From 45835e731d41d45e92973b4845d7f75e6997cb22 Mon Sep 17 00:00:00 2001
From: Sean Silva <chisophugis@gmail.com>
Date: Sat, 2 Jul 2016 23:47:27 +0000
Subject: Remove dead TLI arg of isKnownNonNull and propagate deadness. NFC.

This actually uncovered a surprisingly large chain of ultimately unused
TLI args.
From what I can gather, this argument is a remnant of when
isKnownNonNull would look at the TLI directly.
The current approach seems to be that InferFunctionAttrs runs early in
the pipeline and uses TLI to annotate the TLI-dependent non-null
information as return attributes.

This also removes the dependence of functionattrs on TLI altogether.

llvm-svn: 274455
---
 llvm/lib/Transforms/IPO/FunctionAttrs.cpp | 27 ++++++---------------------
 1 file changed, 6 insertions(+), 21 deletions(-)

(limited to 'llvm/lib/Transforms/IPO/FunctionAttrs.cpp')

diff --git a/llvm/lib/Transforms/IPO/FunctionAttrs.cpp b/llvm/lib/Transforms/IPO/FunctionAttrs.cpp
index 4ae9b17..a21a320 100644
--- a/llvm/lib/Transforms/IPO/FunctionAttrs.cpp
+++ b/llvm/lib/Transforms/IPO/FunctionAttrs.cpp
@@ -782,7 +782,7 @@ static bool addNoAliasAttrs(const SCCNodeSet &SCCNodes) {
 /// \p Speculative based on whether the returned conclusion is a speculative
 /// conclusion due to SCC calls.
 static bool isReturnNonNull(Function *F, const SCCNodeSet &SCCNodes,
-                            const TargetLibraryInfo &TLI, bool &Speculative) {
+                            bool &Speculative) {
   assert(F->getReturnType()->isPointerTy() &&
          "nonnull only meaningful on pointer types");
   Speculative = false;
@@ -796,7 +796,7 @@ static bool isReturnNonNull(Function *F, const SCCNodeSet &SCCNodes,
     Value *RetVal = FlowsToReturn[i];
 
     // If this value is locally known to be non-null, we're good
-    if (isKnownNonNull(RetVal, &TLI))
+    if (isKnownNonNull(RetVal))
       continue;
 
     // Otherwise, we need to look upwards since we can't make any local
@@ -845,8 +845,7 @@ static bool isReturnNonNull(Function *F, const SCCNodeSet &SCCNodes,
 }
 
 /// Deduce nonnull attributes for the SCC.
-static bool addNonNullAttrs(const SCCNodeSet &SCCNodes,
-                            const TargetLibraryInfo &TLI) {
+static bool addNonNullAttrs(const SCCNodeSet &SCCNodes) {
   // Speculative that all functions in the SCC return only nonnull
   // pointers.  We may refute this as we analyze functions.
   bool SCCReturnsNonNull = true;
@@ -873,7 +872,7 @@ static bool addNonNullAttrs(const SCCNodeSet &SCCNodes,
       continue;
 
     bool Speculative = false;
-    if (isReturnNonNull(F, SCCNodes, TLI, Speculative)) {
+    if (isReturnNonNull(F, SCCNodes, Speculative)) {
       if (!Speculative) {
         // Mark the function eagerly since we may discover a function
         // which prevents us from speculating about the entire SCC
@@ -987,16 +986,9 @@ static bool addNoRecurseAttrs(const SCCNodeSet &SCCNodes) {
 
 PreservedAnalyses PostOrderFunctionAttrsPass::run(LazyCallGraph::SCC &C,
                                                   CGSCCAnalysisManager &AM) {
-  Module &M = *C.begin()->getFunction().getParent();
-  const ModuleAnalysisManager &MAM =
-      AM.getResult<ModuleAnalysisManagerCGSCCProxy>(C).getManager();
   FunctionAnalysisManager &FAM =
       AM.getResult<FunctionAnalysisManagerCGSCCProxy>(C).getManager();
 
-  // FIXME: Need some way to make it more reasonable to assume that this is
-  // always cached.
-  TargetLibraryInfo &TLI = *MAM.getCachedResult<TargetLibraryAnalysis>(M);
-
   // We pass a lambda into functions to wire them up to the analysis manager
   // for getting function analyses.
   auto AARGetter = [&](Function &F) -> AAResults & {
@@ -1039,7 +1031,7 @@ PreservedAnalyses PostOrderFunctionAttrsPass::run(LazyCallGraph::SCC &C,
   // more precise attributes as well.
   if (!HasUnknownCall) {
     Changed |= addNoAliasAttrs(SCCNodes);
-    Changed |= addNonNullAttrs(SCCNodes, TLI);
+    Changed |= addNonNullAttrs(SCCNodes);
     Changed |= removeConvergentAttrs(SCCNodes);
     Changed |= addNoRecurseAttrs(SCCNodes);
   }
@@ -1059,13 +1051,9 @@ struct PostOrderFunctionAttrsLegacyPass : public CallGraphSCCPass {
   void getAnalysisUsage(AnalysisUsage &AU) const override {
     AU.setPreservesCFG();
     AU.addRequired<AssumptionCacheTracker>();
-    AU.addRequired<TargetLibraryInfoWrapperPass>();
     getAAResultsAnalysisUsage(AU);
     CallGraphSCCPass::getAnalysisUsage(AU);
   }
-
-private:
-  TargetLibraryInfo *TLI;
 };
 }
 
@@ -1074,7 +1062,6 @@ INITIALIZE_PASS_BEGIN(PostOrderFunctionAttrsLegacyPass, "functionattrs",
                       "Deduce function attributes", false, false)
 INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
 INITIALIZE_PASS_DEPENDENCY(CallGraphWrapperPass)
-INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)
 INITIALIZE_PASS_END(PostOrderFunctionAttrsLegacyPass, "functionattrs",
                     "Deduce function attributes", false, false)
 
@@ -1083,8 +1070,6 @@ Pass *llvm::createPostOrderFunctionAttrsLegacyPass() { return new PostOrderFunct
 bool PostOrderFunctionAttrsLegacyPass::runOnSCC(CallGraphSCC &SCC) {
   if (skipSCC(SCC))
     return false;
-
-  TLI = &getAnalysis<TargetLibraryInfoWrapperPass>().getTLI();
   bool Changed = false;
 
   // We compute dedicated AA results for each function in the SCC as needed. We
@@ -1123,7 +1108,7 @@ bool PostOrderFunctionAttrsLegacyPass::runOnSCC(CallGraphSCC &SCC) {
   // more precise attributes as well.
   if (!ExternalNode) {
     Changed |= addNoAliasAttrs(SCCNodes);
-    Changed |= addNonNullAttrs(SCCNodes, *TLI);
+    Changed |= addNonNullAttrs(SCCNodes);
     Changed |= removeConvergentAttrs(SCCNodes);
     Changed |= addNoRecurseAttrs(SCCNodes);
   }
-- 
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