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Make order of argument addition deterministic. In particular, the layout 

of ConstantInt objects in memory used to determine which order arguments
were added in in some cases.

llvm-svn: 14276
This commit is contained in:
Chris Lattner 2004-06-21 00:07:58 +00:00
parent baaed7ee90
commit 1c676f76b6
1 changed files with 35 additions and 10 deletions
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45
llvm/lib/Transforms/IPO/ArgumentPromotion.cpp
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@ -185,7 +185,7 @@ bool ArgPromotion::isSafeToPromoteArgument(Argument *Arg) const {
// We can only promote this argument if all of the uses are loads, or are GEP
// instructions (with constant indices) that are subsequently loaded.
std::vector<LoadInst*> Loads;
std::vector<std::vector<Constant*> > GEPIndices;
std::vector<std::vector<ConstantInt*> > GEPIndices;
for (Value::use_iterator UI = Arg->use_begin(), E = Arg->use_end();
UI != E; ++UI)
if (LoadInst *LI = dyn_cast<LoadInst>(*UI)) {
@ -200,9 +200,9 @@ bool ArgPromotion::isSafeToPromoteArgument(Argument *Arg) const {
return isSafeToPromoteArgument(Arg);
}
// Ensure that all of the indices are constants.
std::vector<Constant*> Operands;
std::vector<ConstantInt*> Operands;
for (unsigned i = 1, e = GEP->getNumOperands(); i != e; ++i)
if (Constant *C = dyn_cast<Constant>(GEP->getOperand(i)))
if (ConstantInt *C = dyn_cast<ConstantInt>(GEP->getOperand(i)))
Operands.push_back(C);
else
return false; // Not a constant operand GEP!
@ -279,6 +279,29 @@ bool ArgPromotion::isSafeToPromoteArgument(Argument *Arg) const {
return true;
}
namespace {
/// GEPIdxComparator - Provide a strong ordering for GEP indices. All Value*
/// elements are instances of ConstantInt.
///
struct GEPIdxComparator {
bool operator()(const std::vector<Value*> &LHS,
const std::vector<Value*> &RHS) const {
unsigned idx = 0;
for (; idx < LHS.size() && idx < RHS.size(); ++idx) {
if (LHS[idx] != RHS[idx]) {
return cast<ConstantInt>(LHS[idx])->getRawValue() <
cast<ConstantInt>(RHS[idx])->getRawValue();
}
}
// Return less than if we ran out of stuff in LHS and we didn't run out of
// stuff in RHS.
return idx == LHS.size() && idx != RHS.size();
}
};
}
/// DoPromotion - This method actually performs the promotion of the specified
/// arguments. At this point, we know that it's safe to do so.
void ArgPromotion::DoPromotion(Function *F, std::vector<Argument*> &Args2Prom) {
@ -289,6 +312,8 @@ void ArgPromotion::DoPromotion(Function *F, std::vector<Argument*> &Args2Prom) {
const FunctionType *FTy = F->getFunctionType();
std::vector<const Type*> Params;
typedef std::set<std::vector<Value*>, GEPIdxComparator> ScalarizeTable;
// ScalarizedElements - If we are promoting a pointer that has elements
// accessed out of it, keep track of which elements are accessed so that we
// can add one argument for each.
@ -296,7 +321,7 @@ void ArgPromotion::DoPromotion(Function *F, std::vector<Argument*> &Args2Prom) {
// Arguments that are directly loaded will have a zero element value here, to
// handle cases where there are both a direct load and GEP accesses.
//
std::map<Argument*, std::set<std::vector<Value*> > > ScalarizedElements;
std::map<Argument*, ScalarizeTable> ScalarizedElements;
// OriginalLoads - Keep track of a representative load instruction from the
// original function so that we can tell the alias analysis implementation
@ -311,7 +336,7 @@ void ArgPromotion::DoPromotion(Function *F, std::vector<Argument*> &Args2Prom) {
} else {
// Okay, this is being promoted. Check to see if there are any GEP uses
// of the argument.
std::set<std::vector<Value*> > &ArgIndices = ScalarizedElements[I];
ScalarizeTable &ArgIndices = ScalarizedElements[I];
for (Value::use_iterator UI = I->use_begin(), E = I->use_end(); UI != E;
++UI) {
Instruction *User = cast<Instruction>(*UI);
@ -327,7 +352,7 @@ void ArgPromotion::DoPromotion(Function *F, std::vector<Argument*> &Args2Prom) {
}
// Add a parameter to the function for each element passed in.
for (std::set<std::vector<Value*> >::iterator SI = ArgIndices.begin(),
for (ScalarizeTable::iterator SI = ArgIndices.begin(),
E = ArgIndices.end(); SI != E; ++SI)
Params.push_back(GetElementPtrInst::getIndexedType(I->getType(), *SI));
@ -377,8 +402,8 @@ void ArgPromotion::DoPromotion(Function *F, std::vector<Argument*> &Args2Prom) {
Args.push_back(*AI); // Unmodified argument
else if (!I->use_empty()) {
// Non-dead argument: insert GEPs and loads as appropriate.
std::set<std::vector<Value*> > &ArgIndices = ScalarizedElements[I];
for (std::set<std::vector<Value*> >::iterator SI = ArgIndices.begin(),
ScalarizeTable &ArgIndices = ScalarizedElements[I];
for (ScalarizeTable::iterator SI = ArgIndices.begin(),
E = ArgIndices.end(); SI != E; ++SI) {
Value *V = *AI;
LoadInst *OrigLoad = OriginalLoads[*SI];
@ -446,7 +471,7 @@ void ArgPromotion::DoPromotion(Function *F, std::vector<Argument*> &Args2Prom) {
// Otherwise, if we promoted this argument, then all users are load
// instructions, and all loads should be using the new argument that we
// added.
std::set<std::vector<Value*> > &ArgIndices = ScalarizedElements[I];
ScalarizeTable &ArgIndices = ScalarizedElements[I];
while (!I->use_empty()) {
if (LoadInst *LI = dyn_cast<LoadInst>(I->use_back())) {
@ -464,7 +489,7 @@ void ArgPromotion::DoPromotion(Function *F, std::vector<Argument*> &Args2Prom) {
unsigned ArgNo = 0;
Function::aiterator TheArg = I2;
for (std::set<std::vector<Value*> >::iterator It = ArgIndices.begin();
for (ScalarizeTable::iterator It = ArgIndices.begin();
*It != Operands; ++It, ++TheArg) {
assert(It != ArgIndices.end() && "GEP not handled??");
}