Displaying 2 results from an estimated 2 matches for "lowestcost".
2009 May 01
0
[LLVMdev] RFC: AVX Pattern Specification [LONG]
...it would make sense for tblgen to generate some C++ code that
looks like this:
// MatchVectorShuffle - Matches a shuffle node against the available
instructions,
// returning the lowest cost one as well as the actual cost of it.
unsigned MatchVectorShuffle(VectorShuffleSDNode *N) {
unsigned LowestCost = ~0;
if (N can be matched by movddup) {
unsigned movddupcost = ... // can be either constant, or
callback into subtarget info
if (LowestCost > movddupcost)
LowestCost = movddupcost;
operands = [whatever]
opcode = X86::MOVDDUP;
}
}
if (N can be m...
2009 May 01
4
[LLVMdev] RFC: AVX Pattern Specification [LONG]
On Friday 01 May 2009 13:46, Chris Lattner wrote:
> Right, a lot of these problems can be solved by some nice refactoring
> stuff. I'm also hoping that some of the complexity in defining
> shuffle matching code can be helped by making the definition of the
> shuffle patterns more declarative within the td file. It would be
> really nice to say that "this shuffle does a