Start using a new strategy with a combination of merge and unmerges.
This allows scalarizing before lowering, which in cases like
<2 x s128> avoids producing giant illegal shifts.
Summary:
Applying this cleanup:
- MIRBuilder.buildInstr(TargetOpcode::G_ASHR)
- .addDef(Shifted)
- .addUse(Res)
- .addUse(ShiftAmt);
+ MIRBuilder.buildAShr(Shifted, Res, ShiftAmt);
caused an assertion failure here:
llc: /home/jayfoad2/git/llvm-project/llvm/lib/CodeGen/MachineRegisterInfo.cpp:404: llvm::MachineInstr *llvm::MachineRegisterInfo::getVRegDef(unsigned int) const: Assertion `(I.atEnd() || std::next(I) == def_instr_end()) && "getVRegDef assumes a single definition or no definition"' failed.
#4 0x00000000050a6d96 in llvm::MachineRegisterInfo::getVRegDef (this=0x74606a0, Reg=2147483650) at /home/jayfoad2/git/llvm-project/llvm/lib/CodeGen/MachineRegisterInfo.cpp:403
#5 0x00000000066148f6 in llvm::getConstantVRegValWithLookThrough (VReg=2147483650, MRI=..., LookThroughInstrs=false, HandleFConstant=true) at /home/jayfoad2/git/llvm-project/llvm/lib/CodeGen/GlobalISel/Utils.cpp:244
#6 0x00000000066147da in llvm::getConstantVRegVal (VReg=2147483650, MRI=...) at /home/jayfoad2/git/llvm-project/llvm/lib/CodeGen/GlobalISel/Utils.cpp:210
#7 0x0000000006615367 in llvm::ConstantFoldBinOp (Opcode=101, Op1=2147483650, Op2=2147483656, MRI=...) at /home/jayfoad2/git/llvm-project/llvm/lib/CodeGen/GlobalISel/Utils.cpp:341
#8 0x000000000657eee0 in llvm::CSEMIRBuilder::buildInstr (this=0x7465010, Opc=101, DstOps=..., SrcOps=..., Flag=...) at /home/jayfoad2/git/llvm-project/llvm/lib/CodeGen/GlobalISel/CSEMIRBuilder.cpp:160
#9 0x0000000003645958 in llvm::MachineIRBuilder::buildAShr (this=0x7465010, Dst=..., Src0=..., Src1=..., Flags=...) at /home/jayfoad2/git/llvm-project/llvm/include/llvm/CodeGen/GlobalISel/MachineIRBuilder.h:1298
#10 0x00000000065c35b1 in llvm::LegalizerHelper::lower (this=0x7fffffffb5f8, MI=..., TypeIdx=0, Ty=...) at /home/jayfoad2/git/llvm-project/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp:2020
because at this point there are two instructions defining Res: the
original G_SMULO/G_UMULO and the new G_MUL that we built. The fix is
to modify the original mul in place, so that there is only ever one
definition of Res.
Reviewers: arsenm, aditya_nandakumar
Subscribers: wdng, rovka, hiraditya, volkan, Petar.Avramovic, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72842
Commit 9965b12fd1b was supposed to change the offset constant when
lowering load/stores, but only introduced this change for loads. This
patch adds the same fix for stores.
This is passed to legalizeCustom, but not intrinsic. Also remove the
MRI argument, since you can get that from the MachineIRBuilder.
I'm not sure why MachineIRBuilder has a private observer member, and
this is passed separately.
G_CTPOP is generated from llvm.ctpop.<type> intrinsics, clang generates
these intrinsics from __builtin_popcount and __builtin_popcountll.
Add lower and narrow scalar for G_CTPOP.
Lower G_CTPOP for MIPS32.
Differential Revision: https://reviews.llvm.org/D73216
llvm.cttz.<type> intrinsic has additional i1 argument is_zero_undef,
it tells whether zero as the first argument produces a defined result.
G_CTTZ is generated from llvm.cttz.<type> (<type> <src>, i1 false)
intrinsics, clang generates these intrinsics from __builtin_ctz and
__builtin_ctzll.
G_CTTZ_ZERO_UNDEF comes from llvm.cttz.<type> (<type> <src>, i1 true).
Clang generates such intrinsics as parts of expansion of builtin_ffs
and builtin_ffsll. It is also traditionally part of and many
algorithms that are now predicated on avoiding zero-value inputs.
Add narrow scalar (algorithm uses G_CTTZ_ZERO_UNDEF) for G_CTTZ.
Lower G_CTTZ and G_CTTZ_ZERO_UNDEF for MIPS32.
Differential Revision: https://reviews.llvm.org/D73215
llvm.ctlz.<type> intrinsic has additional i1 argument is_zero_undef,
it tells whether zero as the first argument produces a defined result.
MIPS clz instruction returns 32 for zero input.
G_CTLZ is generated from llvm.ctlz.<type> (<type> <src>, i1 false)
intrinsics, clang generates these intrinsics from __builtin_clz and
__builtin_clzll.
G_CTLZ_ZERO_UNDEF can also be generated from llvm.ctlz with true as
second argument. It is also traditionally part of and many algorithms
that are now predicated on avoiding zero-value inputs.
Add narrow scalar for G_CTLZ (algorithm uses G_CTLZ_ZERO_UNDEF).
Lower G_CTLZ_ZERO_UNDEF and select G_CTLZ for MIPS32.
