Do not inline functions with (dynamic) alloca into
functions that don't already have a (dynamic) alloca.
Dynamic allocas cause inefficient codegen and we shouldn't
propagate this (behavior follows gcc). Two existing tests
assumed such inlining would be done; they are hacked by
adding an alloca in the caller, preserving the point of
the tests.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61946 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Utils/InlineCost.cpp b/lib/Transforms/Utils/InlineCost.cpp
index 29d4f79..82e310b 100644
--- a/lib/Transforms/Utils/InlineCost.cpp
+++ b/lib/Transforms/Utils/InlineCost.cpp
@@ -126,6 +126,11 @@
NumInsts += 5;
}
+ if (const AllocaInst *AI = dyn_cast<AllocaInst>(II)) {
+ if (!isa<ConstantInt>(AI->getArraySize()))
+ this->usesDynamicAlloca = true;
+ }
+
if (isa<ExtractElementInst>(II) || isa<VectorType>(II->getType()))
++NumVectorInsts;
@@ -173,7 +178,7 @@
SmallPtrSet<const Function *, 16> &NeverInline) {
Instruction *TheCall = CS.getInstruction();
Function *Callee = CS.getCalledFunction();
- const Function *Caller = TheCall->getParent()->getParent();
+ Function *Caller = TheCall->getParent()->getParent();
// Don't inline a directly recursive call.
if (Caller == Callee ||
@@ -219,11 +224,24 @@
// If we haven't calculated this information yet, do so now.
if (CalleeFI.NumBlocks == 0)
CalleeFI.analyzeFunction(Callee);
-
+
// If we should never inline this, return a huge cost.
if (CalleeFI.NeverInline)
return InlineCost::getNever();
+ // Get infomation about the caller...
+ FunctionInfo &CallerFI = CachedFunctionInfo[Caller];
+
+ // If we haven't calculated this information yet, do so now.
+ if (CallerFI.NumBlocks == 0)
+ CallerFI.analyzeFunction(Caller);
+
+ // Don't inline a callee with dynamic alloca into a caller without them.
+ // Functions containing dynamic alloca's are inefficient in various ways;
+ // don't create more inefficiency.
+ if (CalleeFI.usesDynamicAlloca && !CallerFI.usesDynamicAlloca)
+ return InlineCost::getNever();
+
// FIXME: It would be nice to kill off CalleeFI.NeverInline. Then we
// could move this up and avoid computing the FunctionInfo for
// things we are going to just return always inline for. This