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RE: Help with another constraint

Hi Revital1,
	 Thank you very much for your help. The ISA I am using
(OpenRISC) does not provide an alternative for moving a constant into
memory. The only way of doing this is to move the constant into a
register (which i am doing) and then move that register value into
memory. So what can I do in that case?


Baljai V. Iyer.

Balaji V. Iyer
PhD Student, 
Center for Efficient, Scalable and Reliable Computing,
Department of Electrical and Computer Engineering,
North Carolina State University.

-----Original Message-----
From: Revital1 Eres [] 
Sent: Wednesday, December 12, 2007 7:14 AM
To: Balaji V. Iyer
Cc:;; 'Rask Ingemann Lambertsen'
Subject: RE: Help with another constraint


I think you should add the pair of constraints m and I respectively to
the description of the instruction in your md file (and a relevant case
8 to handle such instruction), i.e.:

 (define_insn "movqi"
-  [(set (match_operand:QI 0 "nonimmediate_operand" "=p,q,m,m,p,q,p,q")
-        (match_operand:QI 1 "general_operand"
+  [(set (match_operand:QI 0 "nonimmediate_operand"
+        (match_operand:QI 1 "general_operand"
@@ -17,6 +17,8 @@
      case 6:
      case 7:
        return \"l.addi  \\t%0,r0,%1\\t # move immediate\";,
+     case 8:
+       return ...;
        return \"invalid alternative\";

It seems that the pair m and I is missing (which indicate the memory =
constant instruction).  You could look for which_alternative variable in
GCC internals for more details on this.


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