Setting values of portions of registers based on bit values

A method, comprising:

• assigning a first architectural register of a processor to a first physical register;
• receiving, at the processor, a first instruction to assign a portion of the first architectural register a zero value;
• in response to the first instruction, setting a first flag of the processor to a first state and maintaining a first value at the first physical register different than the zero value, whereby the first flag indicates that the portion of the first architectural register is assigned the zero value while storing the first value;
• and
• in response to the first flag being set, maintaining the assignment of the first architectural register to the first physical register;
• and
• in response to a second instruction, reading a second portion of the first architectural register while suppressing transfer of the first value stored at the portion of the first architectural register to a memory.

A processor, comprising:

• a register file comprising a first register;
• a first flag corresponding to the first register, the first flag configured to indicate if a first portion of the first register is assigned a zero value different than a non-zero value stored at the first register;
• and
• a set of execution units configured to:
• set the first flag to a first state in response to a first instruction;
• and
• in response to a second instruction reading a second portion of the first register different than the first portion while suppressing transfer of the first portion of the first register to a memory responsive to the first flag of the processor having the first state.