[PATCH] D16842: [Power9] Implement new vsx instructions: insert, extract, test data class, min/max, reverse, permute, splat

Nemanja Ivanovic via llvm-commits llvm-commits at lists.llvm.org
Fri Feb 5 03:53:05 PST 2016

nemanjai added a comment.

Thanks for summarizing and addressing the comments. One of the key aspects of the vsfrc/vssrc/vsrc classes is whether the entire register is used or just the left 64 bits. So vector instructions operate on the entire register and we use the vsrc register class whereas scalar ones operate on the scalar portion of the register.
So your summary is correct with respect to the usage of the register classes.

P.S. There are no operations on integer scalars in vector registers - the moves are used only for:

1. Conversion between integers and FP
2. Bitcasting between integers and FP
3. Freeing up a GPR by moving the value into a VSR (to be moved back when needed)


More information about the llvm-commits mailing list