llvm/lib/Target/TargetData.cpp

611 lines
22 KiB
C++
Raw Normal View History

//===-- TargetData.cpp - Data size & alignment routines --------------------==//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines target properties related to datatype size/offset/alignment
// information.
//
// This structure should be created once, filled in if the defaults are not
// correct and then passed around by const&. None of the members functions
// require modification to the object.
//
//===----------------------------------------------------------------------===//
#include "llvm/Target/TargetData.h"
#include "llvm/Module.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Constants.h"
#include "llvm/Support/GetElementPtrTypeIterator.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/ManagedStatic.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/System/Mutex.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/StringExtras.h"
#include <algorithm>
#include <cstdlib>
using namespace llvm;
// Handle the Pass registration stuff necessary to use TargetData's.
// Register the default SparcV9 implementation...
static RegisterPass<TargetData> X("targetdata", "Target Data Layout", false,
true);
char TargetData::ID = 0;
//===----------------------------------------------------------------------===//
// Support for StructLayout
//===----------------------------------------------------------------------===//
StructLayout::StructLayout(const StructType *ST, const TargetData &TD) {
StructAlignment = 0;
StructSize = 0;
NumElements = ST->getNumElements();
// Loop over each of the elements, placing them in memory.
for (unsigned i = 0, e = NumElements; i != e; ++i) {
const Type *Ty = ST->getElementType(i);
unsigned TyAlign = ST->isPacked() ? 1 : TD.getABITypeAlignment(Ty);
// Add padding if necessary to align the data element properly.
if ((StructSize & (TyAlign-1)) != 0)
StructSize = TargetData::RoundUpAlignment(StructSize, TyAlign);
// Keep track of maximum alignment constraint.
StructAlignment = std::max(TyAlign, StructAlignment);
MemberOffsets[i] = StructSize;
StructSize += TD.getTypeAllocSize(Ty); // Consume space for this data item
}
// Empty structures have alignment of 1 byte.
if (StructAlignment == 0) StructAlignment = 1;
// Add padding to the end of the struct so that it could be put in an array
// and all array elements would be aligned correctly.
if ((StructSize & (StructAlignment-1)) != 0)
StructSize = TargetData::RoundUpAlignment(StructSize, StructAlignment);
}
/// getElementContainingOffset - Given a valid offset into the structure,
/// return the structure index that contains it.
unsigned StructLayout::getElementContainingOffset(uint64_t Offset) const {
const uint64_t *SI =
std::upper_bound(&MemberOffsets[0], &MemberOffsets[NumElements], Offset);
assert(SI != &MemberOffsets[0] && "Offset not in structure type!");
--SI;
assert(*SI <= Offset && "upper_bound didn't work");
assert((SI == &MemberOffsets[0] || *(SI-1) <= Offset) &&
(SI+1 == &MemberOffsets[NumElements] || *(SI+1) > Offset) &&
"Upper bound didn't work!");
// Multiple fields can have the same offset if any of them are zero sized.
// For example, in { i32, [0 x i32], i32 }, searching for offset 4 will stop
// at the i32 element, because it is the last element at that offset. This is
// the right one to return, because anything after it will have a higher
// offset, implying that this element is non-empty.
return SI-&MemberOffsets[0];
}
//===----------------------------------------------------------------------===//
// TargetAlignElem, TargetAlign support
//===----------------------------------------------------------------------===//
TargetAlignElem
TargetAlignElem::get(AlignTypeEnum align_type, unsigned char abi_align,
unsigned char pref_align, uint32_t bit_width) {
assert(abi_align <= pref_align && "Preferred alignment worse than ABI!");
TargetAlignElem retval;
retval.AlignType = align_type;
retval.ABIAlign = abi_align;
retval.PrefAlign = pref_align;
retval.TypeBitWidth = bit_width;
return retval;
}
bool
TargetAlignElem::operator==(const TargetAlignElem &rhs) const {
return (AlignType == rhs.AlignType
&& ABIAlign == rhs.ABIAlign
&& PrefAlign == rhs.PrefAlign
&& TypeBitWidth == rhs.TypeBitWidth);
}
std::ostream &
TargetAlignElem::dump(std::ostream &os) const {
return os << AlignType
<< TypeBitWidth
<< ":" << (int) (ABIAlign * 8)
<< ":" << (int) (PrefAlign * 8);
}
const TargetAlignElem TargetData::InvalidAlignmentElem =
TargetAlignElem::get((AlignTypeEnum) -1, 0, 0, 0);
//===----------------------------------------------------------------------===//
// TargetData Class Implementation
//===----------------------------------------------------------------------===//
/*!
A TargetDescription string consists of a sequence of hyphen-delimited
specifiers for target endianness, pointer size and alignments, and various
primitive type sizes and alignments. A typical string looks something like:
<br><br>
"E-p:32:32:32-i1:8:8-i8:8:8-i32:32:32-i64:32:64-f32:32:32-f64:32:64"
<br><br>
(note: this string is not fully specified and is only an example.)
\p
Alignments come in two flavors: ABI and preferred. ABI alignment (abi_align,
below) dictates how a type will be aligned within an aggregate and when used
as an argument. Preferred alignment (pref_align, below) determines a type's
alignment when emitted as a global.
\p
Specifier string details:
<br><br>
<i>[E|e]</i>: Endianness. "E" specifies a big-endian target data model, "e"
specifies a little-endian target data model.
<br><br>
<i>p:@verbatim<size>:<abi_align>:<pref_align>@endverbatim</i>: Pointer size,
ABI and preferred alignment.
<br><br>
<i>@verbatim<type><size>:<abi_align>:<pref_align>@endverbatim</i>: Numeric type
alignment. Type is
one of <i>i|f|v|a</i>, corresponding to integer, floating point, vector, or
aggregate. Size indicates the size, e.g., 32 or 64 bits.
\p
The default string, fully specified, is:
<br><br>
"E-p:64:64:64-a0:0:8-f32:32:32-f64:64:64"
"-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64"
"-v64:64:64-v128:128:128"
<br><br>
Note that in the case of aggregates, 0 is the default ABI and preferred
alignment. This is a special case, where the aggregate's computed worst-case
alignment will be used.
