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Message
From: Balaji V. Iyer<bviyer@n...>
Date: Wed Dec 12 13:53:15 CET 2007
Subject: [openrisc] 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?
Thanks,
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 [mailto:ERES@i...]
Sent: Wednesday, December 12, 2007 7:14 AM
To: Balaji V. Iyer
Cc: gcc@g...; openrisc@o...; 'Rask Ingemann Lambertsen'
Subject: RE: Help with another constraint
Hello,
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"
"m,m,p,q,p,q,I,I"))]
+ [(set (match_operand:QI 0 "nonimmediate_operand"
"=p,q,m,m,p,q,p,q,m")
+ (match_operand:QI 1 "general_operand"
"m,m,p,q,p,q,I,I,I"))]
""
"*
switch(which_alternative)
@@ -17,6 +17,8 @@
case 6:
case 7:
return \"l.addi \\t%0,r0,%1\\t # move immediate\";,
+ case 8:
+ return ...;
default:
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.
Revital
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