ptlsim/qemu: Disable compiler optimizations #73
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This is unfortunate, but after obtaining the default, official MARSS image and running the FFT simulation with ./start_sim and ./stop_sim, it seems broken. It errors out with: ``` Switching to simulation ptlsim_ptlcall_init: mapped PTLcall MMIO page at phys 0x8fffff000, virt 0x7f9520458000 PTLCALL type PTLCALL_ENQUEUE MARSSx86::Command received : -run Warning: only one action (from -run, -stop, -kill) can be specified at once ``` I'm running Debian Bullseye (stable) with the default GCC and build tools shipped with it, so nothing fancy here. Knowing that `ptlsim`, has a lot of reliance on undefined behavior throughout its codebase, I disabled compiler optimizations and everything began working as expected again. There's practical ways to fuzz for what's breaking things here, but this was a rather obvious error. There could also be subtle ones that invalidate or produce poor/bad/fake simulation results. Until uses of undefined behavior are squashed or at least somewhat fuzzed for, disable compiler optimizations to prevent surprises. Signed-off-by: Tyler J. Stachecki <[email protected]>
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This is unfortunate, but after obtaining the default,
official MARSS image and running the FFT simulation with
./start_sim and ./stop_sim, it seems broken. It errors
out with:
I'm running Debian Bullseye (stable) with the default GCC
and build tools shipped with it, so nothing fancy here.
Knowing that
ptlsim, has a lot of reliance on undefinedbehavior throughout its codebase, I disabled compiler
optimizations and everything began working as expected
again.
There's practical ways to fuzz for what's breaking things
here, but this was a rather obvious error. There could also
be subtle ones that invalidate or produce poor/bad/fake
simulation results. Until uses of undefined behavior are
squashed or at least somewhat fuzzed for, disable compiler
optimizations to prevent surprises.
Signed-off-by: Tyler J. Stachecki [email protected]