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| author | Josh Bleecher Snyder <josharian@gmail.com> | 2017-08-10 06:46:36 -0700 |
|---|---|---|
| committer | Josh Bleecher Snyder <josharian@gmail.com> | 2017-08-14 00:51:02 +0000 |
| commit | a6136ded32878f9225e26b03ce9d9e84b0198af8 (patch) | |
| tree | e2f2a7ddd2c0488091fc302dda8832f297f4683d /src/runtime | |
| parent | 38044eca7c67981aa0c98847a35ec2daf0763d0e (diff) | |
| download | go-a6136ded32878f9225e26b03ce9d9e84b0198af8.tar.xz | |
runtime: remove indentation in evacuate
Combine conditions into a single if statement.
This is more readable.
It should generate identical machine code, but it doesn't.
The new code is shorter.
Change-Id: I9bf52f8f288b0df97a2b9b4e4183f6ca74175e8a
Reviewed-on: https://go-review.googlesource.com/54651
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Martin Möhrmann <moehrmann@google.com>
Diffstat (limited to 'src/runtime')
| -rw-r--r-- | src/runtime/hashmap.go | 42 |
1 files changed, 20 insertions, 22 deletions
diff --git a/src/runtime/hashmap.go b/src/runtime/hashmap.go index 11ce0cbc4b..e8e61a7fd1 100644 --- a/src/runtime/hashmap.go +++ b/src/runtime/hashmap.go @@ -1088,28 +1088,26 @@ func evacuate(t *maptype, h *hmap, oldbucket uintptr) { // Compute hash to make our evacuation decision (whether we need // to send this key/value to bucket x or bucket y). hash := alg.hash(k2, uintptr(h.hash0)) - if h.flags&iterator != 0 { - if !t.reflexivekey && !alg.equal(k2, k2) { - // If key != key (NaNs), then the hash could be (and probably - // will be) entirely different from the old hash. Moreover, - // it isn't reproducible. Reproducibility is required in the - // presence of iterators, as our evacuation decision must - // match whatever decision the iterator made. - // Fortunately, we have the freedom to send these keys either - // way. Also, tophash is meaningless for these kinds of keys. - // We let the low bit of tophash drive the evacuation decision. - // We recompute a new random tophash for the next level so - // these keys will get evenly distributed across all buckets - // after multiple grows. - if top&1 != 0 { - hash |= newbit - } else { - hash &^= newbit - } - top = uint8(hash >> (sys.PtrSize*8 - 8)) - if top < minTopHash { - top += minTopHash - } + if h.flags&iterator != 0 && !t.reflexivekey && !alg.equal(k2, k2) { + // If key != key (NaNs), then the hash could be (and probably + // will be) entirely different from the old hash. Moreover, + // it isn't reproducible. Reproducibility is required in the + // presence of iterators, as our evacuation decision must + // match whatever decision the iterator made. + // Fortunately, we have the freedom to send these keys either + // way. Also, tophash is meaningless for these kinds of keys. + // We let the low bit of tophash drive the evacuation decision. + // We recompute a new random tophash for the next level so + // these keys will get evenly distributed across all buckets + // after multiple grows. + if top&1 != 0 { + hash |= newbit + } else { + hash &^= newbit + } + top = uint8(hash >> (sys.PtrSize*8 - 8)) + if top < minTopHash { + top += minTopHash } } useX = hash&newbit == 0 |