[Bug target/114810] [14 Regression] internal compiler error: in lra_split_hard_reg_for, at lra-assigns.cc:1868 (unable to find a register to spill) {*andndi3_doubleword_bmi} with -m32 -mstackrealign -O2 -mbmi -fno-exceptions -fno-plt

[ubizjak at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114810

--- Comment #4 from Uroš Bizjak <ubizjak at gmail dot com> ---
An interesting observation, when the insn is defined only with problematic
alternative:

(define_insn_and_split "*andn<dwi>3_doubleword_bmi"
  [(set (match_operand:<DWI> 0 "register_operand" "=&r")
        (and:<DWI>
          (not:<DWI> (match_operand:<DWI> 1 "register_operand" "r"))
          (match_operand:<DWI> 2 "nonimmediate_operand" "ro")))
   (clobber (reg:CC FLAGS_REG))]

the compilation succeeds, and a spill to memory is emitted:


(insn 1170 65 1177 7 (set (mem/c:DI (plus:SI (reg/f:SI 6 bp)
                (const_int -168 [0xffffffffffffff58])) [71 %sfp+-144 S8 A64])
        (reg:DI 0 ax [orig:217 _13 ] [217])) "pr114810.C":296:36 84
{*movdi_internal}
     (nil))

...

(insn 987 1154 1111 7 (parallel [
            (set (reg:DI 3 bx [453])
                (and:DI (not:DI (reg:DI 0 ax [452]))
                    (mem/c:DI (plus:SI (reg/f:SI 6 bp)
                            (const_int -168 [0xffffffffffffff58])) [71
%sfp+-144 S8 A64])))
            (clobber (reg:CC 17 flags))
        ]) "pr114810.C":296:6 703 {*andndi3_doubleword_bmi}
     (nil))