BTB meaning in Computer Hardware ?

Answer: What is Branch Target Buffer mean?

In computer architecture, a branch target predictor is the part of a processor that predicts the target of a taken conditional branch or an unconditional branch instruction before the target of the branch instruction is computed by the execution unit of the processor.

Branch target prediction is not the same as branch prediction which attempts to guess whether a conditional branch will be taken or not-taken (i.e., binary).

In more parallel processor designs, as the instruction cache latency grows longer and the fetch width grows wider, branch target extraction becomes a bottleneck. The recurrence is:

Instruction cache fetches block of instructionsInstructions in block are scanned to identify branchesFirst predicted taken branch is identifiedTarget of that branch is computedInstruction fetch restarts at branch target

In machines where this recurrence takes two cycles, the machine loses one full cycle of fetch after every predicted taken branch. As predicted branches happen every 10 instructions or so, this can force a substantial drop in fetch bandwidth. Some machines with longer instruction cache latencies would have an even larger loss. To ameliorate the loss, some machines implement branch target prediction: given the address of a branch, they predict the target of that branch. A refinement of the idea predicts the start of a sequential run of instructions given the address of the start of the previous sequential run of instructions.

This predictor reduces the recurrence above to:

Hash the address of the first instruction in a runFetch the prediction for the addresses of the targets of branches in that run of instructionsSelect the address corresponding to the branch predicted taken

As the predictor RAM can be 5–10% of the size of the instruction cache, the fetch happens much faster than the instruction cache fetch, and so this recurrence is much faster. If it were not fast enough, it could be parallelized, by predicting target addresses of target branches.

reference

Full Form	Category
Biblical Theology Bulletin	Academic & Science
Biological Testing Branch	Academic & Science
Betou	Airport Code
Book To Bill	Business
Bangladesh Tourism Board	Community
Bringing Tap Back	Community
Be The Boy	Community
Buffer Target Branch	Computer Assembly Language
Branch Target Buffer	Computer Hardware
Bass Treble Boost	Computing
Basic Test Battery	Computing
Bing Toolbox	Computing
Black To Black	Computing
Board Technical Bulletin	Computing
Break The Bank	Computing
By The Bye	Computing
BitBall	Cryptocurrency
Believe Train Become	General
Behind the Bookcase	General
Bring That Booty	General
Billionaire Trap Boys	General
Bench To Bedside	General
Behind The Bows	General
Blacker Than Black	General
Bukit Tok Beng	General
Business To Business	General
Biturbo Boxer	General
Big Throttle Body	General
Buggy Team Belgie	General
Banco Toyota Do Brasil	General
BarTender Ben	General
Beyond Traditional Borders	General
Beyond The Bell	General
Belgian Trading and Bunkering	General
Beyond the Border	General
By the Books	General
Behind the Barriers	General
Behind THE	General
Back-To-Birth	General
TV BTBcxTV	General
Burnt Transparent Blue	General
Bog Trash Brown	General
Beyond The Basics	General
Breed The Best	General
Bid To Buy	General
Back To Basics	General
Better Than Bane	General
Bad To The Bone	General
Beat The Boner	General
Behind The Back	General
Big Time Ballaz	General
Belize Tourism Board	Governmental
Bangkok Tourist Bureau	Governmental
By The Book	Internet
Bakri Tamponade Balloon	Medical
Bone Tendon Bone	Medical
bovine TuBerculosis	Medical
Bob The Builder	Messaging
By The By	Messaging
Believed-to-be	Military and Defence
Back To Base	Sports
Beating The Beast	Sports