Technologies for prediction-based register renaming
Systems and methods are disclosed for register renaming. For example, an integrated circuit is described that includes a first cluster including a first set of physical registers and a first execution resource circuit, wherein the inputs for operations of the first execution resource circuit are of a first data type; a second cluster including a second set of physical registers and a second execution resource circuit, wherein the inputs for operations of the second execution resource circuit are of a second data type that is different than the first data type; and a register renaming circuit configured to: determine a data type prediction for a result of a first instruction that will be mapped to a first logical register; and, based on the data type prediction matching the first data type, rename the first logical register to be mapped to a physical register of the first set of physical registers.
1 . An integrated circuit for executing instructions comprising:
a first cluster including a first set of physical registers and a first execution resource circuit configured to perform operations that take contents of one or more registers of the first set of physical registers as first inputs, wherein the first inputs for operations of the first execution resource circuit are of a first data type;
a second cluster including a second set of physical registers and a second execution resource circuit configured to perform operations that take contents of one or more registers of the second set of physical registers as second inputs, wherein the second inputs for operations of the second execution resource circuit are of a second data type that is different than the first data type; and
a register renaming circuit configured to:
determine a data type prediction for a result of a first instruction that will be mapped to a first logical register;
based on the data type prediction matching the first data type, rename the first logical register to be mapped to a first physical register of the first set of physical registers;
detect a misprediction where a second instruction, to be executed after the first instruction, will access the first logical register as an input of the second data type; and
responsive to the misprediction, issue a micro-operation (micro-op) before the second instruction, wherein the micro-op copies a value of the first logical register mapped to the first physical register to a second physical register of the second set of physical registers.
2 . The integrated circuit of claim 1 , in which the first instruction is an untyped transfer instruction.
3 . The integrated circuit of claim 1 , in which the first instruction is a load instruction.
4 . The integrated circuit of claim 1 , in which the data type prediction is determined based on an opcode of the first instruction.
5 . The integrated circuit of claim 1 , in which the data type prediction is determined based on an opcode of a queued instruction that will access the result of the first instruction, wherein the queued instruction is stored in an instruction buffer.
6 . The integrated circuit of claim 1 , in which the data type prediction is determined based on a current data type of data currently mapped to the first logical register.
7 . A method for executing instructions comprising:
determining a data type prediction for a result of a first instruction that will be mapped to a first logical register;
based on the data type prediction matching a first data type, renaming the first logical register to be mapped to a physical register of a first cluster chosen from among a plurality of clusters, wherein the plurality of clusters includes:
the first cluster, which includes a first set of physical registers and a first execution resource circuit configured to perform operations that take contents of one or more registers of the first set of physical registers as first inputs, wherein the first inputs for operations of the first execution resource circuit are of the first data type; and
a second cluster, which includes a second set of physical registers and a second execution resource circuit configured to perform operations that take contents of one or more registers of the second set of physical registers as second inputs, wherein the second inputs for operations of the second execution resource circuit are of a second data type that is different than the first data type;
detecting a misprediction where a second instruction, to be executed after the first instruction, will access the first logical register as an input of the second data type; and
responsive to the misprediction, issuing a micro-operation (micro-op) before the second instruction, wherein the micro-op copies a value of the first logical register mapped to a first physical register of the first set of physical registers to a second physical register of the second set of physical registers.
8 . The method of claim 7 , in which the first instruction is an untyped transfer instruction.
9 . The method of claim 7 , in which the first instruction is a load instruction.
10 . The method of claim 7 , in which the data type prediction is determined based on an opcode of the first instruction.
11 . The method of claim 7 , in which the data type prediction is determined based on an opcode of a queued instruction that will access the result of the first instruction, wherein the queued instruction is stored in an instruction buffer.
12 . The method of claim 7 , in which the data type prediction is determined based on a current data type of data currently mapped to the first logical register.