*/
void TargetData::init(const std::string &TargetDescription) {
std::string temp = TargetDescription;
LittleEndian = false;
PointerMemSize = 8;
PointerABIAlign = 8;
PointerPrefAlign = PointerABIAlign;
// Default alignments
setAlignment(INTEGER_ALIGN, 1, 1, 1); // i1
setAlignment(INTEGER_ALIGN, 1, 1, 8); // i8
setAlignment(INTEGER_ALIGN, 2, 2, 16); // i16
setAlignment(INTEGER_ALIGN, 4, 4, 32); // i32
setAlignment(INTEGER_ALIGN, 4, 8, 64); // i64
setAlignment(FLOAT_ALIGN, 4, 4, 32); // float
setAlignment(FLOAT_ALIGN, 8, 8, 64); // double
setAlignment(VECTOR_ALIGN, 8, 8, 64); // v2i32, v1i64, ...
setAlignment(VECTOR_ALIGN, 16, 16, 128); // v16i8, v8i16, v4i32, ...
setAlignment(AGGREGATE_ALIGN, 0, 8, 0); // struct
while (!temp.empty()) {
std::string token = getToken(temp, "-");
std::string arg0 = getToken(token, ":");
const char *p = arg0.c_str();
switch(*p) {
case 'E':
LittleEndian = false;
break;
case 'e':
LittleEndian = true;
break;
case 'p':
PointerMemSize = atoi(getToken(token,":").c_str()) / 8;
PointerABIAlign = atoi(getToken(token,":").c_str()) / 8;
PointerPrefAlign = atoi(getToken(token,":").c_str()) / 8;
if (PointerPrefAlign == 0)
PointerPrefAlign = PointerABIAlign;
break;
case 'i':
case 'v':
case 'f':
case 'a':
case 's': {
AlignTypeEnum align_type = STACK_ALIGN; // Dummy init, silence warning
switch(*p) {
case 'i': align_type = INTEGER_ALIGN; break;
case 'v': align_type = VECTOR_ALIGN; break;
case 'f': align_type = FLOAT_ALIGN; break;
case 'a': align_type = AGGREGATE_ALIGN; break;
case 's': align_type = STACK_ALIGN; break;
}
uint32_t size = (uint32_t) atoi(++p);
unsigned char abi_align = atoi(getToken(token, ":").c_str()) / 8;
unsigned char pref_align = atoi(getToken(token, ":").c_str()) / 8;
if (pref_align == 0)
pref_align = abi_align;
setAlignment(align_type, abi_align, pref_align, size);
break;
}
default:
break;
}
}
}
TargetData::TargetData(const Module *M)
: ImmutablePass(&ID) {
init(M->getDataLayout());
}
void
TargetData::setAlignment(AlignTypeEnum align_type, unsigned char abi_align,
unsigned char pref_align, uint32_t bit_width) {
assert(abi_align <= pref_align && "Preferred alignment worse than ABI!");
for (unsigned i = 0, e = Alignments.size(); i != e; ++i) {
if (Alignments[i].AlignType == align_type &&
Alignments[i].TypeBitWidth == bit_width) {
// Update the abi, preferred alignments.
Alignments[i].ABIAlign = abi_align;
Alignments[i].PrefAlign = pref_align;
return;
}
}
Alignments.push_back(TargetAlignElem::get(align_type, abi_align,
pref_align, bit_width));
}
/// getAlignmentInfo - Return the alignment (either ABI if ABIInfo = true or
/// preferred if ABIInfo = false) the target wants for the specified datatype.
unsigned TargetData::getAlignmentInfo(AlignTypeEnum AlignType,
uint32_t BitWidth, bool ABIInfo,
const Type *Ty) const {
// Check to see if we have an exact match and remember the best match we see.
int BestMatchIdx = -1;
int LargestInt = -1;
for (unsigned i = 0, e = Alignments.size(); i != e; ++i) {
if (Alignments[i].AlignType == AlignType &&
Alignments[i].TypeBitWidth == BitWidth)
return ABIInfo ? Alignments[i].ABIAlign : Alignments[i].PrefAlign;
// The best match so far depends on what we're looking for.
if (AlignType == VECTOR_ALIGN && Alignments[i].AlignType == VECTOR_ALIGN) {
// If this is a specification for a smaller vector type, we will fall back
// to it. This happens because <128 x double> can be implemented in terms
// of 64 <2 x double>.
if (Alignments[i].TypeBitWidth < BitWidth) {
// Verify that we pick the biggest of the fallbacks.
if (BestMatchIdx == -1 ||
Alignments[BestMatchIdx].TypeBitWidth < Alignments[i].TypeBitWidth)
BestMatchIdx = i;
}
} else if (AlignType == INTEGER_ALIGN &&
Alignments[i].AlignType == INTEGER_ALIGN) {
// The "best match" for integers is the smallest size that is larger than
// the BitWidth requested.
if (Alignments[i].TypeBitWidth > BitWidth && (BestMatchIdx == -1 ||
Alignments[i].TypeBitWidth < Alignments[BestMatchIdx].TypeBitWidth))
BestMatchIdx = i;
// However, if there isn't one that's larger, then we must use the
// largest one we have (see below)
if (LargestInt == -1 ||
Alignments[i].TypeBitWidth > Alignments[LargestInt].TypeBitWidth)
LargestInt = i;
}
}
// Okay, we didn't find an exact solution. Fall back here depending on what
// is being looked for.
if (BestMatchIdx == -1) {
// If we didn't find an integer alignment, fall back on most conservative.
if (AlignType == INTEGER_ALIGN) {
BestMatchIdx = LargestInt;
} else {
assert(AlignType == VECTOR_ALIGN && "Unknown alignment type!");
// If we didn't find a vector size that is smaller or equal to this type,
// then we will end up scalarizing this to its element type. Just return
// the alignment of the element.
return getAlignment(cast<VectorType>(Ty)->getElementType(), ABIInfo);
}
}
// Since we got a "best match" index, just return it.
return ABIInfo ? Alignments[BestMatchIdx].ABIAlign
: Alignments[BestMatchIdx].PrefAlign;
}
namespace {
/// LayoutInfo - The lazy cache of structure layout information maintained by
/// TargetData. Note that the struct types must have been free'd before
/// llvm_shutdown is called (and thus this is deallocated) because all the
/// targets with cached elements should have been destroyed.
///
typedef std::pair<const TargetData*,const StructType*> LayoutKey;
struct DenseMapLayoutKeyInfo {
static inline LayoutKey getEmptyKey() { return LayoutKey(0, 0); }
static inline LayoutKey getTombstoneKey() {
return LayoutKey((TargetData*)(intptr_t)-1, 0);
}
static unsigned getHashValue(const LayoutKey &Val) {
return DenseMapInfo<void*>::getHashValue(Val.first) ^
DenseMapInfo<void*>::getHashValue(Val.second);
}
static bool isEqual(const LayoutKey &LHS, const LayoutKey &RHS) {
return LHS == RHS;
}
static bool isPod() { return true; }
};
typedef DenseMap<LayoutKey, StructLayout*, DenseMapLayoutKeyInfo> LayoutInfoTy;
}
static ManagedStatic<LayoutInfoTy> LayoutInfo;
static ManagedStatic<sys::SmartMutex<true> > LayoutLock;
TargetData::~TargetData() {
if (!LayoutInfo.isConstructed())
return;
sys::SmartScopedLock<true> Lock(*LayoutLock);
// Remove any layouts for this TD.
LayoutInfoTy &TheMap = *LayoutInfo;
for (LayoutInfoTy::iterator I = TheMap.begin(), E = TheMap.end(); I != E; ) {
if (I->first.first == this) {
I->second->~StructLayout();
free(I->second);
TheMap.erase(I++);
} else {
++I;
}
}
}
const StructLayout *TargetData::getStructLayout(const StructType *Ty) const {
LayoutInfoTy &TheMap = *LayoutInfo;
sys::SmartScopedLock<true> Lock(*LayoutLock);
StructLayout *&SL = TheMap[LayoutKey(this, Ty)];
if (SL) return SL;
// Otherwise, create the struct layout. Because it is variable length, we
// malloc it, then use placement new.
int NumElts = Ty->getNumElements();
StructLayout *L =
(StructLayout *)malloc(sizeof(StructLayout)+(NumElts-1)*sizeof(uint64_t));
// Set SL before calling StructLayout's ctor. The ctor could cause other
// entries to be added to TheMap, invalidating our reference.
