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Appendix B
Statistics for CMS image cms4.4.03raptor
Figure 6 – Bundle Issue Chart
|
Total Instructions |
231313 |
|
|
Total Nops |
70363 |
0.304189561 |
|
Bundles |
Count |
Percentage |
|
LSU|ALU1|ALU0|imm32 |
13386 |
0.13154869 |
|
LSU|ALU1|ALU0|BRU |
9911 |
0.097398705 |
|
LSU|ALU1 |
25401 |
0.249624104 |
|
ALU0|imm32 |
5409 |
0.053156048 |
|
ALU0|ALU1 |
31625 |
0.31078943 |
|
ALU0|BRU |
16025 |
0.157483023 |
|
Total |
101757 |
Chart 1 – Bundle Frequency and nop Count
IPC figures are not provided since this obviously depends on the dynamic behavior of the code. With that in mind, most bundles appear to contain only two instructions; the quad-issue format is possible in only 22% of the code, primarily due to the limitations previously identified in the hardware.
Opcode Map and Instruction Descriptions
See the insn_name_table structure in CrusoeReport-Part2-Disasm.cpp for a map of the most common instruction opcodes and mnemonics. These instructions make up the vast majority of the CMS code.
Detailed Per-Unit Opcode Usage Statistics
The frequency of 9-bit opcodes used with different functional units is useful for determining the meaning and operation of the corresponding instructions.
The included CrusoeReport-Part2-histograms.txt file contains this data for each functional unit and bundle slot. The high 6 bits of the 9 bit opcode are in the rows, while the low 3 bits are in the columns.
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