[x86] Remove the duplicated code for testing whether we can widen the

elements of a shuffle mask and simplify how it works. No functionality
changed now that the bug that was here has been fixed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215696 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chandler Carruth 2014-08-15 07:41:57 +00:00
parent 407460e67d
commit 437928be5c

View File

@ -19493,18 +19493,10 @@ static bool combineX86ShufflesRecursively(SDValue Op, SDValue Root,
// elements, and shrink them to the half-width mask. It does this in a loop
// so it will reduce the size of the mask to the minimal width mask which
// performs an equivalent shuffle.
while (Mask.size() > 1) {
SmallVector<int, 16> NewMask;
for (int i = 0, e = Mask.size()/2; i < e; ++i) {
if (Mask[2*i] % 2 != 0 || Mask[2*i] + 1 != Mask[2*i + 1]) {
NewMask.clear();
break;
}
NewMask.push_back(Mask[2*i] / 2);
}
if (NewMask.empty())
break;
Mask.swap(NewMask);
while (Mask.size() > 1 && canWidenShuffleElements(Mask)) {
for (int i = 0, e = Mask.size() / 2; i < e; ++i)
Mask[i] = Mask[2 * i] / 2;
Mask.resize(Mask.size() / 2);
}
return combineX86ShuffleChain(Op, Root, Mask, Depth, HasPSHUFB, DAG, DCI,