From 98a27ce03f092ab5464e65725f7d1fa0c03652f2 Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Mon, 31 Aug 2009 04:09:04 +0000
Subject: [PATCH] simplify some code by making the SCCNodes set contain
 Function*'s instead of CallGraphNode*'s.  This also papers over a callgraph
 problem where a pass (in this case, MemCpyOpt) introduces a new function into
 the module (llvm.memset.i64) but doesn't add it to the call graph (nor should
 it, since it is a function pass).

While it might be a good idea for MemCpyOpt to not synthesize
functions in a runOnFunction(), there is no need for FunctionAttrs
to be boneheaded, so fix it there.  This fixes an assertion building
176.gcc.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80535 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Transforms/IPO/FunctionAttrs.cpp | 21 +++++++++------------
 1 file changed, 9 insertions(+), 12 deletions(-)

diff --git a/lib/Transforms/IPO/FunctionAttrs.cpp b/lib/Transforms/IPO/FunctionAttrs.cpp
index 7b72a5ff969..26b4152291e 100644
--- a/lib/Transforms/IPO/FunctionAttrs.cpp
+++ b/lib/Transforms/IPO/FunctionAttrs.cpp
@@ -54,7 +54,7 @@ namespace {
 
     // IsFunctionMallocLike - Does this function allocate new memory?
     bool IsFunctionMallocLike(Function *F,
-                              SmallPtrSet<CallGraphNode*, 8> &) const;
+                              SmallPtrSet<Function*, 8> &) const;
 
     // AddNoAliasAttrs - Deduce noalias attributes for the SCC.
     bool AddNoAliasAttrs(const std::vector<CallGraphNode *> &SCC);
@@ -93,13 +93,12 @@ bool FunctionAttrs::PointsToLocalMemory(Value *V) {
 
 /// AddReadAttrs - Deduce readonly/readnone attributes for the SCC.
 bool FunctionAttrs::AddReadAttrs(const std::vector<CallGraphNode *> &SCC) {
-  SmallPtrSet<CallGraphNode*, 8> SCCNodes;
-  CallGraph &CG = getAnalysis<CallGraph>();
+  SmallPtrSet<Function*, 8> SCCNodes;
 
   // Fill SCCNodes with the elements of the SCC.  Used for quickly
   // looking up whether a given CallGraphNode is in this SCC.
   for (unsigned i = 0, e = SCC.size(); i != e; ++i)
-    SCCNodes.insert(SCC[i]);
+    SCCNodes.insert(SCC[i]->getFunction());
 
   // Check if any of the functions in the SCC read or write memory.  If they
   // write memory then they can't be marked readnone or readonly.
@@ -133,9 +132,9 @@ bool FunctionAttrs::AddReadAttrs(const std::vector<CallGraphNode *> &SCC) {
       // Some instructions can be ignored even if they read or write memory.
       // Detect these now, skipping to the next instruction if one is found.
       CallSite CS = CallSite::get(I);
-      if (CS.getInstruction()) {
+      if (CS.getInstruction() && CS.getCalledFunction()) {
         // Ignore calls to functions in the same SCC.
-        if (SCCNodes.count(CG[CS.getCalledFunction()]))
+        if (SCCNodes.count(CS.getCalledFunction()))
           continue;
       } else if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
         // Ignore loads from local memory.
@@ -226,9 +225,7 @@ bool FunctionAttrs::AddNoCaptureAttrs(const std::vector<CallGraphNode *> &SCC) {
 /// IsFunctionMallocLike - A function is malloc-like if it returns either null
 /// or a pointer that doesn't alias any other pointer visible to the caller.
 bool FunctionAttrs::IsFunctionMallocLike(Function *F,
-                              SmallPtrSet<CallGraphNode*, 8> &SCCNodes) const {
-  CallGraph &CG = getAnalysis<CallGraph>();
-
+                              SmallPtrSet<Function*, 8> &SCCNodes) const {
   UniqueVector<Value *> FlowsToReturn;
   for (Function::iterator I = F->begin(), E = F->end(); I != E; ++I)
     if (ReturnInst *Ret = dyn_cast<ReturnInst>(I->getTerminator()))
@@ -275,7 +272,7 @@ bool FunctionAttrs::IsFunctionMallocLike(Function *F,
           if (CS.paramHasAttr(0, Attribute::NoAlias))
             break;
           if (CS.getCalledFunction() &&
-              SCCNodes.count(CG[CS.getCalledFunction()]))
+              SCCNodes.count(CS.getCalledFunction()))
             break;
         } // fall-through
         default:
@@ -291,12 +288,12 @@ bool FunctionAttrs::IsFunctionMallocLike(Function *F,
 
 /// AddNoAliasAttrs - Deduce noalias attributes for the SCC.
 bool FunctionAttrs::AddNoAliasAttrs(const std::vector<CallGraphNode *> &SCC) {
-  SmallPtrSet<CallGraphNode*, 8> SCCNodes;
+  SmallPtrSet<Function*, 8> SCCNodes;
 
   // Fill SCCNodes with the elements of the SCC.  Used for quickly
   // looking up whether a given CallGraphNode is in this SCC.
   for (unsigned i = 0, e = SCC.size(); i != e; ++i)
-    SCCNodes.insert(SCC[i]);
+    SCCNodes.insert(SCC[i]->getFunction());
 
   // Check each function in turn, determining which functions return noalias
   // pointers.