lib/Target/SystemZ/README.txt File Reference

Functions
The initial backend is deliberately restricted to z10 We should add support for later architectures at some point If an asm ties an i32 r result to an i64 the input will be treated as an leaving the upper bits uninitialised For i64 store i32 i32 *dst ret void from CodeGen SystemZ asm ll will use LHI rather than LGHI to load This seems to be a general target independent problem The tuning of the choice between LOAD	ADDRESS (LA) and addition in SystemZISelDAGToDAG.cpp is suspect. It should be tweaked based on performance measurements. -- There is no scheduling support. -- We don 't use the BRANCH ON INDEX instructions. -- We only use MVC

Variables
The initial backend is deliberately restricted to z10 We should add support for later architectures at some point If an asm ties an i32 r result to an i64	input
The initial backend is deliberately restricted to z10 We should add support for later architectures at some point If an asm ties an i32 r result to an i64 the input will be treated as an	i32
The initial backend is deliberately restricted to z10 We should add support for later architectures at some point If an asm ties an i32 r result to an i64 the input will be treated as an leaving the upper bits uninitialised For	example
The initial backend is deliberately restricted to z10 We should add support for later architectures at some point If an asm ties an i32 r result to an i64 the input will be treated as an leaving the upper bits uninitialised For i64 store i32	val
The initial backend is deliberately restricted to z10 We should add support for later architectures at some point If an asm ties an i32 r result to an i64 the input will be treated as an leaving the upper bits uninitialised For i64 store i32 i32 *dst ret void from CodeGen SystemZ asm ll will use LHI rather than LGHI to load This seems to be a general target independent problem The tuning of the choice between LOAD XC and CLC for constant length block operations We could extend them to variable length operations	too
therefore end up	as
therefore end up	r2
therefore end up llgh	r0
therefore end up llgh r3 lr r0 br r14 but truncating the load would	give
therefore end up llgh r3 lr r0 br r14 but truncating the load would lh r3 br r14 Functions	like
therefore end up llgh r3 lr r0 br r14 but truncating the load would lh r3 br r14 Functions ret i64 and ought to be implemented ngr r0 br r14 but two address optimizations reverse the order of the AND and	force
therefore end up llgh r3 lr r0 br r14 but truncating the load would lh r3 br r14 Functions ret i64 and ought to be implemented ngr r0 br r14 but two address optimizations reverse the order of the AND and ngr r2 lgr r0 br r14 CodeGen SystemZ and ll has several examples of this Out of range displacements are usually handled by loading the full address into a register In many cases it would be better to create an anchor point instead E g	for
therefore end up llgh r3 lr r0 br r14 but truncating the load would lh r3 br r14 Functions ret i64 and ought to be implemented ngr r0 br r14 but two address optimizations reverse the order of the AND and ngr r2 lgr r0 br r14 CodeGen SystemZ and ll has several examples of this Out of range displacements are usually handled by loading the full address into a register In many cases it would be better to create an anchor point instead E g i64	base

Function Documentation

ADDRESS()

The initial backend is deliberately restricted to z10 We should add support for later architectures at some point If an asm ties an i32 r result to an i64 the input will be treated as an leaving the upper bits uninitialised For i64 store i32 i32* dst ret void from CodeGen SystemZ asm ll will use LHI rather than LGHI to load This seems to be a general target independent problem The tuning of the choice between LOAD ADDRESS

(

LA

)

Variable Documentation

as

therefore end up llgh r3 lr r0 br r14 but truncating the load would lh r3 br r14 Functions ret i64 and ought to be implemented as

Definition at line 84 of file README.txt.

base

therefore end up llgh r3 lr r0 br r14 but truncating the load would lh r3 br r14 Functions ret i64 and ought to be implemented ngr r0 br r14 but two address optimizations reverse the order of the AND and ngr r2 lgr r0 br r14 CodeGen SystemZ and ll has several examples of this Out of range displacements are usually handled by loading the full address into a register In many cases it would be better to create an anchor point instead E g i64 base

Initial value:

{
  %addr = add i64 %base, 524288
  %bptr = inttoptr i64 %addr to i128 *
  %a = load volatile i128 *%aptr
  %b = load i128 *%bptr
  %add = add i128 %a, %b
  store i128 %add, i128 *%aptr
  ret void
}
 
(from CodeGen/SystemZ/int-add-08.ll) we load %base+524288 and %base+524296
into separate registers

Definition at line 125 of file README.txt.

Referenced by llvm::object::ELFObjectFile< ELFT >::dynamic_relocation_sections(), llvm::object::ELFFile< ELFT >::dynamicEntries(), findBasePointers(), getNumberOfRelocations(), llvm::object::ELFObjectFile< ELFT >::getSectionContents(), llvm::object::XCOFFObjectFile::getSectionContents(), llvm::object::ELFFile< ELFT >::getSegmentContents(), readSIB(), llvm::object::ELFFile< ELFT >::sections(), and llvm::object::ELFFile< ELFT >::toMappedAddr().

example

The initial backend is deliberately restricted to z10 We should add support for later architectures at some point If an asm ties an i32 r result to an i64 the input will be treated as an leaving the upper bits uninitialised For example

Definition at line 15 of file README.txt.

for

therefore end up llgh r3 lr r0 br r14 but truncating the load would lh r3 br r14 Functions ret i64 and ought to be implemented ngr r0 br r14 but two address optimizations reverse the order of the AND and ngr r2 lgr r0 br r14 CodeGen SystemZ and ll has several examples of this Out of range displacements are usually handled by loading the full address into a register In many cases it would be better to create an anchor point instead E g for

Definition at line 125 of file README.txt.

force

therefore end up llgh r3 lr r0 br r14 but truncating the load would lh r3 br r14 Functions ret i64 and ought to be implemented ngr r0 br r14 but two address optimizations reverse the order of the AND and force

Definition at line 112 of file README.txt.

