Joel Sing 90e8b8cdae cmd/compile: intrinsify math/bits.Bswap on riscv64
For riscv64/rva22u64 and above, we can intrinsify math/bits.Bswap
using the REV8 machine instruction.

On a StarFive VisionFive 2 with GORISCV64=rva22u64:

                 │     rb.1     │                rb.2                 │
                 │    sec/op    │   sec/op     vs base                │
ReverseBytes-4     18.790n ± 0%   4.026n ± 0%  -78.57% (p=0.000 n=10)
ReverseBytes16-4    6.710n ± 0%   5.368n ± 0%  -20.00% (p=0.000 n=10)
ReverseBytes32-4   13.420n ± 0%   5.368n ± 0%  -60.00% (p=0.000 n=10)
ReverseBytes64-4   17.450n ± 0%   4.026n ± 0%  -76.93% (p=0.000 n=10)
geomean             13.11n        4.649n       -64.54%

Change-Id: I26eee34270b1721f7304bb1cddb0fda129b20ece
Reviewed-on: https://go-review.googlesource.com/c/go/+/660855
Reviewed-by: Mark Ryan <markdryan@rivosinc.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Meng Zhuo <mengzhuo1203@gmail.com>
Reviewed-by: Carlos Amedee <carlos@golang.org>
Reviewed-by: Junyang Shao <shaojunyang@google.com>
2025-05-01 05:57:13 -07:00
..
2024-03-25 19:21:35 +00:00
2023-01-31 19:43:07 +00:00
2023-04-11 20:56:32 +00:00
2020-11-28 02:31:54 +00:00
2019-11-01 20:13:05 +00:00
2024-04-04 14:29:45 +00:00
2021-10-06 15:53:04 +00:00

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 test cmd/internal/testdir

To run just tests from specified files in this directory, execute:

../bin/go test cmd/internal/testdir -run='Test/(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.