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Title: gh-146640: Optimize int operations by mutating uniquely-referenced operands in place (JIT only) by eendebakpt · Pull Request #146641 · python/cpython · GitHub

Open Graph Title: gh-146640: Optimize int operations by mutating uniquely-referenced operands in place (JIT only) by eendebakpt · Pull Request #146641 · python/cpython

X Title: gh-146640: Optimize int operations by mutating uniquely-referenced operands in place (JIT only) by eendebakpt · Pull Request #146641 · python/cpython

Description: In this PR we add inplace binary operations for int type, similar to #146397. A complication compared to the float case is that the int operations can return small ints which should not be modified in place. In this PR we: Use PyJitRef_MakeUnique(sym_new_compact_int(ctx)); to mark that a symbol is an int that is either unique or one of the small ints. Add _BINARY_OP_ADD_INT_INPLACE (with variations for the other operations) that handles both small ints as input and overflows. An alternative to handling these cases in the opcode would be do deopt. Here we decided not to deopts because this could lead to many deopts. There is a PyStackRef_DUP(TARGET); inside the macro to get the stack effects right. I tried optimizing that, but it requires changing the structure of the opcode following _BINARY_OP_ADD_INT (the POP_TOP ones). I estimate that it is not worth the complexity to try to eliminate that. Micro benchmark results: Pattern main (ns/iter) branch (ns/iter) Speedup Notes total += a*b + c (non-small) 34.4 27.8 1.24x inplace mutation on unique a*b result total += a + b (non-small) 19.8 13.0 1.52x a+b result is unique, inplace on += t = a + b (plain assign) 13.4 14.1 -- no +=, not affected total += a*b + c*d (chain) 40.4 34.6 1.17x two unique products, inplace on + total += a*b + 1 (small int) 23.2 24.1 -- TARGET is small int, fallback to standard All values are non-small integers (> 1024) unless noted. Selected pyperformance benchmarks: ### deltablue ### Mean +- std dev: 1.95 ms +- 0.03 ms -> 1.97 ms +- 0.03 ms: 1.01x slower Not significant ### scimark_fft ### Mean +- std dev: 208 ms +- 5 ms -> 206 ms +- 1 ms: 1.01x faster Not significant ### scimark_lu ### Mean +- std dev: 58.1 ms +- 0.2 ms -> 58.7 ms +- 0.8 ms: 1.01x slower Not significant ### scimark_monte_carlo ### Mean +- std dev: 41.7 ms +- 1.7 ms -> 41.6 ms +- 0.8 ms: 1.00x faster Not significant ### scimark_sor ### Mean +- std dev: 66.8 ms +- 0.6 ms -> 64.3 ms +- 0.5 ms: 1.04x faster Significant (t=26.88) ### scimark_sparse_mat_mult ### Mean +- std dev: 3.64 ms +- 0.03 ms -> 3.64 ms +- 0.04 ms: 1.00x slower Not significant ### spectral_norm ### Mean +- std dev: 56.4 ms +- 0.2 ms -> 51.5 ms +- 0.4 ms: 1.10x faster Significant (t=79.61) Issue: gh-146640

Open Graph Description: In this PR we add inplace binary operations for int type, similar to #146397. A complication compared to the float case is that the int operations can return small ints which should not be modified...

X Description: In this PR we add inplace binary operations for int type, similar to #146397. A complication compared to the float case is that the int operations can return small ints which should not be modified...

Opengraph URL: https://github.com/python/cpython/pull/146641

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