[clang][PowerPC] Enable -fstack-clash-protection option for ppc64

Differential Revision: https://reviews.llvm.org/D81355

clang/docs/ReleaseNotes.rst

@@ -94,8 +94,8 @@ New Compiler Flags
 ------------------
 
 - -fstack-clash-protection will provide a protection against the stack clash
-  attack for x86 and s390x architectures through automatic probing of each page
-  of allocated stack.
+  attack for x86, s390x and ppc64 architectures through automatic probing of
+  each page of allocated stack.
 
 - -ffp-exception-behavior={ignore,maytrap,strict} allows the user to specify
   the floating-point exception behavior. The default setting is ``ignore``.

clang/lib/Basic/Targets/PPC.h

@@ -343,6 +343,10 @@ public:
   const char *getFloat128Mangling() const override { return "u9__ieee128"; }
 
   bool hasExtIntType() const override { return true; }
+
+  bool isSPRegName(StringRef RegName) const override {
+    return RegName.equals("r1") || RegName.equals("x1");
+  }
 };
 
 class LLVM_LIBRARY_VISIBILITY PPC32TargetInfo : public PPCTargetInfo {

clang/lib/Driver/ToolChains/Clang.cpp

@@ -2966,7 +2966,8 @@ static void RenderSCPOptions(const ToolChain &TC, const ArgList &Args,
   if (!EffectiveTriple.isOSLinux())
     return;
 
-  if (!EffectiveTriple.isX86() && !EffectiveTriple.isSystemZ())
+  if (!EffectiveTriple.isX86() && !EffectiveTriple.isSystemZ() &&
+      !EffectiveTriple.isPPC64())
     return;
 
   if (Args.hasFlag(options::OPT_fstack_clash_protection,

clang/test/CodeGen/stack-clash-protection.c

@@ -1,6 +1,8 @@
 // Check the correct function attributes are generated
 // RUN: %clang_cc1 -triple x86_64-linux -O0 -S -emit-llvm -o- %s -fstack-clash-protection | FileCheck %s
 // RUN: %clang_cc1 -triple s390x-linux-gnu -O0 -S -emit-llvm -o- %s -fstack-clash-protection | FileCheck %s
+// RUN: %clang_cc1 -triple powerpc64le-linux-gnu -O0 -S -emit-llvm -o- %s -fstack-clash-protection | FileCheck %s
+// RUN: %clang_cc1 -triple powerpc64-linux-gnu -O0 -S -emit-llvm -o- %s -fstack-clash-protection | FileCheck %s
 
 // CHECK: define void @large_stack() #[[A:.*]] {
 void large_stack() {