* gen_lowpart vs big endian insv
@ 2006-06-03 0:31 DJ Delorie
0 siblings, 0 replies; only message in thread
From: DJ Delorie @ 2006-06-03 0:31 UTC (permalink / raw)
To: gcc
h8300 has an HImode insv pattern. If you try to use it with an SImode
argument, expmed.c uses gen_lowpart to force it into the desired mode.
However, gen_lowpart eventually fails for pseudos on big endian:
rtx
gen_rtx_SUBREG (enum machine_mode mode, rtx reg, int offset)
{
gcc_assert (validate_subreg (mode, GET_MODE (reg), reg, offset));
return gen_rtx_raw_SUBREG (mode, reg, offset);
}
validate_subreg refuses to use a subreg to change the address of a
pseudo that could be in memory (i.e. SI->HI on big endian).
So... where is the bug or false assumption here? The test case is
h8300-elf vs gcc.dg/20040310-1.c with "-O1 -msx"
Thanks,
DJ
^ permalink raw reply [flat|nested] only message in thread
only message in thread, other threads:[~2006-06-03 0:31 UTC | newest]
Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2006-06-03 0:31 gen_lowpart vs big endian insv DJ Delorie
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).