------- Comment #15 from amodra at bigpond dot net dot au 2006-03-24 14:23
-------
Appears to be the peephole in rs6000.md immediately after this comment:
;; after inserting conditional returns we can sometimes have
;; unnecessary register moves.
(subreg:DF (reg:DI 3 3 [128]) 0) is a valid gpc_reg_operand. Try this (totally
untested) patch.
Index: gcc/config/rs6000/rs6000.md
===================================================================
--- gcc/config/rs6000/rs6000.md (revision 112347)
+++ gcc/config/rs6000/rs6000.md (working copy)
@@ -9771,18 +9771,20 @@
"operands[0] = widen_memory_access (operands[0], V2DFmode, 0);
operands[1] = gen_rtx_REG (V2DFmode, REGNO (operands[1]));")
-;; after inserting conditional returns we can sometimes have
+;; After inserting conditional returns we can sometimes have
;; unnecessary register moves. Unfortunately we cannot have a
;; modeless peephole here, because some single SImode sets have early
;; clobber outputs. Although those sets expand to multi-ppc-insn
;; sequences, using get_attr_length here will smash the operands
;; array. Neither is there an early_cobbler_p predicate.
+;; Disallow subregs for E500 so we don't munge frob_di_df_2.
(define_peephole2
[(set (match_operand:DF 0 "gpc_reg_operand" "")
(match_operand:DF 1 "any_operand" ""))
(set (match_operand:DF 2 "gpc_reg_operand" "")
(match_dup 0))]
- "peep2_reg_dead_p (2, operands[0])"
+ "!(TARGET_E500_DOUBLE && GET_CODE (operands[2]) == SUBREG)
+ && peep2_reg_dead_p (2, operands[0])"
[(set (match_dup 2) (match_dup 1))])
(define_peephole2
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26459
