This flag was set in the presence of stacksave/stackrestore in order to force
a frame pointer.
This should however not be needed per the comment in MachineFrameInfo.h
stating that a a variable sized object "...is the sole condition which
prevents frame pointer elimination", and experiments have also shown that
there seems to be no effect whatsoever on code generation with ManipulatesSP.
Review: Ulrich Weigand
This patch adds support for prologue and epilogue generation for the z/OS target under the XPLINK64 ABI for functions with a stack size of less than 1048576 bytes (huge stack frames).
Reviewed By: uweigand
Differential Revision: https://reviews.llvm.org/D114457
This patch adds support for prologue and epilogue generation for
the z/OS target under the XPLINK64 ABI for functions with a stack
size of less than 1048576 bytes (huge stack frames).
Reviewed by: uweigand, Kai
Differential Revision: https://reviews.llvm.org/D114457
Memset with a constant length was implemented with a single store followed by
a series of MVC:s. This patch changes this so that one store of the byte is
emitted for each MVC, which avoids data dependencies between the MVCs. An
MVI/STC + MVC(len-1) is done for each block.
In addition, memset with a variable length is now also handled without a
libcall. Since the byte is first stored and then MVC is used from that
address, a length of two must now be subtracted instead of one for the loop
and EXRL. This requires an extra check for the one-byte case, which is
handled in a special block with just a single MVI/STC (like GCC).
Review: Ulrich Weigand
Differential Revision: https://reviews.llvm.org/D112004
It was discovered that an extra register COPY remained when expanding a
(variable length) memory operation with a loop and there was another use of
the involved address register(s) afterwards.
A simple fix for this is to COPY the address registers before the loop and
use that new vreg instead.
Review: Ulrich Weigand
Differential Revision: https://reviews.llvm.org/D112065
- This patch provides the initial implementation for lowering a call on z/OS according to the XPLINK64 calling convention
- A series of changes have been made to SystemZCallingConv.td to account for these additional XPLINK64 changes including adding a new helper function to shadow the stack along with allocation of a register wherever appropriate
- For the cases of copying a f64 to a gr64 and a f128 / 128-bit vector type to a gr64, a `CCBitConvertToType` has been added and has been bitcasted appropriately in the lowering phase
- Support for the ADA register (R5) will be provided in a later patch.
Reviewed By: uweigand
Differential Revision: https://reviews.llvm.org/D111662
This patch fixes the bug that consisted of treating variable / immediate
length mem operations (such as memcpy, memset, ...) differently. The variable
length case needs to have the length minus 1 passed due to the use of EXRL
target instructions. However, the DAGCombiner can convert a register length
argument into a constant one, and whenever that happened one byte too little
would end up being performed.
This is also a refactorization by reducing the number of opcodes and variants
involved. For any opcode (variable or constant length), only the length minus
one is passed on to the ISD node. The rest of the logic is now instead
handled during isel pseudo expansion.
Review: Ulrich Weigand
Differential Revision: https://reviews.llvm.org/D111729
Seem to cause test failures in compiler-rt.
Revert "[SystemZ] Implement memcmp of variable length with CLC."
This reverts commit 7a4e9a0c73.
Revert "[SystemZ] Implement memcpy of variable length with MVC."
This reverts commit c6c13c58ee.
Following the same pattern of memset/memcpy, this patch implements a variable
length memcmp with a CLC loop followed by an EXRL instruction.
Review: Ulrich Weigand
Differential Revision: https://reviews.llvm.org/D107380
Instead of making a memcpy libcall, emit an MVC loop and an EXRL instruction
the same way as is already done for memset 0.
Review: Ulrich Weigand
Differential Revision: https://reviews.llvm.org/D106874
This patch changes hard-coded usages of SystemZ::R15D with calls to the getStackPointerRegister function. Uses in the LowerCall function are avoided to avoid merge conflicts with an expected upcoming patch.
Reviewed By: uweigand
Differential Revision: https://reviews.llvm.org/D109702
The type legalizer has by default no method of doing this bitcast other than
storing and reloading the value from stack.
This patch implements a custom lowering of this operation using extractions
of subregs (z13 and earlier using FP128 register pairs), or of vector
elements (with 'vector enhancements 1' using VR128 FP registers).
Review: Ulrich Weigand
Differential Revision: https://reviews.llvm.org/D110346
This patch adds class SystemZFrameLowering which is a SystemZ-specific class
detailing special registers used by calling conventions on the target.
