JIT: Allow liveness to remove some nodes with contained side effects #116819
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Contained operands with side effects can usually be handled by clearing their containment status. This is what we did before 3091730 which changed the DCE to skip nodes with contained side effects. However, the only case that does not support its own standalone codegen is currently embedded mask ops, so switch to check more specifically for this case. This fixes a case where after removing a call node we could end up with a unused `FIELD_LIST` with a contained IND node, and also fixes the regressions seen because of 3091730.
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Tagging subscribers to this area: @JulieLeeMSFT, @jakobbotsch |
a74nh
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Jun 20, 2025
| // Only embedded mask ops do not support standalone codegen. All other | ||
| // nodes can be uncontained. | ||
| // | ||
| bool Compiler::fgCanUncontainOrRemoveOperands(GenTree* node) |
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I'm happy that this won't break anything I was fixing.
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PTAL @dotnet/jit-contrib Minor diffs. Essentially just undoing the regressions from #116144 |
amanasifkhalid
approved these changes
Jun 20, 2025
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Contained operands with side effects can usually be handled by clearing their containment status. This is what we did before #116144 which changed the DCE to skip nodes with contained side effects. However, the only case that does not support its own standalone codegen is currently embedded mask ops, so switch to check more specifically for this case.
This fixes a case where after removing a call node we could end up with a unused
FIELD_LISTwith a contained IND node, and also fixes the regressions seen because of #116144.Also switches
GenTree::VisitOperandsto return the visit result, and switchesNodeOrContainedOperandsMayThrow()to use it (it is slightly more efficient than the iterator version).Most ideally we would just allow these embedded mask ops to work as top-level nodes, like all other containment candidates.
Fix #116814