Summary:
We used to assume V->RAUW only modifies the operand list of V's user.
However, if V and V's user are Constants, RAUW may replace and invalidate V's
user entirely.
This patch fixes the above issue by letting the caller replace the
operand instead of calling RAUW on Constants.
Test Plan: @nested_const_expr and @rauw in access-non-generic.ll
Reviewers: broune, jholewinski
Reviewed By: broune, jholewinski
Subscribers: jholewinski, llvm-commits
Differential Revision: http://reviews.llvm.org/D10345
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239435 91177308-0d34-0410-b5e6-96231b3b80d8
This gets all the handler info through to the asm printer and we can
look at the .xdata tables now. I've convinced one small catch-all test
case to work, but other than that, it would be a stretch to say this is
functional.
The state numbering algorithm avoids doing any scope reconstruction as
we do for C++ to simplify the implementation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239433 91177308-0d34-0410-b5e6-96231b3b80d8
Store instructions do not modify register values and therefore it's safe
to form a store pair even if the source register has been read in between
the two store instructions.
Previously, the read of w1 (see below) prevented the formation of a stp.
str w0, [x2]
ldr w8, [x2, #8]
add w0, w8, w1
str w1, [x2, #4]
ret
We now generate the following code.
stp w0, w1, [x2]
ldr w8, [x2, #8]
add w0, w8, w1
ret
All correctness tests with -Ofast on A57 with Spec200x and EEMBC pass.
Performance results for SPEC2K were within noise.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239432 91177308-0d34-0410-b5e6-96231b3b80d8
that was resetting it.
Remove the uses of DisableTailCalls in subclasses of TargetLowering and use
the value of function attribute "disable-tail-calls" instead. Also,
unconditionally add pass TailCallElim to the pipeline and check the function
attribute at the start of runOnFunction to disable the pass on a per-function
basis.
This is part of the work to remove TargetMachine::resetTargetOptions, and since
DisableTailCalls was the last non-fast-math option that was being reset in that
function, we should be able to remove the function entirely after the work to
propagate IR-level fast-math flags to DAG nodes is completed.
Out-of-tree users should remove the uses of DisableTailCalls and make changes
to attach attribute "disable-tail-calls"="true" or "false" to the functions in
the IR.
rdar://problem/13752163
Differential Revision: http://reviews.llvm.org/D10099
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239427 91177308-0d34-0410-b5e6-96231b3b80d8
array of bytes. The generation of this byte arrays was expecting
the host to be little endian, which prevents big endian hosts to be
used in the generation of the PTX code. This patch fixes the
problem by changing the way the bytes are extracted so that it
works for either little and big endian.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239412 91177308-0d34-0410-b5e6-96231b3b80d8
Specified the llvm namespace for the 2 calls to make_unique() which caused
compilation errors in Visual Studio 2013.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239405 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
For some branches, GAS accepts an immediate instead of the 2nd register operand.
We only implement this for BNE and BEQ for now. Other branch instructions can be added later, if needed.
Reviewers: dsanders
Reviewed By: dsanders
Subscribers: seanbruno, emaste, llvm-commits
Differential Revision: http://reviews.llvm.org/D9666
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239396 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This cleans up most allocas NVPTXLowerKernelArgs emits for byval
parameters.
Test Plan: makes bug21465.ll more stronger to verify no redundant local load/store.
Reviewers: eliben, jholewinski
Reviewed By: eliben, jholewinski
Subscribers: jholewinski, llvm-commits
Differential Revision: http://reviews.llvm.org/D10322
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239368 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This was a longstanding FIXME and is a necessary precursor to cases
where foldOperandImpl may have to create more than one instruction
(e.g. to constrain a register class). This is the split out NFC changes from
D6262.
Reviewers: pete, ributzka, uweigand, mcrosier
Reviewed By: mcrosier
Subscribers: mcrosier, ted, llvm-commits
Differential Revision: http://reviews.llvm.org/D10174
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239336 91177308-0d34-0410-b5e6-96231b3b80d8
on a per-function basis.
