- Factor out code to query and modify the sign bit of a floatingpoint
value as an integer. This also works if none of the targets integer
types is big enough to hold all bits of the floatingpoint value.
- Legalize FABS(x) as FCOPYSIGN(x, 0.0) if FCOPYSIGN is available,
otherwise perform bit manipulation on the sign bit. The previous code
used "x >u 0 ? x : -x" which is incorrect for x being -0.0! It also
takes 34 instructions on ARM Cortex-M4. With this patch we only
require 5:
vldr d0, LCPI0_0
vmov r2, r3, d0
lsrs r2, r3, #31
bfi r1, r2, #31, #1
bx lr
(This could be further improved if the compiler would recognize that
r2, r3 is zero).
- Only lower FCOPYSIGN(x, y) = sign(x) ? -FABS(x) : FABS(x) if FABS is
available otherwise perform bit manipulation on the sign bit.
- Perform the sign(x) test by masking out the sign bit and comparing
with 0 rather than shifting the sign bit to the highest position and
testing for "<s 0". For x86 copysignl (on 80bit values) this gets us:
testl $32768, %eax
rather than:
shlq $48, %rax
sets %al
testb %al, %al
Differential Revision: http://reviews.llvm.org/D11172
llvm-svn: 252839
First create a list of candidates, then transform. This simplifies the code in
that you have don't have to worry that you may be using an invalidated
iterator.
Previously, each time we created a memset/memcpy we would reevaluate the entire
loop potentially resulting in lots of redundant work for large basic blocks.
llvm-svn: 252817
When working with tokens, it is often the case that one has instructions
which consume a token and produce a new token. Currently, we have no
mechanism to represent an initial token state.
Instead, we can create a notional "empty token" by inventing a new
constant which captures the semantics we would like. This new constant
is called ConstantTokenNone and is written textually as "token none".
Differential Revision: http://reviews.llvm.org/D14581
llvm-svn: 252811
Summary:
This change introduces the notion of "deoptimization" operand bundles.
LLVM can recognize and optimize these in more precise ways than it can a
generic "unknown" operand bundles.
The current form of this special recognition / optimization is an enum
entry in LLVMContext, a LangRef blurb and a verifier rule. Over time we
will teach LLVM to do more aggressive optimization around deoptimization
operand bundles, exploiting known facts about kinds of state
deoptimization operand bundles are allowed to track.
Reviewers: reames, majnemer, chandlerc, dexonsmith
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D14551
llvm-svn: 252806
This is a step towards consolidating some of the information regarding
attributes in a single place.
This patch moves the enum attributes in Attributes.h to the table-gen
file. Additionally, it adds definitions of target independent string
attributes that will be used in follow-up commits by the inliner to
check attribute compatibility.
rdar://problem/19836465
llvm-svn: 252796
This is a follow-up from the previous discussion on the thread:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20151019/307763.html
The LibLTO lto_get_error_message() API reads error messages from a std::string
sLastErrorString. Instead of passing this string around as an argument, this
patch creates a diagnostic handler and then sends this handler to the
constructor of LTOCodeGenerator.
Differential Revision: http://reviews.llvm.org/D14313
llvm-svn: 252791
Summary:
Don't fold
(zext (and (load x), cst)) -> (and (zextload x), (zext cst))
if
(and (load x) cst)
will match as a zextload already and has additional users.
For example, the following IR:
%load = load i32, i32* %ptr, align 8
%load16 = and i32 %load, 65535
%load64 = zext i32 %load16 to i64
store i32 %load16, i32* %dst1, align 4
store i64 %load64, i64* %dst2, align 8
used to produce the following aarch64 code:
ldr w8, [x0]
and w9, w8, #0xffff
and x8, x8, #0xffff
str w9, [x1]
str x8, [x2]
but with this change produces the following aarch64 code:
ldrh w8, [x0]
str w8, [x1]
str x8, [x2]
Reviewers: resistor, mcrosier
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D14340
llvm-svn: 252789
Summary: Other personalities don't use this special frame slot.
