Part 2 of 2
This patch add support for combining target shuffles into blends-with-zero.
Differential Revision: http://reviews.llvm.org/D17483
llvm-svn: 261745
Part 1 of 2
This patch attempts to replace the insertion of zero scalars with a vector blend with zero, avoiding the use of the integer insertion instructions (which are particularly slow on many targets).
(Part 2 will add support for combining multiple blends-with-zero).
Differential Revision: http://reviews.llvm.org/D17483
llvm-svn: 261743
The x86_mmx type is used for MMX intrinsics, parameters and
return values where these use MMX registers, and is also
supported in load, store, and bitcast.
Only the above operations generate MMX instructions, and optimizations
do not operate on or produce MMX intrinsics.
MMX-sized vectors <2 x i32> etc. are lowered to XMM or split into
smaller pieces. Optimizations may occur on these forms and the
result casted back to x86_mmx, provided the result feeds into a
previous existing x86_mmx operation.
The point of all this is prevent optimizations from introducing
MMX operations, which is unsafe due to the EMMS problem.
llvm-svn: 115243
Simon Pilgrim