Previously some of the passes were conditionally added to ARM's pass pipeline
based on the target machine's subtarget. This patch makes changes to add those
passes unconditionally and execute them conditonally based on the predicate
functor passed to the pass constructors. This enables running different sets of
passes for different functions in the module.
rdar://problem/20542263
Differential Revision: http://reviews.llvm.org/D8717
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239325 91177308-0d34-0410-b5e6-96231b3b80d8
While we have some code to transform specification like {ax} into
{eax}/{rax} if the operand type isn't 16bit, we should reject cases
where there is no sane way to do this, like the i128 type in the
example.
Related to rdar://21042280
Differential Revision: http://reviews.llvm.org/D10260
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239309 91177308-0d34-0410-b5e6-96231b3b80d8
This patch adds support for system register MMFR4_EL1 (memory model feature register) in the assembler.
This register provides information about the implemented memory model and memory management support.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239302 91177308-0d34-0410-b5e6-96231b3b80d8
These are added mainly for the benefit of clang, but this also means that they
are now allowed in .fpu directives and we emit the correct .fpu directive when
single-precision-only is used.
Differential Revision: http://reviews.llvm.org/D10238
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239151 91177308-0d34-0410-b5e6-96231b3b80d8
Add getFPUFeatures to TargetParser, which gets the list of subtarget features
that are enabled/disabled for each FPU, and use it when handling the .fpu
directive.
No functional change in this commit, though clang will start behaving
differently once it starts using this.
Differential Revision: http://reviews.llvm.org/D10237
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239150 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Only restoring AvailableFeatures is not enough and will lead to buggy behaviour.
For example, if we have a feature enabled and we ".set pop", the next time we try
to ".set" that feature nothing will happen because the "!(STI.getFeatureBits()[Feature])"
check will be false, because we didn't restore STI.FeatureBits.
In order to fix this, we need to make MipsAssemblerOptions remember the STI.FeatureBits
instead of the AvailableFeatures and then regenerate AvailableFeatures each time we ".set pop".
This is because, AFAIK, there is no way to convert from AvailableFeatures back to STI.FeatureBits,
but the reverse is possible by using ComputeAvailableFeatures(STI.FeatureBits).
I also moved the updating of AssemblerOptions inside the "if" statement in
setFeatureBits() and clearFeatureBits(), as there is no reason to update if
nothing changes.
Reviewers: dsanders, mkuper
Reviewed By: dsanders
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D9156
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239144 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
A small bit that I missed when I updated the X86 backend to account for
the Win64 calling convention on non-Windows. Now we don't use dead
non-volatile registers when emitting a Win64 indirect tail call on
non-Windows.
Should fix PR23710.
Test Plan: Added test for the correct behavior based on the case I posted to PR23710.
Reviewers: rnk
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D10258
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239111 91177308-0d34-0410-b5e6-96231b3b80d8
NVPTXISelDAGToDAG translates "addrspacecast to param" to
NVPTX::nvvm_ptr_gen_to_param
Added an llc test in bug21465.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239100 91177308-0d34-0410-b5e6-96231b3b80d8
Now that we can look at users, we can trivially do this: when we would
have otherwise disabled GlobalMerge (currently -O<3), we can just run
it for minsize functions, as it's usually a codesize win.
Differential Revision: http://reviews.llvm.org/D10054
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239087 91177308-0d34-0410-b5e6-96231b3b80d8
Fix the FIXME and remove this old as(1) compat option. It was useful for
bringup of the integrated assembler to diff object files, but now it's
just causing more relocations than strictly necessary to be generated.
rdar://21201804
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239084 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
With this patch, NVPTXLowerKernelArgs converts a kernel pointer argument to a
pointer in the global address space. This change, along with
NVPTXFavorNonGenericAddrSpaces, allows the NVPTX backend to emit ld.global.*
and st.global.* for accessing kernel pointer arguments.
