Add peephole optimization to eliminate some mask AND operations.
On KNC, the various vector comparison instructions can optionally
be masked; if a mask is provided, the result is effectively that
the value returned is the AND of the mask with the result of the
comparison.
This change adds an optimization pass to the C++ backend that looks
for vector ANDs where one operand is a comparison and rewrites
them--e.g. "and(equalfloat(a, b), c)" is changed to
"_equal_float_and_mask(a, b, c)", saving an instruction in the end.
Issue #319.
Merge commit '8ef6bc16364d4c08aa5972141748110160613087'
Conflicts:
examples/intrinsics/knc.h
examples/intrinsics/sse4.h
Fixes include adding "_float" and "_double" suffixes as appropriate as well
as providing a number of missing implementations.
This fixes a number of failures in the half* tests.
On KNC, the various vector comparison instructions can optionally
be masked; if a mask is provided, the result is effectively that
the value returned is the AND of the mask with the result of the
comparison.
This change adds an optimization pass to the C++ backend that looks
for vector ANDs where one operand is a comparison and rewrites
them--e.g. "__and(__equal_float(a, b), c)" is changed to
"__equal_float_and_mask(a, b, c)", saving an instruction in the end.
Issue #319.
e.g. "__equal()" -> "__equal_float()", etc.
No functional change; this is necessary groundwork for a forthcoming
peephole optimization that eliminates ANDs of masks in some cases.
When we have a constant vector of primitive types, we now generate
a definition of a static const array of the individual values. This
in turn allows us to emit a simple aligned vector load to get the
constant vector value, rather than inefficiently inserting the values
into a vector.
Issue #318.
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.
If --opt=fast-math is used then the generated code contains:
#define ISPC_FAST_MATH 1
Otherwise it contains:
#undef ISPC_FAST_MATH
This allows the generic headers to support the user's request.
This should help with performance of the generated code.
Updated the relevant header files (sse4.h, generic-16.h, generic-32.h, generic-64.h)
Updated generic-32.h and generic-64.h to the new memory API
(Rather than implicitly with a using declaration.) This will
allow for some further changes to ISPC's C backend, without collision
with ISPC's namespace. This change aims to have no effect on the code
generated by the compiler, it should be a big no-op; except for its
side-effects on maintainability.
Rather than XOR'ing with a temporary 'all-on' vector, we call
__not. Also, we call out to __and_not1 and __and_not2, for an
AND where the first or second operand, respectively, has had
NOT applied to it.
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.
