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-rw-r--r--lib/Analysis/PHITransAddr.cpp154
1 files changed, 83 insertions, 71 deletions
diff --git a/lib/Analysis/PHITransAddr.cpp b/lib/Analysis/PHITransAddr.cpp
index 8e4fa03f2134..93da5a48518d 100644
--- a/lib/Analysis/PHITransAddr.cpp
+++ b/lib/Analysis/PHITransAddr.cpp
@@ -12,22 +12,27 @@
//===----------------------------------------------------------------------===//
#include "llvm/Analysis/PHITransAddr.h"
+#include "llvm/Instructions.h"
#include "llvm/Analysis/Dominators.h"
#include "llvm/Analysis/InstructionSimplify.h"
#include "llvm/Support/Debug.h"
+#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
static bool CanPHITrans(Instruction *Inst) {
if (isa<PHINode>(Inst) ||
- isa<BitCastInst>(Inst) ||
isa<GetElementPtrInst>(Inst))
return true;
-
+
+ if (isa<CastInst>(Inst) &&
+ Inst->isSafeToSpeculativelyExecute())
+ return true;
+
if (Inst->getOpcode() == Instruction::Add &&
isa<ConstantInt>(Inst->getOperand(1)))
return true;
-
+
// cerr << "MEMDEP: Could not PHI translate: " << *Pointer;
// if (isa<BitCastInst>(PtrInst) || isa<GetElementPtrInst>(PtrInst))
// cerr << "OP:\t\t\t\t" << *PtrInst->getOperand(0);
@@ -50,7 +55,7 @@ static bool VerifySubExpr(Value *Expr,
// If this is a non-instruction value, there is nothing to do.
Instruction *I = dyn_cast<Instruction>(Expr);
if (I == 0) return true;
-
+
// If it's an instruction, it is either in Tmp or its operands recursively
// are.
SmallVectorImpl<Instruction*>::iterator Entry =
@@ -59,16 +64,17 @@ static bool VerifySubExpr(Value *Expr,
InstInputs.erase(Entry);
return true;
}
-
+
// If it isn't in the InstInputs list it is a subexpr incorporated into the
// address. Sanity check that it is phi translatable.
if (!CanPHITrans(I)) {
- errs() << "Non phi translatable instruction found in PHITransAddr, either "
- "something is missing from InstInputs or CanPHITrans is wrong:\n";
+ errs() << "Non phi translatable instruction found in PHITransAddr:\n";
errs() << *I << '\n';
+ llvm_unreachable("Either something is missing from InstInputs or "
+ "CanPHITrans is wrong.");
return false;
}
-
+
// Validate the operands of the instruction.
for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i)
if (!VerifySubExpr(I->getOperand(i), InstInputs))
@@ -82,19 +88,20 @@ static bool VerifySubExpr(Value *Expr,
/// returns false.
bool PHITransAddr::Verify() const {
if (Addr == 0) return true;
-
- SmallVector<Instruction*, 8> Tmp(InstInputs.begin(), InstInputs.end());
-
+
+ SmallVector<Instruction*, 8> Tmp(InstInputs.begin(), InstInputs.end());
+
if (!VerifySubExpr(Addr, Tmp))
return false;
-
+
if (!Tmp.empty()) {
- errs() << "PHITransAddr inconsistent, contains extra instructions:\n";
+ errs() << "PHITransAddr contains extra instructions:\n";
for (unsigned i = 0, e = InstInputs.size(); i != e; ++i)
errs() << " InstInput #" << i << " is " << *InstInputs[i] << "\n";
+ llvm_unreachable("This is unexpected.");
return false;
}
-
+
// a-ok.
return true;
}
@@ -111,11 +118,11 @@ bool PHITransAddr::IsPotentiallyPHITranslatable() const {
}
-static void RemoveInstInputs(Value *V,
+static void RemoveInstInputs(Value *V,
SmallVectorImpl<Instruction*> &InstInputs) {
Instruction *I = dyn_cast<Instruction>(V);
if (I == 0) return;
-
+
// If the instruction is in the InstInputs list, remove it.