Differential Revision: https://reviews.llvm.org/D73214
This was assuming the narrow target was the source type. Respect the
requested type when these don't match by using intermediate
merges. This avoids producing very wide, illegal shift expansions.
This now develops the same problem G_ZEXT/G_ANYEXT have where the
requested type is assumed to be the source type. This will be fixed
separately by creating intermediate merges.
Bitcast only really applies between scalars and vectors. Implement as
an unmerge and remerge. The test needs to tolerate failure since one
of the unmerges currently fails to legalize.
We're planning to remove the shufflemask operand from ShuffleVectorInst
(D72467); fix GlobalISel so it doesn't depend on that Constant.
The change to prelegalizercombiner-shuffle-vector.mir happens because
the input contains a literal "-1" in the mask (so the parser/verifier
weren't really handling it properly). We now treat it as equivalent to
"undef" in all contexts.
Differential Revision: https://reviews.llvm.org/D72663
G_BITREVERSE is generated from llvm.bitreverse.<type> intrinsics,
clang genrates these intrinsics from __builtin_bitreverse32 and
__builtin_bitreverse64.
Add lower and narrowscalar for G_BITREVERSE.
Lower G_BITREVERSE on MIPS32.
Recommit notes:
Introduce temporary variables in order to make sure
instructions get inserted into MachineFunction in same order
regardless of compiler used to build llvm.
Differential Revision: https://reviews.llvm.org/D71363
G_BITREVERSE is generated from llvm.bitreverse.<type> intrinsics,
clang genrates these intrinsics from __builtin_bitreverse32 and
__builtin_bitreverse64.
Add lower and narrowscalar for G_BITREVERSE.
Lower G_BITREVERSE on MIPS32.
Differential Revision: https://reviews.llvm.org/D71363
G_BSWAP is generated from llvm.bswap.<type> intrinsics, clang genrates
these intrinsics from __builtin_bswap32 and __builtin_bswap64.
Add lower and narrowscalar for G_BSWAP.
Lower G_BSWAP on MIPS32, select G_BSWAP on MIPS32 revision 2 and later.
Differential Revision: https://reviews.llvm.org/D71362
https://reviews.llvm.org/D70922
This adds a hook to allow targets to define exactly what extension
operation should be performed for widening constants. This handles cases
like widening i1 true which would end up becoming -1 which affects code
quality during combines.
Additionally, in order to stay consistent with how DAG is promoting
constants, we now signextend for byte sized types and zero extend
otherwise (by default). Targets can of course override this if
necessary.
Summary:
G_GEP is rather poorly named. It's a simple pointer+scalar addition and
doesn't support any of the complexities of getelementptr. I therefore
propose that we rename it. There's a G_PTR_MASK so let's follow that
convention and go with G_PTR_ADD
Reviewers: volkan, aditya_nandakumar, bogner, rovka, arsenm
Subscribers: sdardis, jvesely, wdng, nhaehnle, hiraditya, jrtc27, atanasyan, arphaman, Petar.Avramovic, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D69734
We need to propagate this information from the IR in order to be able to safely
do tail call optimizations on the intrinsics during legalization. Assuming
it's safe to do tail call opt without checking for the marker isn't safe because
the mem libcall may use allocas from the caller.
This adds an extra immediate operand to the end of the intrinsics and fixes the
legalizer to handle it.
Differential Revision: https://reviews.llvm.org/D68151
llvm-svn: 373140
We currently always set the HasCalls on MFI during translation and legalization if
we're handling a call or legalizing to a libcall. However, if that call is later
optimized to a tail call then we don't need the flag. The flag being set to true
causes frame lowering to always save and restore FP/LR, which adds unnecessary code.
This change does the same thing as SelectionDAG and ports over some code that scans
instructions after selection, using TargetInstrInfo to determine if target opcodes
are known calls.
Code size geomean improvements on CTMark:
-O0 : 0.1%
-Os : 0.3%
Differential Revision: https://reviews.llvm.org/D67868
llvm-svn: 372443
r371901 was overeager and widenScalarDst() and the like in the legalizer
attempt to increment the insert point given in order to add new instructions
after the currently legalizing inst. In cases where the insertion point is not
exactly the current instruction, then callers need to de-compensate for the
behaviour by decrementing the insertion iterator before calling them. It's not
a nice state of affairs, for now just undo the problematic parts of the change.
llvm-svn: 372050
For some reason we sometimes insert new instructions one instruction before
the first non-PHI when legalizing. This can result in having non-PHI
instructions before PHIs, which mean that PHI elimination doesn't catch them.
Differential Revision: https://reviews.llvm.org/D67570
llvm-svn: 371901
Because memory intrinsics are handled differently than other calls, we need to
check them for tail call eligiblity in the legalizer. This allows us to still
inline them when it's beneficial to do so, but also tail call when possible.
This adds simple tail calling support for when the intrinsic is followed by a
return.
It ports the attribute checks from `TargetLowering::isInTailCallPosition` into
a similarly-named function in LegalizerHelper.cpp. The target-specific
`isUsedByReturnOnly` hook is not ported here.
Update tailcall-mem-intrinsics.ll to show that GlobalISel can now tail call
memory intrinsics.
Update legalize-memcpy-et-al.mir to have a case where we don't tail call.
Differential Revision: https://reviews.llvm.org/D67566
llvm-svn: 371893
