cmd/asm, cmd/internal/obj/ppc64: minor updates to assembler for ppc64x #23845
Description
What version of Go are you using (go version)?
tip
Does this issue reproduce with the latest release?
Issues to be addressed occur in the latest release
What operating system and processor architecture are you using (go env)?
ppc64le & ppc64
Multiple minor changes are planned for the assembler for ppc64x, including:
Add the opcodes for "immediate shifted" versions of the add, and, or, and xor instructions. These opcodes currently don't exist in the Go asm set, and the Power instructions are generated but in a way that is not clear. Adding these will making it easier for those writing algorithms in Go asm for Power, and also make it more straightforward when we split the cases now where sometimes an Go assembler instruction results in 2 or 3 Power instructions.
Add a few new opcodes for new functions like Round and load/store byte reversed.
Fix some cases where immediate values are loaded with more instructions than necessary.