Reviewers: majnemer, andrew.w.kaylor, rnk
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D14580
llvm-svn: 252778
This patch adds DWARF values for the Delphi language and Borland C++
language extensions.
Reviewed by: dblaikie
Subscribers: llvm-commits, majnemer
Differential Revision: http://reviews.llvm.org/D14522
llvm-svn: 252776
Summary: Inlined callsites need to be emitted in debug info so that sample profile can be annotated to the correct inlined instance.
Reviewers: dnovillo, dblaikie
Subscribers: dblaikie, llvm-commits
Differential Revision: http://reviews.llvm.org/D14511
llvm-svn: 252768
The discriminators pass relied on the presence of llvm.dbg.cu to decide
whether to add discriminators, but this fails in the case where debug
info is only enabled partially when -fprofile-sample-use is active.
The reason llvm.dbg.cu is not present in these cases is to prevent
codegen from emitting debug info (as it is only used for the sample
profile pass).
This changes the discriminators pass to also emit discriminators even
when debug info is not being emitted.
llvm-svn: 252763
MIPS32 has instructions for efficient count-leading/trailing-zeros, so this should be
considered a cheap operation (and therefore fair game for speculation) for any MIPS32
implementation.
The net result of allowing this speculation for the regression tests in this patch is
that we get this code:
ctlz:
jr $ra
clz $2, $4
cttz:
addiu $1, $4, -1
not $2, $4
and $1, $2, $1
clz $1, $1
addiu $2, $zero, 32
jr $ra
subu $2, $2, $1
Instead of:
ctlz:
beqz $4, $BB0_2
addiu $2, $zero, 32
clz $2, $4
$BB0_2:
jr $ra
nop
cttz:
beqz $4, $BB1_2
addiu $2, $zero, 32
addiu $1, $4, -1
not $2, $4
and $1, $2, $1
clz $1, $1
addiu $2, $zero, 32
subu $2, $2, $1
$BB1_2:
jr $ra
nop
See D14469 for the larger motivation.
Differential Revision: http://reviews.llvm.org/D14500
llvm-svn: 252755
The committer didn't respond at http://reviews.llvm.org/D14338, so we've got to fix this for them.
This test doesn't pass with thumbv6, so I suppose what they meant is thumbv7.
llvm-svn: 252754
Summary:
Only DSPr2 is present because it appears we've never added DSPr1 tests.
We'll have to correct that in a later patch.
Reviewers: vkalintiris
Subscribers: llvm-commits, dsanders
Differential Revision: http://reviews.llvm.org/D14448
llvm-svn: 252752
I missed the side-effects of ParseBFI in my previous attempt (r252748).
Thanks dblaikie for the suggestion of adding a void use of the unused
variable instead.
llvm-svn: 252751
Summary:
This patch adds a new CMake module for working with ExternalProjects. This wrapper for ExternalProject supports using just-built tools and can hook up dependencies properly so that projects get cleared out.
The example usage here is for the llvm test-suite. In this example, the test-suite is setup as dependent on clang and lld if they are in-tree. If the clang or lld binaries change the test-suite is re-configured, cleaned, and rebuilt.
This cleanup and abstraction wrapping ExternalProject can be extended and applied to other runtime libraries like compiler-rt and libcxx.
Reviewers: samsonov, jroelofs, rengolin, jmolloy
Subscribers: jmolloy, llvm-commits
Differential Revision: http://reviews.llvm.org/D14513
llvm-svn: 252747
If we have a chain of BFIs, we may be able to combine several together into one merged BFI. We can do this if the "from" bits from one BFI OR'd with the "from" bits from the other BFI form a contiguous range, and the same with the "to" bits.
llvm-svn: 252740
Measurements primarily on AArch64 have shown this feature does not
significantly effect compile-time. The are no significant perf changes in LNT,
but for AArch64 at least, there are wins in third party benchmarks.
As discussed on llvm-dev, we're going to try turning this on by default and see
how other targets react to the change.
llvm-svn: 252733
If possible and profitable, replace lea %reg, 1(%reg) and lea %reg, -1(%reg) with inc %reg and dec %reg respectively.
