This can happen pretty often in code that looks like:
int foo = bar - 1;
if (foo < 0)
do stuff
In this case, bar < 1 is an equivalent condition.
This transform requires that the add instruction be annotated with nsw.
llvm-svn: 221045
Summary:
This patch extends the 'show' and 'merge' commands in llvm-profdata to handle
sample PGO formats. Using the 'merge' command it is now possible to convert
one sample PGO format to another.
The only format that is currently not working is 'gcc'. I still need to
implement support for it in lib/ProfileData.
The changes in the sample profile support classes are needed for the
merge operation.
Reviewers: bogner
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D6065
llvm-svn: 221032
"[x86] Simplify vector selection if condition value type matches vselect value type and true value is all ones or false value is all zeros."
llvm-svn: 221028
There is quiet a bit of logic that is common to any GlobalValue but was
duplicated for Functions, GlobalVariables and GlobalAliases.
While at it, merge visibility even when comdats are used, fixing pr21415.
llvm-svn: 221014
We need to figure out how to track ptrtoint values all the
way until result is converted back to a pointer in order
to correctly rewrite the pointer type.
llvm-svn: 220997
Now that we have initial support for VSX, we can begin adding
intrinsics for programmer access to VSX instructions. This patch adds
basic support for VSX intrinsics in general, and tests it by
implementing intrinsics for minimum and maximum for the vector double
data type.
The LLVM portion of this is quite straightforward. There is a
companion patch for Clang.
llvm-svn: 220988
This patch adds an optimization in CodeGenPrepare to move an extractelement
right before a store when the target can combine them.
The optimization may promote any scalar operations to vector operations in the
way to make that possible.
** Context **
Some targets use different register files for both vector and scalar operations.
This means that transitioning from one domain to another may incur copy from one
register file to another. These copies are not coalescable and may be expensive.
For example, according to the scheduling model, on cortex-A8 a vector to GPR
move is 20 cycles.
** Motivating Example **
Let us consider an example:
define void @foo(<2 x i32>* %addr1, i32* %dest) {
%in1 = load <2 x i32>* %addr1, align 8
%extract = extractelement <2 x i32> %in1, i32 1
%out = or i32 %extract, 1
store i32 %out, i32* %dest, align 4
ret void
}
As it is, this IR generates the following assembly on armv7:
vldr d16, [r0] @vector load
vmov.32 r0, d16[1] @ cross-register-file copy: 20 cycles
orr r0, r0, #1 @ scalar bitwise or
str r0, [r1] @ scalar store
bx lr
Whereas we could generate much faster code:
vldr d16, [r0] @ vector load
vorr.i32 d16, #0x1 @ vector bitwise or
vst1.32 {d16[1]}, [r1:32] @ vector extract + store
bx lr
Half of the computation made in the vector is useless, but this allows to get
rid of the expensive cross-register-file copy.
** Proposed Solution **
To avoid this cross-register-copy penalty, we promote the scalar operations to
vector operations. The penalty will be removed if we manage to promote the whole
chain of computation in the vector domain.
Currently, we do that only when the chain of computation ends by a store and the
target is able to combine an extract with a store.
Stores are the most likely candidates, because other instructions produce values
that would need to be promoted and so, extracted as some point[1]. Moreover,
this is customary that targets feature stores that perform a vector extract (see
AArch64 and X86 for instance).
The proposed implementation relies on the TargetTransformInfo to decide whether
or not it is beneficial to promote a chain of computation in the vector domain.
Unfortunately, this interface is rather inaccurate for this level of details and
although this optimization may be beneficial for X86 and AArch64, the inaccuracy
will lead to the optimization being too aggressive.
Basically in TargetTransformInfo, everything that is legal has a cost of 1,
whereas, even if a vector type is legal, usually a vector operation is slightly
more expensive than its scalar counterpart. That will lead to too many
promotions that may not be counter balanced by the saving of the
cross-register-file copy. For instance, on AArch64 this penalty is just 4
cycles.
For now, the optimization is just enabled for ARM prior than v8, since those
processors have a larger penalty on cross-register-file copies, and the scope is
limited to basic blocks. Because of these two factors, we limit the effects of
the inaccuracy. Indeed, I did not want to build up a fancy cost model with block
frequency and everything on top of that.
[1] We can imagine targets that can combine an extractelement with other
instructions than just stores. If we want to go into that direction, the current
interfaces must be augmented and, moreover, I think this becomes a global isel
problem.
Differential Revision: http://reviews.llvm.org/D5921
<rdar://problem/14170854>
llvm-svn: 220978
In a case where we have a no {un,}signed wrap flag on the increment, if
RHS - Start is constant then we can avoid inserting a max operation bewteen
the two, since we can statically determine which is greater.
This allows us to unroll loops such as:
void testcase3(int v) {
for (int i=v; i<=v+1; ++i)
f(i);
}
llvm-svn: 220960
Since block address values can be larger than 2GB in 64-bit code, they
cannot be loaded simply using an @l / @ha pair, but instead must be
loaded from the TOC, just like GlobalAddress, ConstantPool, and
JumpTable values are.
The commit also fixes a bug in PPCLinuxAsmPrinter::doFinalization where
temporary labels could not be used as TOC values, since code would
attempt (and fail) to use GetOrCreateSymbol to create a symbol of the
same name as the temporary label.
llvm-svn: 220959
Since JIT->MCJIT migration, most of the ExecutionEngine interface
became deprecated and/or broken. This especially affected the OCaml
bindings, as runFunction is no longer available, and unlike in C,
it is not possible to coerce a pointer to a function and call it
in OCaml.
