HAL Id: inria-00073060
https://hal.inria.fr/inria-00073060
Submitted on 24 May 2006
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De-aliased Hybrid Branch Predictors
André Seznec, Pierre Michaud
To cite this version:
André Seznec, Pierre Michaud. De-aliased Hybrid Branch Predictors. [Research Report] RR-3618,
INRIA. 1999. �inria-00073060�
ISSN 0249-6399
a p p o r t
d e r e c h e r c h e
INSTITUT NATIONAL DE RECHERCHE EN INFORMATIQUE ET EN AUTOMATIQUE
De-aliased Hybrid Branch Predictors
Andr´e Seznec, Pierre Michaud
N ˚ 3618
F´evrier 1999
TH ` EME 1
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3 3.2 3.4 3.6 3.8 4 4.2 4.4 4.6 4.8
0 2 4 6 8 10 12
% misprediction
global history length e-gsk 3*4K gshare 32K 2Bc-gskew 4*2K 2Bc-gshare 16K YAGS 2K + 2*1K
3 3.5 4 4.5 5 5.5 6 6.5 7 7.5
0 2 4 6 8 10 12
% misprediction
global history length e-gsk 3*4K gshare 32K 2Bc-gskew 4*2K 2Bc-gshare 16K YAGS 2K + 2*1K
QD Ñ Q6
5 5.5 6 6.5 7 7.5 8 8.5 9
0 2 4 6 8 10 12
% misprediction
global history length e-gsk 3*4K gshare 32K 2Bc-gskew 4*2K 2Bc-gshare 16K YAGS 2K + 2*1K
2.4 2.6 2.8 3 3.2 3.4 3.6 3.8 4 4.2 4.4
0 2 4 6 8 10 12
% misprediction
global history length e-gsk 3*4K gshare 32K 2Bc-gskew 4*2K 2Bc-gshare 16K YAGS 2K + 2*1K
Í Q Î P Ñ
6 6.5 7 7.5 8 8.5 9 9.5 10 10.5 11
0 2 4 6 8 10 12
% misprediction
global history length e-gsk 3*4K gshare 32K 2Bc-gskew 4*2K 2Bc-gshare 16K YAGS 2K + 2*1K
3 3.5 4 4.5 5 5.5
0 2 4 6 8 10 12
% misprediction
global history length e-gsk 3*4K gshare 32K 2Bc-gskew 4*2K 2Bc-gshare 16K YAGS 2K + 2*1K
Í QD3 JÒ Í
3 3.5 4 4.5 5 5.5 6 6.5 7 7.5
0 2 4 6 8 10 12
% misprediction
global history length e-gsk 3*4K gshare 32K 2Bc-gskew 4*2K 2Bc-gshare 16K YAGS 2K + 2*1K
3 3.5 4 4.5 5 5.5 6 6.5 7 7.5
0 2 4 6 8 10 12
% misprediction
global history length e-gsk 3*4K gshare 32K 2Bc-gskew 4*2K 2Bc-gshare 16K YAGS 2K + 2*1K
Í
OÑ Q KO Ò
ÍZÑ Î WW
R$#&%('*)
2 2.5 3 3.5 4 4.5 5
0 2 4 6 8 10 12 14
% misprediction
global history length e-gskew 48K gshare 128K 2Bc-gskew 32K 2Bc-gshare 64K YAGS 8K + 2*4K
2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5
0 2 4 6 8 10 12 14
% misprediction
global history length e-gskew 48K gshare 128K 2Bc-gskew 32K 2Bc-gshare 64K YAGS 8K + 2*4K
QD Ñ Q6
4.5 5 5.5 6 6.5 7 7.5 8 8.5 9
0 2 4 6 8 10 12 14
% misprediction
global history length e-gskew 48K gshare 128K 2Bc-gskew 32K 2Bc-gshare 64K YAGS 8K + 2*4K
2 2.5 3 3.5 4 4.5
0 2 4 6 8 10 12 14
% misprediction
global history length e-gskew 48K gshare 128K 2Bc-gskew 32K 2Bc-gshare 64K YAGS 8K + 2*4K
Í Q Î P Ñ
4 5 6 7 8 9 10 11
0 2 4 6 8 10 12 14
% misprediction
global history length e-gskew 48K gshare 128K 2Bc-gskew 32K 2Bc-gshare 64K YAGS 8K + 2*4K
2.5 3 3.5 4 4.5 5
0 2 4 6 8 10 12 14
% misprediction
global history length e-gskew 48K gshare 128K 2Bc-gskew 32K 2Bc-gshare 64K YAGS 8K + 2*4K
Í QD3 JÒ Í
2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5
0 2 4 6 8 10 12 14
% misprediction
e-gskew 48K gshare 128K 2Bc-gskew 32K 2Bc-gshare 64K YAGS 8K + 2*4K
2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5
0 2 4 6 8 10 12 14
% misprediction
e-gskew 48K gshare 128K 2Bc-gskew 32K 2Bc-gshare 64K YAGS 8K + 2*4K
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R$#&%('*)
2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5
1 3 5 7 9 inf
% misprediction
Branch quantum (x 50,000) gskew 48K gshare 128K 2Bc-gskew 32K 2Bc-gshare 64K YAGS 8K + 2*4K
3 3.5 4 4.5 5 5.5 6 6.5 7
1 3 5 7 9 inf
% misprediction
Branch quantum (x 50,000) gskew 48K gshare 128K 2Bc-gskew 32K 2Bc-gshare 64K YAGS 8K + 2*4K
QD Ñ Q6
4.5 5 5.5 6 6.5 7 7.5 8 8.5 9 9.5
1 3 5 7 9 inf
% misprediction
Branch quantum (x 50,000) gskew 48K gshare 128K 2Bc-gskew 32K 2Bc-gshare 64K YAGS 8K + 2*4K
2 2.5 3 3.5 4 4.5 5 5.5
1 3 5 7 9 inf
% misprediction
Branch quantum (x 50,000) gskew 48K gshare 128K 2Bc-gskew 32K 2Bc-gshare 64K YAGS 8K + 2*4K
Í Q Î P Ñ
5 6 7 8 9 10 11
1 3 5 7 9 inf
% misprediction
Branch quantum (x 50,000) gskew 48K gshare 128K 2Bc-gskew 32K 2Bc-gshare 64K YAGS 8K + 2*4K
2 3 4 5 6 7 8
1 3 5 7 9 inf
% misprediction
Branch quantum (x 50,000) gskew 48K gshare 128K 2Bc-gskew 32K 2Bc-gshare 64K YAGS 8K + 2*4K
Í QD3 JÒ Í
2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5
1 3 5 7 9 inf
% misprediction
gskew 48K gshare 128K 2Bc-gskew 32K 2Bc-gshare 64K YAGS 8K + 2*4K
2 3 4 5 6 7 8 9
1 3 5 7 9 inf
% misprediction
gskew 48K gshare 128K 2Bc-gskew 32K 2Bc-gshare 64K YAGS 8K + 2*4K
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address address
history n
n
majority
history table
e-pskew prediction P0
P1
n
n
n
majority vote BIM
G0
Meta2
G1
n
Meta1
e-gskew prediction bimodal prediction
vote
PREDICTION
MUX MUX
metaprediction2
metaprediction1
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