summaryrefslogtreecommitdiffstats
path: root/llvm
diff options
context:
space:
mode:
Diffstat (limited to 'llvm')
-rw-r--r--llvm/include/llvm/GlobalVariable.h9
-rw-r--r--llvm/lib/Transforms/Scalar/InstructionCombining.cpp7
-rw-r--r--llvm/lib/Transforms/Scalar/SCCP.cpp4
-rw-r--r--llvm/lib/Transforms/Utils/CloneFunction.cpp3
4 files changed, 15 insertions, 8 deletions
diff --git a/llvm/include/llvm/GlobalVariable.h b/llvm/include/llvm/GlobalVariable.h
index bcbf3213462..ae64ccf614b 100644
--- a/llvm/include/llvm/GlobalVariable.h
+++ b/llvm/include/llvm/GlobalVariable.h
@@ -78,6 +78,15 @@ public:
///
inline bool hasInitializer() const { return !isDeclaration(); }
+ /// hasDefinitiveInitializer - Whether the global variable has an initializer,
+ /// and this is the initializer that will be used in the final executable.
+ inline bool hasDefinitiveInitializer() const {
+ return hasInitializer() &&
+ // The initializer of a global variable with weak linkage may change at
+ // link time.
+ !mayBeOverridden();
+ }
+
/// getInitializer - Return the initializer for this global variable. It is
/// illegal to call this method if the global is external, because we cannot
/// tell what the value is initialized to!
diff --git a/llvm/lib/Transforms/Scalar/InstructionCombining.cpp b/llvm/lib/Transforms/Scalar/InstructionCombining.cpp
index 6af0afd55e1..26963280bbe 100644
--- a/llvm/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/llvm/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -11227,15 +11227,14 @@ Instruction *InstCombiner::visitLoadInst(LoadInst &LI) {
// Instcombine load (constant global) into the value loaded.
if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Op))
- if (GV->isConstant() && !GV->isDeclaration() && !GV->mayBeOverridden())
+ if (GV->isConstant() && GV->hasDefinitiveInitializer())
return ReplaceInstUsesWith(LI, GV->getInitializer());
// Instcombine load (constantexpr_GEP global, 0, ...) into the value loaded.
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Op)) {
if (CE->getOpcode() == Instruction::GetElementPtr) {
if (GlobalVariable *GV = dyn_cast<GlobalVariable>(CE->getOperand(0)))
- if (GV->isConstant() && !GV->isDeclaration() &&
- !GV->mayBeOverridden())
+ if (GV->isConstant() && GV->hasDefinitiveInitializer())
if (Constant *V =
ConstantFoldLoadThroughGEPConstantExpr(GV->getInitializer(), CE))
return ReplaceInstUsesWith(LI, V);
@@ -11259,7 +11258,7 @@ Instruction *InstCombiner::visitLoadInst(LoadInst &LI) {
// If this load comes from anywhere in a constant global, and if the global
// is all undef or zero, we know what it loads.
if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Op->getUnderlyingObject())){
- if (GV->isConstant() && GV->hasInitializer() && !GV->mayBeOverridden()) {
+ if (GV->isConstant() && GV->hasDefinitiveInitializer()) {
if (GV->getInitializer()->isNullValue())
return ReplaceInstUsesWith(LI, Constant::getNullValue(LI.getType()));
else if (isa<UndefValue>(GV->getInitializer()))
diff --git a/llvm/lib/Transforms/Scalar/SCCP.cpp b/llvm/lib/Transforms/Scalar/SCCP.cpp
index a49bcc84547..d2a70ea9d00 100644
--- a/llvm/lib/Transforms/Scalar/SCCP.cpp
+++ b/llvm/lib/Transforms/Scalar/SCCP.cpp
@@ -1131,7 +1131,7 @@ void SCCPSolver::visitLoadInst(LoadInst &I) {
// Transform load (constant global) into the value loaded.
if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Ptr)) {
if (GV->isConstant()) {
- if (!GV->isDeclaration() && !GV->mayBeOverridden()) {
+ if (GV->hasDefinitiveInitializer()) {
markConstant(IV, &I, GV->getInitializer());
return;
}
@@ -1150,7 +1150,7 @@ void SCCPSolver::visitLoadInst(LoadInst &I) {
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ptr))
if (CE->getOpcode() == Instruction::GetElementPtr)
if (GlobalVariable *GV = dyn_cast<GlobalVariable>(CE->getOperand(0)))
- if (GV->isConstant() && !GV->isDeclaration() && !GV->mayBeOverridden())
+ if (GV->isConstant() && GV->hasDefinitiveInitializer())
if (Constant *V =
ConstantFoldLoadThroughGEPConstantExpr(GV->getInitializer(), CE)) {
markConstant(IV, &I, V);
diff --git a/llvm/lib/Transforms/Utils/CloneFunction.cpp b/llvm/lib/Transforms/Utils/CloneFunction.cpp
index 5dc2d1cdc3a..d7b4bd3fd67 100644
--- a/llvm/lib/Transforms/Utils/CloneFunction.cpp
+++ b/llvm/lib/Transforms/Utils/CloneFunction.cpp
@@ -335,8 +335,7 @@ ConstantFoldMappedInstruction(const Instruction *I) {
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ops[0]))
if (!LI->isVolatile() && CE->getOpcode() == Instruction::GetElementPtr)
if (GlobalVariable *GV = dyn_cast<GlobalVariable>(CE->getOperand(0)))
- if (GV->isConstant() && !GV->isDeclaration() &&
- !GV->mayBeOverridden())
+ if (GV->isConstant() && GV->hasDefinitiveInitializer())
return ConstantFoldLoadThroughGEPConstantExpr(GV->getInitializer(),
CE);
OpenPOWER on IntegriCloud