Minor changes:
1. refactor: extract function convertToPointerInAddrSpace
2. fix a bug in the test case in bug21465.ll
Test Plan: lower-kernel-ptr-arg.ll
Reviewers: eliben, meheff, jholewinski
Reviewed By: jholewinski
Subscribers: wengxt, jholewinski, llvm-commits
Differential Revision: http://reviews.llvm.org/D10154
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239082 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
-march=bpf -> host endian
-march=bpf_le -> little endian
-match=bpf_be -> big endian
Test Plan:
v1 was tested by IBM s390 guys and appears to be working there.
It bit rots too fast here.
Reviewers: chandlerc, tstellarAMD
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D10177
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239071 91177308-0d34-0410-b5e6-96231b3b80d8
Now that we sometimes know the address space, this can
theoretically do a better job.
This needs better test coverage, but this mostly depends on
first updating the loop optimizatiosn to provide the address
space.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239053 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This is the first of several patches to eliminate StringRef forms of GNU
triples from the internals of LLVM. After this is complete, GNU triples
will be replaced by a more authoratitive representation in the form of
an LLVM TargetTuple.
Reviewers: rengolin
Reviewed By: rengolin
Subscribers: ted, llvm-commits, rengolin, jholewinski
Differential Revision: http://reviews.llvm.org/D10236
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239036 91177308-0d34-0410-b5e6-96231b3b80d8
The fix is just that getOther had not been updated for packing the st_other
values in fewer bits and could return spurious values:
- unsigned Other = (getFlags() & (0x3f << ELF_STO_Shift)) >> ELF_STO_Shift;
+ unsigned Other = (getFlags() & (0x7 << ELF_STO_Shift)) >> ELF_STO_Shift;
Original message:
Pack the MCSymbolELF bit fields into MCSymbol's Flags.
This reduces MCSymolfELF from 64 bytes to 56 bytes on x86_64.
While at it, also make getOther/setOther easier to use by accepting unshifted
STO_* values.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239012 91177308-0d34-0410-b5e6-96231b3b80d8
This reduces MCSymolfELF from 64 bytes to 56 bytes on x86_64.
While at it, also make getOther/setOther easier to use by accepting unshifted
STO_* values.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239006 91177308-0d34-0410-b5e6-96231b3b80d8
The first try (r238051) to land this was reverted due to ExecutionEngine build failure;
that was hopefully addressed by r238788.
The second try (r238842) to land this was reverted due to BUILD_SHARED_LIBS failure;
that was hopefully addressed by r238953.
This patch adds a TargetRecip class for processing many recip codegen possibilities.
The class is intended to handle both command-line options to llc as well
as options passed in from a front-end such as clang with the -mrecip option.
The x86 backend is updated to use the new functionality.
Only -mcpu=btver2 with -ffast-math should see a functional change from this patch.
All other x86 CPUs continue to *not* use reciprocal estimates by default with -ffast-math.
Differential Revision: http://reviews.llvm.org/D8982
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239001 91177308-0d34-0410-b5e6-96231b3b80d8
The existing code would unnecessarily break LDRD/STRD apart with
non-adjacent registers, on thumb2 this is not necessary.
Ideally on thumb2 we shouldn't match for ldrd/strd pre-regalloc anymore
as there is not reason to set register hints anymore, changing that is
something for a future patch however.
Differential Revision: http://reviews.llvm.org/D9694
Recommiting after the revert in r238821, the buildbot still failed with
the patch removed so there seems to be another reason for the breakage.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238935 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
But still handle them the same way since I don't know how they differ on
this target.
Of these, /U[qytnms]/ do not have backend tests but are accepted by clang.
No functional change intended.
