Software Pipelining Feedback From The Iircas4 C Code - Texas Instruments TMS320C6000 Programmer's Manual

Example 2–15. Software Pipelining Feedback From the iircas4 C Code
;*–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––*
;* SOFTWARE PIPELINE INFORMATION
;*
;* Known Minimum Trip Count
;* Known Max Trip Count Factor
;* Loop Carried Dependency Bound(^) : 2
;* Unpartitioned Resource Bound
;* Partitioned Resource Bound(*)
;* Resource Partition:
;*
;* .L units
;* .S units
;* .D units
;* .M units
;* .X cross paths
;* .T address paths
;* Long read paths
;* Long write paths
;* Logical
;* Addition ops (.LSD)
;* Bound(.L .S .LS)
;* Bound(.L .S .D .LS .LSD)
;*
;* Searching for software pipeline schedule at ...
;* ii = 5
;* done
;*
;* Epilog not entirely removed
;* Collapsed epilog stages
;*
;* Prolog not removed
;* Collapsed prolog stages
;*
;* Minimum required memory pad : 16 bytes
;*
;* Minimum safe trip count
;*
;*–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––*
A–side
ops (.LS)
Schedule found with 4 iterations in parallel
From the feedback in the generated .asm file, we can see that the compiler
generated a suboptimal partition. Partitioning is placing operations and oper-
ands on the A side or B side. We can see that the Unpartioned Resource
Bound is 4 while the Partitioned Resource Bound is 5. When the Partitioned
: 10
: 1
: 4
: 5
B–side
0 0
1 0
2 4
4 4
5* 3
2 4
1 1
0 0
2 1 (.L or .S unit)
4 3 (.L or .S or .D unit)
2 1
3 3
: 2
: 0
: 2
Compiler Optimization Tutorial
Lesson 5: Writing Linear Assembly
2-27