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Non-call exceptions versus cse
- From: Joern Rennecke <joern dot rennecke at superh dot com>
- To: Andrew Haley <aph at redhat dot com>
- Cc: gcc-patches at gcc dot gnu dot org
- Date: Tue, 19 Nov 2002 19:38:53 +0000
- Subject: Non-call exceptions versus cse
- Organization: SuperH UK Ltd.
> because the load from foo->bar may trap, in which case nn will not be
> set. We don't want data flow analysis incorrectly to conclude that
> the original value of nn is dead after this fragment.
> As far as I can see it's never correct to CSE two instructions if the
> first one may trap.
But this will disable cse of most memory references, integer divides, and
floating point operations.
Isn't it rather the job of flow to check an instruction for side effects
before removing it?
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