https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98470
--- Comment #1 from jcmvbkbc at gcc dot gnu.org ---
It happens at the reload pass when reload transforms the following RTL that
comes to it from the IRA pass:
(insn 20 163 164 30 (set (reg:SF 162 [ iftmp.0_87 ])
(mem/u/c:SF (symbol_ref/u:SI ("*.LC0") [flags 0x2]) [0 S4 A32]))
"float-ice.c":11:17 45 {movsf_internal}
(expr_list:REG_EQUIV (mem/u/c:SF (symbol_ref/u:SI ("*.LC0") [flags 0x2])
[0 S4 A32])
(nil)))
...
(insn 538 168 169 32 (set (reg:SF 71 [ iftmp.0_87 ])
(reg:SF 162 [ iftmp.0_87 ])) "float-ice.c":11:17 45 {movsf_internal}
(nil))
to the following RTL:
(insn 538 168 169 32 (set (reg:SF 19 f0 [orig:71 iftmp.0_87 ] [71])
(mem/u/c:SF (symbol_ref/u:SI ("*.LC0") [flags 0x2]) [0 S4 A32]))
"float-ice.c":11:17 45 {movsf_internal}
(nil))
which tries to load a literal into a hardware FP register. There's no opcode
for it in the xtensa ISA, there's no constraint that would match it in the
movsf_internal and the predicate in this instruction definition evaluates to
false on such input, but the substitution happens anyway.
