In the latest reload.c, the function combine_reloads() includes
a wrong evaluation order of expressions to check if there is any
available hard register.
In the following statements in combine_reloads(),
the candidate register must be checked whether it is a
hard register or not before invoking the function
reg_overlap_mentioned_for_reload_p(). Otherwise,
reg_overlap_mentioned_for_reload_p() will fail and die
when it is invoked and the candidate register is a pseudo register.
File: reload.c
Revision: 1.268, Thu Feb 24 22:06:06 2005 UTC (5 weeks, 1 day ago) by dje
1837: /* See if some hard register that dies in this insn and is not used in
1838: the output is the right class. Only works if the register we pick
1839: up can fully hold our output reload. */
1840: for (note = REG_NOTES (this_insn); note; note = XEXP (note, 1))
1841: if (REG_NOTE_KIND (note) == REG_DEAD
1842: && REG_P (XEXP (note, 0))
1843: && ! reg_overlap_mentioned_for_reload_p (XEXP (note, 0),
1844: rld[output_reload].out)
1845: && REGNO (XEXP (note, 0)) < FIRST_PSEUDO_REGISTER
--
Summary: Wrong evaluation order of expressions in
combine_reloads() in reload.c
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: rtl-optimization
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: kumura at r2 dot dion dot ne dot jp
CC: gcc-bugs at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20728
