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authorRichard Henderson <rth@redhat.com>2001-05-21 23:58:17 -0700
committerRichard Henderson <rth@gcc.gnu.org>2001-05-21 23:58:17 -0700
commit0a33d11eaba21d9f47d3576dbd29c661f656135d (patch)
treec0a10a585f843312330734edc25eecf84e6f94a5 /gcc/combine.c
parentc93d7fae7b9825449c023d42eb40641c0ad80be2 (diff)
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combine.c (subst): Do not substitute for a register as a destination...
* combine.c (subst): Do not substitute for a register as a destination subreg/strict_low_part/zero_extract. From-SVN: r42429
Diffstat (limited to 'gcc/combine.c')
-rw-r--r--gcc/combine.c11
1 files changed, 10 insertions, 1 deletions
diff --git a/gcc/combine.c b/gcc/combine.c
index e3ad70a..675b1fe 100644
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -3394,7 +3394,16 @@ subst (x, from, to, in_dest, unique_copy)
}
else if (fmt[i] == 'e')
{
- if (COMBINE_RTX_EQUAL_P (XEXP (x, i), from))
+ /* If this is a register being set, ignore it. */
+ new = XEXP (x, i);
+ if (in_dest
+ && (code == SUBREG || code == STRICT_LOW_PART
+ || code == ZERO_EXTRACT)
+ && i == 0
+ && GET_CODE (new) == REG)
+ ;
+
+ else if (COMBINE_RTX_EQUAL_P (XEXP (x, i), from))
{
/* In general, don't install a subreg involving two
modes not tieable. It can worsen register