rol

The Language Reference - Instructions - rol

The command this: rol rotates the contents of this left by one bit, making the rightmost bit (bit 0) equal to the carry flag, and then shifting the leftmost bit (bit 7) into the carry flag. The zero and negative p-flags are modified accordingly.

Usage	Opcode, 6502 mnemonic
a: rol	0x2A, rol
@direct: rol	0x2E, rol
@direct[x]: rol	0x3E, rol
@zp: rol	0x26, rol
@zp[x]: rol	0x36, rol

See also: shl, shr, ror