In practice, LLVM 3.5 shipped completely unusable
Llvm_executionengine.
The GenericValue interface and runFunction were essentially
a poor man's FFI. As such, this interface was removed and instead
a dependency on ctypes >=0.3 added, which handled platform-specific
aspects of accessing data and calling functions.
The new interface does not expose JIT (which is a shim around MCJIT),
as well as the interpreter (which can't handle a lot of valid IR).
Llvm_executionengine.add_global_mapping is currently unusable
due to PR20656.
llvm-svn: 220957
r212242 introduced a legalizer hook, originally to let AArch64 widen
v1i{32,16,8} rather than scalarize, because the legalizer expected, when
scalarizing the result of a conversion operation, to already have
scalarized the operands. On AArch64, v1i64 is legal, so that commit
ensured operations such as v1i32 = trunc v1i64 wouldn't assert.
It did that by choosing to widen v1 types whenever possible. However,
v1i1 types, for which there's no legal widened type, would still trigger
the assert.
This commit fixes that, by only scalarizing a trunc's result when the
operand has already been scalarized, and introducing an extract_elt
otherwise.
This is similar to r205625.
Fixes PR20777.
llvm-svn: 220937
Earlier this summer I fixed an issue where we were incorrectly combining
multiple loads that had different constraints such alignment, invariance,
temporality, etc. Apparently in one case I made copt paste error and swapped
alignment and invariance.
Tests included.
rdar://18816719
llvm-svn: 220933
The langref says:
LLVM explicitly allows declarations of global variables to be marked
constant, even if the final definition of the global is not. This
capability can be used to enable slightly better optimization of the
program, but requires the language definition to guarantee that
optimizations based on the ‘constantness’ are valid for the
translation units that do not include the definition.
Given that definition, when merging two declarations, we have to drop
constantness if of of them is not marked contant, since the Module
without the constant marker might not have the necessary guarantees.
llvm-svn: 220927
If we load from a location with range metadata, we can use information about the ranges of the loaded value for optimization purposes. This helps to remove redundant checks and canonicalize checks for other optimization passes. This particular patch checks whether a value is known to be non-zero from the range metadata.
Currently, these tests are against InstCombine. In theory, all of these should be InstSimplify since we're not inserting any new instructions. Moving the code may follow in a separate change.
Reviewed by: Hal
Differential Revision: http://reviews.llvm.org/D5947
llvm-svn: 220925
Summary:
This patch finishes up support for handling sampling profiles in both
text and binary formats. The new binary format uses uleb128 encoding to
represent numeric values. This makes profiles files about 25% smaller.
The profile writer class can write profiles in the existing text and the
new binary format. In subsequent patches, I will add the capability to
read (and perhaps write) profiles in the gcov format used by GCC.
Additionally, I will be adding support in llvm-profdata to manipulate
sampling profiles.
There was a bit of refactoring needed to separate some code that was in
the reader files, but is actually common to both the reader and writer.
The new test checks that reading the same profile encoded as text or
raw, produces the same results.
Reviewers: bogner, dexonsmith
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D6000
llvm-svn: 220915
Summary:
The previous calling convention prevented custom functions from being able
to access argument labels unless it knew how many variadic arguments there
were, and of which type. This restriction made it impossible to correctly
model functions in the printf family, as it is legal to pass more arguments
than required to those functions. We now pass arguments in the following order:
non-vararg arguments
labels for non-vararg arguments
[if vararg function, pointer to array of labels for vararg arguments]
[if non-void function, pointer to label for return value]
vararg arguments
Differential Revision: http://reviews.llvm.org/D6028
llvm-svn: 220906
Prior to this commit, the Llvm_target tests (ab)used
the Llvm_executionengine as a mechanism to initialize at least some
target. This needlessly restricted tests to builds which can emit
code for their host architecture.
llvm-svn: 220901
This commit updates the OCaml bindings and tests to use ocamlfind.
The bindings are migrated in order to use ctypes, which are now
required for MCJIT-backed Llvm_executionengine.
The tests are migrated in order to use OUnit and to verify that
the distributed META.llvm allows to build working executables.
Every OCaml toolchain invocation is now chained through ocamlfind,
which (in theory) allows to cross-compile the OCaml bindings.
The configure script now checks for ctypes (>= 0.2.3) and
OUnit (>= 2). The code depending on these libraries will be added
later. The configure script does not check the package versions
in order to keep changes less invasive.
Additionally, OCaml bindings will now be automatically enabled
if ocamlfind is detected on the system, rather than ocamlc, as it
was before.
llvm-svn: 220899
The also-emit-llvm option only supported getting the IR before optimizations.
This patch replaces it with a more generic save-temps option that saves the IR
both before and after optimizations.
llvm-svn: 220885
Summary: This helps llvm-objdump -r to print out the symbol name along
with the relocation type on x86. Adjust existing tests from checking
for "Unknown" to check for the symbol now.
Test Plan: Adjusted test/Object tests.
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D5987
llvm-svn: 220866
In practice this means:
* Always using -g flag.
* Embedding -cclib -lstdc++ into the corresponding cma/cmxa file.
This also moves -lstdc++ in a single place.
* Using caml_named_value instead of a homegrown mechanism.
llvm-svn: 220843
David Majnemer