https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106574
--- Comment #10 from Michael Hudson-Doyle <michael.hudson at canonical dot com> --- FWIW, I see a similar error on ppc64el with what looks like a similar cause. (I also see other errors that do not go away with s/O3/O2/ so that might be something slightly different). O3: (kinetic-ppc64el)root@bobonevm3:/build/glibc-9T9BfE/glibc-2.36/build-tree/ppc64el-libc# ./elf/ld64.so.2 --library-path .:./elf:./math ./math/test-ibm128-y1 testing long double (without inline functions) Failure: Test: y1_downward (0x2p+0) Result: is: -1.07032431540937546888370772277496e-01 -0x1.b667a3914664758b0c44371e580p-4 should be: -1.07032431540937546888370772277477e-01 -0x1.b667a3914664758b0c44371e520p-4 difference: 1.84889274661174641893373882488153e-32 0x1.800000000000000000000000000p-106 ulp : 12.0000 max.ulp : 11.0000 Maximal error of `y1_downward' is : 12 ulp accepted: 11 ulp Failure: Test: y1_upward (0x1.c1bc2ep+0) Result: is: -2.49838507061808223791568937534715e-01 -0x1.ffab54c8e53c466a84209c10030p-3 should be: -2.49838507061808223791568937534759e-01 -0x1.ffab54c8e53c466a84209c100a0p-3 difference: 4.31408307542740831084539059139024e-32 0x1.c00000000000000000000000000p-105 ulp : 14.0000 max.ulp : 9.0000 Failure: Test: y1_upward (0x2p+0) Result: is: -1.07032431540937546888370772277458e-01 -0x1.b667a3914664758b0c44371e4c0p-4 should be: -1.07032431540937546888370772277475e-01 -0x1.b667a3914664758b0c44371e518p-4 difference: 1.69481835106076755068926058947474e-32 0x1.600000000000000000000000000p-106 ulp : 11.0000 max.ulp : 9.0000 Maximal error of `y1_upward' is : 14 ulp accepted: 9 ulp Test suite completed: 175 test cases plus 171 tests for exception flags and 171 tests for errno executed. O2: (kinetic-ppc64el)root@bobonevm3:/build/glibc-9T9BfE/glibc-2.36/build-tree/ppc64el-libc# ./elf/ld64.so.2 --library-path .:./elf:./math ./math/test-ibm128-y1 testing long double (without inline functions) Failure: Test: y1_upward (0x1.c1bc2ep+0) Result: is: -2.49838507061808223791568937534728e-01 -0x1.ffab54c8e53c466a84209c10050p-3 should be: -2.49838507061808223791568937534759e-01 -0x1.ffab54c8e53c466a84209c100a0p-3 difference: 3.08148791101957736488956470813589e-32 0x1.400000000000000000000000000p-105 ulp : 10.0000 max.ulp : 9.0000 Failure: Test: y1_upward (0x2p+0) Result: is: -1.07032431540937546888370772277458e-01 -0x1.b667a3914664758b0c44371e4c0p-4 should be: -1.07032431540937546888370772277475e-01 -0x1.b667a3914664758b0c44371e518p-4 difference: 1.69481835106076755068926058947474e-32 0x1.600000000000000000000000000p-106 ulp : 11.0000 max.ulp : 9.0000 Maximal error of `y1_upward' is : 11 ulp accepted: 9 ulp Test suite completed: 175 test cases plus 171 tests for exception flags and 171 tests for errno executed. 3 errors occurred. (I also see llround errors on ppc64el, no idea what's going on there...)