Patch by: anton.nadolsky@intel.com
Differential Revision: http://reviews.llvm.org/D14059
llvm-svn: 252722
Re-implement `ilist_node::getNextNode()` and `getPrevNode()` without
relying on the sentinel having a "next" pointer. Instead, get access to
the owning list and compare against the `begin()` and `end()` iterators.
This only works when the node *can* get access to the owning list. The
new support is in `ilist_node_with_parent<>`, and any class `Ty`
inheriting from `ilist_node<NodeTy>` that wants `getNextNode()` and/or
`getPrevNode()` should inherit from
`ilist_node_with_parent<NodeTy, ParentTy>` instead. The requirements:
- `NodeTy` must have a `getParent()` function that returns the parent.
- `ParentTy` must have a `getSublistAccess()` static that, given a(n
ignored) `NodeTy*` (to determine which list), returns a member field
pointer to the appropriate `ilist<>`.
This isn't the cleanest way to get access to the owning list, but it
leverages the API already used in the IR hierarchy (see, e.g.,
`Instruction::getSublistAccess()`).
If anyone feels like ripping out the calls to `getNextNode()` and
`getPrevNode()` and replacing with direct iterator logic, they can also
remove the access function, etc., but as an incremental step, I'm
maintaining the API where it's currently used in tree.
If these requirements are *not* met, call sites with access to the ilist
can call `iplist<NodeTy>::getNextNode(NodeTy*)` directly, as in
ilistTest.cpp.
Why rewrite this?
The old code was broken, calling `getNext()` on a sentinel that possibly
didn't have a "next" pointer at all! The new code avoids that
particular flavour of UB (see the commit message for r252538 for more
details about the "lucky" memory layout that made this function so
interesting).
There's still some UB here: the end iterator gets downcast to `NodeTy*`,
even when it's a sentinel (which is typically
`ilist_half_node<NodeTy*>`). I'll tackle that in follow-up commits.
See this llvm-dev thread for more details:
http://lists.llvm.org/pipermail/llvm-dev/2015-October/091115.html
What's the danger?
There might be some code that relies on `getNextNode()` or
`getPrevNode()` *never* returning `nullptr` -- i.e., that relies on them
being broken when the sentinel is an `ilist_half_node<NodeTy>`. I tried
to root out those cases with the audits I did leading up to r252380, but
it's possible I missed one or two. I hope not.
(If (1) you have out-of-tree code, (2) you've reverted r252380
temporarily, and (3) you get some weird crashes with this commit, then I
recommend un-reverting r252380 and auditing the compile errors looking
for "strange" implicit conversions.)
llvm-svn: 252694
Right now isTruePredicate is only ever called with Pred == ICMP_SLE or
ICMP_ULE, and the ICMP_SLT and ICMP_ULT cases are dead. This change
removes the untested dead code so that the function is not misleading.
llvm-svn: 252676
Summary:
This change teaches isImpliedCondition to prove things like
(A | 15) < L ==> (A | 14) < L
if the low 4 bits of A are known to be zero.
Depends on D14391
Reviewers: majnemer, reames, hfinkel
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D14392
llvm-svn: 252673
This change would add functionality if isImpliedCondition worked on
vector types; but since it bail out on vector predicates this change is
an NFC.
llvm-svn: 252672
Summary:
Move handling of the SONAME option from add_llvm_library
to llvm_add_library, so that it can be used in sub-projects.
In particular, this makes it possible to have consistently
named shared libraries for LLVM, Clang and LLDB.
Also, base the SONAME and symlinks on the output name
by extracting the OUTPUT_NAME property, rather than assuming
it is the same as the target name.
Reviewers: beanz
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D14539
llvm-svn: 252669
Summary:
This patch adds documentation on compiling CUDA with LLVM as requested by many
engineers and researchers. It includes not only user guides but also some
internals (mostly optimizations) so that early adopters can start hacking and
contributing.
Quite a few researchers who contacted us haven't used LLVM before, which is
unsurprising as it hasn't been long since LLVM picked up CUDA. So I added a
short summary to help these folks get started with LLVM.
