The control flow here cannot ever use the uninitialized value, but it's
too hard for the compiler to figure that out. Clang warns:
llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp:2600:28: error: variable 'CarrySum' is used uninitialized whenever 'for' loop exits because its condition is false [-Werror,-Wsometimes-uninitialized]
for (unsigned i = 2; i < Factors.size(); ++i)
^~~~~~~~~~~~~~~~~~
llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp:2604:26: note: uninitialized use occurs here
CarrySumPrevDstIdx = CarrySum;
^~~~~~~~
llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp:2600:28: note: remove the condition if it is always true
for (unsigned i = 2; i < Factors.size(); ++i)
^~~~~~~~~~~~~~~~~~
llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp:2583:22: note: initialize the variable 'CarrySum' to silence this warning
unsigned CarrySum;
^
= 0
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@355818 91177308-0d34-0410-b5e6-96231b3b80d8
Narrow Scalar G_MUL for MIPS32.
Revisit NarrowScalar implementation in LegalizerHelper.
Introduce new helper function multiplyRegisters.
It performs generic multiplication of values held in multiple registers.
Generated instructions use only types NarrowTy and i1.
Destination can be same or two times size of the source.
Differential Revision: https://reviews.llvm.org/D58824
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@355814 91177308-0d34-0410-b5e6-96231b3b80d8
Legalize/select llvm.ctlz.*
Add select-ctlz to show that we actually select them. Update arm64-clrsb.ll and
arm64-vclz.ll to show that we perform valid transformations in optimized builds,
and document where GISel can improve.
Differential Revision: https://reviews.llvm.org/D58155
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@354299 91177308-0d34-0410-b5e6-96231b3b80d8
Select G_BR and G_BRCOND for MIPS32.
Unconditional branch G_BR does not have register operand,
for that reason we only add tests.
Since conditional branch G_BRCOND compares register to zero on MIPS32,
explicit extension must be performed on i1 condition in order to set
high bits to appropriate value.
Differential Revision: https://reviews.llvm.org/D58182
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@354022 91177308-0d34-0410-b5e6-96231b3b80d8
Make behavior of G_LOAD in widenScalar same as for G_ZEXTLOAD and
G_SEXTLOAD. That is perform widenScalarDst to size given by the target
and avoid additional checks in common code. Targets can reorder or add
additional rules in LegalizeRuleSet for the opcode to achieve desired
behavior.
Select extending load that does not have specified type of extension
into zero extending load.
Select truncating store that stores number of bytes indicated by size
in MachineMemoperand.
Differential Revision: https://reviews.llvm.org/D57454
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@353520 91177308-0d34-0410-b5e6-96231b3b80d8
This is pretty much directly ported from SelectionDAG. Doesn't include
the shift by non-constant but known bits version, since there isn't a
globalisel version of computeKnownBits yet.
This shows a disadvantage of targets not specifically which type
should be used for the shift amount. If type 0 is legalized before
type 1, the operations on the shift amount type use the wider type
(which are also less likely to legalize). This can be avoided by
targets specifying legalization actions on type 1 earlier than for
type 0.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@353455 91177308-0d34-0410-b5e6-96231b3b80d8
Introduce a new function which handles instructions with multiple type
indices, but have the same number of vector elements.
Also legalize v2s16 shifts when applicable.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@353432 91177308-0d34-0410-b5e6-96231b3b80d8
The fewerElementsVectors implementation for load/stores
handles the scalar reduction case just as well, so drop
the redundant code in narrowScalar. This also introduces
support for narrowing irregular size breakdowns for
scalars.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@353125 91177308-0d34-0410-b5e6-96231b3b80d8
Don't handle vector conditions.
I think this can be merged in the future with
fewerElementsVectorSelect, although this becomes slightly tricky with
a vector condition.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@353122 91177308-0d34-0410-b5e6-96231b3b80d8
For the scalar case only.
Also move the similar G_MERGE_VALUES handling to a separate function
and cleanup to make them look more similar.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@352979 91177308-0d34-0410-b5e6-96231b3b80d8
Also fix an alignment bug getMachineMemOperand. If the
tracked value is null, the offset isn't tracked so the
base alignment needs to be reduced.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@352716 91177308-0d34-0410-b5e6-96231b3b80d8
This teaches the legalizer to handle G_FEXP in AArch64. As a result, it also
allows us to select G_FEXP.
It...
- Updates the legalizer-info tests
- Adds a test for legalizing exp
- Updates the existing fp tests to show that we can now select G_FEXP
https://reviews.llvm.org/D57483
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@352692 91177308-0d34-0410-b5e6-96231b3b80d8
This teaches GlobalISel to emit a RTLib call for @llvm.log2 when it encounters
it.
It updates the existing floating point tests to show that we don't fall back on
the intrinsic, and select the correct instructions. It also adds a legalizer
test for G_FLOG2.
https://reviews.llvm.org/D57357
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@352673 91177308-0d34-0410-b5e6-96231b3b80d8
This was ignoring the memory size, and producing multiple loads/stores
if the operand size was different from the memory size.
I assume this is the intent of not having an explicit G_ANYEXTLOAD
(although I think that would probably be better).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@352523 91177308-0d34-0410-b5e6-96231b3b80d8