SL = L;
new (L) StructLayout(Ty, *this);
return L;
}
/// InvalidateStructLayoutInfo - TargetData speculatively caches StructLayout
/// objects. If a TargetData object is alive when types are being refined and
/// removed, this method must be called whenever a StructType is removed to
/// avoid a dangling pointer in this cache.
void TargetData::InvalidateStructLayoutInfo(const StructType *Ty) const {
if (!LayoutInfo.isConstructed()) return; // No cache.
sys::SmartScopedLock<true> Lock(*LayoutLock);
LayoutInfoTy::iterator I = LayoutInfo->find(LayoutKey(this, Ty));
if (I == LayoutInfo->end()) return;
I->second->~StructLayout();
free(I->second);
LayoutInfo->erase(I);
}
std::string TargetData::getStringRepresentation() const {
std::string repr;
repr.append(LittleEndian ? "e" : "E");
repr.append("-p:").append(itostr((int64_t) (PointerMemSize * 8))).
append(":").append(itostr((int64_t) (PointerABIAlign * 8))).
append(":").append(itostr((int64_t) (PointerPrefAlign * 8)));
for (align_const_iterator I = Alignments.begin();
I != Alignments.end();
++I) {
repr.append("-").append(1, (char) I->AlignType).
append(utostr((int64_t) I->TypeBitWidth)).
append(":").append(utostr((uint64_t) (I->ABIAlign * 8))).
append(":").append(utostr((uint64_t) (I->PrefAlign * 8)));
}
return repr;
}
Executive summary: getTypeSize -> getTypeStoreSize / getABITypeSize. The meaning of getTypeSize was not clear - clarifying it is important now that we have x86 long double and arbitrary precision integers. The issue with long double is that it requires 80 bits, and this is not a multiple of its alignment. This gives a primitive type for which getTypeSize differed from getABITypeSize. For arbitrary precision integers it is even worse: there is the minimum number of bits needed to hold the type (eg: 36 for an i36), the maximum number of bits that will be overwriten when storing the type (40 bits for i36) and the ABI size (i.e. the storage size rounded up to a multiple of the alignment; 64 bits for i36). This patch removes getTypeSize (not really - it is still there but deprecated to allow for a gradual transition). Instead there is: (1) getTypeSizeInBits - a number of bits that suffices to hold all values of the type. For a primitive type, this is the minimum number of bits. For an i36 this is 36 bits. For x86 long double it is 80. This corresponds to gcc's TYPE_PRECISION. (2) getTypeStoreSizeInBits - the maximum number of bits that is written when storing the type (or read when reading it). For an i36 this is 40 bits, for an x86 long double it is 80 bits. This is the size alias analysis is interested in (getTypeStoreSize returns the number of bytes). There doesn't seem to be anything corresponding to this in gcc. (3) getABITypeSizeInBits - this is getTypeStoreSizeInBits rounded up to a multiple of the alignment. For an i36 this is 64, for an x86 long double this is 96 or 128 depending on the OS. This is the spacing between consecutive elements when you form an array out of this type (getABITypeSize returns the number of bytes). This is TYPE_SIZE in gcc. Since successive elements in a SequentialType (arrays, pointers and vectors) need to be aligned, the spacing between them will be given by getABITypeSize. This means that the size of an array is the length times the getABITypeSize. It also means that GEP computations need to use getABITypeSize when computing offsets. Furthermore, if an alloca allocates several elements at once then these too need to be aligned, so the size of the alloca has to be the number of elements multiplied by getABITypeSize. Logically speaking this doesn't have to be the case when allocating just one element, but it is simpler to also use getABITypeSize in this case. So alloca's and mallocs should use getABITypeSize. Finally, since gcc's only notion of size is that given by getABITypeSize, if you want to output assembler etc the same as gcc then getABITypeSize is the size you want. Since a store will overwrite no more than getTypeStoreSize bytes, and a read will read no more than that many bytes, this is the notion of size appropriate for alias analysis calculations. In this patch I have corrected all type size uses except some of those in ScalarReplAggregates, lib/Codegen, lib/Target (the hard cases). I will get around to auditing these too at some point, but I could do with some help. Finally, I made one change which I think wise but others might consider pointless and suboptimal: in an unpacked struct the amount of space allocated for a field is now given by the ABI size rather than getTypeStoreSize. I did this because every other place that reserves memory for a type (eg: alloca) now uses getABITypeSize, and I didn't want to make an exception for unpacked structs, i.e. I did it to make things more uniform. This only effects structs containing long doubles and arbitrary precision integers. If someone wants to pack these types more tightly they can always use a packed struct. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43620 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-01 20:53:16 +00:00
uint64_t TargetData::getTypeSizeInBits(const Type *Ty) const {
assert(Ty->isSized() && "Cannot getTypeInfo() on a type that is unsized!");
switch (Ty->getTypeID()) {
case Type::LabelTyID:
case Type::PointerTyID:
Executive summary: getTypeSize -> getTypeStoreSize / getABITypeSize. The meaning of getTypeSize was not clear - clarifying it is important now that we have x86 long double and arbitrary precision integers. The issue with long double is that it requires 80 bits, and this is not a multiple of its alignment. This gives a primitive type for which getTypeSize differed from getABITypeSize. For arbitrary precision integers it is even worse: there is the minimum number of bits needed to hold the type (eg: 36 for an i36), the maximum number of bits that will be overwriten when storing the type (40 bits for i36) and the ABI size (i.e. the storage size rounded up to a multiple of the alignment; 64 bits for i36). This patch removes getTypeSize (not really - it is still there but deprecated to allow for a gradual transition). Instead there is: (1) getTypeSizeInBits - a number of bits that suffices to hold all values of the type. For a primitive type, this is the minimum number of bits. For an i36 this is 36 bits. For x86 long double it is 80. This corresponds to gcc's TYPE_PRECISION. (2) getTypeStoreSizeInBits - the maximum number of bits that is written when storing the type (or read when reading it). For an i36 this is 40 bits, for an x86 long double it is 80 bits. This is the size alias analysis is interested in (getTypeStoreSize returns the number of bytes). There doesn't seem to be anything corresponding to this in gcc. (3) getABITypeSizeInBits - this is getTypeStoreSizeInBits rounded up to a multiple of the alignment. For an i36 this is 64, for an x86 long double this is 96 or 128 depending on the OS. This is the spacing between consecutive elements when you form an array out of this type (getABITypeSize returns the number of bytes). This is TYPE_SIZE in gcc. Since successive elements in a SequentialType (arrays, pointers and vectors) need to be aligned, the spacing between them will be given by getABITypeSize. This means that the size of an array is the length times the getABITypeSize. It also means that GEP computations need to use getABITypeSize when computing offsets. Furthermore, if an alloca allocates several elements at once then these too need to be aligned, so the size of the alloca has to be the number of elements multiplied by getABITypeSize. Logically speaking this doesn't have to be the case when allocating just one element, but it is simpler to also use getABITypeSize in this case. So alloca's and mallocs should use getABITypeSize. Finally, since gcc's only notion of size is that given by getABITypeSize, if you want to output assembler etc the same as gcc then getABITypeSize is the size you want. Since a store will overwrite no more than getTypeStoreSize bytes, and a read will read no more than that many bytes, this is the notion of size appropriate for alias analysis calculations. In this patch I have corrected all type size uses except some of those in ScalarReplAggregates, lib/Codegen, lib/Target (the hard cases). I will get around to auditing these too at some point, but I could do with some help. Finally, I made one change which I think wise but others might consider pointless and suboptimal: in an unpacked struct the amount of space allocated for a field is now given by the ABI size rather than getTypeStoreSize. I did this because every other place that reserves memory for a type (eg: alloca) now uses getABITypeSize, and I didn't want to make an exception for unpacked structs, i.e. I did it to make things more uniform. This only effects structs containing long doubles and arbitrary precision integers. If someone wants to pack these types more tightly they can always use a packed struct. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43620 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-01 20:53:16 +00:00
return getPointerSizeInBits();
case Type::ArrayTyID: {
const ArrayType *ATy = cast<ArrayType>(Ty);
return getTypeAllocSizeInBits(ATy->getElementType())*ATy->getNumElements();
}
case Type::StructTyID:
// Get the layout annotation... which is lazily created on demand.
