https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90912
--- Comment #3 from Witold Krecicki <wpk at culm dot net> ---
It seems to be a bad interaction between GCC and Solaris linker, with GNU ld it
works correctly on all optimization levels - gcc -v below. Unfortunately gcc
shipped with Solaris is using Solaris linker.
```
Using built-in specs.
COLLECT_GCC=/usr/gcc/9-gnuld/bin/gcc
COLLECT_LTO_WRAPPER=/usr/gcc/9-gnuld/lib/gcc/x86_64-pc-solaris2.11/9.1.0/lto-wrapper
Target: x86_64-pc-solaris2.11
Configured with: ../configure --prefix=/usr/gcc/9-gnuld
--mandir=/usr/gcc/9-gnuld/share/man --bindir=/usr/gcc/9-gnuld/bin
--sbindir=/usr/gcc/9-gnuld/sbin --libdir=/usr/gcc/9-gnuld/lib
--infodir=/usr/gcc/9-gnuld/share/info --libexecdir=/usr/gcc/9-gnuld/lib
--enable-languages=c,c++,fortran,objc --enable-shared --enable-initfini-array
--disable-rpath --with-system-zlib --with-build-config=no
--with-gmp-include=/usr/include --with-mpfr-include=/usr/include
--with-gnu-ld=/usr/gnu/bin/ld --with-ld=/usr/gnu/bin/ld --with-gnu-as
--with-as=/usr/gnu/bin/as --disable-bootstrap 'BOOT_CFLAGS=-g -O2'
x86_64-pc-solaris2.11
Thread model: posix
gcc version 9.1.0 (GCC)
COLLECT_GCC_OPTIONS='-v' '-O2' '-fPIC' '-mtune=generic' '-march=x86-64'
/usr/gcc/9-gnuld/lib/gcc/x86_64-pc-solaris2.11/9.1.0/cc1 -quiet -v tls-test.c
-quiet -dumpbase tls-test.c -mtune=generic -march=x86-64 -auxbase tls-test -O2
-version -fPIC -o /var/tmp//ccFCnhKb.s
GNU C17 (GCC) version 9.1.0 (x86_64-pc-solaris2.11)
compiled by GNU C version 9.1.0, GMP version 6.1.2, MPFR version 3.1.5,
MPC version 1.0.3, isl version isl-0.18-GMP
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
ignoring nonexistent directory "/usr/local/include"
ignoring nonexistent directory
"/usr/gcc/9-gnuld/lib/gcc/x86_64-pc-solaris2.11/9.1.0/../../../../x86_64-pc-solaris2.11/include"
#include "..." search starts here:
#include <...> search starts here:
/usr/gcc/9-gnuld/lib/gcc/x86_64-pc-solaris2.11/9.1.0/include
/usr/gcc/9-gnuld/include
/usr/gcc/9-gnuld/lib/gcc/x86_64-pc-solaris2.11/9.1.0/include-fixed
/usr/include
End of search list.
GNU C17 (GCC) version 9.1.0 (x86_64-pc-solaris2.11)
compiled by GNU C version 9.1.0, GMP version 6.1.2, MPFR version 3.1.5,
MPC version 1.0.3, isl version isl-0.18-GMP
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: 8d00c2a77a592f334e9eb5693e454f4c
COLLECT_GCC_OPTIONS='-v' '-O2' '-fPIC' '-mtune=generic' '-march=x86-64'
/usr/gnu/bin/as -v -V -Qy -s --64 -o /var/tmp//cciW7WLb.o /var/tmp//ccFCnhKb.s
GNU assembler version 2.30 (x86_64-pc-solaris2.11) using BFD version (GNU
Binutils) 2.30
COMPILER_PATH=/usr/gcc/9-gnuld/lib/gcc/x86_64-pc-solaris2.11/9.1.0/:/usr/gcc/9-gnuld/lib/gcc/x86_64-pc-solaris2.11/9.1.0/:/usr/gcc/9-gnuld/lib/gcc/x86_64-pc-solaris2.11/:/usr/gcc/9-gnuld/lib/gcc/x86_64-pc-solaris2.11/9.1.0/:/usr/gcc/9-gnuld/lib/gcc/x86_64-pc-solaris2.11/:/usr/ccs/bin/
LIBRARY_PATH=/usr/gcc/9-gnuld/lib/gcc/x86_64-pc-solaris2.11/9.1.0/:/usr/gcc/9-gnuld/lib/gcc/x86_64-pc-solaris2.11/9.1.0/../../../amd64/:/lib/amd64/:/usr/lib/amd64/:/usr/gcc/9-gnuld/lib/gcc/x86_64-pc-solaris2.11/9.1.0/../../../:/lib/:/usr/lib/
COLLECT_GCC_OPTIONS='-v' '-O2' '-fPIC' '-mtune=generic' '-march=x86-64'
/usr/gcc/9-gnuld/lib/gcc/x86_64-pc-solaris2.11/9.1.0/collect2 -plugin
/usr/gcc/9-gnuld/lib/gcc/x86_64-pc-solaris2.11/9.1.0/liblto_plugin.so
-plugin-opt=/usr/gcc/9-gnuld/lib/gcc/x86_64-pc-solaris2.11/9.1.0/lto-wrapper
-plugin-opt=-fresolution=/var/tmp//cce7p_6a.res -plugin-opt=-pass-through=-lgcc
-plugin-opt=-pass-through=-lgcc_eh -plugin-opt=-pass-through=-lc
-plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lgcc_eh
--eh-frame-hdr -V -m elf_x86_64_sol2 -Y P,/lib/amd64:/usr/lib/amd64 -Qy
/usr/lib/amd64/crt1.o
/usr/gcc/9-gnuld/lib/gcc/x86_64-pc-solaris2.11/9.1.0/crtp.o
/usr/lib/amd64/crti.o /usr/lib/amd64/values-Xa.o /usr/lib/amd64/values-xpg6.o
/usr/gcc/9-gnuld/lib/gcc/x86_64-pc-solaris2.11/9.1.0/crtbegin.o
-L/usr/gcc/9-gnuld/lib/gcc/x86_64-pc-solaris2.11/9.1.0
-L/usr/gcc/9-gnuld/lib/gcc/x86_64-pc-solaris2.11/9.1.0/../../../amd64
-L/lib/amd64 -L/usr/lib/amd64
-L/usr/gcc/9-gnuld/lib/gcc/x86_64-pc-solaris2.11/9.1.0/../../..
/var/tmp//cciW7WLb.o -lgcc -lgcc_eh -lc -lgcc -lgcc_eh
/usr/gcc/9-gnuld/lib/gcc/x86_64-pc-solaris2.11/9.1.0/crtend.o
/usr/lib/amd64/crtn.o
GNU ld (GNU Binutils) 2.30
Supported emulations:
elf_x86_64_sol2
elf_x86_64
elf_i386_sol2
elf_i386_ldso
elf_i386
elf_iamcu
elf_l1om
elf_k1om
COLLECT_GCC_OPTIONS='-v' '-O2' '-fPIC' '-mtune=generic' '-march=x86-64'
```
