These compute the average of two given values, rounding up and down,
respectively, if the result isn't exact. When possible, these are
mapped to target-specific intrinsics (PADD[BW] on IA and VH[R]ADD[US]
on NEON.)
A subsequent commit will add pattern-matching to generate calls to
these intrinsincs when the corresponding patterns are detected in the
IR.)
The stdilb code just calls the signed int{32,64} functions,
which gives the right result for the unsigned case anyway.
The various targets didn't consistently define the unsigned
variants in any case.
For KNC (gather/scatter), it's not helpful to factor base+offsets gathers
and scatters into base_ptr + {1/2/4/8} * varying_offsets + const_offsets.
Now, if a HW instruction is available for gather/scatter, we just factor
into base + {1/2/4/8} * offsets (if possible). Not only is this simpler,
but it's also what we need to pass a value along to the scale by
2/4/8 available directly in those instructions.
Finishes issue #325.
No functional change; just preparation for having a path that doesn't
factor the offsets into constant and varying parts, which will be better
for AVX2 and KNC.
Flag 32-bit vector types as only requiring 32-bit alignment (preemptive
bug fix for 32xi1 vectors).
Force module datalayouts to be the same before linking them to silence
an LLVM warning.
Finishes issue #309.
If we have a vector of all zeros, a __setzero_* function call is emitted,
permitting calling specialized intrinsics for this. Undefined values
are reflected with an __undef_* call, which similarly allows passing that
information along.
This change also includes a cleanup to the signature of the __smear_*
functions; since they already have different names depending on the
scalar value type, we don't need to use the trick of passing an
undefined value of the return vector type as the first parameter as
an indirect way to overload by return value.
Issue #317.
Now that we never ever run with the mask all off, we no longer need
that logic in a built-in function so that we can check the mask. In
the one place where it was used (turning gathers to the same location
into a load and broadcast), we now just emit the code for that
directly.
Previously, we'd bitcast e.g. a vector of floats to a vector of i32s and then
use the i32 variant of masked_load/masked_store/gather/scatter. Now, we have
separate float/double variants of each of those.
Change function suffix to "_i32", etc, from "_32"
Improve load_and_broadcast macro in util.m4 to grab vector width from
WIDTH variable rather than taking it as a parameter.
In ee1fe3aa9f, the LLVM_VERSION define was updated to never
have the 'svn' suffix and the build was updated to handle LLVM
3.2. This file had a check for LLVM_3_1svn that was no longer
hitting.
This fixes some issues with unnecessary loads and stores
in generated C++ code for the generic targets.
Now, the __smear* functions in generated C++ code have an unused first
parameter of the desired return type; this allows us to have headers
that include variants of __smear for multiple target widths. (This
approach is necessary since we can't overload by return type in C++.)
Issue #256.
When we're able to turn a general gather/scatter into the "base + offsets"
form, we now try to extract out any constant components of the offsets and
then pass them as a separate parameter to the gather/scatter function
implementation.
We then in turn carefully emit code for the addressing calculation so that
these constant offsets match LLVM's patterns to detect this case, such that
we get the constant offsets directly encoded in the instruction's addressing
calculation in many cases, saving arithmetic instructions to do these
calculations.
Improves performance of stencil by ~15%. Other workloads unchanged.
Specifically, don't use vector select for masked store blend there,
but emit a call to a undefined __masked_store_blend_*() functions.
Added implementations of these functions to the sse4.h and generic-16.h
in examples/instrinsics. (Calls to these will never be generated with
LLVM 3.1).
This pass handles the "all on" and "all off" mask cases appropriately.
Also renamed load_masked stuff in built-ins to masked_load for consistency with
masked_store.
When used, these targets end up with calls to undefined functions for all
of the various special vector stuff ispc needs to compile ispc programs
(masked store, gather, min/max, sqrt, etc.).
These targets are not yet useful for anything, but are a step toward
having an option to C++ code with calls out to intrinsics.
Reorganized the directory structure a bit and put the LLVM bitcode used
to define target-specific stuff (as well as some generic built-ins stuff)
into a builtins/ directory.
Note that for building on Windows, it's now necessary to set a LLVM_VERSION
environment variable (with values like LLVM_2_9, LLVM_3_0, LLVM_3_1svn, etc.)
