Understanding integer_cst
Primrose.Mbanefo@Infineon.com
Primrose.Mbanefo@Infineon.com
Wed Dec 7 15:34:00 GMT 2005
Hello,
A limitiation by some other software means that I am working with gcc .3
.4 1
And I am therefore using the accompanying manuals.
I do not understand the gcc internal documentation on the integer_cst
expression trees.
An expression is given to calculate the value of the constant:
( (TREE_INT_CST_HIGH(e) << HOST_BITS_PER_WIDE_INT)
+ TREE_INT_CST_LOW(e))
Using the expression, what is wrong in the following example:
Example
-----------
Given integer = 5
HOST_BITS_PER_WIDE_INT = 4 //just an example
HOST_WIDE_INT is a type for which the integers are
HOST_BITS_PER_WIDE_INT bits long.
Binary representation of given integer is 0|1|0|1
TREE_INT_CST_HIGH = 0|0|0|1
TREE_INT_CST_LOW = 0|0|0|1
-----------
This definitely does not yield 5 if I apply that expression, so, I
imagine there is something wrong somewhere.
If it does, then maybe I did not understand the expression?
Could anybody please tell me where my thinking went wrong?
Thanks a lot,
Primrose Mbanefo
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