SystemZELFFrameLowering and SystemZXPLINKFrameLowering implement this class
for ELF and XPLINK64 respectively. Previous functionality in SystemZFrameLowering
is moved to SystemZELFFrameLowering. SystemZXPLINKFrameLowering can then be
implemented in future patches.
Reviewed By: uweigand, Kai
Differential Revision: https://reviews.llvm.org/D108777
Benchmarking has shown that it is worthwhile to implement a variable length
memset of 0 with XC (exclusive or) like gcc does, instead of using a libcall.
This requires the use of the EXecute Relative Long (EXRL) instruction which
can now be done in a framework that can also be used with other target
instructions (not just XC).
Review: Ulrich Weigand
Differential Revision: https://reviews.llvm.org/D103865
Since this method can apply to cmpxchg operations, make sure it's clear
what value we're actually retrieving. This will help ensure we don't
accidentally ignore the failure ordering of cmpxchg in the future.
We could potentially introduce a getOrdering() method on AtomicSDNode
that asserts the operation isn't cmpxchg, but not sure that's
worthwhile.
Differential Revision: https://reviews.llvm.org/D103338
Support virtual, physical and tied i128 register operands in inline assembly.
i128 is on SystemZ not really supported and is not a legal type and generally
such a value will be split into two i64 parts. There are however some
instructions that require a pair of two GPR64 registers contained in the GR128
bit reg class, which is untyped.
For inline assmebly operands, it proved to be very cumbersome to first follow
the general behavior of splitting an i128 operand into two parts and then
later rebuild the INLINEASM MI to have one GR128 register. Instead, some
minor common code changes were made to SelectionDAGBUilder to only create one
GR128 register part to begin with. In particular:
- getNumRegisters() now has an optional parameter "RegisterVT" which is
passed by AddInlineAsmOperands() and GetRegistersForValue().
- The bitcasting in GetRegistersForValue is not performed if RegVT is
Untyped.
- The RC for a tied use in AddInlineAsmOperands() is now computed either from
the tied def (virtual register), or by getMinimalPhysRegClass() (physical
register).
- InstrEmitter.cpp:EmitCopyFromReg() has been fixed so that the register
class (DstRC) can also be computed for an illegal type.
In the SystemZ backend getNumRegisters(), splitValueIntoRegisterParts() and
joinRegisterPartsIntoValue() have been implemented to handle i128 operands.
Differential Revision: https://reviews.llvm.org/D100788
Review: Ulrich Weigand
Expand 128 bit shifts instead of using a libcall.
This patch removes the 128 bit shift libcalls and thereby causes
ExpandShiftWithUnknownAmountBit() to be called.
Review: Ulrich Weigand
Differential Revision: https://reviews.llvm.org/D101993
In order to use __builtin_frame_address(0) with packed stack and no
backchain, the address of where the backchain would have been written is
returned (like GCC).
This address may either contain a saved register or be unused.
Review: Ulrich Weigand
Differential Revision: https://reviews.llvm.org/D101897
Rename ELF specific variables, making it easier to add the XPLink
variables in future patches.
Reviewed By: abhina.sreeskantharajan, Kai
Differential Revision: https://reviews.llvm.org/D98199
Even though the implementation in emitAtomicCmpSwapW() was correct, it made
Valgrind report an error. Instead of using a RISBG on CmpVal, an LL[CH]R can
be made on the OldVal, and the problem is avoided.
Review: Ulrich Weigand
Differential Revision: https://reviews.llvm.org/D97604
When a large "irregular" (e.g. i96) integer call argument is converted to
indirect, 64-bit parts are stored to the stack. The full stack space
(e.g. i128) was not allocated prior to this patch, but rather just the exact
space of the original type. This caused neighboring values on the stack to be
overwritten.
Thanks to Josh Stone for reporting this.
Review: Ulrich Weigand
Fixes https://bugs.llvm.org/show_bug.cgi?id=49322
Differential Revision: https://reviews.llvm.org/D97514
We're immediately dereferencing the casted pointer, so use cast<> which will assert instead of dyn_cast<> which can return null.
Fixes static analyzer warning.
- New function SDValue getBackchainAddress() used by
lowerDYNAMIC_STACKALLOC() and lowerSTACKRESTORE() to properly handle the
backchain offset also with packed-stack.