I expect this document to evolve substantially down the road. The user guides
will be much simplified after the Clang integration is done. However, the
internals should continue growing to include for example performance debugging
and key areas to improve.
Reviewers: chandlerc, meheff, broune, tra
Subscribers: silvas, jingyue, llvm-commits, eliben
Differential Revision: http://reviews.llvm.org/D14370
llvm-svn: 252660
This patch adds a pass for doing PowerPC peephole optimizations at the
MI level while the code is still in SSA form. This allows for easy
modifications to the instructions while depending on a subsequent pass
of DCE. Both passes are very fast due to the characteristics of SSA.
At this time, the only peepholes added are for cleaning up various
redundancies involving the XXPERMDI instruction. However, I would
expect this will be a useful place to add more peepholes for
inefficiencies generated during instruction selection. The pass is
placed after VSX swap optimization, as it is best to let that pass
remove unnecessary swaps before performing any remaining clean-ups.
The utility of these clean-ups are demonstrated by changes to four
existing test cases, all of which now have tighter expected code
generation. I've also added Eric Schweiz's bugpoint-reduced test from
PR25157, for which we now generate tight code. One other test started
failing for me, and I've fixed it
(test/Transforms/PlaceSafepoints/finite-loops.ll) as well; this is not
related to my changes, and I'm not sure why it works before and not
after. The problem is that the CHECK-NOT: of "statepoint" from test1
fails because of the "statepoint" in test2, and so forth. Adding a
CHECK-LABEL in between keeps the different occurrences of that string
properly scoped.
llvm-svn: 252651
already emitted and fix a latent bug in DIECloner where the DW_CHILDREN_yes
flag is set based on the number of children in the input DIE rather than
the number of children that are actually being cloned.
rdar://problem/23439845
llvm-svn: 252649
Summary:
The module linker lazy links some "discardable if unused" global
values (e.g. linkonce), materializing and linking them only
if they are referenced in the module. If a comdat group contains a
linkonce member that is not referenced, however, it would not be
materialized and linked, leading to an incomplete comdat group.
If there are other object files not part of the same LTO link that also
define and use that comdat group, the linker may select the incomplete
group leading to link time unsats.
To solve this, whenever a global value body is linked, make sure we
materialize any other members of the same comdat group that are not yet
materialized. This ensures they are in the lazy link list and get linked
as well.
Added new test and adjusted old test to remove parts that didn't
make sense with fix.
Reviewers: rafael
Subscribers: dexonsmith, davidxl, llvm-commits
Differential Revision: http://reviews.llvm.org/D14516
llvm-svn: 252647
This was an omission in the patch that landed initial support for
operand bundles. So far we haven't hit this, but we will once the
inliner is able to inline calls to functions that contain calls with
operand bundles.
llvm-svn: 252645
ARM V6T2 has instructions for efficient count-leading/trailing-zeros, so this should be
considered a cheap operation (and therefore fair game for speculation) for any ARM V6T2
implementation.
The net result of allowing this speculation for the regression tests in this patch is
that we get this code:
ctlz:
clz r0, r0
bx lr
cttz:
rbit r0, r0
clz r0, r0
bx lr
Instead of:
ctlz:
cmp r0, #0
moveq r0, #32
clzne r0, r0
bx lr
cttz:
cmp r0, #0
moveq r0, #32
rbitne r0, r0
clzne r0, r0
bx lr
This will help solve a general speculation/despeculation problem noted in PR24818:
https://llvm.org/bugs/show_bug.cgi?id=24818
Differential Revision: http://reviews.llvm.org/D14469
llvm-svn: 252639
This allows avoiding the default Expand behavior which
introduces stack usage. Bitcast the scalar and replace
the missing elements with undef.
This is covered by existing tests and used by a future
commit which makes 64-bit vectors legal types on AMDGPU.
llvm-svn: 252632
This is for AMDGPU to implement v2i64 extract as extract of
half of a v4i32.
