Comment 19 for bug 1953128

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In , Jakub-gcc (jakub-gcc) wrote :

Inline asm that only works with memory but in constraints says it accepts both immediate constant and memory is IMNSHO just broken, it is just fine if the compiler makes a different choice.
If "nor" with constant input on arm has meant actually just "or", then sure, systemtap could be changed and after a couple of years it will propagate to all stap copies used in the wild, but it is quite severe misoptimization of one of the most common cases. The systemtap macros don't really know what argument will be passed to them, whether a constant, something that lives in memory, something that lives in a register and ideally wants as few actual instructions before those macros as possible to arrange the arguments so that debugger can inspect them.