Reviewers: t.p.northover
Reviewed By: t.p.northover
Subscribers: t.p.northover, aemerson, llvm-commits
Differential Revision: http://reviews.llvm.org/D8203
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238921 91177308-0d34-0410-b5e6-96231b3b80d8
Intel® Memory Protection Extensions (Intel® MPX) is a new feature in Skylake.
It is a part of KNL and SKX sets. It is also a part of Skylake client.
I added definition of %bnd0 - %bnd3 registers, each register is a pair of 64-bit integers.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238916 91177308-0d34-0410-b5e6-96231b3b80d8
This patch removes the old X86ISD::FSRL op - which allowed float vectors to use the byte right shift operations (causing a domain switch....).
Since the refactoring of the shuffle lowering code this no longer has any use.
Differential Revision: http://reviews.llvm.org/D10169
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238906 91177308-0d34-0410-b5e6-96231b3b80d8
Now that we have a dedicated type for ELF symbol, these helper functions can
become member function of MCSymbolELF.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238864 91177308-0d34-0410-b5e6-96231b3b80d8
The first try (r238051) to land this was reverted due to bot failures
that were hopefully addressed by r238788.
This patch adds a TargetRecip class for processing many recip codegen possibilities.
The class is intended to handle both command-line options to llc as well
as options passed in from a front-end such as clang with the -mrecip option.
The x86 backend is updated to use the new functionality.
Only -mcpu=btver2 with -ffast-math should see a functional change from this patch.
All other x86 CPUs continue to *not* use reciprocal estimates by default with -ffast-math.
Differential Revision: http://reviews.llvm.org/D8982
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238842 91177308-0d34-0410-b5e6-96231b3b80d8
using lowerVectorShuffleWithSHUFPS() and other shuffle-helpers routines.
Added matching of VALIGN instruction.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238830 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
With this change we are able to realign the stack dynamically, whenever it
contains objects with alignment requirements that are larger than the
alignment specified from the given ABI.
We have to use the $fp register as the frame pointer when we perform
dynamic stack realignment. In complex stack frames, with variably-sized
objects, we reserve additionally the callee-saved register $s7 as the
base pointer in order to reference locals.
Reviewers: dsanders
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D8633
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238829 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit r238795, as it broke the Thumb2 self-hosting buildbot.
Since self-hosting issues with Clang are hard to investigate, I'm taking the
liberty to revert now, so we can investigate it offline.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238821 91177308-0d34-0410-b5e6-96231b3b80d8
This create a MCSymbolELF class and moves SymbolSize since only ELF
needs a size expression.
This reduces the size of MCSymbol from 56 to 48 bytes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238801 91177308-0d34-0410-b5e6-96231b3b80d8
The existing code would unnecessarily break LDRD/STRD apart with
non-adjacent registers, on thumb2 this is not necessary.
Ideally on thumb2 we shouldn't match for ldrd/strd pre-regalloc anymore
as there is not reason to set register hints anymore, changing that is
something for a future patch however.
Differential Revision: http://reviews.llvm.org/D9694
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238795 91177308-0d34-0410-b5e6-96231b3b80d8
Previously CCMP/FCCMP instructions were only used by the
AArch64ConditionalCompares pass for control flow. This patch uses them
for SELECT like instructions as well by matching patterns in ISelLowering.
PR20927, rdar://18326194
Differential Revision: http://reviews.llvm.org/D8232
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238793 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: Implement bswap intrinsic for MIPS FastISel. It's very different for misp32 r1/r2 .
Based on a patch by Reed Kotler.
Test Plan:
bswap1.ll
test-suite
Reviewers: dsanders, rkotler
Subscribers: llvm-commits, rfuhler
Differential Revision: http://reviews.llvm.org/D7219
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238760 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Implement the intrinsics memset, memcopy and memmove in MIPS FastISel.
Make some needed infrastructure fixes so that this can work.
Based on a patch by Reed Kotler.