return getStructLayout(cast<StructType>(Ty))->getSizeInBits();
Executive summary: getTypeSize -> getTypeStoreSize / getABITypeSize. The meaning of getTypeSize was not clear - clarifying it is important now that we have x86 long double and arbitrary precision integers. The issue with long double is that it requires 80 bits, and this is not a multiple of its alignment. This gives a primitive type for which getTypeSize differed from getABITypeSize. For arbitrary precision integers it is even worse: there is the minimum number of bits needed to hold the type (eg: 36 for an i36), the maximum number of bits that will be overwriten when storing the type (40 bits for i36) and the ABI size (i.e. the storage size rounded up to a multiple of the alignment; 64 bits for i36). This patch removes getTypeSize (not really - it is still there but deprecated to allow for a gradual transition). Instead there is: (1) getTypeSizeInBits - a number of bits that suffices to hold all values of the type. For a primitive type, this is the minimum number of bits. For an i36 this is 36 bits. For x86 long double it is 80. This corresponds to gcc's TYPE_PRECISION. (2) getTypeStoreSizeInBits - the maximum number of bits that is written when storing the type (or read when reading it). For an i36 this is 40 bits, for an x86 long double it is 80 bits. This is the size alias analysis is interested in (getTypeStoreSize returns the number of bytes). There doesn't seem to be anything corresponding to this in gcc. (3) getABITypeSizeInBits - this is getTypeStoreSizeInBits rounded up to a multiple of the alignment. For an i36 this is 64, for an x86 long double this is 96 or 128 depending on the OS. This is the spacing between consecutive elements when you form an array out of this type (getABITypeSize returns the number of bytes). This is TYPE_SIZE in gcc. Since successive elements in a SequentialType (arrays, pointers and vectors) need to be aligned, the spacing between them will be given by getABITypeSize. This means that the size of an array is the length times the getABITypeSize. It also means that GEP computations need to use getABITypeSize when computing offsets. Furthermore, if an alloca allocates several elements at once then these too need to be aligned, so the size of the alloca has to be the number of elements multiplied by getABITypeSize. Logically speaking this doesn't have to be the case when allocating just one element, but it is simpler to also use getABITypeSize in this case. So alloca's and mallocs should use getABITypeSize. Finally, since gcc's only notion of size is that given by getABITypeSize, if you want to output assembler etc the same as gcc then getABITypeSize is the size you want. Since a store will overwrite no more than getTypeStoreSize bytes, and a read will read no more than that many bytes, this is the notion of size appropriate for alias analysis calculations. In this patch I have corrected all type size uses except some of those in ScalarReplAggregates, lib/Codegen, lib/Target (the hard cases). I will get around to auditing these too at some point, but I could do with some help. Finally, I made one change which I think wise but others might consider pointless and suboptimal: in an unpacked struct the amount of space allocated for a field is now given by the ABI size rather than getTypeStoreSize. I did this because every other place that reserves memory for a type (eg: alloca) now uses getABITypeSize, and I didn't want to make an exception for unpacked structs, i.e. I did it to make things more uniform. This only effects structs containing long doubles and arbitrary precision integers. If someone wants to pack these types more tightly they can always use a packed struct. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43620 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-01 20:53:16 +00:00
case Type::IntegerTyID:
return cast<IntegerType>(Ty)->getBitWidth();
case Type::VoidTyID:
Executive summary: getTypeSize -> getTypeStoreSize / getABITypeSize. The meaning of getTypeSize was not clear - clarifying it is important now that we have x86 long double and arbitrary precision integers. The issue with long double is that it requires 80 bits, and this is not a multiple of its alignment. This gives a primitive type for which getTypeSize differed from getABITypeSize. For arbitrary precision integers it is even worse: there is the minimum number of bits needed to hold the type (eg: 36 for an i36), the maximum number of bits that will be overwriten when storing the type (40 bits for i36) and the ABI size (i.e. the storage size rounded up to a multiple of the alignment; 64 bits for i36). This patch removes getTypeSize (not really - it is still there but deprecated to allow for a gradual transition). Instead there is: (1) getTypeSizeInBits - a number of bits that suffices to hold all values of the type. For a primitive type, this is the minimum number of bits. For an i36 this is 36 bits. For x86 long double it is 80. This corresponds to gcc's TYPE_PRECISION. (2) getTypeStoreSizeInBits - the maximum number of bits that is written when storing the type (or read when reading it). For an i36 this is 40 bits, for an x86 long double it is 80 bits. This is the size alias analysis is interested in (getTypeStoreSize returns the number of bytes). There doesn't seem to be anything corresponding to this in gcc. (3) getABITypeSizeInBits - this is getTypeStoreSizeInBits rounded up to a multiple of the alignment. For an i36 this is 64, for an x86 long double this is 96 or 128 depending on the OS. This is the spacing between consecutive elements when you form an array out of this type (getABITypeSize returns the number of bytes). This is TYPE_SIZE in gcc. Since successive elements in a SequentialType (arrays, pointers and vectors) need to be aligned, the spacing between them will be given by getABITypeSize. This means that the size of an array is the length times the getABITypeSize. It also means that GEP computations need to use getABITypeSize when computing offsets. Furthermore, if an alloca allocates several elements at once then these too need to be aligned, so the size of the alloca has to be the number of elements multiplied by getABITypeSize. Logically speaking this doesn't have to be the case when allocating just one element, but it is simpler to also use getABITypeSize in this case. So alloca's and mallocs should use getABITypeSize. Finally, since gcc's only notion of size is that given by getABITypeSize, if you want to output assembler etc the same as gcc then getABITypeSize is the size you want. Since a store will overwrite no more than getTypeStoreSize bytes, and a read will read no more than that many bytes, this is the notion of size appropriate for alias analysis calculations. In this patch I have corrected all type size uses except some of those in ScalarReplAggregates, lib/Codegen, lib/Target (the hard cases). I will get around to auditing these too at some point, but I could do with some help. Finally, I made one change which I think wise but others might consider pointless and suboptimal: in an unpacked struct the amount of space allocated for a field is now given by the ABI size rather than getTypeStoreSize. I did this because every other place that reserves memory for a type (eg: alloca) now uses getABITypeSize, and I didn't want to make an exception for unpacked structs, i.e. I did it to make things more uniform. This only effects structs containing long doubles and arbitrary precision integers. If someone wants to pack these types more tightly they can always use a packed struct. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43620 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-01 20:53:16 +00:00
