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Use bseti when profitable. Many cases of poor constant synthesis are failure to use bseti.Use "uw" variants of shifts/arithmetic instructions when the constant has bit 0x80000000 set.Use shNadd for constants evenly divisible by 9, 5 or 3.Use blcri in conjunction with lui or addi to clear a small number of bits, particularly in the high 33 bits of a 64bit word- Adjust constant so low 13 bits are 0x1800, recursively re-synthesize and restore low bits with trailing addi.
- Use pack for repeating constants
- Use pack as synthesis of last resort
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