Comment # 3 on bug 1223152 from Martin Jambor

Meanwhile, to investigate with CPU time, I resorted to debug counters.
The failure can still be reproduced when adding:

  %global optflags %{optflags} -fdbg-cnt=merged_ipa_icf:86-86

to the spec file and conversely goes away with:

  %global optflags %{optflags} -fdbg-cnt=merged_ipa_icf:1-85:87-4095

Unfortunately IPA-ICF does not dump stuff differently when not merging
functions because of a debug counter so I hacked it a little to do so
and with just doing the 86th merge and with -fdump-ipa-icf-details the
key message appeared in the following dump files (before I stopped the
stalled test run):

./fuzz/cmp-test.wpa.083i.icf:crypto/o_str.c:225:23: optimized: Semantically
equivallent nodes merged.
./fuzz/punycode-test.wpa.083i.icf:crypto/engine/eng_rdrand.c:52:12: optimized:
Semantically equivallent nodes merged.
./providers/fips.so.wpa.083i.icf:crypto/dsa/dsa_sign.c:79:5: optimized:
Semantically equivallent nodes merged.
./test/algorithmid_test.wpa.083i.icf:crypto/rand/rand_lib.c:917:13: optimized:
Semantically equivallent nodes merged.
./test/cmactest.wpa.083i.icf:crypto/rand/rand_lib.c:917:13: optimized:
Semantically equivallent nodes merged.
./test/acvp_test.wpa.083i.icf:crypto/params.c:968:12: optimized: Semantically
equivallent nodes merged.
./test/asn1_internal_test.wpa.083i.icf:crypto/evp/kdf_meth.c:20:12: optimized:
Semantically equivallent nodes merged.
./test/bn_internal_test.wpa.083i.icf:crypto/rsa/rsa_backend.c:328:24:
optimized: Semantically equivallent nodes merged.
./test/asn1_dsa_internal_test.wpa.083i.icf:crypto/rsa/rsa_backend.c:328:24:
optimized: Semantically equivallent nodes merged.
./test/cmp_ctx_test.wpa.083i.icf:providers/implementations/rands/drbg_ctr.c:355:12:
optimized: Semantically equivallent nodes merged.
./test/chacha_internal_test.wpa.083i.icf:crypto/rsa/rsa_backend.c:328:24:
optimized: Semantically equivallent nodes merged.
./test/cmp_asn_test.wpa.083i.icf:crypto/rsa/rsa_backend.c:328:24: optimized:
Semantically equivallent nodes merged.
./test/cmp_protect_test.wpa.083i.icf:crypto/o_str.c:225:23: optimized:
Semantically equivallent nodes merged.
./test/cmp_server_test.wpa.083i.icf:providers/implementations/rands/drbg_ctr.c:355:12:
optimized: Semantically equivallent nodes merged.
./test/cmp_msg_test.wpa.083i.icf:providers/implementations/rands/drbg_ctr.c:355:12:
optimized: Semantically equivallent nodes merged.
./test/cmp_hdr_test.wpa.083i.icf:crypto/rand/rand_lib.c:917:13: optimized:
Semantically equivallent nodes merged.
./test/cmp_status_test.wpa.083i.icf:crypto/rand/rand_lib.c:917:13: optimized:
Semantically equivallent nodes merged.
./test/cmp_client_test.wpa.083i.icf:crypto/rsa/rsa_backend.c:328:24: optimized:
Semantically equivallent nodes merged.
./test/cipher_overhead_test.wpa.083i.icf:crypto/evp/evp_fetch.c:573:13:
optimized: Semantically equivallent nodes merged.
./test/context_internal_test.wpa.083i.icf:crypto/rsa/rsa_backend.c:328:24:
optimized: Semantically equivallent nodes merged.
./test/cmp_vfy_test.wpa.083i.icf:providers/implementations/rands/drbg_ctr.c:355:12:
optimized: Semantically equivallent nodes merged.
./test/ctype_internal_test.wpa.083i.icf:crypto/rsa/rsa_backend.c:328:24:
optimized: Semantically equivallent nodes merged.
./test/curve448_internal_test.wpa.083i.icf:crypto/o_str.c:225:23: optimized:
Semantically equivallent nodes merged.
./test/destest.wpa.083i.icf:crypto/rand/rand_lib.c:917:13: optimized:
Semantically equivallent nodes merged.
./test/dhtest.wpa.083i.icf:crypto/rand/rand_lib.c:917:13: optimized:
Semantically equivallent nodes merged.
./test/drbgtest.wpa.083i.icf:crypto/rsa/rsa_backend.c:328:24: optimized:
Semantically equivallent nodes merged.
./test/dsa_no_digest_size_test.wpa.083i.icf:crypto/rand/rand_lib.c:917:13:
optimized: Semantically equivallent nodes merged.
./test/dsatest.wpa.083i.icf:crypto/rand/rand_lib.c:917:13: optimized:
Semantically equivallent nodes merged.
./test/ec_internal_test.wpa.083i.icf:crypto/rsa/rsa_backend.c:328:24:
optimized: Semantically equivallent nodes merged.
./test/ecdsatest.wpa.083i.icf:crypto/provider_conf.c:60:20: optimized:
Semantically equivallent nodes merged.
./test/ectest.wpa.083i.icf:crypto/evp/legacy_sha.c:61:1: optimized:
Semantically equivallent nodes merged.
