Bug 38267 - rtl epilogues worse than non-rtl epilogues for dbr scheduling
Summary: rtl epilogues worse than non-rtl epilogues for dbr scheduling
Status: UNCONFIRMED
Alias: None
Product: gcc
Classification: Unclassified
Component: middle-end (show other bugs)
Version: 4.2.1
: P3 normal
Target Milestone: ---
Assignee: Not yet assigned to anyone
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2008-11-25 19:32 UTC by Jorn Wolfgang Rennecke
Modified: 2009-01-24 21:41 UTC (History)
2 users (show)

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Description Jorn Wolfgang Rennecke 2008-11-25 19:32:37 UTC
The rtl epilogues are inserted after the USE which indicates where
the return value is.  As a result, an instruction that calculates the
return value cannot be placed in the delay slot of the return
instruction.  That is something that we did get right when we
had non-rtl epilogues - the epilogue_delay could well contain an insn to calculate
the function result.
Comment 1 Hans-Peter Nilsson 2009-01-24 21:34:16 UTC
A test-case and a target would help here.