(this is a corrected patch)

Calling _chkstk is required on ELF as well as COFF on Windows. Without 
_chkstk, functions requiring large stack crash in initialization code.

Previous code tested for COFF format but not Mach-O and this patch modifies 
the code to test for Windows OS (both Windows target and MingW target) 
but not Mach-O object format: Looks like macho environment was used to 
build some EFI code.
 
Credits to Andrew MacPherson.

llvm-svn: 193289

3 files changed, 4 insertions, 2 deletions

diff --git a/llvm/lib/Target/X86/X86FrameLowering.cpp b/llvm/lib/Target/X86/X86FrameLowering.cpp
index adcd4f7dedc..a06ba9d750a 100644
--- a/llvm/lib/Target/X86/X86FrameLowering.cpp
+++ b/llvm/lib/Target/X86/X86FrameLowering.cpp
@@ -606,7 +606,7 @@ void X86FrameLowering::emitPrologue(MachineFunction &MF) const {
   // responsible for adjusting the stack pointer.  Touching the stack at 4K
   // increments is necessary to ensure that the guard pages used by the OS
   // virtual memory manager are allocated in correct sequence.
-  if (NumBytes >= 4096 && STI.isTargetCOFF() && !STI.isTargetEnvMacho()) {
+  if (NumBytes >= 4096 && STI.isOSWindows() && !STI.isTargetEnvMacho()) {
     const char *StackProbeSymbol;
     bool isSPUpdateNeeded = false;
 
diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index cc409fb3c51..31ff797960e 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -631,7 +631,7 @@ void X86TargetLowering::resetOperationActions() {
   setOperationAction(ISD::STACKSAVE,          MVT::Other, Expand);
   setOperationAction(ISD::STACKRESTORE,       MVT::Other, Expand);
 
-  if (Subtarget->isTargetCOFF() && !Subtarget->isTargetEnvMacho())
+  if (Subtarget->isOSWindows() && !Subtarget->isTargetEnvMacho())
     setOperationAction(ISD::DYNAMIC_STACKALLOC, Subtarget->is64Bit() ?
                        MVT::i64 : MVT::i32, Custom);
   else if (TM.Options.EnableSegmentedStacks)
diff --git a/llvm/lib/Target/X86/X86Subtarget.h b/llvm/lib/Target/X86/X86Subtarget.h
index fb357c46756..dd8c0811ce5 100644
--- a/llvm/lib/Target/X86/X86Subtarget.h
+++ b/llvm/lib/Target/X86/X86Subtarget.h
@@ -333,6 +333,8 @@ public:
   }
   bool isTargetEnvMacho() const { return TargetTriple.isEnvironmentMachO(); }
 
+  bool isOSWindows() const { return TargetTriple.isOSWindows(); }
+
   bool isTargetWin64() const {
     return In64BitMode && TargetTriple.isOSWindows();
   }