Test Plan:
memtest1.ll
The patch passes test-suite for mips32 r1/r2 and at O0/O2
Reviewers: rkotler, dsanders
Subscribers: llvm-commits, rfuhler
Differential Revision: http://reviews.llvm.org/D7158
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238759 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: Implement the LLVM assembly urem/srem and sdiv/udiv instructions in MIPS FastISel.
Based on a patch by Reed Kotler.
Test Plan:
srem1.ll
div1.ll
test-suite at O0/O2 for mips32 r1/r2
Reviewers: dsanders, rkotler
Subscribers: llvm-commits, rfuhler
Differential Revision: http://reviews.llvm.org/D7028
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238757 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: Implement the LLVM IR select statement for MIPS FastISelsel.
Based on a patch by Reed Kotler.
Test Plan:
"Make check" test included now.
Passes test-suite at O2/O0 mips32 r1/r2.
Reviewers: dsanders, rkotler
Subscribers: llvm-commits, rfuhler
Differential Revision: http://reviews.llvm.org/D6774
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238756 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
The contents of the HI/LO registers are unpredictable after the execution of
the MUL instruction. In addition to implicitly defining these registers in the
MUL instruction definition, we have to mark those registers as dead too.
Without this the fast register allocator is running out of registers when the
MUL instruction is followed by another one that tries to allocate the AC0
register.
Based on a patch by Reed Kotler.
Reviewers: dsanders, rkotler
Subscribers: llvm-commits, rfuhler
Differential Revision: http://reviews.llvm.org/D9825
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238755 91177308-0d34-0410-b5e6-96231b3b80d8
This is important because of different addressing modes
depending on the address space for GPU targets.
This only adds the argument, and does not update
any of the uses to provide the correct address space.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238723 91177308-0d34-0410-b5e6-96231b3b80d8
The original version didn't properly account for the base register
being modified before the final jump, so caused miscompilations in
Chromium and LLVM. I've fixed this and tested with an LLVM self-host
(I don't have the means to build & test Chromium).
The general idea remains the same: in pathological cases jump tables
can be too far away from the instructions referencing them (like other
constants) so they need to be movable.
Should fix PR23627.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238680 91177308-0d34-0410-b5e6-96231b3b80d8
That comment misleads the current discussions in mentioned bug. Leave
the discussions to the bug. Also, adding a future change FIXME.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238653 91177308-0d34-0410-b5e6-96231b3b80d8
best approach of each.
For vNi16, we use SHL + ADD + SRL pattern that seem easily the best.
For vNi32, we use the PUNPCK + PSADBW + PACKUSWB pattern. In some cases
there is a huge improvement with this in IACA's estimated throughput --
over 2x higher throughput!!!! -- but the measurements are too good to be
true. In one narrow case, the SHL + ADD + SHL + ADD + SRL pattern looks
slightly faster, but I'm not sure I believe any of the measurements at
this point. Both are the exact same uops though. Hard to be confident of
anything past that.
If anyone wants to collect very detailed (Agner-level) timings with the
result of this patch, or with the i32 case replaced with SHL + ADD + SHl
+ ADD + SRL, I'd be very interested. Note that you'll need to test it on
both Ivybridge and Haswell, with both SSE3, SSSE3, and AVX selected as
I saw unique behavior in each of these buckets with IACA all of which
should be checked against measured performance.
But this patch is still a useful improvement by dropping duplicate work
and getting the much nicer PSADBW lowering for v2i64.
I'd still like to rephrase this in terms of generic horizontal sum. It's
a bit lame to have a special case of that just for popcount.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238652 91177308-0d34-0410-b5e6-96231b3b80d8
The plan was to move the whole table into the already existing ArchExtNames
but some fields depend on a table-generated file, and we don't yet have this
feature in the generic lib/Support side.
Once the minimum target-specific table-generated files are available in a
generic fashion to these libraries, we'll have to keep it in the ASM parser.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238651 91177308-0d34-0410-b5e6-96231b3b80d8
shorter one. NFC.
