https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87444
Bug ID: 87444
Summary: 'gcc -marc=native' sets L2 cache size equal to L3
cache size on i7 and i5 CPU
Product: gcc
Version: 7.3.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: other
Assignee: unassigned at gcc dot gnu.org
Reporter: studio at anchev dot net
Target Milestone: ---
STR:
gcc -### -march=native /usr/include/stdlib.h
lscpu | grep -i cache
OS: openSUSE Leap 15.0
EXPECTED:
gcc's output should show --param "l2-cache-size=<the same L2 cache which lscpu
shows>"
ACTUAL:
gcc outputs:
... --param "l2-cache-size=8192" ...
[~]: lscpu | grep -i cache
L1d cache: 32K
L1i cache: 32K
L2 cache: 256K
L3 cache: 8192K
The architecture is properly detected (ivybridge) but it seems l2-cache-size
equals the L3 cache, which is incorrect. The CPU model is "Intel(R) Core(TM)
i7-3770 CPU @ 3.40GHz"
A fellow openSUSE Leap 15.0 user shared that the same happens on "Intel(R)
Core(TM) i5-3210M CPU @ 2.50GHz" but not on AMD.
My own test on other machines shows that on "Intel(R) Xeon(TM) CPU 2.80GHz"
(nocona) and on "Intel(R) Celeron(R) M processor 1.50GHz" (pentium-m)
l2-cache-size is detected correctly. The nocona is running openSUSE Leap 15.0
and the pentium-m is running openSUSE Tumbleweed (32 bit).