SmallVectorImpl<Instruction*>::iterator Entry =
std::find(InstInputs.begin(), InstInputs.end(), I);
@@ -123,9 +130,9 @@ static void RemoveInstInputs(Value *V,
InstInputs.erase(Entry);
return;
}
-
+
assert(!isa<PHINode>(I) && "Error, removing something that isn't an input");
-
+
// Otherwise, it must have instruction inputs itself. Zap them recursively.
for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) {
if (Instruction *Op = dyn_cast<Instruction>(I->getOperand(i)))
@@ -139,7 +146,7 @@ Value *PHITransAddr::PHITranslateSubExpr(Value *V, BasicBlock *CurBB,
// If this is a non-instruction value, it can't require PHI translation.
Instruction *Inst = dyn_cast<Instruction>(V);
if (Inst == 0) return V;
-
+
// Determine whether 'Inst' is an input to our PHI translatable expression.
bool isInput = std::count(InstInputs.begin(), InstInputs.end(), Inst);
@@ -156,16 +163,16 @@ Value *PHITransAddr::PHITranslateSubExpr(Value *V, BasicBlock *CurBB,
// In either case, the instruction itself isn't an input any longer.
InstInputs.erase(std::find(InstInputs.begin(), InstInputs.end(), Inst));
-
+
// If this is a PHI, go ahead and translate it.
if (PHINode *PN = dyn_cast<PHINode>(Inst))
return AddAsInput(PN->getIncomingValueForBlock(PredBB));
-
+
// If this is a non-phi value, and it is analyzable, we can incorporate it
// into the expression by making all instruction operands be inputs.
if (!CanPHITrans(Inst))
return 0;
-
+
// All instruction operands are now inputs (and of course, they may also be
// defined in this block, so they may need to be phi translated themselves.
for (unsigned i = 0, e = Inst->getNumOperands(); i != e; ++i)
@@ -176,31 +183,34 @@ Value *PHITransAddr::PHITranslateSubExpr(Value *V, BasicBlock *CurBB,
// Ok, it must be an intermediate result (either because it started that way
// or because we just incorporated it into the expression). See if its
// operands need to be phi translated, and if so, reconstruct it.
-
- if (BitCastInst *BC = dyn_cast<BitCastInst>(Inst)) {
- Value *PHIIn = PHITranslateSubExpr(BC->getOperand(0), CurBB, PredBB, DT);
+
+ if (CastInst *Cast = dyn_cast<CastInst>(Inst)) {
+ if (!Cast->isSafeToSpeculativelyExecute()) return 0;
+ Value *PHIIn = PHITranslateSubExpr(Cast->getOperand(0), CurBB, PredBB, DT);
if (PHIIn == 0) return 0;
- if (PHIIn == BC->getOperand(0))
- return BC;
-
+ if (PHIIn == Cast->getOperand(0))
+ return Cast;
+
// Find an available version of this cast.
-
+
// Constants are trivial to find.
if (Constant *C = dyn_cast<Constant>(PHIIn))
- return AddAsInput(ConstantExpr::getBitCast(C, BC->getType()));
-
- // Otherwise we have to see if a bitcasted version of the incoming pointer
+ return AddAsInput(ConstantExpr::getCast(Cast->getOpcode(),
+ C, Cast->getType()));
+
+ // Otherwise we have to see if a casted version of the incoming pointer
// is available. If so, we can use it, otherwise we have to fail.
for (Value::use_iterator UI = PHIIn->use_begin(), E = PHIIn->use_end();
UI != E; ++UI) {
- if (BitCastInst *BCI = dyn_cast<BitCastInst>(*UI))
- if (BCI->getType() == BC->getType() &&
- (!DT || DT->dominates(BCI->getParent(), PredBB)))
- return BCI;
+ if (CastInst *CastI = dyn_cast<CastInst>(*UI))
+ if (CastI->getOpcode() == Cast->getOpcode() &&
+ CastI->getType() == Cast->getType() &&
+ (!DT || DT->dominates(CastI->getParent(), PredBB)))
+ return CastI;
}
return 0;
}
-
+
// Handle getelementptr with at least one PHI translatable operand.
