commit 67ae13575900e8efd056672987249fd0adbf5e73
author James Molloy <james.molloy@arm.com> Thu Dec 20 16:04:27 2012 +0000
committer James Molloy <james.molloy@arm.com> Thu Dec 20 16:04:27 2012 +0000
tree c297968f698f92b4b2d7b06c6d892a2299061887
parent 6af228a92a7b8414fa3c1b3c37ee659d32e66e1b

Add a new attribute, 'noduplicate'. If a function contains a noduplicate call, the call cannot be duplicated - Jump threading, loop unrolling, loop unswitching, and loop rotation are inhibited if they would duplicate the call.

Similarly inlining of the function is inhibited, if that would duplicate the call (in particular inlining is still allowed when there is only one callsite and the function has internal linkage).



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170704 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Analysis/CodeMetrics.cpp

diff --git a/lib/Analysis/CodeMetrics.cpp b/lib/Analysis/CodeMetrics.cpp
index 84b3266..401c1be 100644
--- a/lib/Analysis/CodeMetrics.cpp
+++ b/lib/Analysis/CodeMetrics.cpp
@@ -165,6 +165,14 @@
     if (isa<ExtractElementInst>(II) || II->getType()->isVectorTy())
       ++NumVectorInsts;
 
+    if (const CallInst *CI = dyn_cast<CallInst>(II))
+      if (CI->hasFnAttr(Attribute::NoDuplicate))
+        notDuplicatable = true;
+
+    if (const InvokeInst *InvI = dyn_cast<InvokeInst>(II))
+      if (InvI->hasFnAttr(Attribute::NoDuplicate))
+        notDuplicatable = true;
+
     ++NumInsts;
   }
 
@@ -182,8 +190,7 @@
   // if someone is using a blockaddress without an indirectbr, and that
   // reference somehow ends up in another function or global, we probably
   // don't want to inline this function.
-  if (isa<IndirectBrInst>(BB->getTerminator()))
-    containsIndirectBr = true;
+  notDuplicatable |= isa<IndirectBrInst>(BB->getTerminator());
 
   // Remember NumInsts for this BB.
   NumBBInsts[BB] = NumInsts - NumInstsBeforeThisBB;