http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50447
Bug #: 50447
Summary: [avr] Better support of AND, OR, XOR and PLUS with
constant integers for 16- and 32-bit values
Classification: Unclassified
Product: gcc
Version: 4.6.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: g...@gcc.gnu.org
Target: avr
The current implementation sometimes leads to poor code for several reasons:
o Insn "*iorsi3_clobber" is hidden behind "iorsi3" and thus will never
be used.
o There are no such insn for AND, XOR, PLUS so that the constant gets
reloaded to a same-width register where a QI was sufficient.
o If a clobber is needed, the value in the clobber reg is not reused.
o Work out if a clobber is actually needed.
