mirror of
https://github.com/RPCSX/llvm.git
synced 2024-12-14 23:48:49 +00:00
b6984558c5
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@4017 91177308-0d34-0410-b5e6-96231b3b80d8
187 lines
7.7 KiB
C++
187 lines
7.7 KiB
C++
//===-- TransformInternals.cpp - Implement shared functions for transforms --=//
|
|
//
|
|
// This file defines shared functions used by the different components of the
|
|
// Transforms library.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "TransformInternals.h"
|
|
#include "llvm/Type.h"
|
|
#include "llvm/Analysis/Expressions.h"
|
|
#include "llvm/Function.h"
|
|
#include "llvm/iOther.h"
|
|
|
|
// TargetData Hack: Eventually we will have annotations given to us by the
|
|
// backend so that we know stuff about type size and alignments. For now
|
|
// though, just use this, because it happens to match the model that GCC uses.
|
|
//
|
|
const TargetData TD("LevelRaise: Should be GCC though!");
|
|
|
|
|
|
static const Type *getStructOffsetStep(const StructType *STy, uint64_t &Offset,
|
|
std::vector<Value*> &Indices) {
|
|
assert(Offset < TD.getTypeSize(STy) && "Offset not in composite!");
|
|
const StructLayout *SL = TD.getStructLayout(STy);
|
|
|
|
// This loop terminates always on a 0 <= i < MemberOffsets.size()
|
|
unsigned i;
|
|
for (i = 0; i < SL->MemberOffsets.size()-1; ++i)
|
|
if (Offset >= SL->MemberOffsets[i] && Offset < SL->MemberOffsets[i+1])
|
|
break;
|
|
|
|
assert(Offset >= SL->MemberOffsets[i] &&
|
|
(i == SL->MemberOffsets.size()-1 || Offset < SL->MemberOffsets[i+1]));
|
|
|
|
// Make sure to save the current index...
|
|
Indices.push_back(ConstantUInt::get(Type::UByteTy, i));
|
|
Offset = SL->MemberOffsets[i];
|
|
return STy->getContainedType(i);
|
|
}
|
|
|
|
|
|
// getStructOffsetType - Return a vector of offsets that are to be used to index
|
|
// into the specified struct type to get as close as possible to index as we
|
|
// can. Note that it is possible that we cannot get exactly to Offset, in which
|
|
// case we update offset to be the offset we actually obtained. The resultant
|
|
// leaf type is returned.
|
|
//
|
|
// If StopEarly is set to true (the default), the first object with the
|
|
// specified type is returned, even if it is a struct type itself. In this
|
|
// case, this routine will not drill down to the leaf type. Set StopEarly to
|
|
// false if you want a leaf
|
|
//
|
|
const Type *getStructOffsetType(const Type *Ty, unsigned &Offset,
|
|
std::vector<Value*> &Indices,
|
|
bool StopEarly) {
|
|
if (Offset == 0 && StopEarly && !Indices.empty())
|
|
return Ty; // Return the leaf type
|
|
|
|
uint64_t ThisOffset;
|
|
const Type *NextType;
|
|
if (const StructType *STy = dyn_cast<StructType>(Ty)) {
|
|
ThisOffset = Offset;
|
|
NextType = getStructOffsetStep(STy, ThisOffset, Indices);
|
|
} else if (const ArrayType *ATy = dyn_cast<ArrayType>(Ty)) {
|
|
assert(Offset < TD.getTypeSize(ATy) && "Offset not in composite!");
|
|
|
|
NextType = ATy->getElementType();
|
|
unsigned ChildSize = TD.getTypeSize(NextType);
|
|
Indices.push_back(ConstantSInt::get(Type::LongTy, Offset/ChildSize));
|
|
ThisOffset = (Offset/ChildSize)*ChildSize;
|
|
} else {
|
|
Offset = 0; // Return the offset that we were able to acheive
|
|
return Ty; // Return the leaf type
|
|
}
|
|
|
|
unsigned SubOffs = Offset - ThisOffset;
|
|
const Type *LeafTy = getStructOffsetType(NextType, SubOffs,
|
|
Indices, StopEarly);
|
|
Offset = ThisOffset + SubOffs;
|
|
return LeafTy;
|
|
}
|
|
|
|
// ConvertableToGEP - This function returns true if the specified value V is
|
|
// a valid index into a pointer of type Ty. If it is valid, Idx is filled in
|
|
// with the values that would be appropriate to make this a getelementptr
|
|
// instruction. The type returned is the root type that the GEP would point to
|
|
//
|
|
const Type *ConvertableToGEP(const Type *Ty, Value *OffsetVal,
|
|
std::vector<Value*> &Indices,
|
|
BasicBlock::iterator *BI) {
|
|
const CompositeType *CompTy = dyn_cast<CompositeType>(Ty);
|
|
if (CompTy == 0) return 0;
|
|
|
|
// See if the cast is of an integer expression that is either a constant,
|
|
// or a value scaled by some amount with a possible offset.
