https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112758
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Component|target |rtl-optimization
Last reconfirmed| |2023-11-29
Summary|Inconsistent Bitwise AND |[13/14 Regression]
|Operation Result between |Inconsistent Bitwise AND
|int and long long int on |Operation Result between
|Different Optimization |int and long long int
|Levels in GCC Trunk |
Keywords| |needs-bisection
Ever confirmed|0 |1
Target Milestone|--- |13.3
Status|UNCONFIRMED |NEW
--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Trying 21, 18 -> 22:
21: r149:DI=0xffff00ffffffffff
18: r147:DI=sign_extend([r143:DI+low(`globalVar')])
REG_DEAD r143:DI
22: r148:DI=r147:DI&r149:DI
REG_DEAD r149:DI
REG_DEAD r147:DI
REG_EQUAL r147:DI&0xffff00ffffffffff
Successfully matched this instruction:
(set (reg:DI 148)
(zero_extend:DI (mem/c:SI (lo_sum:DI (reg/f:DI 143)
(symbol_ref:DI ("globalVar") [flags 0x86] <var_decl
0x7f79b69e8090 globalVar>)) [1 globalVarD.2927+0 S4 A32])))
allowing combination of insns 18, 21 and 22
original costs 32 + 4 + 4 = 40
replacement cost 32
That is almost definitely wrong.
Was working in GCC 12 but started to go wrong in GCC 13.
