diff --git a/llvm/include/llvm/IR/Value.h b/llvm/include/llvm/IR/Value.h index fb61a2ac70d9..5fba3d571442 100644 --- a/llvm/include/llvm/IR/Value.h +++ b/llvm/include/llvm/IR/Value.h @@ -260,14 +260,24 @@ public: /// this value. bool hasValueHandle() const { return HasValueHandle; } - /// stripPointerCasts - This method strips off any unneeded pointer casts and - /// all-zero GEPs from the specified value, returning the original uncasted - /// value. If this is called on a non-pointer value, it returns 'this'. + /// \brief This method strips off any unneeded pointer casts, + /// all-zero GEPs and aliases from the specified value, returning the original + /// uncasted value. If this is called on a non-pointer value, it returns + /// 'this'. Value *stripPointerCasts(); const Value *stripPointerCasts() const { return const_cast(this)->stripPointerCasts(); } + /// \brief This method strips off any unneeded pointer casts and + /// all-zero GEPs from the specified value, returning the original + /// uncasted value. If this is called on a non-pointer value, it returns + /// 'this'. + Value *stripPointerCastsNoFollowAliases(); + const Value *stripPointerCastsNoFollowAliases() const { + return const_cast(this)->stripPointerCastsNoFollowAliases(); + } + /// stripInBoundsConstantOffsets - This method strips off unneeded pointer casts and /// all-constant GEPs from the specified value, returning the original /// pointer value. If this is called on a non-pointer value, it returns diff --git a/llvm/lib/IR/Value.cpp b/llvm/lib/IR/Value.cpp index e9eb012e6cef..89a3c0578cfd 100644 --- a/llvm/lib/IR/Value.cpp +++ b/llvm/lib/IR/Value.cpp @@ -333,6 +333,7 @@ namespace { // Various metrics for how much to strip off of pointers. enum PointerStripKind { PSK_ZeroIndices, + PSK_ZeroIndicesAndAliases, PSK_InBoundsConstantIndices, PSK_InBounds }; @@ -350,6 +351,7 @@ static Value *stripPointerCastsAndOffsets(Value *V) { do { if (GEPOperator *GEP = dyn_cast(V)) { switch (StripKind) { + case PSK_ZeroIndicesAndAliases: case PSK_ZeroIndices: if (!GEP->hasAllZeroIndices()) return V; @@ -367,7 +369,7 @@ static Value *stripPointerCastsAndOffsets(Value *V) { } else if (Operator::getOpcode(V) == Instruction::BitCast) { V = cast(V)->getOperand(0); } else if (GlobalAlias *GA = dyn_cast(V)) { - if (GA->mayBeOverridden()) + if (StripKind == PSK_ZeroIndices || GA->mayBeOverridden()) return V; V = GA->getAliasee(); } else { @@ -381,6 +383,10 @@ static Value *stripPointerCastsAndOffsets(Value *V) { } // namespace Value *Value::stripPointerCasts() { + return stripPointerCastsAndOffsets(this); +} + +Value *Value::stripPointerCastsNoFollowAliases() { return stripPointerCastsAndOffsets(this); } diff --git a/llvm/lib/Transforms/IPO/ConstantMerge.cpp b/llvm/lib/Transforms/IPO/ConstantMerge.cpp index b63495b9685f..a7bf18896b52 100644 --- a/llvm/lib/Transforms/IPO/ConstantMerge.cpp +++ b/llvm/lib/Transforms/IPO/ConstantMerge.cpp @@ -27,6 +27,7 @@ #include "llvm/IR/DataLayout.h" #include "llvm/IR/DerivedTypes.h" #include "llvm/IR/Module.h" +#include "llvm/IR/Operator.h" #include "llvm/Pass.h" using namespace llvm; @@ -68,10 +69,11 @@ static void FindUsedValues(GlobalVariable *LLVMUsed, if (LLVMUsed == 0) return; ConstantArray *Inits = cast(LLVMUsed->getInitializer()); - for (unsigned i = 0, e = Inits->getNumOperands(); i != e; ++i) - if (GlobalValue *GV = - dyn_cast(Inits->getOperand(i)->stripPointerCasts())) - UsedValues.insert(GV); + for (unsigned i = 0, e = Inits->getNumOperands(); i != e; ++i) { + Value *Operand = Inits->getOperand(i)->stripPointerCastsNoFollowAliases(); + GlobalValue *GV = cast(Operand); + UsedValues.insert(GV); + } } // True if A is better than B. diff --git a/llvm/test/Transforms/ConstantMerge/merge-both.ll b/llvm/test/Transforms/ConstantMerge/merge-both.ll index b00345557c83..316267648f1f 100644 --- a/llvm/test/Transforms/ConstantMerge/merge-both.ll +++ b/llvm/test/Transforms/ConstantMerge/merge-both.ll @@ -26,6 +26,9 @@ declare void @helper([16 x i8]*) ; CHECK-NEXT: @var6 = private constant [16 x i8] c"foo1bar2foo3bar\00", align 16 ; CHECK-NEXT: @var8 = private constant [16 x i8] c"foo1bar2foo3bar\00" +@var4a = alias %struct.foobar* @var4 +@llvm.used = appending global [1 x %struct.foobar*] [%struct.foobar* @var4a], section "llvm.metadata" + define i32 @main() { entry: call void @zed(%struct.foobar* @var1, %struct.foobar* @var2)