https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98957
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Priority|P3 |P1
Summary|[x86] Odd code generation |[11 Regression] [x86] Odd
|for 8-bit left shift |code generation for 8-bit
| |left shift
Ever confirmed|0 |1
Status|UNCONFIRMED |NEW
Last reconfirmed| |2021-02-04
Target Milestone|--- |11.0
Keywords| |needs-bisection
--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Indeed odd. -mtune=core-avx2 outputs just
movl %edi, %eax
shrb $7, %al
ret
which is also what generic tuning produces. This must be some partial
reg stall stuff, not sure which.
Maybe there's again some flags aliasing going on in the backend. Marking as
regression for investigation.
