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Paradoxical subregs and !INSN_SCHEDULING. Why?
- From: Hans-Peter Nilsson <hp at bitrange dot com>
- To: gcc at gcc dot gnu dot org
- Date: Sun, 19 Dec 2004 21:40:23 -0500 (EST)
- Subject: Paradoxical subregs and !INSN_SCHEDULING. Why?
Why are paradoxical subregs allowed and even generated in
combine (rather, recognized as valid combination attempts by
e.g. register_operand through general_operand) when not
INSN_SCHEDULING? Is it because of a hope that combine will do
better than with the actual registers and that the pesky
scheduler (boo-hoo) doesn't handle the invalid (IMO)
intermediate-paradoxical-code?
To me it just seems an odd case causing bugs like PR
target/18701.
brgds, H-P