[PowerPC] Make -pg generate calls to _mcount not mcount

At least on REL6 (Linux/glibc 2.12), the proper symbol for generating gprof
data is _mcount, not mcount. Prior to this change, compiling with -pg would
generate linking errors (because of unresolved references to mcount), after
this change -pg seems at least minimally functional.

llvm-svn: 205144

2 files changed, 14 insertions, 0 deletions

diff --git a/clang/lib/Basic/Targets.cpp b/clang/lib/Basic/Targets.cpp
index 6811b3096a1..3d294cefa00 100644
--- a/clang/lib/Basic/Targets.cpp
+++ b/clang/lib/Basic/Targets.cpp
@@ -355,6 +355,16 @@ public:
   LinuxTargetInfo(const llvm::Triple &Triple) : OSTargetInfo<Target>(Triple) {
     this->UserLabelPrefix = "";
     this->WIntType = TargetInfo::UnsignedInt;
+
+    switch (Triple.getArch()) {
+    default:
+      break;
+    case llvm::Triple::ppc:
+    case llvm::Triple::ppc64:
+    case llvm::Triple::ppc64le:
+      this->MCountName = "_mcount";
+      break;
+    }
   }
 
   const char *getStaticInitSectionSpecifier() const override {
diff --git a/clang/test/CodeGen/mcount.c b/clang/test/CodeGen/mcount.c
index 1cf3d6a0716..5c608bcd365 100644
--- a/clang/test/CodeGen/mcount.c
+++ b/clang/test/CodeGen/mcount.c
@@ -1,4 +1,8 @@
 // RUN: %clang_cc1 -pg -triple i386-unknown-unknown -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -pg -triple powerpc-unknown-gnu-linux -emit-llvm -o - %s | FileCheck -check-prefix=CHECK-PPC %s
+// RUN: %clang_cc1 -pg -triple powerpc64-unknown-gnu-linux -emit-llvm -o - %s | FileCheck -check-prefix=CHECK-PPC %s
+// RUN: %clang_cc1 -pg -triple powerpc64le-unknown-gnu-linux -emit-llvm -o - %s | FileCheck -check-prefix=CHECK-PPC %s
 void foo(void) {
 // CHECK: call void @mcount()
+// CHECK-PPC: call void @_mcount()
 }