https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91026
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Summary|switch expansion produces a |[9/10 Regression] switch
|jump table with trivial |expansion produces a jump
|entries |table with trivial entries
Target Milestone|--- |10.4
--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
In GCC 11, we do the right thing again.
On the trunk we even do even better by using btq:
cmpb $18, %dil
ja .L3
movl $348018, %eax
btq %rdi, %rax
setc %al
ret
.L3:
xorl %eax, %eax
ret
Note clang does not so good job:
addb $-1, %dil
cmpb $18, %dil
setb %cl
movzbl %dil, %eax
movl $174009, %edx # imm = 0x2A7B9
btl %eax, %edx
setb %al
andb %cl, %al
retq
