From 6feb333695f913cd7b525f9a2d5b887f4b0fca1f Mon Sep 17 00:00:00 2001 From: Nick Lewycky Date: Sun, 2 Nov 2008 16:46:26 +0000 Subject: [PATCH] Changes from Duncan's review: * merge two weak functions by making them both alias a third non-weak fn * don't reimplement CallSite::hasArgument * whitelist the safe linkage types git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58568 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/IPO/MergeFunctions.cpp | 37 +++++++++++++++++++------- test/Transforms/MergeFunc/fold-weak.ll | 11 ++++++++ 2 files changed, 39 insertions(+), 9 deletions(-) create mode 100644 test/Transforms/MergeFunc/fold-weak.ll diff --git a/lib/Transforms/IPO/MergeFunctions.cpp b/lib/Transforms/IPO/MergeFunctions.cpp index 6737b34b874..3c5c258f710 100644 --- a/lib/Transforms/IPO/MergeFunctions.cpp +++ b/lib/Transforms/IPO/MergeFunctions.cpp @@ -54,6 +54,7 @@ #include "llvm/Instructions.h" #include "llvm/Module.h" #include "llvm/Pass.h" +#include "llvm/Support/CallSite.h" #include "llvm/Support/Compiler.h" #include "llvm/Support/Debug.h" #include @@ -265,6 +266,28 @@ static bool fold(std::vector &FnVec, unsigned i, unsigned j) { } } + if (F->hasWeakLinkage() && G->hasWeakLinkage()) { + GlobalAlias *GA_F = new GlobalAlias(F->getType(), F->getLinkage(), "", + 0, F->getParent()); + GA_F->takeName(F); + GA_F->setVisibility(F->getVisibility()); + F->setAlignment(std::max(F->getAlignment(), G->getAlignment())); + F->replaceAllUsesWith(GA_F); + F->setName("folded." + GA_F->getName()); + F->setLinkage(GlobalValue::ExternalLinkage); + GA_F->setAliasee(F); + + GlobalAlias *GA_G = new GlobalAlias(G->getType(), G->getLinkage(), "", + F, G->getParent()); + GA_G->takeName(G); + GA_G->setVisibility(G->getVisibility()); + G->replaceAllUsesWith(GA_G); + G->eraseFromParent(); + + ++NumFunctionsMerged; + return true; + } + DOUT << "Failed on " << F->getName() << " and " << G->getName() << "\n"; ++NumMergeFails; @@ -289,13 +312,9 @@ static bool hasAddressTaken(User *U) { return true; // Make sure we aren't passing U as a parameter to call instead of the - // callee. getOperand(0) is the callee for both CallInst and InvokeInst. - // Check the other operands to see if any of them is F. - for (User::op_iterator OI = I->op_begin() + 1, OE = I->op_end(); OI != OE; - ++OI) { - if (*OI == U) - return true; - } + // callee. + if (CallSite(cast(Use)).hasArgument(U)) + return true; } return false; @@ -310,8 +329,8 @@ bool MergeFunctions::runOnModule(Module &M) { if (F->isDeclaration() || F->isIntrinsic()) continue; - if (F->hasLinkOnceLinkage() || F->hasCommonLinkage() || - F->hasDLLImportLinkage() || F->hasDLLExportLinkage()) + if (!F->hasInternalLinkage() && !F->hasExternalLinkage() && + !F->hasWeakLinkage()) continue; if (hasAddressTaken(F)) diff --git a/test/Transforms/MergeFunc/fold-weak.ll b/test/Transforms/MergeFunc/fold-weak.ll new file mode 100644 index 00000000000..d98fde0228f --- /dev/null +++ b/test/Transforms/MergeFunc/fold-weak.ll @@ -0,0 +1,11 @@ +; RUN: llvm-as < %s | opt -mergefunc | llvm-dis | grep {alias weak} | count 2 + +define weak i32 @sum(i32 %x, i32 %y) { + %sum = add i32 %x, %y + ret i32 %sum +} + +define weak i32 @add(i32 %x, i32 %y) { + %sum = add i32 %x, %y + ret i32 %sum +}