Re:GNU Assembler Patches For Optimizing The Intel Jump Condi...
by my123 on Thursday November 14, 2019 @07:01AM
(#21534720)
If only the microcode workaround affected just Jcc...
> The MCU prevents jump instructions from being cached in the Decoded ICache when the jump instructions cross a 32-byte boundary or when they end on a 32-byte boundary. In this context, Jump Instructions include all jumptypes: conditional jump (Jcc), macro-fusedop-Jcc(where opis one ofcmp, test, add, sub, and, inc, ordec), direct unconditional jump, indirect jump, direct/indirect call, and return
These patches are just to recover some of the performance penalty...
> The MCU prevents jump instructions from being cached in the Decoded ICache when the jump instructions cross a 32-byte boundary or when they end on a 32-byte boundary. In this context, Jump Instructions include all jumptypes: conditional jump (Jcc), macro-fusedop-Jcc(where opis one ofcmp, test, add, sub, and, inc, ordec), direct unconditional jump, indirect jump, direct/indirect call, and return
These patches are just to recover some of the performance penalty...