In addition to being much shorter to type and requiring fewer arguments,
this change saves over 30 lines from this one file, all wasted on total
boilerplate...
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238640 91177308-0d34-0410-b5e6-96231b3b80d8
around a value using its existing SDLoc.
Start using this in just one function to save omg lines of code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238638 91177308-0d34-0410-b5e6-96231b3b80d8
shifting vectors of bytes as x86 doesn't have direct support for that.
This removes a bunch of redundant masking in the generated code for SSE2
and SSE3.
In order to avoid the really significant code size growth this would
have triggered, I also factored the completely repeatative logic for
shifting and masking into two lambdas which in turn makes all of this
much easier to read IMO.
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in-register LUT technique.
Summary:
A description of this technique can be found here:
http://wm.ite.pl/articles/sse-popcount.html
The core of the idea is to use an in-register lookup table and the
PSHUFB instruction to compute the population count for the low and high
nibbles of each byte, and then to use horizontal sums to aggregate these
into vector population counts with wider element types.
On x86 there is an instruction that will directly compute the horizontal
sum for the low 8 and high 8 bytes, giving vNi64 popcount very easily.
Various tricks are used to get vNi32 and vNi16 from the vNi8 that the
LUT computes.
The base implemantion of this, and most of the work, was done by Bruno
in a follow up to D6531. See Bruno's detailed post there for lots of
timing information about these changes.
I have extended Bruno's patch in the following ways:
0) I committed the new tests with baseline sequences so this shows
a diff, and regenerated the tests using the update scripts.
1) Bruno had noticed and mentioned in IRC a redundant mask that
I removed.
2) I introduced a particular optimization for the i32 vector cases where
we use PSHL + PSADBW to compute the the low i32 popcounts, and PSHUFD
+ PSADBW to compute doubled high i32 popcounts. This takes advantage
of the fact that to line up the high i32 popcounts we have to shift
them anyways, and we can shift them by one fewer bit to effectively
divide the count by two. While the PSHUFD based horizontal add is no
faster, it doesn't require registers or load traffic the way a mask
would, and provides more ILP as it happens on different ports with
high throughput.
3) I did some code cleanups throughout to simplify the implementation
logic.
4) I refactored it to continue to use the parallel bitmath lowering when
SSSE3 is not available to preserve the performance of that version on
SSE2 targets where it is still much better than scalarizing as we'll
still do a bitmath implementation of popcount even in scalar code
there.
With #1 and #2 above, I analyzed the result in IACA for sandybridge,
ivybridge, and haswell. In every case I measured, the throughput is the
same or better using the LUT lowering, even v2i64 and v4i64, and even
compared with using the native popcnt instruction! The latency of the
LUT lowering is often higher than the latency of the scalarized popcnt
instruction sequence, but I think those latency measurements are deeply
misleading. Keeping the operation fully in the vector unit and having
many chances for increased throughput seems much more likely to win.
With this, we can lower every integer vector popcount implementation
using the LUT strategy if we have SSSE3 or better (and thus have
PSHUFB). I've updated the operation lowering to reflect this. This also
fixes an issue where we were scalarizing horribly some AVX lowerings.
Finally, there are some remaining cleanups. There is duplication between
the two techniques in how they perform the horizontal sum once the byte
population count is computed. I'm going to factor and merge those two in
a separate follow-up commit.
Differential Revision: http://reviews.llvm.org/D10084
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a separate routine, generalize it to work for all the integer vector
sizes, and do general code cleanups.
This dramatically improves lowerings of byte and short element vector
popcount, but more importantly it will make the introduction of the
LUT-approach much cleaner.
The biggest cleanup I've done is to just force the legalizer to do the
bitcasting we need. We run these iteratively now and it makes the code
much simpler IMO. Other changes were minor, and mostly naming and
splitting things up in a way that makes it more clear what is going on.
