Post #2409971

@JamesWidman@mastodon.social But the extra storage for ECC bits is built into the macros anyway so a common trick is to make I$ parity protected only (so error detection but no correction) and then you get spare bits you can use for other sideband data. Historical uses include said instruction marker bits. IIRC the original Opteron arch also threw some branch prediction state bits for cold I$ lines in there.