FAST INDEX TREE FOR ACCELERATED BRANCH PREDICTION
First Claim
1. A computer-implemented method for accelerated branch prediction using a fast index tree (FIT), the method comprising:
- determining, by a computer, that searching of a branch target buffer is to be performed under FIT control;
saving a current search address for searching of the branch target buffer;
searching the branch target buffer at the saved current search address for a branch prediction;
determining, by the computer, a FIT next-search address based on reading branch taken and branch not taken paths for a next search level of predicted branches from a FIT structure;
re-indexing the searching of the branch target buffer based on the FIT next-search address;
determining, by the computer, whether the searching at the saved current search address located the branch prediction;
based on the searching at the saved current search address locating the branch prediction, continuing the searching of the branch target buffer under FIT control with the current search address set based on the FIT next-search address; and
based on the searching at the saved current search address failing to locate the branch prediction, re-indexing the searching of the branch target buffer with the saved current search address and performing the searching of the branch target buffer without FIT control.
1 Assignment
0 Petitions
Accused Products
Abstract
Embodiments relate to using a fast index tree for accelerated branch prediction. A computer-implemented method includes determining, by a computer, that searching of a branch target buffer is to be performed under FIT control. A current search address is saved. The branch target buffer is searched at the saved current search address for a branch prediction. A FIT next-search address is determined based on reading branch taken and branch not taken paths for a next search level of predicted branches from a FIT structure. The searching is re-indexed based on the FIT next-search address. Based on locating the branch prediction, the searching is continued under FIT control with the current search address set based on the FIT next-search address. Based on failing to locate the branch prediction, the searching is re-indexed with the saved current search address, and the searching is performed without FIT control.
-
Citations
7 Claims
-
1. A computer-implemented method for accelerated branch prediction using a fast index tree (FIT), the method comprising:
-
determining, by a computer, that searching of a branch target buffer is to be performed under FIT control; saving a current search address for searching of the branch target buffer; searching the branch target buffer at the saved current search address for a branch prediction; determining, by the computer, a FIT next-search address based on reading branch taken and branch not taken paths for a next search level of predicted branches from a FIT structure; re-indexing the searching of the branch target buffer based on the FIT next-search address; determining, by the computer, whether the searching at the saved current search address located the branch prediction; based on the searching at the saved current search address locating the branch prediction, continuing the searching of the branch target buffer under FIT control with the current search address set based on the FIT next-search address; and based on the searching at the saved current search address failing to locate the branch prediction, re-indexing the searching of the branch target buffer with the saved current search address and performing the searching of the branch target buffer without FIT control. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
Specification