This is covered by existing tests and used by a future
commit which makes 64-bit vectors legal types on AMDGPU.
llvm-svn: 252630
This is a cleaned up version of a patch by John Regehr with permission. Originally found via the souper tool.
If we add an odd number to x, then bitwise-and the result with x, we know that the low bit of the result must be zero. Either it was zero in x originally, or the add cleared it in the temporary value. As a result, one of the two values anded together must have the bit cleared.
Differential Revision: http://reviews.llvm.org/D14315
llvm-svn: 252629
When configuring various llvm projects that use AddLLVM.cmake, this warning is
emitted many times, flooding the screen:
Policy CMP0007 is not set: list command no longer ignores empty elements.
The fix is removing an extra semicolon.
Differential Revision: http://reviews.llvm.org/D14339
llvm-svn: 252628
Ensure WeakAny variables are imported as ExternalWeak declarations. To
handle WeakAny more consistently and fix this issue:
1) Update helper doImportAsDefinition to properly flag WeakAny variables
and aliases as not importing defintions.
Update callers of doImportAsDefinition to remove now redundant checks for
WeakAny aliases, or ignore aliases, as appropriate.
2) Add any !doImportAsDefinition GVs to DoNotLinkFromSource set during
linking of the GV prototype, where we usually add GVs to the
DoNotLinkFromSource set for other reasons.
Remove now unnecessary adding of WeakAny aliases to
DoNotLinkFromSource set from copyGlobalAliasProto.
Remove now unnecessary guard against linking non-imported function
bodies from ModuleLinker::run.
llvm-svn: 252626
AArch64 has instructions for efficient count-leading/trailing-zeros, so this should be
considered a cheap operation (and therefore fair game for speculation) for any AArch64
implementation.
The net result of allowing this speculation for the regression tests in this
patch is that we get this code:
ctlz:
clz w0, w0
ret
cttz:
rbit w8, w0
clz w0, w8
ret
Instead of:
ctlz:
cbz w0, .LBB0_2
clz w0, w0
ret
.LBB0_2:
orr w0, wzr, #0x20
ret
cttz:
cbz w0, .LBB1_2
rbit w8, w0
clz w0, w8
ret
.LBB1_2:
orr w0, wzr, #0x20
ret
See D14469 for the larger motivation.
Differential Revision: http://reviews.llvm.org/D14505
llvm-svn: 252625
This is one of the problems noted in PR25016:
https://llvm.org/bugs/show_bug.cgi?id=25016
and:
http://lists.llvm.org/pipermail/llvm-dev/2015-October/090998.html
The spilling problem is independent and not addressed by this patch.
The MachineCombiner was doing reassociations that don't improve or even worsen the critical path.
This is caused by inclusion of the "slack" factor when calculating the critical path of the original
code sequence. If we don't add that, then we have a more conservative cost comparison of the old code
sequence vs. a new sequence. The more liberal calculation must be preserved, however, for the AArch64
MULADD patterns because benchmark regressions were observed without that.
The two failing test cases now have identical asm that does what we want:
a + b + c + d ---> (a + b) + (c + d)
Differential Revision: http://reviews.llvm.org/D13417
llvm-svn: 252616
Added fixes for stage2 failures: CMOV is not commutable; commuting the operands results in the condition being flipped! d'oh!
Original commit message:
If we have a CMOV, OR and AND combination such as:
if (x & CN)
y |= CM;
And:
* CN is a single bit;
* All bits covered by CM are known zero in y;
Then we can convert this to a sequence of BFI instructions. This will always be a win if CM is a single bit, will always be no worse than the TST & OR sequence if CM is two bits, and for thumb will be no worse if CM is three bits (due to the extra IT instruction).
llvm-svn: 252606
This is fix for PR24059.
When we are hoisting instruction above some condition it may turn out
that metadata on this instruction was control dependant on the condition.
This metadata becomes invalid and we need to drop it.
This patch should cover most obvious places of speculative execution (which
I have found by greping isSafeToSpeculativelyExecute). I think there are more
cases but at least this change covers the severe ones.
Differential Revision: http://reviews.llvm.org/D14398
llvm-svn: 252604
David Blaikie