./test/endecode_test.wpa.083i.icf:include/internal/refcount.h:47:19: optimized:
Semantically equivallent nodes merged.
./test/endecoder_legacy_test.wpa.083i.icf:providers/implementations/keymgmt/ecx_kmgmt.c:425:12:
optimized: Semantically equivallent nodes merged.
./test/evp_libctx_test.wpa.083i.icf:crypto/o_str.c:225:23: optimized:
Semantically equivallent nodes merged.
./test/evp_pkey_provided_test.wpa.083i.icf:crypto/o_str.c:225:23: optimized:
Semantically equivallent nodes merged.
./test/ext_internal_test.wpa.083i.icf:test/testutil/options.c:69:5: optimized:
Semantically equivallent nodes merged.
./test/ffc_internal_test.wpa.083i.icf:crypto/rand/rand_lib.c:917:13: optimized:
Semantically equivallent nodes merged.
./test/hexstr_test.wpa.083i.icf:crypto/rsa/rsa_backend.c:328:24: optimized:
Semantically equivallent nodes merged.
./test/hmactest.wpa.083i.icf:crypto/rand/rand_lib.c:917:13: optimized:
Semantically equivallent nodes merged.
./test/ideatest.wpa.083i.icf:crypto/rsa/rsa_backend.c:328:24: optimized:
Semantically equivallent nodes merged.
./test/keymgmt_internal_test.wpa.083i.icf:crypto/rsa/rsa_backend.c:328:24:
optimized: Semantically equivallent nodes merged.
./test/modes_internal_test.wpa.083i.icf:crypto/evp/signature.c:295:5:
optimized: Semantically equivallent nodes merged.
./test/namemap_internal_test.wpa.083i.icf:crypto/provider_conf.c:60:20:
optimized: Semantically equivallent nodes merged.
./test/nodefltctxtest.wpa.083i.icf:crypto/rsa/rsa_backend.c:328:24: optimized:
Semantically equivallent nodes merged.
./test/param_build_test.wpa.083i.icf:crypto/provider_core.c:1265:7: optimized:
Semantically equivallent nodes merged.
./test/params_test.wpa.083i.icf:crypto/rsa/rsa_backend.c:328:24: optimized:
Semantically equivallent nodes merged.
./test/poly1305_internal_test.wpa.083i.icf:crypto/rsa/rsa_backend.c:328:24:
optimized: Semantically equivallent nodes merged.
./test/property_test.wpa.083i.icf:crypto/o_str.c:225:23: optimized:
Semantically equivallent nodes merged.
./test/prov_config_test.wpa.083i.icf:crypto/rsa/rsa_backend.c:328:24:
optimized: Semantically equivallent nodes merged.
./test/provfetchtest.wpa.083i.icf:crypto/evp/evp_fetch.c:573:13: optimized:
Semantically equivallent nodes merged.
./test/provider_internal_test.wpa.083i.icf:crypto/rsa/rsa_backend.c:328:24:
optimized: Semantically equivallent nodes merged.
./test/provider_test.wpa.083i.icf:crypto/rsa/rsa_backend.c:328:24: optimized:
Semantically equivallent nodes merged.
./test/punycode_test.wpa.083i.icf:crypto/rsa/rsa_backend.c:328:24: optimized:
Semantically equivallent nodes merged.
./test/rc2test.wpa.083i.icf:crypto/rsa/rsa_backend.c:328:24: optimized:
Semantically equivallent nodes merged.
./test/rc4test.wpa.083i.icf:crypto/rsa/rsa_backend.c:328:24: optimized:
Semantically equivallent nodes merged.
./test/rc5test.wpa.083i.icf:crypto/rsa/rsa_backend.c:328:24: optimized:
Semantically equivallent nodes merged.
./test/rdcpu_sanitytest.wpa.083i.icf:crypto/rsa/rsa_backend.c:328:24:
optimized: Semantically equivallent nodes merged.
./test/rsa_mp_test.wpa.083i.icf:crypto/rsa/rsa_backend.c:328:24: optimized:
Semantically equivallent nodes merged.
./test/rsa_sp800_56b_test.wpa.083i.icf:crypto/rsa/rsa_backend.c:328:24:
optimized: Semantically equivallent nodes merged.
./test/rsa_test.wpa.083i.icf:crypto/rand/rand_lib.c:917:13: optimized:
Semantically equivallent nodes merged.
./test/siphash_internal_test.wpa.083i.icf:crypto/rsa/rsa_backend.c:328:24:
optimized: Semantically equivallent nodes merged.
./test/sm3_internal_test.wpa.083i.icf:crypto/rsa/rsa_backend.c:328:24:
optimized: Semantically equivallent nodes merged.
./test/sparse_array_test.wpa.083i.icf:crypto/rsa/rsa_backend.c:328:24:
optimized: Semantically equivallent nodes merged.
./test/ssl_old_test.wpa.083i.icf:include/internal/packet.h:176:31: optimized:
Semantically equivallent nodes merged.
./test/timing_load_creds.wpa.083i.icf:providers/implementations/ciphers/cipher_aes.c:59:1:
optimized: Semantically equivallent nodes merged.
./test/tls13encryptiontest.wpa.083i.icf:include/internal/packet.h:536:31:
optimized: Semantically equivallent nodes merged.
./test/x509_internal_test.wpa.083i.icf:crypto/rand/rand_lib.c:917:13:
optimized: Semantically equivallent nodes merged.