if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Inst)) {
SmallVector<Value*, 8> GEPOps;
@@ -208,22 +218,22 @@ Value *PHITransAddr::PHITranslateSubExpr(Value *V, BasicBlock *CurBB,
for (unsigned i = 0, e = GEP->getNumOperands(); i != e; ++i) {
Value *GEPOp = PHITranslateSubExpr(GEP->getOperand(i), CurBB, PredBB, DT);
if (GEPOp == 0) return 0;
-
+
AnyChanged |= GEPOp != GEP->getOperand(i);
GEPOps.push_back(GEPOp);
}
-
+
if (!AnyChanged)
return GEP;
-
+
// Simplify the GEP to handle 'gep x, 0' -> x etc.
- if (Value *V = SimplifyGEPInst(&GEPOps[0], GEPOps.size(), TD)) {
+ if (Value *V = SimplifyGEPInst(&GEPOps[0], GEPOps.size(), TD, DT)) {
for (unsigned i = 0, e = GEPOps.size(); i != e; ++i)
RemoveInstInputs(GEPOps[i], InstInputs);
-
+
return AddAsInput(V);
}
-
+
// Scan to see if we have this GEP available.
Value *APHIOp = GEPOps[0];
for (Value::use_iterator UI = APHIOp->use_begin(), E = APHIOp->use_end();
@@ -245,7 +255,7 @@ Value *PHITransAddr::PHITranslateSubExpr(Value *V, BasicBlock *CurBB,
}
return 0;
}
-
+
// Handle add with a constant RHS.
if (Inst->getOpcode() == Instruction::Add &&
isa<ConstantInt>(Inst->getOperand(1))) {
@@ -253,10 +263,10 @@ Value *PHITransAddr::PHITranslateSubExpr(Value *V, BasicBlock *CurBB,
Constant *RHS = cast<ConstantInt>(Inst->getOperand(1));
bool isNSW = cast<BinaryOperator>(Inst)->hasNoSignedWrap();
bool isNUW = cast<BinaryOperator>(Inst)->hasNoUnsignedWrap();
-
+
Value *LHS = PHITranslateSubExpr(Inst->getOperand(0), CurBB, PredBB, DT);
if (LHS == 0) return 0;
-
+
// If the PHI translated LHS is an add of a constant, fold the immediates.
if (BinaryOperator *BOp = dyn_cast<BinaryOperator>(LHS))
if (BOp->getOpcode() == Instruction::Add)
@@ -264,16 +274,16 @@ Value *PHITransAddr::PHITranslateSubExpr(Value *V, BasicBlock *CurBB,
LHS = BOp->getOperand(0);
RHS = ConstantExpr::getAdd(RHS, CI);
isNSW = isNUW = false;
-
+
// If the old 'LHS' was an input, add the new 'LHS' as an input.
if (std::count(InstInputs.begin(), InstInputs.end(), BOp)) {
RemoveInstInputs(BOp, InstInputs);
AddAsInput(LHS);
}
}
-
+
// See if the add simplifies away.
- if (Value *Res = SimplifyAddInst(LHS, RHS, isNSW, isNUW, TD)) {
+ if (Value *Res = SimplifyAddInst(LHS, RHS, isNSW, isNUW, TD, DT)) {
// If we simplified the operands, the LHS is no longer an input, but Res
// is.
RemoveInstInputs(LHS, InstInputs);
@@ -283,7 +293,7 @@ Value *PHITransAddr::PHITranslateSubExpr(Value *V, BasicBlock *CurBB,
// If we didn't modify the add, just return it.
if (LHS == Inst->getOperand(0) && RHS == Inst->getOperand(1))
return Inst;
-
+
// Otherwise, see if we have this add available somewhere.
for (Value::use_iterator UI = LHS->use_begin(), E = LHS->use_end();
UI != E; ++UI) {
@@ -294,10 +304,10 @@ Value *PHITransAddr::PHITranslateSubExpr(Value *V, BasicBlock *CurBB,
(!DT || DT->dominates(BO->getParent(), PredBB)))
return BO;
}
-
+
return 0;
}
-
+
// Otherwise, we failed.
return 0;
}
@@ -335,13 +345,13 @@ PHITranslateWithInsertion(BasicBlock *CurBB, BasicBlock *PredBB,
const DominatorTree &DT,
SmallVectorImpl<Instruction*> &NewInsts) {
unsigned NISize = NewInsts.size();
-
+
// Attempt to PHI translate with insertion.
