https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116645
Bug ID: 116645
Summary: Huge performance loss after 13.2.0 compiler upgrade
Product: gcc
Version: 13.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: joern274 at googlemail dot com
Target Milestone: ---
After upgrading g++ compiler from version 11.4.0 (Ubuntu 22.04 LTS) to version
13.2.0 (Ubuntu 24.04 LTS) the compile time for auto-generated verilator code
increased by a factor of *five*.
According to -ftime-report this is mostly due to "reload CSE regs" but I don't
know what this means.
Using this line to compile:
g++ -Os -I. -MMD -I/usr/local/share/verilator/include
-I/usr/local/share/verilator/include/vltstd -DVM_COVERAGE=0 -DVM_SC=0
-DVM_TIMING=0 -DVM_TRACE=1 -DVM_TRACE_FST=0 -DVM_TRACE_VCD=1 -faligned-new
-fcf-protection=none -Wno-bool-operation -Wno-shadow -Wno-sign-compare
-Wno-tautological-compare -Wno-uninitialized -Wno-unused-but-set-parameter
-Wno-unused-but-set-variable -Wno-unused-parameter -Wno-unused-variable -O3
-I/usr/include -c -o Vanalytic_filter_h_a4__ALL.o
Vanalytic_filter_h_a4__ALL.cpp