return 8;
case Type::FloatTyID:
Executive summary: getTypeSize -> getTypeStoreSize / getABITypeSize. The meaning of getTypeSize was not clear - clarifying it is important now that we have x86 long double and arbitrary precision integers. The issue with long double is that it requires 80 bits, and this is not a multiple of its alignment. This gives a primitive type for which getTypeSize differed from getABITypeSize. For arbitrary precision integers it is even worse: there is the minimum number of bits needed to hold the type (eg: 36 for an i36), the maximum number of bits that will be overwriten when storing the type (40 bits for i36) and the ABI size (i.e. the storage size rounded up to a multiple of the alignment; 64 bits for i36). This patch removes getTypeSize (not really - it is still there but deprecated to allow for a gradual transition). Instead there is: (1) getTypeSizeInBits - a number of bits that suffices to hold all values of the type. For a primitive type, this is the minimum number of bits. For an i36 this is 36 bits. For x86 long double it is 80. This corresponds to gcc's TYPE_PRECISION. (2) getTypeStoreSizeInBits - the maximum number of bits that is written when storing the type (or read when reading it). For an i36 this is 40 bits, for an x86 long double it is 80 bits. This is the size alias analysis is interested in (getTypeStoreSize returns the number of bytes). There doesn't seem to be anything corresponding to this in gcc. (3) getABITypeSizeInBits - this is getTypeStoreSizeInBits rounded up to a multiple of the alignment. For an i36 this is 64, for an x86 long double this is 96 or 128 depending on the OS. This is the spacing between consecutive elements when you form an array out of this type (getABITypeSize returns the number of bytes). This is TYPE_SIZE in gcc. Since successive elements in a SequentialType (arrays, pointers and vectors) need to be aligned, the spacing between them will be given by getABITypeSize. This means that the size of an array is the length times the getABITypeSize. It also means that GEP computations need to use getABITypeSize when computing offsets. Furthermore, if an alloca allocates several elements at once then these too need to be aligned, so the size of the alloca has to be the number of elements multiplied by getABITypeSize. Logically speaking this doesn't have to be the case when allocating just one element, but it is simpler to also use getABITypeSize in this case. So alloca's and mallocs should use getABITypeSize. Finally, since gcc's only notion of size is that given by getABITypeSize, if you want to output assembler etc the same as gcc then getABITypeSize is the size you want. Since a store will overwrite no more than getTypeStoreSize bytes, and a read will read no more than that many bytes, this is the notion of size appropriate for alias analysis calculations. In this patch I have corrected all type size uses except some of those in ScalarReplAggregates, lib/Codegen, lib/Target (the hard cases). I will get around to auditing these too at some point, but I could do with some help. Finally, I made one change which I think wise but others might consider pointless and suboptimal: in an unpacked struct the amount of space allocated for a field is now given by the ABI size rather than getTypeStoreSize. I did this because every other place that reserves memory for a type (eg: alloca) now uses getABITypeSize, and I didn't want to make an exception for unpacked structs, i.e. I did it to make things more uniform. This only effects structs containing long doubles and arbitrary precision integers. If someone wants to pack these types more tightly they can always use a packed struct. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43620 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-01 20:53:16 +00:00
return 32;
case Type::DoubleTyID:
Executive summary: getTypeSize -> getTypeStoreSize / getABITypeSize. The meaning of getTypeSize was not clear - clarifying it is important now that we have x86 long double and arbitrary precision integers. The issue with long double is that it requires 80 bits, and this is not a multiple of its alignment. This gives a primitive type for which getTypeSize differed from getABITypeSize. For arbitrary precision integers it is even worse: there is the minimum number of bits needed to hold the type (eg: 36 for an i36), the maximum number of bits that will be overwriten when storing the type (40 bits for i36) and the ABI size (i.e. the storage size rounded up to a multiple of the alignment; 64 bits for i36). This patch removes getTypeSize (not really - it is still there but deprecated to allow for a gradual transition). Instead there is: (1) getTypeSizeInBits - a number of bits that suffices to hold all values of the type. For a primitive type, this is the minimum number of bits. For an i36 this is 36 bits. For x86 long double it is 80. This corresponds to gcc's TYPE_PRECISION. (2) getTypeStoreSizeInBits - the maximum number of bits that is written when storing the type (or read when reading it). For an i36 this is 40 bits, for an x86 long double it is 80 bits. This is the size alias analysis is interested in (getTypeStoreSize returns the number of bytes). There doesn't seem to be anything corresponding to this in gcc. (3) getABITypeSizeInBits - this is getTypeStoreSizeInBits rounded up to a multiple of the alignment. For an i36 this is 64, for an x86 long double this is 96 or 128 depending on the OS. This is the spacing between consecutive elements when you form an array out of this type (getABITypeSize returns the number of bytes). This is TYPE_SIZE in gcc. Since successive elements in a SequentialType (arrays, pointers and vectors) need to be aligned, the spacing between them will be given by getABITypeSize. This means that the size of an array is the length times the getABITypeSize. It also means that GEP computations need to use getABITypeSize when computing offsets. Furthermore, if an alloca allocates several elements at once then these too need to be aligned, so the size of the alloca has to be the number of elements multiplied by getABITypeSize. Logically speaking this doesn't have to be the case when allocating just one element, but it is simpler to also use getABITypeSize in this case. So alloca's and mallocs should use getABITypeSize. Finally, since gcc's only notion of size is that given by getABITypeSize, if you want to output assembler etc the same as gcc then getABITypeSize is the size you want. Since a store will overwrite no more than getTypeStoreSize bytes, and a read will read no more than that many bytes, this is the notion of size appropriate for alias analysis calculations. In this patch I have corrected all type size uses except some of those in ScalarReplAggregates, lib/Codegen, lib/Target (the hard cases). I will get around to auditing these too at some point, but I could do with some help. Finally, I made one change which I think wise but others might consider pointless and suboptimal: in an unpacked struct the amount of space allocated for a field is now given by the ABI size rather than getTypeStoreSize. I did this because every other place that reserves memory for a type (eg: alloca) now uses getABITypeSize, and I didn't want to make an exception for unpacked structs, i.e. I did it to make things more uniform. This only effects structs containing long doubles and arbitrary precision integers. If someone wants to pack these types more tightly they can always use a packed struct. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43620 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-01 20:53:16 +00:00
return 64;
case Type::PPC_FP128TyID:
