Full comparison in 'cbranchsi4' leads to error in gcc 4.0

[Sami Khawam]

Hi,

I am porting gcc (version 4.0) to a CPU supporting conditional jumps, which does 
not have a CC register. I have combined the comparision and jump operation in 
the definition of "cbranchsi4" as show at the end of this message.

This works fine on gcc 3.4, however on gcc 4.0 it creates an error during 
optimization. According to my investigation, the error occurs when there is a 
division by a constant power of 2 which needs to be transformed into shifting. 
The error generated is:

internal compiler error: in emit_cmp_and_jump_insn_1, at optabs.c:3599


The definition of cbranchsi4 in the machine-description:

(define_insn "cbranchsi4"
     [(set (pc) (if_then_else
		(match_operator 0 "comparison_operator"
				[(match_operand:SI 1 "register_operand" "r")
				 (match_operand:SI 2 "nonmemory_operand" "r")])	
		(label_ref (match_operand 3 "" ""))
		(pc)))]
     ""
   "c%C0jump %1 %2 %3"
   [(set_attr "type" "branch")
    (set_attr "length" "1")]
)



Regards,

Sami Khawam

The University of Edinburgh
http://www.see.ed.ac.uk/~sxk