[llvm-commits] [llvm] r153814 - /llvm/trunk/lib/Transforms/IPO/InlineAlways.cpp

[Matt Beaumont-Gay]

On Sat, Mar 31, 2012 at 06:17, Chandler Carruth <chandlerc at gmail.com> wrote:
> --- llvm/trunk/lib/Transforms/IPO/InlineAlways.cpp (original)
> +++ llvm/trunk/lib/Transforms/IPO/InlineAlways.cpp Sat Mar 31 08:17:18 2012
> @@ -32,7 +32,6 @@
>
>   // AlwaysInliner only inlines functions that are mark as "always inline".
>   class AlwaysInliner : public Inliner {
> -    InlineCostAnalyzer CA;
>   public:
>     // Use extremely low threshold.
>     AlwaysInliner() : Inliner(ID, -2000000000, /*InsertLifetime*/true) {
> @@ -43,24 +42,7 @@
>       initializeAlwaysInlinerPass(*PassRegistry::getPassRegistry());
>     }
>     static char ID; // Pass identification, replacement for typeid
> -    InlineCost getInlineCost(CallSite CS) {
> -      Function *Callee = CS.getCalledFunction();
> -      // We assume indirect calls aren't calling an always-inline function.
> -      if (!Callee) return InlineCost::getNever();
> -
> -      // We can't inline calls to external functions.
> -      // FIXME: We shouldn't even get here.
> -      if (Callee->isDeclaration()) return InlineCost::getNever();
> -
> -      // Return never for anything not marked as always inline.
> -      if (!Callee->hasFnAttr(Attribute::AlwaysInline))
> -        return InlineCost::getNever();
> -
> -      // We still have to check the inline cost in case there are reasons to
> -      // not inline which trump the always-inline attribute such as setjmp and
> -      // indirectbr.
> -      return CA.getInlineCost(CS, getInlineThreshold(CS));
> -    }
> +    virtual InlineCost getInlineCost(CallSite CS);
>     virtual bool doFinalization(CallGraph &CG) {
>       return removeDeadFunctions(CG, /*AlwaysInlineOnly=*/true);
>     }
> @@ -81,9 +63,70 @@
>   return new AlwaysInliner(InsertLifetime);
>  }
>
> +/// \brief Minimal filter to detect invalid constructs for inlining.
> +static bool isInlineViable(Function &F) {
> +  bool ReturnsTwice = F.hasFnAttr(Attribute::ReturnsTwice);
> +  for (Function::iterator BI = F.begin(), BE = F.end(); BI != BE; ++BI) {
> +    // Disallow inlining of functions which contain an indirect branch.
> +    if (isa<IndirectBrInst>(BI->getTerminator()))
> +      return false;
> +
> +    for (BasicBlock::iterator II = BI->begin(), IE = BI->end(); II != IE;
> +         ++II) {
> +      CallSite CS(II);
> +      if (!CS)
> +        continue;
> +
> +      // Disallow recursive calls.
> +      if (&F == CS.getCalledFunction())
> +        return false;
> +
> +      // Disallow calls which expose returns-twice to a function not previously
> +      // attributed as such.
> +      if (ReturnsTwice && CS.isCall() &&

Er, should be "if (!ReturnsTwice && ...)", no?

Also, tests?

-Matt