Some rules for PPC64 were checking for a case
where a shift followed by an 'and' of a mask could
be lowered, depending on the format of the mask. The
function to verify if the mask was valid for this purpose
was not checking if the mask was 0 which we don't want to
allow. This case can happen if previous optimizations
resulted in that mask value.
This fixes isPPC64ValidShiftMask to check for a mask of 0 and return
false.
This also adds a codegen testcase to verify it doesn't try to
match the rules in the future.
Fixes#42610
Change-Id: I565d94e88495f51321ab365d6388c01e791b4dbb
Reviewed-on: https://go-review.googlesource.com/c/go/+/270358
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Paul Murphy <murp@ibm.com>
Reviewed-by: Carlos Eduardo Seo <carlos.seo@linaro.org>
Trust: Lynn Boger <laboger@linux.vnet.ibm.com>
The test directory contains tests of the Go tool chain and runtime.
It includes black box tests, regression tests, and error output tests.
They are run as part of all.bash.
To run just these tests, execute:
../bin/go run run.go
To run just tests from specified files in this directory, execute:
../bin/go run run.go -- file1.go file2.go ...
Standard library tests should be written as regular Go tests in the appropriate package.
The tool chain and runtime also have regular Go tests in their packages.
The main reasons to add a new test to this directory are:
it is most naturally expressed using the test runner; or
it is also applicable to gccgo and other Go tool chains.
0ae3b7cb74