case Type::FP128TyID:
Executive summary: getTypeSize -> getTypeStoreSize / getABITypeSize. The meaning of getTypeSize was not clear - clarifying it is important now that we have x86 long double and arbitrary precision integers. The issue with long double is that it requires 80 bits, and this is not a multiple of its alignment. This gives a primitive type for which getTypeSize differed from getABITypeSize. For arbitrary precision integers it is even worse: there is the minimum number of bits needed to hold the type (eg: 36 for an i36), the maximum number of bits that will be overwriten when storing the type (40 bits for i36) and the ABI size (i.e. the storage size rounded up to a multiple of the alignment; 64 bits for i36). This patch removes getTypeSize (not really - it is still there but deprecated to allow for a gradual transition). Instead there is: (1) getTypeSizeInBits - a number of bits that suffices to hold all values of the type. For a primitive type, this is the minimum number of bits. For an i36 this is 36 bits. For x86 long double it is 80. This corresponds to gcc's TYPE_PRECISION. (2) getTypeStoreSizeInBits - the maximum number of bits that is written when storing the type (or read when reading it). For an i36 this is 40 bits, for an x86 long double it is 80 bits. This is the size alias analysis is interested in (getTypeStoreSize returns the number of bytes). There doesn't seem to be anything corresponding to this in gcc. (3) getABITypeSizeInBits - this is getTypeStoreSizeInBits rounded up to a multiple of the alignment. For an i36 this is 64, for an x86 long double this is 96 or 128 depending on the OS. This is the spacing between consecutive elements when you form an array out of this type (getABITypeSize returns the number of bytes). This is TYPE_SIZE in gcc. Since successive elements in a SequentialType (arrays, pointers and vectors) need to be aligned, the spacing between them will be given by getABITypeSize. This means that the size of an array is the length times the getABITypeSize. It also means that GEP computations need to use getABITypeSize when computing offsets. Furthermore, if an alloca allocates several elements at once then these too need to be aligned, so the size of the alloca has to be the number of elements multiplied by getABITypeSize. Logically speaking this doesn't have to be the case when allocating just one element, but it is simpler to also use getABITypeSize in this case. So alloca's and mallocs should use getABITypeSize. Finally, since gcc's only notion of size is that given by getABITypeSize, if you want to output assembler etc the same as gcc then getABITypeSize is the size you want. Since a store will overwrite no more than getTypeStoreSize bytes, and a read will read no more than that many bytes, this is the notion of size appropriate for alias analysis calculations. In this patch I have corrected all type size uses except some of those in ScalarReplAggregates, lib/Codegen, lib/Target (the hard cases). I will get around to auditing these too at some point, but I could do with some help. Finally, I made one change which I think wise but others might consider pointless and suboptimal: in an unpacked struct the amount of space allocated for a field is now given by the ABI size rather than getTypeStoreSize. I did this because every other place that reserves memory for a type (eg: alloca) now uses getABITypeSize, and I didn't want to make an exception for unpacked structs, i.e. I did it to make things more uniform. This only effects structs containing long doubles and arbitrary precision integers. If someone wants to pack these types more tightly they can always use a packed struct. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43620 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-01 20:53:16 +00:00
return 128;
// In memory objects this is always aligned to a higher boundary, but
Executive summary: getTypeSize -> getTypeStoreSize / getABITypeSize. The meaning of getTypeSize was not clear - clarifying it is important now that we have x86 long double and arbitrary precision integers. The issue with long double is that it requires 80 bits, and this is not a multiple of its alignment. This gives a primitive type for which getTypeSize differed from getABITypeSize. For arbitrary precision integers it is even worse: there is the minimum number of bits needed to hold the type (eg: 36 for an i36), the maximum number of bits that will be overwriten when storing the type (40 bits for i36) and the ABI size (i.e. the storage size rounded up to a multiple of the alignment; 64 bits for i36). This patch removes getTypeSize (not really - it is still there but deprecated to allow for a gradual transition). Instead there is: (1) getTypeSizeInBits - a number of bits that suffices to hold all values of the type. For a primitive type, this is the minimum number of bits. For an i36 this is 36 bits. For x86 long double it is 80. This corresponds to gcc's TYPE_PRECISION. (2) getTypeStoreSizeInBits - the maximum number of bits that is written when storing the type (or read when reading it). For an i36 this is 40 bits, for an x86 long double it is 80 bits. This is the size alias analysis is interested in (getTypeStoreSize returns the number of bytes). There doesn't seem to be anything corresponding to this in gcc. (3) getABITypeSizeInBits - this is getTypeStoreSizeInBits rounded up to a multiple of the alignment. For an i36 this is 64, for an x86 long double this is 96 or 128 depending on the OS. This is the spacing between consecutive elements when you form an array out of this type (getABITypeSize returns the number of bytes). This is TYPE_SIZE in gcc. Since successive elements in a SequentialType (arrays, pointers and vectors) need to be aligned, the spacing between them will be given by getABITypeSize. This means that the size of an array is the length times the getABITypeSize. It also means that GEP computations need to use getABITypeSize when computing offsets. Furthermore, if an alloca allocates several elements at once then these too need to be aligned, so the size of the alloca has to be the number of elements multiplied by getABITypeSize. Logically speaking this doesn't have to be the case when allocating just one element, but it is simpler to also use getABITypeSize in this case. So alloca's and mallocs should use getABITypeSize. Finally, since gcc's only notion of size is that given by getABITypeSize, if you want to output assembler etc the same as gcc then getABITypeSize is the size you want. Since a store will overwrite no more than getTypeStoreSize bytes, and a read will read no more than that many bytes, this is the notion of size appropriate for alias analysis calculations. In this patch I have corrected all type size uses except some of those in ScalarReplAggregates, lib/Codegen, lib/Target (the hard cases). I will get around to auditing these too at some point, but I could do with some help. Finally, I made one change which I think wise but others might consider pointless and suboptimal: in an unpacked struct the amount of space allocated for a field is now given by the ABI size rather than getTypeStoreSize. I did this because every other place that reserves memory for a type (eg: alloca) now uses getABITypeSize, and I didn't want to make an exception for unpacked structs, i.e. I did it to make things more uniform. This only effects structs containing long doubles and arbitrary precision integers. If someone wants to pack these types more tightly they can always use a packed struct. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43620 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-01 20:53:16 +00:00
// only 80 bits contain information.
