From e6c1fc9a4463064004c436869ff7c91660582895 Mon Sep 17 00:00:00 2001
From: Saleem Abdulrasool <compnerd@compnerd.org>
Date: Thu, 20 Nov 2014 18:01:26 +0000
Subject: [PATCH] X86: use the correct alloca symbol for Windows Itanium

Windows itanium targets the MSVCRT, and the stack probe symbol is provided by
MSVCRT.  This corrects the emission of stack probes on i686-windows-itanium.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222439 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/X86/X86ISelLowering.cpp         |  6 ++++--
 lib/Target/X86/X86Subtarget.h              |  4 ++++
 test/CodeGen/X86/windows-itanium-alloca.ll | 16 ++++++++++++++++
 3 files changed, 24 insertions(+), 2 deletions(-)
 create mode 100644 test/CodeGen/X86/windows-itanium-alloca.ll

diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index a904e510268..8979b9e22a8 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -20609,8 +20609,10 @@ X86TargetLowering::EmitLoweredWinAlloca(MachineInstr *MI,
         .addReg(X86::RAX);
     }
   } else {
-    const char *StackProbeSymbol =
-      Subtarget->isTargetKnownWindowsMSVC() ? "_chkstk" : "_alloca";
+    const char *StackProbeSymbol = (Subtarget->isTargetKnownWindowsMSVC() ||
+                                    Subtarget->isTargetWindowsItanium())
+                                       ? "_chkstk"
+                                       : "_alloca";
 
     BuildMI(*BB, MI, DL, TII->get(X86::CALLpcrel32))
       .addExternalSymbol(StackProbeSymbol)
diff --git a/lib/Target/X86/X86Subtarget.h b/lib/Target/X86/X86Subtarget.h
index 8ce553d7092..091b6c4fbbd 100644
--- a/lib/Target/X86/X86Subtarget.h
+++ b/lib/Target/X86/X86Subtarget.h
@@ -426,6 +426,10 @@ public:
     return TargetTriple.isWindowsGNUEnvironment();
   }
 
+  bool isTargetWindowsItanium() const {
+    return TargetTriple.isWindowsItaniumEnvironment();
+  }
+
   bool isTargetCygMing() const { return TargetTriple.isOSCygMing(); }
 
   bool isOSWindows() const { return TargetTriple.isOSWindows(); }
diff --git a/test/CodeGen/X86/windows-itanium-alloca.ll b/test/CodeGen/X86/windows-itanium-alloca.ll
new file mode 100644
index 00000000000..0a06cdef879
--- /dev/null
+++ b/test/CodeGen/X86/windows-itanium-alloca.ll
@@ -0,0 +1,16 @@
+; RUN: llc -mtriple i686-windows-itanium -filetype asm -o - %s | FileCheck %s
+
+target datalayout = "e-m:w-p:32:32-i64:64-f80:32-n8:16:32-S32"
+target triple = "i686--windows-itanium"
+
+declare void @external(i8*)
+
+define dllexport void @alloca(i32 %sz) {
+entry:
+  %vla = alloca i8, i32 %sz, align 1
+  call void @external(i8* %vla)
+  ret void
+}
+
+; CHECK: __chkstk
+
-- 
2.40.0