Referenced by llvm::checkForCycles(), and llvm::GCNIterativeScheduler::scheduleMinReg().

give

therefore end up llgh r3 lr r0 br r14 but truncating the load would give

Definition at line 91 of file README.txt.

i32

The initial backend is deliberately restricted to z10 We should add support for later architectures at some point If an asm ties an i32 r result to an i64 the input will be treated as an i32

Definition at line 11 of file README.txt.

input

The initial backend is deliberately restricted to z10 We should add support for later architectures at some point If an asm ties an i32 r result to an i64 input

inline

Definition at line 10 of file README.txt.

Referenced by llvm::LTOModule::getDependentLibrary(), llvm::LTOModule::getDependentLibraryCount(), llvm::yaml::ScalarTraits< FlowStringRef >::input(), llvm::yaml::ScalarTraits< FlowStringValue >::input(), llvm::yaml::BlockScalarTraits< BlockStringValue >::input(), llvm::yaml::BlockScalarTraits< StringBlockVal >::input(), llvm::yaml::ScalarTraits< UnsignedValue >::input(), into(), parseInt(), and llvm::VersionTuple::tryParse().

like

therefore end up llgh r3 lr r0 br r14 but truncating the load would lh r3 br r14 Functions like

Definition at line 100 of file README.txt.

r0

therefore end up llgh r3 lr r0 br r14 but truncating the load would lh r3 br r14 Functions ret i64 and ought to be implemented ngr r0 br r14 but two address optimizations reverse the order of the AND and ngr r0

Definition at line 85 of file README.txt.

r2

therefore end up llgh r3 lr r0 br r14 but truncating the load would lh r3 br r14 Functions ret i64 and ought to be implemented ngr r0 br r14 but two address optimizations reverse the order of the AND and ngr r2 lgr r2

Definition at line 84 of file README.txt.

too

The initial backend is deliberately restricted to z10 We should add support for later architectures at some point If an asm ties an i32 r result to an i64 the input will be treated as an leaving the upper bits uninitialised For i64 store i32 i32* dst ret void from CodeGen SystemZ asm ll will use LHI rather than LGHI to load This seems to be a general target independent problem The tuning of the choice between LOAD XC and CLC for constant length block operations We could extend them to variable length operations too

Definition at line 40 of file README.txt.

val

The initial backend is deliberately restricted to z10 We should add support for later architectures at some point If an asm ties an i32 r result to an i64 the input will be treated as an leaving the upper bits uninitialised For i64 store i32 val

Definition at line 15 of file README.txt.

Referenced by llvm::AVR::fixups::adjustBranchTarget(), llvm::APInt::APInt(), llvm::ScopedHashTableVal< K, V >::Create(), llvm::AArch64_AM::decodeLogicalImmediate(), emitIndirectDst(), executeFCMP_BOOL(), llvm::R600InstrInfo::expandPostRAPseudo(), llvm::DenseMapInfo< omp::TraitProperty >::getHashValue(), llvm::DenseMapInfo< hash_code >::getHashValue(), llvm::getSamplerName(), llvm::getSurfaceName(), llvm::getTextureName(), llvm::PackedVectorBase< T, BitNum, BitVectorTy, false >::getValue(), llvm::PackedVectorBase< T, BitNum, BitVectorTy, true >::getValue(), llvm::ARM_PROC::IFlagsToString(), llvm::ARM_PROC::IModToString(), llvm::ARM_ISB::InstSyncBOptToString(), IsConstantOne(), llvm::isImage(), llvm::isImageReadOnly(), llvm::isImageReadWrite(), llvm::isImageWriteOnly(), isImmMskBitp(), isImmU16(), isImmU6(), isImmUs(), isImmUs2(), isImmUs4(), llvm::isManaged(), llvm::isSampler(), llvm::isSurface(), llvm::isTexture(), llvm::AArch64_AM::isValidDecodeLogicalImmediate(), lle_X_memset(), llvm::ARM_MB::MemBOptToString(), llvm::PackedVector< T, BitNum, BitVectorTy >::reference::operator=(), llvm::GVNExpression::op_inserter::operator=(), llvm::GVNExpression::int_op_inserter::operator=(), llvm::support::detail::packed_endian_specific_integral< ProcessorArchitecture >::packed_endian_specific_integral(), llvm::ARMTargetLowering::PerformIntrinsicCombine(), llvm::ARMInstPrinter::printInstSyncBOption(), llvm::ARMInstPrinter::printMemBOption(), llvm::ARMInstPrinter::printTraceSyncBOption(), llvm::PackedVector< T, BitNum, BitVectorTy >::push_back(), llvm::iplist_impl< simple_ilist< MachineInstr, Options... >, ilist_traits< MachineInstr > >::push_back(), llvm::iplist_impl< simple_ilist< MachineInstr, Options... >, ilist_traits< MachineInstr > >::push_front(), llvm::support::endian::readAtBitAlignment(), llvm::hashing::detail::rotate(), llvm::LLLexer::setIgnoreColonInIdentifiers(), llvm::HexagonPacketizerList::setmemShufDisabled(), llvm::MCAsmLexer::setSkipSpace(), llvm::Type::setSubclassData(), llvm::PackedVectorBase< T, BitNum, BitVectorTy, false >::setValue(), llvm::PackedVectorBase< T, BitNum, BitVectorTy, true >::setValue(), llvm::hashing::detail::shift_mix(), llvm::StoreInst::StoreInst(), llvm::ARM_TSB::TraceSyncBOptToString(), and llvm::support::endian::writeAtBitAlignment().