From 30fe1ae20d02ac8e12cec9d767d855946546a030 Mon Sep 17 00:00:00 2001
From: Benjamin Kramer <benny.kra@googlemail.com>
Date: Fri, 2 Dec 2011 18:37:31 +0000
Subject: [PATCH] Fix quadratic behavior in InlineFunction by fetching the
 personality function of the callee once and not for every invoke in the
 caller.

The callee is usually smaller than the caller, too. This reduces the compile
time of ARMDisassembler.cpp by 32% (Release build). It still takes ages to
compile though.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145690 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Transforms/Utils/InlineFunction.cpp | 60 +++++++++++++------------
 1 file changed, 32 insertions(+), 28 deletions(-)

diff --git a/lib/Transforms/Utils/InlineFunction.cpp b/lib/Transforms/Utils/InlineFunction.cpp
index dd4a659b735..f89e1b1c537 100644
--- a/lib/Transforms/Utils/InlineFunction.cpp
+++ b/lib/Transforms/Utils/InlineFunction.cpp
@@ -924,39 +924,43 @@ bool llvm::InlineFunction(CallSite CS, InlineFunctionInfo &IFI) {
       return false;
   }
 
+  // Get the personality function from the callee if it contains a landing pad.
+  Value *CalleePersonality = 0;
+  for (Function::const_iterator I = CalledFunc->begin(), E = CalledFunc->end();
+       I != E; ++I)
+    if (const InvokeInst *II = dyn_cast<InvokeInst>(I->getTerminator())) {
+      const BasicBlock *BB = II->getUnwindDest();
+      // FIXME: This 'if/dyn_cast' here should become a normal 'cast' once
+      // the new EH system is in place.
+      if (const LandingPadInst *LP =
+          dyn_cast<LandingPadInst>(BB->getFirstNonPHI()))
+        CalleePersonality = LP->getPersonalityFn();
+      break;
+    }
+
   // Find the personality function used by the landing pads of the caller. If it
   // exists, then check to see that it matches the personality function used in
   // the callee.
-  for (Function::const_iterator
-         I = Caller->begin(), E = Caller->end(); I != E; ++I)
-    if (const InvokeInst *II = dyn_cast<InvokeInst>(I->getTerminator())) {
-      const BasicBlock *BB = II->getUnwindDest();
-      // FIXME: This 'isa' here should become go away once the new EH system is
-      // in place.
-      if (!isa<LandingPadInst>(BB->getFirstNonPHI()))
-        continue;
-      const LandingPadInst *LP = cast<LandingPadInst>(BB->getFirstNonPHI());
-      const Value *CallerPersFn = LP->getPersonalityFn();
+  if (CalleePersonality)
+    for (Function::const_iterator I = Caller->begin(), E = Caller->end();
+         I != E; ++I)
+      if (const InvokeInst *II = dyn_cast<InvokeInst>(I->getTerminator())) {
+        const BasicBlock *BB = II->getUnwindDest();
+        // FIXME: This 'isa' here should become go away once the new EH system
+        // is in place.
+        if (!isa<LandingPadInst>(BB->getFirstNonPHI()))
+          continue;
+        const LandingPadInst *LP = cast<LandingPadInst>(BB->getFirstNonPHI());
 
-      // If the personality functions match, then we can perform the
-      // inlining. Otherwise, we can't inline.
-      // TODO: This isn't 100% true. Some personality functions are proper
-      //       supersets of others and can be used in place of the other.
-      for (Function::const_iterator
-             I = CalledFunc->begin(), E = CalledFunc->end(); I != E; ++I)
-        if (const InvokeInst *II = dyn_cast<InvokeInst>(I->getTerminator())) {
-          const BasicBlock *BB = II->getUnwindDest();
-          // FIXME: This 'if/dyn_cast' here should become a normal 'cast' once
-          // the new EH system is in place.
-          if (const LandingPadInst *LP =
-              dyn_cast<LandingPadInst>(BB->getFirstNonPHI()))
-            if (CallerPersFn != LP->getPersonalityFn())
-              return false;
-          break;
-        }
+        // If the personality functions match, then we can perform the
+        // inlining. Otherwise, we can't inline.
+        // TODO: This isn't 100% true. Some personality functions are proper
+        //       supersets of others and can be used in place of the other.
+        if (LP->getPersonalityFn() != CalleePersonality)
+          return false;
 
-      break;
-    }
+        break;
+      }
 
   // Get an iterator to the last basic block in the function, which will have
   // the new function inlined after it.