diff options
| -rw-r--r-- | lib/Transforms/IPO/Inliner.cpp | 22 |
1 files changed, 19 insertions, 3 deletions
diff --git a/lib/Transforms/IPO/Inliner.cpp b/lib/Transforms/IPO/Inliner.cpp index 0d6b39f876..ae904354ee 100644 --- a/lib/Transforms/IPO/Inliner.cpp +++ b/lib/Transforms/IPO/Inliner.cpp @@ -75,7 +75,8 @@ InlinedArrayAllocasTy; /// inline this call site we attempt to reuse already available allocas or add /// any new allocas to the set if not possible. static bool InlineCallIfPossible(CallSite CS, InlineFunctionInfo &IFI, - InlinedArrayAllocasTy &InlinedArrayAllocas) { + InlinedArrayAllocasTy &InlinedArrayAllocas, + int InlineHistory) { Function *Callee = CS.getCalledFunction(); Function *Caller = CS.getCaller(); @@ -92,7 +93,6 @@ static bool InlineCallIfPossible(CallSite CS, InlineFunctionInfo &IFI, !Caller->hasFnAttr(Attribute::StackProtectReq)) Caller->addFnAttr(Attribute::StackProtect); - // Look at all of the allocas that we inlined through this call site. If we // have already inlined other allocas through other calls into this function, // then we know that they have disjoint lifetimes and that we can merge them. @@ -116,6 +116,21 @@ static bool InlineCallIfPossible(CallSite CS, InlineFunctionInfo &IFI, // SmallPtrSet<AllocaInst*, 16> UsedAllocas; + // When processing our SCC, check to see if CS was inlined from some other + // call site. For example, if we're processing "A" in this code: + // A() { B() } + // B() { x = alloca ... C() } + // C() { y = alloca ... } + // Assume that C was not inlined into B initially, and so we're processing A + // and decide to inline B into A. Doing this makes an alloca available for + // reuse and makes a callsite (C) available for inlining. When we process + // the C call site we don't want to do any alloca merging between X and Y + // because their scopes are not disjoint. We could make this smarter by + // keeping track of the inline history for each alloca in the + // InlinedArrayAllocas but this isn't likely to be a significant win. + if (InlineHistory != -1) // Only do merging for top-level call sites in SCC. + return true; + // Loop over all the allocas we have so far and see if they can be merged with // a previously inlined alloca. If not, remember that we had it. for (unsigned AllocaNo = 0, e = IFI.StaticAllocas.size(); @@ -419,7 +434,8 @@ bool Inliner::runOnSCC(CallGraphSCC &SCC) { continue; // Attempt to inline the function. - if (!InlineCallIfPossible(CS, InlineInfo, InlinedArrayAllocas)) + if (!InlineCallIfPossible(CS, InlineInfo, InlinedArrayAllocas, + InlineHistoryID)) continue; ++NumInlined; |