Add InlineCost class for represent the estimated cost of inlining a

function.
 - This explicitly models the costs for functions which should
   "always" or "never" be inlined. This fixes bugs where such costs
   were not previously respected.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58450 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 16 insertions, 3 deletions

diff --git a/lib/Transforms/IPO/InlineAlways.cpp b/lib/Transforms/IPO/InlineAlways.cpp
index 2799d6b22b..d809b5aed1 100644
--- a/lib/Transforms/IPO/InlineAlways.cpp
+++ b/lib/Transforms/IPO/InlineAlways.cpp
@@ -39,7 +39,7 @@ namespace {
     // Use extremely low threshold. 
     AlwaysInliner() : Inliner(&ID, -2000000000) {}
     static char ID; // Pass identification, replacement for typeid
-    int getInlineCost(CallSite CS) {
+    InlineCost getInlineCost(CallSite CS) {
       return CA.getInlineCost(CS, NeverInline);
     }
     float getInlineFudgeFactor(CallSite CS) {
diff --git a/lib/Transforms/IPO/InlineSimple.cpp b/lib/Transforms/IPO/InlineSimple.cpp
index 02cae2a6e6..8ae5235383 100644
--- a/lib/Transforms/IPO/InlineSimple.cpp
+++ b/lib/Transforms/IPO/InlineSimple.cpp
@@ -37,7 +37,7 @@ namespace {
     SimpleInliner() : Inliner(&ID) {}
     SimpleInliner(int Threshold) : Inliner(&ID, Threshold) {}
     static char ID; // Pass identification, replacement for typeid
-    int getInlineCost(CallSite CS) {
+    InlineCost getInlineCost(CallSite CS) {
       return CA.getInlineCost(CS, NeverInline);
     }
     float getInlineFudgeFactor(CallSite CS) {
diff --git a/lib/Transforms/IPO/Inliner.cpp b/lib/Transforms/IPO/Inliner.cpp
index 74af18396d..2321047a37 100644
--- a/lib/Transforms/IPO/Inliner.cpp
+++ b/lib/Transforms/IPO/Inliner.cpp
@@ -76,9 +76,22 @@ static bool InlineCallIfPossible(CallSite CS, CallGraph &CG,
 /// shouldInline - Return true if the inliner should attempt to inline
 /// at the given CallSite.
 bool Inliner::shouldInline(CallSite CS) {
-  int Cost = getInlineCost(CS);
+  InlineCost IC = getInlineCost(CS);
   float FudgeFactor = getInlineFudgeFactor(CS);
   
+  if (IC.isAlways()) {
+    DOUT << "    Inlining: cost=always"
+         << ", Call: " << *CS.getInstruction();
+    return true;
+  }
+  
+  if (IC.isNever()) {
+    DOUT << "    NOT Inlining: cost=never"
+         << ", Call: " << *CS.getInstruction();
+    return false;
+  }
+  
+  int Cost = IC.getValue();
   int CurrentThreshold = InlineThreshold;
   Function *Fn = CS.getCaller();
   if (Fn && !Fn->isDeclaration()