case Type::X86_FP80TyID:
Executive summary: getTypeSize -> getTypeStoreSize / getABITypeSize. The meaning of getTypeSize was not clear - clarifying it is important now that we have x86 long double and arbitrary precision integers. The issue with long double is that it requires 80 bits, and this is not a multiple of its alignment. This gives a primitive type for which getTypeSize differed from getABITypeSize. For arbitrary precision integers it is even worse: there is the minimum number of bits needed to hold the type (eg: 36 for an i36), the maximum number of bits that will be overwriten when storing the type (40 bits for i36) and the ABI size (i.e. the storage size rounded up to a multiple of the alignment; 64 bits for i36). This patch removes getTypeSize (not really - it is still there but deprecated to allow for a gradual transition). Instead there is: (1) getTypeSizeInBits - a number of bits that suffices to hold all values of the type. For a primitive type, this is the minimum number of bits. For an i36 this is 36 bits. For x86 long double it is 80. This corresponds to gcc's TYPE_PRECISION. (2) getTypeStoreSizeInBits - the maximum number of bits that is written when storing the type (or read when reading it). For an i36 this is 40 bits, for an x86 long double it is 80 bits. This is the size alias analysis is interested in (getTypeStoreSize returns the number of bytes). There doesn't seem to be anything corresponding to this in gcc. (3) getABITypeSizeInBits - this is getTypeStoreSizeInBits rounded up to a multiple of the alignment. For an i36 this is 64, for an x86 long double this is 96 or 128 depending on the OS. This is the spacing between consecutive elements when you form an array out of this type (getABITypeSize returns the number of bytes). This is TYPE_SIZE in gcc. Since successive elements in a SequentialType (arrays, pointers and vectors) need to be aligned, the spacing between them will be given by getABITypeSize. This means that the size of an array is the length times the getABITypeSize. It also means that GEP computations need to use getABITypeSize when computing offsets. Furthermore, if an alloca allocates several elements at once then these too need to be aligned, so the size of the alloca has to be the number of elements multiplied by getABITypeSize. Logically speaking this doesn't have to be the case when allocating just one element, but it is simpler to also use getABITypeSize in this case. So alloca's and mallocs should use getABITypeSize. Finally, since gcc's only notion of size is that given by getABITypeSize, if you want to output assembler etc the same as gcc then getABITypeSize is the size you want. Since a store will overwrite no more than getTypeStoreSize bytes, and a read will read no more than that many bytes, this is the notion of size appropriate for alias analysis calculations. In this patch I have corrected all type size uses except some of those in ScalarReplAggregates, lib/Codegen, lib/Target (the hard cases). I will get around to auditing these too at some point, but I could do with some help. Finally, I made one change which I think wise but others might consider pointless and suboptimal: in an unpacked struct the amount of space allocated for a field is now given by the ABI size rather than getTypeStoreSize. I did this because every other place that reserves memory for a type (eg: alloca) now uses getABITypeSize, and I didn't want to make an exception for unpacked structs, i.e. I did it to make things more uniform. This only effects structs containing long doubles and arbitrary precision integers. If someone wants to pack these types more tightly they can always use a packed struct. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43620 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-01 20:53:16 +00:00
return 80;
case Type::VectorTyID:
return cast<VectorType>(Ty)->getBitWidth();
default:
llvm_unreachable("TargetData::getTypeSizeInBits(): Unsupported type");
break;
}
return 0;
}
/*!
\param abi_or_pref Flag that determines which alignment is returned. true
returns the ABI alignment, false returns the preferred alignment.
\param Ty The underlying type for which alignment is determined.
Get the ABI (\a abi_or_pref == true) or preferred alignment (\a abi_or_pref
== false) for the requested type \a Ty.
*/
unsigned char TargetData::getAlignment(const Type *Ty, bool abi_or_pref) const {
int AlignType = -1;
assert(Ty->isSized() && "Cannot getTypeInfo() on a type that is unsized!");
switch (Ty->getTypeID()) {
// Early escape for the non-numeric types.
case Type::LabelTyID:
case Type::PointerTyID:
return (abi_or_pref
? getPointerABIAlignment()
: getPointerPrefAlignment());
case Type::ArrayTyID:
return getAlignment(cast<ArrayType>(Ty)->getElementType(), abi_or_pref);
case Type::StructTyID: {
// Packed structure types always have an ABI alignment of one.
if (cast<StructType>(Ty)->isPacked() && abi_or_pref)
return 1;
// Get the layout annotation... which is lazily created on demand.
const StructLayout *Layout = getStructLayout(cast<StructType>(Ty));
unsigned Align = getAlignmentInfo(AGGREGATE_ALIGN, 0, abi_or_pref, Ty);
return std::max(Align, (unsigned)Layout->getAlignment());
}
case Type::IntegerTyID:
case Type::VoidTyID:
AlignType = INTEGER_ALIGN;
break;
case Type::FloatTyID:
case Type::DoubleTyID:
// PPC_FP128TyID and FP128TyID have different data contents, but the
// same size and alignment, so they look the same here.
case Type::PPC_FP128TyID:
case Type::FP128TyID:
case Type::X86_FP80TyID:
AlignType = FLOAT_ALIGN;
break;
case Type::VectorTyID:
AlignType = VECTOR_ALIGN;
break;
default:
llvm_unreachable("Bad type for getAlignment!!!");
break;
}
Executive summary: getTypeSize -> getTypeStoreSize / getABITypeSize. The meaning of getTypeSize was not clear - clarifying it is important now that we have x86 long double and arbitrary precision integers. The issue with long double is that it requires 80 bits, and this is not a multiple of its alignment. This gives a primitive type for which getTypeSize differed from getABITypeSize. For arbitrary precision integers it is even worse: there is the minimum number of bits needed to hold the type (eg: 36 for an i36), the maximum number of bits that will be overwriten when storing the type (40 bits for i36) and the ABI size (i.e. the storage size rounded up to a multiple of the alignment; 64 bits for i36). This patch removes getTypeSize (not really - it is still there but deprecated to allow for a gradual transition). Instead there is: (1) getTypeSizeInBits - a number of bits that suffices to hold all values of the type. For a primitive type, this is the minimum number of bits. For an i36 this is 36 bits. For x86 long double it is 80. This corresponds to gcc's TYPE_PRECISION. (2) getTypeStoreSizeInBits - the maximum number of bits that is written when storing the type (or read when reading it). For an i36 this is 40 bits, for an x86 long double it is 80 bits. This is the size alias analysis is interested in (getTypeStoreSize returns the number of bytes). There doesn't seem to be anything corresponding to this in gcc. (3) getABITypeSizeInBits - this is getTypeStoreSizeInBits rounded up to a multiple of the alignment. For an i36 this is 64, for an x86 long double this is 96 or 128 depending on the OS. This is the spacing between consecutive elements when you form an array out of this type (getABITypeSize returns the number of bytes). This is TYPE_SIZE in gcc. Since successive elements in a SequentialType (arrays, pointers and vectors) need to be aligned, the spacing between them will be given by getABITypeSize. This means that the size of an array is the length times the getABITypeSize. It also means that GEP computations need to use getABITypeSize when computing offsets. Furthermore, if an alloca allocates several elements at once then these too need to be aligned, so the size of the alloca has to be the number of elements multiplied by getABITypeSize. Logically speaking this doesn't have to be the case when allocating just one element, but it is simpler to also use getABITypeSize in this case. So alloca's and mallocs should use getABITypeSize. Finally, since gcc's only notion of size is that given by getABITypeSize, if you want to output assembler etc the same as gcc then getABITypeSize is the size you want. Since a store will overwrite no more than getTypeStoreSize bytes, and a read will read no more than that many bytes, this is the notion of size appropriate for alias analysis calculations. In this patch I have corrected all type size uses except some of those in ScalarReplAggregates, lib/Codegen, lib/Target (the hard cases). I will get around to auditing these too at some point, but I could do with some help. Finally, I made one change which I think wise but others might consider pointless and suboptimal: in an unpacked struct the amount of space allocated for a field is now given by the ABI size rather than getTypeStoreSize. I did this because every other place that reserves memory for a type (eg: alloca) now uses getABITypeSize, and I didn't want to make an exception for unpacked structs, i.e. I did it to make things more uniform. This only effects structs containing long doubles and arbitrary precision integers. If someone wants to pack these types more tightly they can always use a packed struct. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43620 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-01 20:53:16 +00:00
return getAlignmentInfo((AlignTypeEnum)AlignType, getTypeSizeInBits(Ty),
abi_or_pref, Ty);
}
unsigned char TargetData::getABITypeAlignment(const Type *Ty) const {
return getAlignment(Ty, true);
}
unsigned char TargetData::getCallFrameTypeAlignment(const Type *Ty) const {
for (unsigned i = 0, e = Alignments.size(); i != e; ++i)
if (Alignments[i].AlignType == STACK_ALIGN)
return Alignments[i].ABIAlign;
return getABITypeAlignment(Ty);
}
unsigned char TargetData::getPrefTypeAlignment(const Type *Ty) const {
return getAlignment(Ty, false);
}
unsigned char TargetData::getPreferredTypeAlignmentShift(const Type *Ty) const {
unsigned Align = (unsigned) getPrefTypeAlignment(Ty);
assert(!(Align & (Align-1)) && "Alignment is not a power of two!");
return Log2_32(Align);
}
/// getIntPtrType - Return an unsigned integer type that is the same size or
/// greater to the host pointer size.