Addr = InsertPHITranslatedSubExpr(Addr, CurBB, PredBB, DT, NewInsts);
-
+
// If successful, return the new value.
if (Addr) return Addr;
-
+
// If not, destroy any intermediate instructions inserted.
while (NewInsts.size() != NISize)
NewInsts.pop_back_val()->eraseFromParent();
@@ -367,21 +377,23 @@ InsertPHITranslatedSubExpr(Value *InVal, BasicBlock *CurBB,
// If we don't have an available version of this value, it must be an
// instruction.
Instruction *Inst = cast<Instruction>(InVal);
-
- // Handle bitcast of PHI translatable value.
- if (BitCastInst *BC = dyn_cast<BitCastInst>(Inst)) {
- Value *OpVal = InsertPHITranslatedSubExpr(BC->getOperand(0),
+
+ // Handle cast of PHI translatable value.
+ if (CastInst *Cast = dyn_cast<CastInst>(Inst)) {
+ if (!Cast->isSafeToSpeculativelyExecute()) return 0;
+ Value *OpVal = InsertPHITranslatedSubExpr(Cast->getOperand(0),
CurBB, PredBB, DT, NewInsts);
if (OpVal == 0) return 0;
-
- // Otherwise insert a bitcast at the end of PredBB.
- BitCastInst *New = new BitCastInst(OpVal, InVal->getType(),
- InVal->getName()+".phi.trans.insert",
- PredBB->getTerminator());
+
+ // Otherwise insert a cast at the end of PredBB.
+ CastInst *New = CastInst::Create(Cast->getOpcode(),
+ OpVal, InVal->getType(),
+ InVal->getName()+".phi.trans.insert",
+ PredBB->getTerminator());
NewInsts.push_back(New);
return New;
}
-
+
// Handle getelementptr with at least one PHI operand.
if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Inst)) {
SmallVector<Value*, 8> GEPOps;
@@ -392,8 +404,8 @@ InsertPHITranslatedSubExpr(Value *InVal, BasicBlock *CurBB,
if (OpVal == 0) return 0;
GEPOps.push_back(OpVal);
}
-
- GetElementPtrInst *Result =
+
+ GetElementPtrInst *Result =
GetElementPtrInst::Create(GEPOps[0], GEPOps.begin()+1, GEPOps.end(),
InVal->getName()+".phi.trans.insert",
PredBB->getTerminator());
@@ -401,12 +413,12 @@ InsertPHITranslatedSubExpr(Value *InVal, BasicBlock *CurBB,
NewInsts.push_back(Result);
return Result;
}
-
+
#if 0
// FIXME: This code works, but it is unclear that we actually want to insert
// a big chain of computation in order to make a value available in a block.
// This needs to be evaluated carefully to consider its cost trade offs.
-
+
// Handle add with a constant RHS.
if (Inst->getOpcode() == Instruction::Add &&
isa<ConstantInt>(Inst->getOperand(1))) {
@@ -414,7 +426,7 @@ InsertPHITranslatedSubExpr(Value *InVal, BasicBlock *CurBB,
Value *OpVal = InsertPHITranslatedSubExpr(Inst->getOperand(0),
CurBB, PredBB, DT, NewInsts);
if (OpVal == 0) return 0;
-
+
BinaryOperator *Res = BinaryOperator::CreateAdd(OpVal, Inst->getOperand(1),
InVal->getName()+".phi.trans.insert",
PredBB->getTerminator());
@@ -424,6 +436,6 @@ InsertPHITranslatedSubExpr(Value *InVal, BasicBlock *CurBB,
return Res;
}
#endif
-
+
return 0;
}
generated by cgit v1.2.3 (git 2.25.1) at 2025-11-04 14:06:40 +0000