Enrich inline messages

Summary:
This patch improves Inliner to provide causes/reasons for negative inline decisions.
1. It adds one new message field to InlineCost to report causes for Always and Never instances. All Never and Always instantiations must provide a simple message.
2. Several functions that used to return the inlining results as boolean are changed to return InlineResult which carries the cause for negative decision.
3. Changed remark priniting and debug output messages to provide the additional messages and related inline cost.
4. Adjusted tests for changed printing.

Patch by: yrouban (Yevgeny Rouban)


Reviewers: craig.topper, sammccall, sgraenitz, NutshellySima, shchenz, chandlerc, apilipenko, javed.absar, tejohnson, dblaikie, sanjoy, eraman, xbolva00

Reviewed By: tejohnson, xbolva00

Subscribers: xbolva00, llvm-commits, arsenm, mehdi_amini, eraman, haicheng, steven_wu, dexonsmith

Differential Revision: https://reviews.llvm.org/D49412

llvm-svn: 338494

1 files changed, 16 insertions, 13 deletions

diff --git a/llvm/lib/Transforms/Utils/InlineFunction.cpp b/llvm/lib/Transforms/Utils/InlineFunction.cpp
index ddc6e07e2f5..f8226f529ee 100644
--- a/llvm/lib/Transforms/Utils/InlineFunction.cpp
+++ b/llvm/lib/Transforms/Utils/InlineFunction.cpp
@@ -84,13 +84,15 @@ PreserveAlignmentAssumptions("preserve-alignment-assumptions-during-inlining",
   cl::init(true), cl::Hidden,
   cl::desc("Convert align attributes to assumptions during inlining."));
 
-bool llvm::InlineFunction(CallInst *CI, InlineFunctionInfo &IFI,
-                          AAResults *CalleeAAR, bool InsertLifetime) {
+llvm::InlineResult llvm::InlineFunction(CallInst *CI, InlineFunctionInfo &IFI,
+                                        AAResults *CalleeAAR,
+                                        bool InsertLifetime) {
   return InlineFunction(CallSite(CI), IFI, CalleeAAR, InsertLifetime);
 }
 
-bool llvm::InlineFunction(InvokeInst *II, InlineFunctionInfo &IFI,
-                          AAResults *CalleeAAR, bool InsertLifetime) {
+llvm::InlineResult llvm::InlineFunction(InvokeInst *II, InlineFunctionInfo &IFI,
+                                        AAResults *CalleeAAR,
+                                        bool InsertLifetime) {
   return InlineFunction(CallSite(II), IFI, CalleeAAR, InsertLifetime);
 }
 
@@ -1491,9 +1493,10 @@ static void updateCalleeCount(BlockFrequencyInfo *CallerBFI, BasicBlock *CallBB,
 /// instruction 'call B' is inlined, and 'B' calls 'C', then the call to 'C' now
 /// exists in the instruction stream.  Similarly this will inline a recursive
 /// function by one level.
-bool llvm::InlineFunction(CallSite CS, InlineFunctionInfo &IFI,
-                          AAResults *CalleeAAR, bool InsertLifetime,
-                          Function *ForwardVarArgsTo) {
+llvm::InlineResult llvm::InlineFunction(CallSite CS, InlineFunctionInfo &IFI,
+                                        AAResults *CalleeAAR,
+                                        bool InsertLifetime,
+                                        Function *ForwardVarArgsTo) {
   Instruction *TheCall = CS.getInstruction();
   assert(TheCall->getParent() && TheCall->getFunction()
          && "Instruction not in function!");
@@ -1504,7 +1507,7 @@ bool llvm::InlineFunction(CallSite CS, InlineFunctionInfo &IFI,
   Function *CalledFunc = CS.getCalledFunction();
   if (!CalledFunc ||               // Can't inline external function or indirect
       CalledFunc->isDeclaration()) // call!
-    return false;
+    return "external or indirect";
 
   // The inliner does not know how to inline through calls with operand bundles
   // in general ...
@@ -1518,7 +1521,7 @@ bool llvm::InlineFunction(CallSite CS, InlineFunctionInfo &IFI,
       if (Tag == LLVMContext::OB_funclet)
         continue;
 
-      return false;
+      return "unsupported operand bundle";
     }
   }
 
@@ -1537,7 +1540,7 @@ bool llvm::InlineFunction(CallSite CS, InlineFunctionInfo &IFI,
     if (!Caller->hasGC())
       Caller->setGC(CalledFunc->getGC());
     else if (CalledFunc->getGC() != Caller->getGC())
-      return false;
+      return "incompatible GC";
   }
 
   // Get the personality function from the callee if it contains a landing pad.
@@ -1561,7 +1564,7 @@ bool llvm::InlineFunction(CallSite CS, InlineFunctionInfo &IFI,
     // TODO: This isn't 100% true. Some personality functions are proper
     //       supersets of others and can be used in place of the other.
     else if (CalledPersonality != CallerPersonality)
-      return false;
+      return "incompatible personality";
   }
 
   // We need to figure out which funclet the callsite was in so that we may
@@ -1586,7 +1589,7 @@ bool llvm::InlineFunction(CallSite CS, InlineFunctionInfo &IFI,
             // for catchpads.
             for (const BasicBlock &CalledBB : *CalledFunc) {
               if (isa<CatchSwitchInst>(CalledBB.getFirstNonPHI()))
-                return false;
+                return "catch in cleanup funclet";
             }
           }
         } else if (isAsynchronousEHPersonality(Personality)) {
@@ -1594,7 +1597,7 @@ bool llvm::InlineFunction(CallSite CS, InlineFunctionInfo &IFI,
           // funclet in the callee.
           for (const BasicBlock &CalledBB : *CalledFunc) {
             if (CalledBB.isEHPad())
-              return false;
+              return "SEH in cleanup funclet";
           }
         }
       }