Mask scalar result based on correct instruction metadata#25
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mattsini1 merged 1 commit intopulp-platform:mainfrom Apr 17, 2025
Merged
Mask scalar result based on correct instruction metadata#25mattsini1 merged 1 commit intopulp-platform:mainfrom
mattsini1 merged 1 commit intopulp-platform:mainfrom
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Previously, the scalar result sent back to Spatz's controller was masked based on the instruction currently in the operation queue, which was wrong. This changes it so it considers the correct instruction (i.e., it takes the informations from the result tag).
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Navaneeth-KunhiPurayil
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Verified that all the tests pass
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For VFU instructions with scalar results (e.g., scalar floating point instructions) immediately followed by VFU instructions that commit to the VRF, the first instruction could write back a zero result to the FP register file. (This was maybe similar for the GP register file, but I haven't checked).
This happened because the scalar result was masked based on the
is_scalarflag from the instruction currently in the operation queue (i.e., earlier in the pipeline). If this was an instruction with a vector result, it'sis_scalarflag would be cleared and the scalar result masked.This changes it so it considers the correct instruction (i.e., it takes the information from the result tag's
wbbit).