[Bug target/105778] Shift by register --- unnecessary AND instruction

[ubizjak at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105778

--- Comment #3 from Uroš Bizjak <ubizjak at gmail dot com> ---
Comment on attachment 53058
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=53058
gcc13-pr105778.patch

>+      operands[2] = gen_lowpart (QImode, operands[2]);

We have learned that pre-reload splits need to move operand to a register
before calling gen_lowpart.

>+      emit_insn (gen_ashl<dwi>3_doubleword (operands[0], operands[1],
>+                                          operands[2]));
>+      DONE;