const IntegerType *TargetData::getIntPtrType(LLVMContext &C) const {
return IntegerType::get(C, getPointerSizeInBits());
}
uint64_t TargetData::getIndexedOffset(const Type *ptrTy, Value* const* Indices,
unsigned NumIndices) const {
const Type *Ty = ptrTy;
assert(isa<PointerType>(Ty) && "Illegal argument for getIndexedOffset()");
uint64_t Result = 0;
generic_gep_type_iterator<Value* const*>
TI = gep_type_begin(ptrTy, Indices, Indices+NumIndices);
for (unsigned CurIDX = 0; CurIDX != NumIndices; ++CurIDX, ++TI) {
if (const StructType *STy = dyn_cast<StructType>(*TI)) {
assert(Indices[CurIDX]->getType() ==
Type::getInt32Ty(ptrTy->getContext()) &&
"Illegal struct idx");
unsigned FieldNo = cast<ConstantInt>(Indices[CurIDX])->getZExtValue();
// Get structure layout information...
const StructLayout *Layout = getStructLayout(STy);
// Add in the offset, as calculated by the structure layout info...
Result += Layout->getElementOffset(FieldNo);
// Update Ty to refer to current element
Ty = STy->getElementType(FieldNo);
} else {
// Update Ty to refer to current element
Ty = cast<SequentialType>(Ty)->getElementType();
// Get the array index and the size of each array element.
int64_t arrayIdx = cast<ConstantInt>(Indices[CurIDX])->getSExtValue();
Result += arrayIdx * (int64_t)getTypeAllocSize(Ty);
}
}
return Result;
}
/// getPreferredAlignment - Return the preferred alignment of the specified
/// global. This includes an explicitly requested alignment (if the global
/// has one).
unsigned TargetData::getPreferredAlignment(const GlobalVariable *GV) const {
const Type *ElemType = GV->getType()->getElementType();
unsigned Alignment = getPrefTypeAlignment(ElemType);
if (GV->getAlignment() > Alignment)
Alignment = GV->getAlignment();
if (GV->hasInitializer()) {
if (Alignment < 16) {
// If the global is not external, see if it is large. If so, give it a
// larger alignment.
Executive summary: getTypeSize -> getTypeStoreSize / getABITypeSize. The meaning of getTypeSize was not clear - clarifying it is important now that we have x86 long double and arbitrary precision integers. The issue with long double is that it requires 80 bits, and this is not a multiple of its alignment. This gives a primitive type for which getTypeSize differed from getABITypeSize. For arbitrary precision integers it is even worse: there is the minimum number of bits needed to hold the type (eg: 36 for an i36), the maximum number of bits that will be overwriten when storing the type (40 bits for i36) and the ABI size (i.e. the storage size rounded up to a multiple of the alignment; 64 bits for i36). This patch removes getTypeSize (not really - it is still there but deprecated to allow for a gradual transition). Instead there is: (1) getTypeSizeInBits - a number of bits that suffices to hold all values of the type. For a primitive type, this is the minimum number of bits. For an i36 this is 36 bits. For x86 long double it is 80. This corresponds to gcc's TYPE_PRECISION. (2) getTypeStoreSizeInBits - the maximum number of bits that is written when storing the type (or read when reading it). For an i36 this is 40 bits, for an x86 long double it is 80 bits. This is the size alias analysis is interested in (getTypeStoreSize returns the number of bytes). There doesn't seem to be anything corresponding to this in gcc. (3) getABITypeSizeInBits - this is getTypeStoreSizeInBits rounded up to a multiple of the alignment. For an i36 this is 64, for an x86 long double this is 96 or 128 depending on the OS. This is the spacing between consecutive elements when you form an array out of this type (getABITypeSize returns the number of bytes). This is TYPE_SIZE in gcc. Since successive elements in a SequentialType (arrays, pointers and vectors) need to be aligned, the spacing between them will be given by getABITypeSize. This means that the size of an array is the length times the getABITypeSize. It also means that GEP computations need to use getABITypeSize when computing offsets. Furthermore, if an alloca allocates several elements at once then these too need to be aligned, so the size of the alloca has to be the number of elements multiplied by getABITypeSize. Logically speaking this doesn't have to be the case when allocating just one element, but it is simpler to also use getABITypeSize in this case. So alloca's and mallocs should use getABITypeSize. Finally, since gcc's only notion of size is that given by getABITypeSize, if you want to output assembler etc the same as gcc then getABITypeSize is the size you want. Since a store will overwrite no more than getTypeStoreSize bytes, and a read will read no more than that many bytes, this is the notion of size appropriate for alias analysis calculations. In this patch I have corrected all type size uses except some of those in ScalarReplAggregates, lib/Codegen, lib/Target (the hard cases). I will get around to auditing these too at some point, but I could do with some help. Finally, I made one change which I think wise but others might consider pointless and suboptimal: in an unpacked struct the amount of space allocated for a field is now given by the ABI size rather than getTypeStoreSize. I did this because every other place that reserves memory for a type (eg: alloca) now uses getABITypeSize, and I didn't want to make an exception for unpacked structs, i.e. I did it to make things more uniform. This only effects structs containing long doubles and arbitrary precision integers. If someone wants to pack these types more tightly they can always use a packed struct. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43620 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-01 20:53:16 +00:00
if (getTypeSizeInBits(ElemType) > 128)
Alignment = 16; // 16-byte alignment.
}
}
return Alignment;
}
/// getPreferredAlignmentLog - Return the preferred alignment of the
/// specified global, returned in log form. This includes an explicitly
/// requested alignment (if the global has one).
unsigned TargetData::getPreferredAlignmentLog(const GlobalVariable *GV) const {
return Log2_32(getPreferredAlignment(GV));
}