The other significant change is to use a different final horizontal sum
approach. This is the same number of instructions as the old method, but
shifts left instead of right so that we can clear everything but the
final sum with a single shift right. This seems likely better than
a mask which will usually have to read the mask from memory. It is
certaily fewer u-ops. Also, this will be temporary. This and the LUT
approach share the need of horizontal adds to finish the computation,
and we have more clever approaches than this one that I'll switch over
to.
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It turns out that _except_handler3 and _except_handler4 really use the
same stack allocation layout, at least today. They just make different
choices about encoding the LSDA.
This is in preparation for lowering the llvm.eh.exceptioninfo().
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The value in 'ebp' acts as an implicit argument to the outlined
handlers, and is recovered with frameaddress(1).
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This patch corresponds to review:
http://reviews.llvm.org/D9941
It adds the various FMA instructions introduced in the version 2.07 of
the ISA along with the testing for them. These are operations on single
precision scalar values in VSX registers.
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Small (really small!) C++ exception handling examples work on 32-bit x86
now.
This change disables the use of .seh_* directives in WinException when
CFI is not in use. It also uses absolute symbol references in the tables
instead of imagerel32 relocations.
Also fixes a cache invalidation bug in MMI personality classification.
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MIOperands/ConstMIOperands are classes iterating over the MachineOperand
of a MachineInstr, however MachineInstr::mop_iterator does the same
thing.
I assume these two iterators exist to have a uniform interface to
iterate over the operands of a machine instruction bundle and a single
machine instruction. However in practice I find it more confusing to have 2
different iterator classes, so this patch transforms (nearly all) the
code to use mop_iterators.
The only exception being MIOperands::anlayzePhysReg() and
MIOperands::analyzeVirtReg() still needing an equivalent, I leave that
as an exercise for the next patch.
Differential Revision: http://reviews.llvm.org/D9932
This version is slightly modified from the proposed revision in that it
introduces MachineInstr::getOperandNo to avoid the extra counting
variable in the few loops that previously used MIOperands::getOperandNo.
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This moves all the state numbering code for C++ EH to WinEHPrepare so
that we can call it from the X86 state numbering IR pass that runs
before isel.
Now we just call the same state numbering machinery and insert a bunch
of stores. It also populates MachineModuleInfo with information about
the current function.
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For x86 targets, do not do sibling call optimization when materializing
the callee's address would require a GOT relocation. We can still do
tail calls to internal functions, hidden functions, and protected
functions, because they do not require this kind of relocation. It is
still possible to get GOT relocations when the user explicitly asks for
it with musttail or -tailcallopt, both of which are supposed to
guarantee TCO.
Based on a patch by Chih-hung Hsieh.
Reviewers: srhines, timmurray, danalbert, enh, void, nadav, rnk
Subscribers: joerg, davidxl, llvm-commits
Differential Revision: http://reviews.llvm.org/D9799
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We were previously codegen'ing these as regular load/store operations and
hoping that the register allocator would allocate registers in ascending order
so that we could apply an LDM/STM combine after register allocation. According
to the commit that first introduced this code (r37179), we planned to teach
the register allocator to allocate the registers in ascending order. This
never got implemented, and up to now we've been stuck with very poor codegen.
A much simpler approach for achiveing better codegen is to create LDM/STM
instructions with identical sets of virtual registers, let the register
allocator pick arbitrary registers and order register lists when printing an
MCInst. This approach also avoids the need to repeatedly calculate offsets
which ultimately ought to be eliminated pre-RA in order to decrease register
pressure.
This is implemented by lowering the memcpy intrinsic to a series of SD-only
MCOPY pseudo-instructions which performs a memory copy using a given number
of registers. During SD->MI lowering, we lower MCOPY to LDM/STM. This is a
little unusual, but it avoids the need to encode register lists in the SD,
and we can take advantage of SD use lists to decide whether to use the _UPD
variant of the instructions.
Fixes PR9199.
Differential Revision: http://reviews.llvm.org/D9508
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