tree 59e3dd2d325b857f0733de8d134c2f863e8fa070
parent 541c49144d73f2a03374517091835fa8a43eebe2
author Matthew Dempsky <mdempsky@google.com> 1560307978 -0700
committer Russ Cox <rsc@golang.org> 1562001760 +0000

[release-branch.go1.11] cmd/compile: fix range analysis of small signed integers

For int8, int16, and int32, comparing their unsigned value to MaxInt64
to determine non-negativity doesn't make sense, because they have
negative values whose unsigned representation is smaller than that.
Fix is simply to compare with the appropriate upper bound based on the
value type's size.

Fixes #32582.

Change-Id: Ie7afad7a56af92bd890ba5ff33c86d1df06cfd9a
Reviewed-on: https://go-review.googlesource.com/c/go/+/181797
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
(cherry picked from commit f44404ebbfeff57f3e45ebf4b314a320bb89841f)
Reviewed-on: https://go-review.googlesource.com/c/go/+/181979
Reviewed-by: Russ Cox <rsc@golang.org>