Commit Graph

9 Commits

Author SHA1 Message Date
Elad Cohen ef5798acf5 Support arbitrary address space pointers in masked gather/scatter intrinsics.
Fixes PR31789 - When loop-vectorize tries to use these intrinsics for a
non-default address space pointer we fail with a "Calling a function with a
bad singature!" assertion. This patch solves this by adding the 'vector of
pointers' argument as an overloaded type which will determine the address
space.

Differential revision: https://reviews.llvm.org/D31490

llvm-svn: 302018
2017-05-03 12:28:54 +00:00
Matthew Simpson 11fe2e9f2b Reapply r298620: [LV] Vectorize GEPs
This patch reapplies r298620. The original patch was reverted because of two
issues. First, the patch exposed a bug in InstCombine that caused the Chromium
builds to fail (PR32414). This issue was fixed in r299017. Second, the patch
introduced a bug in the vectorizer's scalars analysis that caused test suite
builds to fail on SystemZ. The scalars analysis was too aggressive and marked a
memory instruction scalar, even though it was going to be vectorized. This
issue has been fixed in the current patch and several new test cases for the
scalars analysis have been added.

llvm-svn: 299770
2017-04-07 14:15:34 +00:00
Ivan Krasin c2124e185c Revert r298620: [LV] Vectorize GEPs
Reason: breaks linking Chromium with LLD + ThinLTO (a pass crashes)
LLVM bug: https://bugs.llvm.org//show_bug.cgi?id=32413

Original change description:

[LV] Vectorize GEPs

This patch adds support for vectorizing GEPs. Previously, we only generated
vector GEPs on-demand when creating gather or scatter operations. All GEPs from
the original loop were scalarized by default, and if a pointer was to be stored
to memory, we would have to build up the pointer vector with insertelement
instructions.

With this patch, we will vectorize all GEPs that haven't already been marked
for scalarization.

The patch refines collectLoopScalars to more exactly identify the scalar GEPs.
The function now more closely resembles collectLoopUniforms. And the patch
moves vector GEP creation out of vectorizeMemoryInstruction and into the main
vectorization loop. The vector GEPs needed for gather and scatter operations
will have already been generated before vectoring the memory accesses.

Original Differential Revision: https://reviews.llvm.org/D30710

llvm-svn: 298735
2017-03-24 20:49:43 +00:00
Matthew Simpson 4e7b71bc86 [LV] Vectorize GEPs
This patch adds support for vectorizing GEPs. Previously, we only generated
vector GEPs on-demand when creating gather or scatter operations. All GEPs from
the original loop were scalarized by default, and if a pointer was to be stored
to memory, we would have to build up the pointer vector with insertelement
instructions.

With this patch, we will vectorize all GEPs that haven't already been marked
for scalarization.

The patch refines collectLoopScalars to more exactly identify the scalar GEPs.
The function now more closely resembles collectLoopUniforms. And the patch
moves vector GEP creation out of vectorizeMemoryInstruction and into the main
vectorization loop. The vector GEPs needed for gather and scatter operations
will have already been generated before vectoring the memory accesses.

Differential Revision: https://reviews.llvm.org/D30710

llvm-svn: 298620
2017-03-23 16:29:58 +00:00
Matthew Simpson df19502b16 [LV] Move insertelement sequence after scalar definitions
After r279649 when getting a vector value from VectorLoopValueMap, we create an
insertelement sequence on-demand if the value has been scalarized instead of
vectorized. We previously inserted this insertelement sequence before the
value's first vector user. However, this insert location is problematic if that
user is the phi node of a first-order recurrence. With this patch, we move the
insertelement sequence after the last scalar instruction we created when
scalarizing the value. Thus, the value's vector definition in the new loop will
immediately follow its scalar definitions. This should fix PR30183.

Reference: https://llvm.org/bugs/show_bug.cgi?id=30183
llvm-svn: 280001
2016-08-29 20:14:04 +00:00
Matthew Simpson abd2be1e2e [LV] Unify vector and scalar maps
This patch unifies the data structures we use for mapping instructions from the
original loop to their corresponding instructions in the new loop. Previously,
we maintained two distinct maps for this purpose: WidenMap and ScalarIVMap.
WidenMap maintained the vector values each instruction from the old loop was
represented with, and ScalarIVMap maintained the scalar values each scalarized
induction variable was represented with. With this patch, all values created
for the new loop are maintained in VectorLoopValueMap.

The change allows for several simplifications. Previously, when an instruction
was scalarized, we had to insert the scalar values into vectors in order to
maintain the mapping in WidenMap. Then, if a user of the scalarized value was
also scalar, we had to extract the scalar values from the temporary vector we
created. We now aovid these unnecessary scalar-to-vector-to-scalar conversions.
If a scalarized value is used by a scalar instruction, the scalar value is used
directly. However, if the scalarized value is needed by a vector instruction,
we generate the needed insertelement instructions on-demand.

A common idiom in several locations in the code (including the scalarization
code), is to first get the vector values an instruction from the original loop
maps to, and then extract a particular scalar value. This patch adds
getScalarValue for this purpose along side getVectorValue as an interface into
VectorLoopValueMap. These functions work together to return the requested
values if they're available or to produce them if they're not.

The mapping has also be made less permissive. Entries can be added to
VectorLoopValue map with the new initVector and initScalar functions.
getVectorValue has been modified to return a constant reference to the mapped
entries.

There's no real functional change with this patch; however, in some cases we
will generate slightly different code. For example, instead of an insertelement
sequence following the definition of an instruction, it will now precede the
first use of that instruction. This can be seen in the test case changes.

Differential Revision: https://reviews.llvm.org/D23169

llvm-svn: 279649
2016-08-24 18:23:17 +00:00
Matthew Simpson 18d8898317 [LV] Generate both scalar and vector integer induction variables
This patch enables the vectorizer to generate both scalar and vector versions
of an integer induction variable for a given loop. Previously, we only
generated a scalar induction variable if we knew all its users were going to be
scalar. Otherwise, we generated a vector induction variable. In the case of a
loop with both scalar and vector users of the induction variable, we would
generate the vector induction variable and extract scalar values from it for
the scalar users. With this patch, we now generate both versions of the
induction variable when there are both scalar and vector users and select which
version to use based on whether the user is scalar or vector.

Differential Revision: https://reviews.llvm.org/D22869

llvm-svn: 277474
2016-08-02 15:25:16 +00:00
Matthew Simpson 102729cf1b [LV] Move vector int induction update to end of latch
This patch moves the update instruction for vectorized integer induction phi
nodes to the end of the latch block. This ensures consistent placement of all
induction updates across all the kinds of int inductions we create (scalar,
splat vector, or vector phi).

Differential Revision: https://reviews.llvm.org/D22416

llvm-svn: 276339
2016-07-21 21:20:15 +00:00
Elena Demikhovsky fc1e969dfc Fixed a bug in vectorizing GEP before gather/scatter intrinsic.
Vectorizing GEP was incorrect and broke SSA in some cases.
 
The patch fixes PR27997 https://llvm.org/bugs/show_bug.cgi?id=27997.

Differential revision: http://reviews.llvm.org/D22035

llvm-svn: 274735
2016-07-07 06:06:46 +00:00