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| author | Daniel R. Carvalho <odanrc@yahoo.com.br> | 2019-12-15 16:24:15 +0100 |
|---|---|---|
| committer | Daniel Carvalho <odanrc@yahoo.com.br> | 2019-12-21 10:58:08 +0000 |
| commit | 8ba0ba4871907aaa08c862534033f2922a3d2ba7 (patch) | |
| tree | 84653473bf4039d0cba9065fbdefdca43ac45ac5 /src/base/sat_counter.hh | |
| parent | c3fecd4520555dfaf6a3836f791e638de1412e28 (diff) | |
| download | gem5-8ba0ba4871907aaa08c862534033f2922a3d2ba7.tar.xz | |
base: Fix negative op-assign of SatCounter
The value of the add and subtract assignment operations can be negative,
and this was not being handled properly previously. Regarding shift
assignment, the standard says it is undefined behaviour if a negative
number is given, so add assertions for these cases.
Change-Id: I2f1e4143c6385caa80fb25f84ca8edb0ca7e62b7
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/23664
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Diffstat (limited to 'src/base/sat_counter.hh')
| -rw-r--r-- | src/base/sat_counter.hh | 23 |
1 files changed, 17 insertions, 6 deletions
diff --git a/src/base/sat_counter.hh b/src/base/sat_counter.hh index 6aeca681d..946da4f26 100644 --- a/src/base/sat_counter.hh +++ b/src/base/sat_counter.hh @@ -44,6 +44,7 @@ #ifndef __BASE_SAT_COUNTER_HH__ #define __BASE_SAT_COUNTER_HH__ +#include <cassert> #include <cstdint> #include "base/logging.hh" @@ -172,6 +173,7 @@ class SatCounter SatCounter& operator>>=(const int& shift) { + assert(shift >= 0); this->counter >>= shift; return *this; } @@ -180,6 +182,7 @@ class SatCounter SatCounter& operator<<=(const int& shift) { + assert(shift >= 0); this->counter <<= shift; if (this->counter > maxVal) { this->counter = maxVal; @@ -191,10 +194,14 @@ class SatCounter SatCounter& operator+=(const int& value) { - if (maxVal - this->counter >= value) { - this->counter += value; + if (value >= 0) { + if (maxVal - this->counter >= value) { + this->counter += value; + } else { + this->counter = maxVal; + } } else { - this->counter = maxVal; + *this -= -value; } return *this; } @@ -203,10 +210,14 @@ class SatCounter SatCounter& operator-=(const int& value) { - if (this->counter > value) { - this->counter -= value; + if (value >= 0) { + if (this->counter > value) { + this->counter -= value; + } else { + this->counter = 0; + } } else { - this->counter = 0; + *this += -value; } return *this; } |