In pdp11.md I have:
(define_insn_and_split "addhi3"
[(set (match_operand:HI 0 "nonimmediate_operand" "=rR,rR,Q,Q")
(plus:HI (match_operand:HI 1 "general_operand" "%0,0,0,0")
(match_operand:HI 2 "general_operand" "rRLM,Qi,rRLM,Qi")))]
""
"#"
"reload_completed"
[(parallel [(set (match_dup 0)
(plus:HI (match_dup 1) (match_dup 2)))
(clobber (reg:CC CC_REGNUM))])]
""
[(set_attr "length" "2,4,4,6")])
While compiling libgcc2.c I see this RTL in the .ira dump file:
(insn 49 48 53 5 (set (reg/f:HI 136)
(plus:HI (reg/f:HI 5 r5)
(const_int -8 [0xfffffffffffffff8])))
"../../../../../gcc/libgcc/libgcc2.c":276:4 68 {addhi3}
(expr_list:REG_EQUIV (plus:HI (reg/f:HI 5 r5)
(const_int -8 [0xfffffffffffffff8]))
(nil)))
Then in the .reload dump it appears this way:
(insn 49 48 53 5 (set (reg/f:HI 5 r5 [136])
(plus:HI (reg/f:HI 6 sp)
(const_int 40 [0x28]))) "../../../../../gcc/libgcc/libgcc2.c":276:4
68 {addhi3}
(expr_list:REG_EQUIV (plus:HI (reg/f:HI 5 r5)
(const_int -8 [0xfffffffffffffff8]))
(nil)))
which obviously causes an ICE because that RTL doesn't meet the constraints.
This happens only when LRA is used.
I also see this in the .reload file, but I don't know what it means:
Choosing alt 1 in insn 49: (0) rR (1) 0 (2) Qi {addhi3}
1 Non-pseudo reload: reject+=2
1 Non input pseudo reload: reject++
Cycle danger: overall += LRA_MAX_REJECT
alt=0,overall=609,losers=1,rld_nregs=2
alt=1: Bad operand -- refuse
alt=2: Bad operand -- refuse
alt=3,overall=0,losers=0,rld_nregs=0
Any ideas? I ran into this when trying to make LRA the default for this target.
paul
