http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50762
--- Comment #6 from Uros Bizjak <ubizjak at gmail dot com> 2011-11-09 18:30:29
UTC ---
(In reply to comment #4)
> It seems to me (part of) the problem is that the operand constraint is too
> generic here:
>
> (define_insn "*lea_4_zext"
> [(set (match_operand:DI 0 "register_operand" "=r")
> (zero_extend:DI
> (match_operand:SI 1 "lea_address_operand" "p")))]
>
> "p" accepts any legitimate address operand, including const_int. But those
> are
> then not actually accepted by the overall pattern (due to the mode check).
>
> When reloading within an address operand, reload verifies only the constraint;
> it does not expect the case where a constraint accepts something that is later
> rejected by some other check.
>
> One fix might be to use a more specific constraint here that does not accept
> const_int.
Unfortunately this approach doesn't work :(
Using following patch:
--cut here--
Index: i386.md
===================================================================
--- i386.md (revision 181207)
+++ i386.md (working copy)
@@ -5560,7 +5560,7 @@
(define_insn "*lea_4_zext"
[(set (match_operand:DI 0 "register_operand" "=r")
(zero_extend:DI
- (match_operand:SI 1 "lea_address_operand" "p")))]
+ (match_operand:SI 1 "lea_address_operand" "j")))]
"TARGET_64BIT"
"lea{l}\t{%a1, %k0|%k0, %a1}"
[(set_attr "type" "lea")
Index: constraints.md
===================================================================
--- constraints.md (revision 181207)
+++ constraints.md (working copy)
@@ -127,6 +127,11 @@
(and (not (match_test "TARGET_X32"))
(match_operand 0 "memory_operand")))
+(define_constraint "j"
+ "@internal ."
+ (and (not (match_code "const_int"))
+ (match_operand 0 "address_operand")))
+
;; Integer constant constraints.
(define_constraint "I"
"Integer constant in the range 0 @dots{} 31, for 32-bit shifts."
--cut here--
results in:
pr50762.c: In function ‘func_59’:
pr50762.c:48:1: error: unable to generate reloads for:
(insn 29 28 30 3 (set (reg:DI 0 ax [77])
(zero_extend:DI (plus:SI (const_int 0 [0])
(const_int 1 [0x1])))) pr50762.c:35 250 {*lea_4_zext}
(expr_list:REG_DEAD (reg/v:SI 59 [ p_60 ])
(nil)))
pr50762.c:48:1: internal compiler error: in find_reloads, at reload.c:3812
Please submit a full bug report,
