https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102814
Bug ID: 102814
Summary: [12 regression] quadratique/exponential time
complexity for max-jump-thread-duplication-stmts
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: dimhen at gmail dot com
Target Milestone: ---
r12-4256 FAST
r12-4444 SLOW
g++ -fpreprocessed -std=c++98 -O2 --param max-jump-thread-duplication-stmts=NNN
-c x.ii
r12-4256 r12-4444
180 0.5s 0.21s
181 0.8s > 100s
190 1.0s 52s
cat x.ii # cvise'd from proprietary codebase
struct a {
a operator+(int);
};
void *operator new(unsigned long, void *c) { return c; }
struct d {
void h(int *j) { new (j) int(); }
};
struct k {
struct {
int e;
int f;
} g;
};
struct n : k {
a m_fn2();
a o();
int m_fn4();
int operator[](int);
int ae;
void s() {
if (g.e != g.f) {
d l;
int *b;
l.h(b);
}
a m = o();
t(m, ae);
}
template <typename af> void u(a, af, af);
void t(a, unsigned char);
};
int ah;
struct v {
n w();
};
void x() {
v p;
n ak = p.w(), al, rapdu;
int q(ak.m_fn4());
int r;
for (int i = 0; q; i++) {
if (i == q - 1) {
al.s();
r = ak.m_fn4();
}
al.s();
al.s();
al.s();
al.s();
a am, an = ak.m_fn2(), ao = an + 1, ap = ak.m_fn2(), aq = ap + ah,
ar = aq + r;
al.u(am, ao, ar);
if (i == q - 1)
al.s();
i &&rapdu[1];
}
}
g++ -v
Using built-in specs.
COLLECT_GCC=/home/dimhen/arch-gcc/gcc_current/bin/g++
COLLECT_LTO_WRAPPER=/home/dimhen/arch-gcc/gcc_current/libexec/gcc/x86_64-pc-linux-gnu/12.0.0/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none
Target: x86_64-pc-linux-gnu
Configured with: /home/dimhen/src/gcc_current/configure
--prefix=/home/dimhen/arch-gcc/gcc_current
--enable-checking=yes,df,fold,rtl,extra --enable-languages=c,c++,lto
--disable-multilib --enable-shared --enable-threads=posix --enable-__cxa_atexit
--enable-gnu-unique-object --enable-linker-build-id
--with-linker-hash-style=gnu --enable-plugin --enable-initfini-array --with-isl
--enable-offload-targets=nvptx-none --without-cuda-driver
--enable-gnu-indirect-function --enable-cet --with-tune=native
--enable-libstdcxx-debug
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 12.0.0 20211015 (experimental) [master r12-4444-ga01704fc45a] (GCC)
