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Re: Autoincrement examples
- To: m dot hayes at elec dot canterbury dot ac dot nz (Michael Hayes)
- Subject: Re: Autoincrement examples
- From: Joern Rennecke <amylaar at cygnus dot co dot uk>
- Date: Thu, 18 Nov 1999 15:32:28 +0000 (GMT)
- Cc: law at cygnus dot com, m dot hayes at elec dot canterbury dot ac dot nz, gcc at gcc dot gnu dot org, amylaar at cygnus dot com
> What were the chief advantages of doing this during regmove? I'm not
> familiar with this pass but I feel the transformations are too late.
> For simple cases it should make no difference, but for more complex
> cases, autoincrement optimisation needs to run before instruction
My loop patches recognize a number of cases where autoincrement considerations
require a different pattern of giv combination.
However, we are not supposed to generate autoincrement before flow. The
point of doin this in regmove is that we alerady got constraint information
there - using autoincrement instead of three-address-adds is much more useful
when you don't actually have a three-address add to start with.