When an extend more than doubles the size of the elements (e.g., a zext
from v16i8 to v16i32), the normal legalization method of splitting the
vectors will run into problems as by the time the destination vector is
legal, the source vector is illegal. The end result is the operation
often becoming scalarized, with the typical horrible performance. For
example, on x86_64, the simple input of:
define void @bar(<16 x i8> %a, <16 x i32>* %p) nounwind {
%tmp = zext <16 x i8> %a to <16 x i32>
store <16 x i32> %tmp, <16 x i32>*%p
ret void
}
Generates:
.section __TEXT,__text,regular,pure_instructions
.section __TEXT,__const
.align 5
LCPI0_0:
.long 255 ## 0xff
.long 255 ## 0xff
.long 255 ## 0xff
.long 255 ## 0xff
.long 255 ## 0xff
.long 255 ## 0xff
.long 255 ## 0xff
.long 255 ## 0xff
.section __TEXT,__text,regular,pure_instructions
.globl _bar
.align 4, 0x90
_bar:
vpunpckhbw %xmm0, %xmm0, %xmm1
vpunpckhwd %xmm0, %xmm1, %xmm2
vpmovzxwd %xmm1, %xmm1
vinsertf128 $1, %xmm2, %ymm1, %ymm1
vmovaps LCPI0_0(%rip), %ymm2
vandps %ymm2, %ymm1, %ymm1
vpmovzxbw %xmm0, %xmm3
vpunpckhwd %xmm0, %xmm3, %xmm3
vpmovzxbd %xmm0, %xmm0
vinsertf128 $1, %xmm3, %ymm0, %ymm0
vandps %ymm2, %ymm0, %ymm0
vmovaps %ymm0, (%rdi)
vmovaps %ymm1, 32(%rdi)
vzeroupper
ret
So instead we can check if there are legal types that enable us to split
more cleverly when the input vector is already legal such that we don't
turn it into an illegal type. If the extend is such that it's more than
doubling the size of the input we check if
- the number of vector elements is even,
- the source type is legal,
- the type of a split source is illegal,
- the type of an extended (by doubling element size) source is legal, and
- the type of that extended source when split is legal.
If the conditions are met, instead of just splitting both the
destination and the source types, we create an extend that only goes up
one "step" (doubling the element width), and the continue legalizing the
rest of the operation normally. The result is that this operates as a
new, more effecient, termination condition for the loop of "split the
operation until the destination type is legal."
With this change, the above example now compiles to:
_bar:
vpxor %xmm1, %xmm1, %xmm1
vpunpcklbw %xmm1, %xmm0, %xmm2
vpunpckhwd %xmm1, %xmm2, %xmm3
vpunpcklwd %xmm1, %xmm2, %xmm2
vinsertf128 $1, %xmm3, %ymm2, %ymm2
vpunpckhbw %xmm1, %xmm0, %xmm0
vpunpckhwd %xmm1, %xmm0, %xmm3
vpunpcklwd %xmm1, %xmm0, %xmm0
vinsertf128 $1, %xmm3, %ymm0, %ymm0
vmovaps %ymm0, 32(%rdi)
vmovaps %ymm2, (%rdi)
vzeroupper
ret
This generalizes a custom lowering that was added a while back to the
ARM backend. That lowering is no longer necessary, and is removed. The
testcases for it, however, provide excellent ARM tests for this change
and so remain.
rdar://14735100
llvm-svn: 193727
Fixing this Windows build error:
..\lib\Target\Mips\MipsSEISelLowering.cpp(997) : error C2027: use of undefined type 'llvm::raw_ostream'
llvm-svn: 193696
Also corrected the definition of the intrinsics for these instructions (the
result register is also the first operand), and added intrinsics for bsel and
bseli to clang (they already existed in the backend).
These four operations are mostly equivalent to bsel, and bseli (the difference
is which operand is tied to the result). As a result some of the tests changed
as described below.
bitwise.ll:
- bsel.v test adapted so that the mask is unknown at compile-time. This stops
it emitting bmnzi.b instead of the intended bsel.v.
- The bseli.b test now tests the right thing. Namely the case when one of the
values is an uimm8, rather than when the condition is a uimm8 (which is
covered by bmnzi.b)
compare.ll:
- bsel.v tests now (correctly) emits bmnz.v instead of bsel.v because this
is the same operation (see MSA.txt).
i8.ll
- CHECK-DAG-ized test.
- bmzi.b test now (correctly) emits equivalent bmnzi.b with swapped operands
because this is the same operation (see MSA.txt).
- bseli.b still emits bseli.b though because the immediate makes it
distinguishable from bmnzi.b.
vec.ll:
- CHECK-DAG-ized test.
- bmz.v tests now (correctly) emits bmnz.v with swapped operands (see
MSA.txt).
- bsel.v tests now (correctly) emits bmnz.v with swapped operands (see
MSA.txt).
llvm-svn: 193693
This required correcting the definition of the bins[lr]i intrinsics because
the result is also the first operand.
It also required removing the (arbitrary) check for 32-bit immediates in
MipsSEDAGToDAGISel::selectVSplat().