- Make a common function getBackchainOffset() for the computation of the
backchain offset and use in some places (NFC).
Review: Ulrich Weigand
Differential Revision: https://reviews.llvm.org/D93171
The SystemZISD::IABS node is no longer needed since ISD::ABS can be used
instead.
Review: Ulrich Weigand
Differential Revision: https://reviews.llvm.org/D91697
We have a frequent pattern where we're merging two KnownBits to get the common/shared bits, and I just fell for the gotcha where I tried to use the & operator to merge them........
In most of lib/Target we know that we are not dealing with scalable
types so it's perfectly fine to replace TypeSize comparison operators
with their fixed width equivalents, making use of getFixedSize()
and so on.
Differential Revision: https://reviews.llvm.org/D89101
In order to correctly load an all-ones FP NaN value into a floating point
register with a VGBM, the analyzed 32/64 FP bits must first be shifted left
(into element 0 of the vector register).
SystemZVectorConstantInfo has so far relied on element replication which has
bypassed the need to do this shift, but now it is clear that this must be
done in order to handle NaNs.
Review: Ulrich Weigand
Differential Revision: https://reviews.llvm.org/D89389
Summary:
This fixes ASan and MSan tests on SystemZ after
commit 6a822e20ce ("[ASan][MSan] Remove EmptyAsm and set the CallInst
to nomerge to avoid from merging.").
Based on commit 80e107ccd0 ("Add NoMerge MIFlag to avoid MIR branch
folding").
Reviewers: uweigand, jonpa
Reviewed By: uweigand
Subscribers: hiraditya, llvm-commits, Andreas-Krebbel
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D82794
Instead of doing multiple unpacks when zero extending vectors (e.g. v2i16 ->
v2i64), benchmarks have shown that it is better to do a VPERM (vector
permute) since that is only one sequential instruction on the critical path.
This patch achieves this by
1. Expand ZERO_EXTEND_VECTOR_INREG into a vector shuffle with a zero vector
instead of (multiple) unpacks.
2. Improve SystemZ::GeneralShuffle to perform a single unpack as the last
operation if Bytes matches it.
Review: Ulrich Weigand
Differential Revision: https://reviews.llvm.org/D78486
Try to avoid creating VGBMs by reusing the permutation mask if it contains a
zero. If the first byte was into (any byte of) a zero vector, then the first
byte of the mask can become zero and reused by putting the mask also as the
first operand. If there instead was a first-byte use of the other source
operand, then that zero index can be reused if the mask is placed as the
second operand.
Review: Ulrich Weigand
Differential Revision: https://reviews.llvm.org/D79925
It's better to reuse the first source value than to use an undef second
operand, because that will make more resulting VPERMs have identical operands
and therefore MachineCSE more successful.
Review: Ulrich Weigand
This patch stores the alignment for ConstantPoolSDNode as an
Align and updates the getConstantPool interface to take a MaybeAlign.
Removing getAlignment() will be done as a follow up.
Differential Revision: https://reviews.llvm.org/D79436
When using vec_load/store_len_r with an immediate length operand
of 16 or larger, LLVM will currently emit an VLRL/VSTRL instruction
with that immediate. This creates a valid encoding (which should be
supported by the assembler), but always traps at runtime. This patch
fixes this by not creating VLRL/VSTRL in those cases.
This would result in loading the length into a register and
calling VLRLR/VSTRLR instead. However, these operations with
a length of 15 or larger are in fact simply equivalent to a
full vector load or store. And in fact the same holds true for
vec_load/store_len as well.
Therefore, add a DAGCombine rule to replace those operations with
plain vector loads or stores if the length is known at compile
time and equal or larger to 15.
The type legalizer will scalarize vector conversions from integer to floating
point if the source element size is less than that of the result.
This is avoided now by inserting a zero/sign-extension of the source vector
before type legalization.
Review: Ulrich Weigand
Differential revision: https://reviews.llvm.org/D75978
Swap the compare operands if LHS is spilled while updating the CCMask:s of
the CC users. This is relatively straight forward since the live-in lists for
the CC register can be assumed to be correct during register allocation
(thanks to 659efa2).
Also fold a spilled operand of an LOCR/SELR into an LOC(G).
Review: Ulrich Weigand
Differential Revision: https://reviews.llvm.org/D67437
Kazu Hirata