View Revisions: Issue #36382

Summary 0036382: [Patch] x86 "OptPass1MOV" improvements
Revision 2019-11-30 00:12 by J. Gareth Moreton
Additional Information The improved optimisations produce smaller and faster code and can sometimes reduce the number of passes required in the peephole optimizer.

Optimizer performance would be greatly improved if register virtualisation is delayed, since the MovMov2Mov optimisation can often remove registers completely, but which have already been reserved earlier when the registers were devirtualised. Also, the optimisation cannot be performed if the stack is used for temporary storage (due to a lack of free registers), something that wouldn't be a problem when the registers are still virtual and assumed to not be modified by another thread. This would be an area of future research.
Revision 2019-11-30 00:11 by J. Gareth Moreton
Additional Information The improved optimisations produce smaller and faster code and can sometimes reduce the number of passes required in the peephole optimizer.

Optimizer performance would be greatly improved if register virtualisation is delayed, since the MovMov2Mov optimisation can often remove registers completely, but which have already been reserved earlier when the registers were devirtualised. Also, the optimisation cannot be performed if the stack is used for temporary storage because of a lack of free registers, something that wouldn't be a problem when the registers are still virtual and assumed to not be modified by another thread. This would be an area of future research.
Revision 2019-11-30 00:07 by J. Gareth Moreton
Additional Information The improved optimisations produce smaller and faster code and can sometimes reduce the number of passes required in the peephole optimizer.

Optimizer performance would be greatly improved if register virtualisation is delayed, since the MovMov2Mov optimisation can often remove registers completely, but which have already been reserved earlier when the registers were devirtualised. This would be an area of future research.