stacks not supported on this platform.");
     }
@@ -1553,6 +1557,9 @@ X86FrameLowering::adjustForSegmentedStacks(MachineFunction &MF) const {
     } else if (STI.isTargetWin32()) {
       TlsReg = X86::FS;
       TlsOffset = 0x14; // pvArbitrary, reserved for application use
+    } else if (STI.isTargetDragonFly()) {
+      TlsReg = X86::FS;
+      TlsOffset = 0x10; // use tls_tcb.tcb_segstack
     } else if (STI.isTargetFreeBSD()) {
       report_fatal_error("Segmented stacks not supported on FreeBSD i386.");
     } else {
@@ -1565,7 +1572,8 @@ X86FrameLowering::adjustForSegmentedStacks(MachineFunction &MF) const {
       BuildMI(checkMBB, DL, TII.get(X86::LEA32r), ScratchReg).addReg(X86::ESP)
         .addImm(1).addReg(0).addImm(-StackSize).addReg(0);
 
-    if (STI.isTargetLinux() || STI.isTargetWin32() || STI.isTargetWin64()) {
+    if (STI.isTargetLinux() || STI.isTargetWin32() || STI.isTargetWin64() ||
+        STI.isTargetDragonFly()) {
       BuildMI(checkMBB, DL, TII.get(X86::CMP32rm)).addReg(ScratchReg)
         .addReg(0).addImm(0).addReg(0).addImm(TlsOffset).addReg(TlsReg);
     } else if (STI.isTargetDarwin()) {
diff --git a/llvm/lib/Target/X86/X86Subtarget.h b/llvm/lib/Target/X86/X86Subtarget.h
index 7533be5473f..754b5b92471 100644
--- a/llvm/lib/Target/X86/X86Subtarget.h
+++ b/llvm/lib/Target/X86/X86Subtarget.h
@@ -404,6 +404,7 @@ public:
 
   bool isTargetDarwin() const { return TargetTriple.isOSDarwin(); }
   bool isTargetFreeBSD() const { return TargetTriple.isOSFreeBSD(); }
+  bool isTargetDragonFly() const { return TargetTriple.isOSDragonFly(); }
   bool isTargetSolaris() const { return TargetTriple.isOSSolaris(); }
 
   bool isTargetELF() const { return TargetTriple.isOSBinFormatELF(); }