This patch aims to improve the code generation for float vector gather on POWER9.
Patterns have been implemented to utilize instructions that deliver improved
performance.
Patch by: Kamau Bridgeman
Differential Revision: https://reviews.llvm.org/D62908
Test case to verify that the expected code is generated for a
vector float gather based on the patterns in tablegen for big
and little endian cases.
Patch by: Kamau Bridgeman
Differential Revision: https://reviews.llvm.org/D69443