Currently using binsli.d with 2 bits set in the mask doesn't select binsli.d
because the constant is legalized into a ConstantPool. Similar things can
happen with binsri.d with more than 10 bits set in the mask. The resulting
code when this happens is correct but not optimal.
llvm-svn: 193687
(or (and $a, $mask), (and $b, $inverse_mask)) => (vselect $mask, $a, $b).
where $mask is a constant splat. This allows bitwise operations to make use
of bsel.
It's also a stepping stone towards matching bins[lr], and bins[lr]i from
normal IR.
Two sets of similar tests have been added in this commit. The bsel_* functions
test the case where binsri cannot be used. The binsr_*_i functions will
start to use the binsri instruction in the next commit.
llvm-svn: 193682
splat.d is implemented but this subtest is currently disabled. This is because
it is difficult to match the appropriate IR on MIPS32. There is a patch under
review that should help with this so I hope to enable the subtest soon.
llvm-svn: 193680
The Type Legalizer recognizes that VSELECT needs to be split, because the type
is to wide for the given target. The same does not always apply to SETCC,
because less space is required to encode the result of a comparison. As a result
VSELECT is split and SETCC is unrolled into scalar comparisons.
This commit fixes the issue by checking for VSELECT-SETCC patterns in the DAG
Combiner. If a matching pattern is found, then the result mask of SETCC is
promoted to the expected vector mask type for the given target. This mask has
usually the same size as the VSELECT return type (except for Intel KNL). Now the
type legalizer will split both VSELECT and SETCC.
This allows the following X86 DAG Combine code to sucessfully detect the MIN/MAX
pattern. This fixes PR16695, PR17002, and <rdar://problem/14594431>.
Reviewed by Nadav
llvm-svn: 193676
Helper functions are added:
emitPostLd: emit a post-increment load operation with given size.
emitPostSt: emit a post-increment store operation with given size.
No functionality change.
llvm-svn: 193656
Adds a subtarget feature for the CRC instructions (optional in v8-A) to the ARM (32-bit) backend.
Differential Revision: http://llvm-reviews.chandlerc.com/D2036
llvm-svn: 193599
By vectorizing a series of srl, or, ... instructions we have obfuscated the
intention so much that the backend does not know how to fold this code away.
radar://15336950
llvm-svn: 193573
an MCExpr, in order to avoid writing an encoded zero value in the immediate
field.
When getUnconditionalBranchTargetOpValue is called with an MCExpr target, we
don't know what the final immediate field value should be. We shouldn't
explicitly set the immediate field to an encoded zero value as zero is encoded
with a non-zero bit pattern. This leads to bits being set that pollute the
final immediate value. The nature of the encoding is such that the polluted
bits only affect very large immediate values, explaining why this hasn't
caused problems earlier.
Fixes <rdar://problem/15155975>.
llvm-svn: 193535
This commit allows the ARM integrated assembler to parse
and assemble the code with .eabi_attribute, .cpu, and
.fpu directives.
To implement the feature, this commit moves the code from
AttrEmitter to ARMTargetStreamers, and several new test
cases related to cortex-m4, cortex-r5, and cortex-a15 are
added.
Besides, this commit also change the Subtarget->isFPOnlySP()
to Subtarget->hasD16() to match the usage of .fpu directive.
This commit changes the test cases:
* Several .eabi_attribute directives in
2010-09-29-mc-asm-header-test.ll are removed because the .fpu
directive already cover the functionality.
* In the Cortex-A15 test case, the value for
Tag_Advanced_SIMD_arch has be changed from 1 to 2,
which is more precise.
llvm-svn: 193524
useAA significantly improves the handling of vector code that has TBAA
information attached. It also helps other cases, as shown by the testsuite
changes here. The only real downside I've seen is that it interferes with
MergeConsecutiveStores. The problem is that that optimization works top
down, starting at the first store in the chain, and looks for cases where
the chain result is only used by a single related store. These related
stores don't alias, so useAA will have rewritten all the later stores to
use a different chain input (typically the same one as the first store).
I think the advantages outweigh the disadvantages though, so for now I've
just disabled alias analysis for the unaligned-01.ll test.
llvm-svn: 193521
Before I just ported the shell of the pass. I've tried to keep everything
nearly identical to the ARM version. I think it will be very easy to eventually
merge these two and create a new more general pass that other targets can
use. I have some improvements I would like to make to allow pools to
be shared across functions and some other things. When I'm all done we
can think about making a more general pass. More to be ported but the
basic mechanism works now almost as good as gcc mips16.
llvm-svn: 193509
When assembling, a .thumb_func directive is supposed to be applicable to the
next symbol definition, even if there are intervening directives. We were
racing ahead to try and find it, and this commit should fix the issue.
Patch by Gabor Ballabas
llvm-svn: 193403
There's a barrier instruction so that should still be used, but most actual
atomic operations are going to need a platform decision on the correct
behaviour (either nop if single-threaded or OS-support otherwise).
rdar://problem/15287210
llvm-svn: 193399
This optimization is not SSE specific so I am moving it to DAGco.
The new scalar_to_vector dag node exposed a missing pattern in the AArch64 target that I needed to add.
llvm-svn: 193393
Jim Grosbach