cmd/compile: internal compiler error: Invalid PPC64 rotate mask [1.16 backport]

[gopherbot]

@pmur requested issue #45589 to be considered for backport to the next 1.16 minor release.

@gopherbot backport to 1.16 please

[pmur]

The original issue was opened against the 1.16 when the merging support was added. It appears to have prevented somebody from compiling non-intuitive code (That is, a 0-length shift feeding an andi).

[gopherbot]

Change https://golang.org/cl/311378 mentions this issue: [release-branch.go1.16] cmd/compile: fix ANDI/SRWI merge on ppc64

[toothrot]

Approved. This is a serious issue with no workaround.

[toothrot]

@pmur @ALTree Does this also impact 1.15? If so, we need to open a backport for 1.15 as well.

[pmur]

@toothrot Nope. 1.16 only.

[cagedmantis]

Thank you for this work @pmur

[gopherbot]

Closed by merging 7e70979 to release-branch.go1.16.