The sign-/zero-extension of the loaded value can be performed by the memory
instruction for free. If the result of the load has only one use and the use is
a sign-/zero-extend, then we emit the proper load instruction. The extend is
only a register copy and will be optimized away later on.
Other instructions that consume the sign-/zero-extended value are also made
aware of this fact, so they don't fold the extend too.
This fixes rdar://problem/18495928.
llvm-svn: 218653
Shift-left immediate with sign-/zero-extensions also works for boolean values.
Update the assert and the test cases to reflect that fact.
This should fix a bug found by Chad.
llvm-svn: 218275
When looking through sign/zero-extensions the code would always assume there is
such an extension instruction and use the wrong operand for the address.
There was also a minor issue in the handling of 'AND' instructions. I
accidentially used a 'cast' instead of a 'dyn_cast'.
llvm-svn: 218161
When folding the intrinsic flag into the branch or select we also have to
consider the fact if the intrinsic got simplified, because it changes the
flag we have to check for.
llvm-svn: 218034
Small optimization in 'simplifyAddress'. When the offset cannot be encoded in
the load/store instruction, then we need to materialize the address manually.
The add instruction can encode a wider range of immediates than the load/store
instructions. This change tries to fold the offset into the add instruction
first before materializing the offset in a register.
llvm-svn: 218031
The 'AND' instruction could be used to mask out the lower 32 bits of a register.
If this is done inside an address computation we might be able to fold the
instruction into the memory instruction itself.
and x1, x1, #0xffffffff ---> ldrb x0, [x0, w1, uxtw]
ldrb x0, [x0, x1]
llvm-svn: 218030
This takes advanatage of the CBZ and CBNZ instruction to further optimize the
common null check pattern into a single instruction.
This is related to rdar://problem/18358882.
llvm-svn: 217972
This adds the last two missing floating-point condition codes (FCMP_UEQ and
FCMP_ONE) also to the branch selection. In these two cases an additonal branch
instruction is required.
This also adds unit tests to checks all the different condition codes.
This is related o rdar://problem/18358882.
llvm-svn: 217966
Allow handling of vectors during return lowering at least for little endian machines.
This was restricted in r208200 to fix it for big endian machines (according to
the comment), but it also disabled it for little endian too.
llvm-svn: 217846
This lowers frem to a runtime libcall inside fast-isel.
The test case also checks the CallLoweringInfo bug that was exposed by this
change.
This fixes rdar://problem/18342783.
llvm-svn: 217833
using static relocation model and small code model.
Summary: currently we generate GOT based relocations for weak symbol
references regardless of the underlying relocation model. This should
be change so that in static relocation model we use a constant pool
load instead.
Patch from: Keith Walker
Reviewers: Renato Golin, Tim Northover
llvm-svn: 217503
This is the final round of renaming. This changes tblgen to emit lower-case
function names for FastEmitInst_* and FastEmit_*, and updates all its uses
in the source code.
Reviewed by Eric
llvm-svn: 217075
Things got a little bit messy over the years and it is time for a little bit
spring cleaning.
This first commit is focused on the FastISel base class itself. It doxyfies all
comments, C++11fies the code where it makes sense, renames internal methods to
adhere to the coding standard, and clang-formats the files.
Reviewed by Eric
llvm-svn: 217060
There is already target-dependent instruction selection support for Adds/Subs to
support compares and the intrinsics with overflow check. This takes advantage of
the existing infrastructure to also support Add/Sub, which allows the folding of
immediates, sign-/zero-extends, and shifts.
This fixes rdar://problem/18207316.
llvm-svn: 217007
This uses the target-dependent selection code for shifts first, which allows us
to create better code for shifts with immediates and sign-/zero-extend folding.
Vector type are not handled yet and the code falls back to target-independent
instruction selection for these cases.
This fixes rdar://problem/17907920.
llvm-svn: 216985
FastISel for AArch64 supports more value types than are actually legal. Use a
dedicated helper function to reflect this.
It is very similar to the isLoadStoreTypeLegal function, with the exception
that vector types are not supported yet.
llvm-svn: 216984
This change moves FastISel for AArch64 to target-dependent instruction selection
only. This change replicates the existing target-independent behavior, therefore
there are no changes to the unit tests or new tests.
Future changes will take advantage of this change and update functionality
and unit tests.
llvm-svn: 216955
When we select a trunc instruction we don't emit any code if the type is already
i32 or smaller. This is because the instruction that uses the truncated value
will deal with it.
This behavior can incorrectly transfer a kill flag, which was meant for the
result of the truncate, onto the source register.
%2 = trunc i32 %1 to i16
... = ... %2 -> ... = ... vreg1 <kill>
... = ... %1 ... = ... vreg1
This commit fixes this by emitting a COPY instruction, so that the result and
source register are distinct virtual registers.
This fixes rdar://problem/18178188.
llvm-svn: 216750
This fix checks first if the instruction to be folded (e.g. sign-/zero-extend,
or shift) is in the same machine basic block as the instruction we are folding
into.
Not doing so can result in incorrect code, because the value might not be
live-out of the basic block, where the value is defined.
This fixes rdar://problem/18169495.
llvm-svn: 216700
Currently instructions are folded very aggressively into the memory operation,
which can lead to the use of killed operands:
%vreg1<def> = ADDXri %vreg0<kill>, 2
%vreg2<def> = LDRBBui %vreg0, 2
... = ... %vreg1 ...
This usually happens when the result is also used by another non-memory
instruction in the same basic block, or any instruction in another basic block.
If the computed address is used by only memory operations in the same basic
block, then it is safe to fold them. This is because all memory operations will
fold the address computation and the original computation will never be emitted.
This fixes rdar://problem/18142857.
llvm-svn: 216629
When the address comes directly from a shift instruction then the address
computation cannot be folded into the memory instruction, because the zero
register is not available as a base register. Simplify addess needs to emit the
shift instruction and use the result as base register.
llvm-svn: 216621
Use the zero register directly when possible to avoid an unnecessary register
copy and a wasted register at -O0. This also uses integer stores to store a
positive floating-point zero. This saves us from materializing the positive zero
in a register and then storing it.
llvm-svn: 216617
When a shift with extension or an add with shift and extension cannot be folded
into the memory operation, then the address calculation has to be materialized
separately. While doing so the code forgot to consider a possible sign-/zero-
extension. This fix folds now also the sign-/zero-extension into the add or
shift instruction which is used to materialize the address.
This fixes rdar://problem/18141718.
llvm-svn: 216511
Juergen Ributzka