|
|
//
|
|
ExprType Expr = ClassifyExpression(OffsetVal);
|
|
|
|
// Get the offset and scale values if they exists...
|
|
// A scale of zero with Expr.Var != 0 means a scale of 1.
|
|
//
|
|
int64_t Offset = Expr.Offset ? getConstantValue(Expr.Offset) : 0;
|
|
int64_t Scale = Expr.Scale ? getConstantValue(Expr.Scale) : 0;
|
|
|
|
if (Expr.Var && Scale == 0) Scale = 1; // Scale != 0 if Expr.Var != 0
|
|
|
|
// Loop over the Scale and Offset values, filling in the Indices vector for
|
|
// our final getelementptr instruction.
|
|
//
|
|
const Type *NextTy = CompTy;
|
|
do {
|
|
if (!isa<CompositeType>(NextTy))
|
|
return 0; // Type must not be ready for processing...
|
|
CompTy = cast<CompositeType>(NextTy);
|
|
|
|
if (const StructType *StructTy = dyn_cast<StructType>(CompTy)) {
|
|
// Step into the appropriate element of the structure...
|
|
uint64_t ActualOffset = (Offset < 0) ? 0 : (uint64_t)Offset;
|
|
NextTy = getStructOffsetStep(StructTy, ActualOffset, Indices);
|
|
Offset -= ActualOffset;
|
|
} else {
|
|
const Type *ElTy = cast<SequentialType>(CompTy)->getElementType();
|
|
if (!ElTy->isSized())
|
|
return 0; // Type is unreasonable... escape!
|
|
unsigned ElSize = TD.getTypeSize(ElTy);
|
|
int64_t ElSizeS = ElSize;
|
|
|
|
// See if the user is indexing into a different cell of this array...
|
|
if (Scale && (Scale >= ElSizeS || -Scale >= ElSizeS)) {
|
|
// A scale n*ElSize might occur if we are not stepping through
|
|
// array by one. In this case, we will have to insert math to munge
|
|
// the index.
|
|
//
|
|
int64_t ScaleAmt = Scale/ElSizeS;
|
|
if (Scale-ScaleAmt*ElSizeS)
|
|
return 0; // Didn't scale by a multiple of element size, bail out
|
|
Scale = 0; // Scale is consumed
|
|
|
|
int64_t Index = Offset/ElSize; // is zero unless Offset > ElSize
|
|
Offset -= Index*ElSize; // Consume part of the offset
|
|
|
|
if (BI) { // Generate code?
|
|
BasicBlock *BB = (*BI)->getParent();
|
|
if (Expr.Var->getType() != Type::LongTy)
|
|
Expr.Var = new CastInst(Expr.Var, Type::LongTy,
|
|
Expr.Var->getName()+"-idxcast", *BI);
|
|
|
|
if (ScaleAmt && ScaleAmt != 1) {
|
|
// If we have to scale up our index, do so now
|
|
Value *ScaleAmtVal = ConstantSInt::get(Type::LongTy, ScaleAmt);
|
|
Expr.Var = BinaryOperator::create(Instruction::Mul, Expr.Var,
|
|
ScaleAmtVal,
|
|
Expr.Var->getName()+"-scale",*BI);
|
|
}
|
|
|
|
if (Index) { // Add an offset to the index
|
|
Value *IndexAmt = ConstantSInt::get(Type::LongTy, Index);
|
|
Expr.Var = BinaryOperator::create(Instruction::Add, Expr.Var,
|
|
IndexAmt,
|
|
Expr.Var->getName()+"-offset",
|
|
*BI);
|
|
}
|
|
}
|
|
|
|
Indices.push_back(Expr.Var);
|
|
Expr.Var = 0;
|
|
} else if (Offset >= (int64_t)ElSize || -Offset >= (int64_t)ElSize) {
|
|
// Calculate the index that we are entering into the array cell with
|
|
uint64_t Index = Offset/ElSize;
|
|
Indices.push_back(ConstantSInt::get(Type::LongTy, Index));
|
|
Offset -= (int64_t)(Index*ElSize); // Consume part of the offset
|
|
|
|
} else if (isa<ArrayType>(CompTy) || Indices.empty()) {
|
|
// Must be indexing a small amount into the first cell of the array
|
|
// Just index into element zero of the array here.
|
|
//
|
|
Indices.push_back(ConstantSInt::get(Type::LongTy, 0));
|
|
} else {
|
|
return 0; // Hrm. wierd, can't handle this case. Bail
|
|
}
|
|
NextTy = ElTy;
|
|
}
|
|
} while (Offset || Scale); // Go until we're done!
|
|
|
|
return NextTy;
|
|
}
|