Add pthread_self function prototype and make it speculatable.

Summary: This allows pthread_self to be pulled out of a loop by LICM.

Reviewers: hfinkel, arsenm, davide

Reviewed By: davide

Subscribers: davide, wdng, llvm-commits

Differential Revision: https://reviews.llvm.org/D32782

llvm-svn: 303495

1 files changed, 9 insertions, 0 deletions

diff --git a/llvm/lib/Analysis/TargetLibraryInfo.cpp b/llvm/lib/Analysis/TargetLibraryInfo.cpp
index 2be5d5caf7c..b12778278ce 100644
--- a/llvm/lib/Analysis/TargetLibraryInfo.cpp
+++ b/llvm/lib/Analysis/TargetLibraryInfo.cpp
@@ -349,6 +349,9 @@ static void initialize(TargetLibraryInfoImpl &TLI, const Triple &T,
     TLI.setUnavailable(LibFunc_atoll);
     TLI.setUnavailable(LibFunc_frexpf);
     TLI.setUnavailable(LibFunc_llabs);
+
+    // Win32 does *not* provide pthread_self.
+    TLI.setUnavailable(LibFunc_pthread_self);
   }
 
   switch (T.getOS()) {
@@ -1263,6 +1266,12 @@ bool TargetLibraryInfoImpl::isValidProtoForLibFunc(const FunctionType &FTy,
             FTy.getParamType(0)->isPointerTy() &&
             FTy.getParamType(1) == SizeTTy && FTy.getParamType(2) == SizeTTy);
 
+  // We do not attempt to match the return value here. i.e. thread identifiers
+  // should be considered opaque, for example, representation using either an
+  // arithmetic type or a structure is permitted. 
+  case LibFunc_pthread_self:
+    return NumParams == 0;
+
   case LibFunc_wcslen:
     return (NumParams == 1 && FTy.getParamType(0)->isPointerTy() &&
             FTy.getReturnType()->isIntegerTy());