teach ipsccp and ipconstprop that a blockaddress doesn't 'take the address' of a function

in a way that should prevent ip constprop.  This allows clang/test/CodeGen/indirect-goto.c
to pass with the new indirect goto lowering.

llvm-svn: 85709

2 files changed, 7 insertions, 2 deletions

diff --git a/llvm/lib/Transforms/IPO/IPConstantPropagation.cpp b/llvm/lib/Transforms/IPO/IPConstantPropagation.cpp
index d9b2e306314..023e642e648 100644
--- a/llvm/lib/Transforms/IPO/IPConstantPropagation.cpp
+++ b/llvm/lib/Transforms/IPO/IPConstantPropagation.cpp
@@ -86,6 +86,9 @@ bool IPCP::PropagateConstantsIntoArguments(Function &F) {
 
   unsigned NumNonconstant = 0;
   for (Value::use_iterator UI = F.use_begin(), E = F.use_end(); UI != E; ++UI) {
+    // Ignore blockaddress uses.
+    if (isa<BlockAddress>(*UI)) continue;
+    
     // Used by a non-instruction, or not the callee of a function, do not
     // transform.
     if (!isa<CallInst>(*UI) && !isa<InvokeInst>(*UI))
diff --git a/llvm/lib/Transforms/Scalar/SCCP.cpp b/llvm/lib/Transforms/Scalar/SCCP.cpp
index 4e5fae8a041..a348e20907e 100644
--- a/llvm/lib/Transforms/Scalar/SCCP.cpp
+++ b/llvm/lib/Transforms/Scalar/SCCP.cpp
@@ -1680,12 +1680,14 @@ static bool AddressIsTaken(GlobalValue *GV) {
         return true;  // Storing addr of GV.
     } else if (isa<InvokeInst>(*UI) || isa<CallInst>(*UI)) {
       // Make sure we are calling the function, not passing the address.
-      CallSite CS = CallSite::get(cast<Instruction>(*UI));
-      if (CS.hasArgument(GV))
+      if (UI.getOperandNo() != 0)
         return true;
     } else if (LoadInst *LI = dyn_cast<LoadInst>(*UI)) {
       if (LI->isVolatile())
         return true;
+    } else if (isa<BlockAddress>(*UI)) {
+      // blockaddress doesn't take the address of the function, it takes addr
+      // of label.
     } else {
       return true;
     }