Hi,
the constraint modifier % applies to all the alternatives of a pattern
and hence is mostly added to the first constraint of an operand. IRA
currently ignores it if the alternative with the % gets disabled by
using the `enabled' attribute or if it is not among the preferred
alternatives.
Fixed with the attached patch by moving the % check to the first loop
which walks unconditionally over all the constraints.
Ok for mainline?
Bye,
-Andreas-
gcc/ChangeLog:
2015-12-14 Andreas Krebbel <kreb...@linux.vnet.ibm.com>
* ira.c (ira_setup_alts): Move the scan for commutative modifier
to the first loop to make it work even with disabled alternatives.
diff --git a/gcc/ira.c b/gcc/ira.c
index 97edf8c..9824e4a 100644
--- a/gcc/ira.c
+++ b/gcc/ira.c
@@ -1800,7 +1800,13 @@ ira_setup_alts (rtx_insn *insn, HARD_REG_SET &alts)
{
insn_constraints[nop * recog_data.n_alternatives + nalt] = p;
while (*p && *p != ',')
- p++;
+ {
+ /* We only support one commutative marker, the first
+ one. We already set commutative above. */
+ if (*p == '%' && commutative < 0)
+ commutative = nop;
+ p++;
+ }
if (*p)
p++;
}
@@ -1831,11 +1837,7 @@ ira_setup_alts (rtx_insn *insn, HARD_REG_SET &alts)
break;
case '%':
- /* We only support one commutative marker, the
- first one. We already set commutative
- above. */
- if (commutative < 0)
- commutative = nop;
+ /* The commutative modifier is handled above. */
break;
case '0': case '1': case '2': case '3': case '4':
