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--- language:expressions [2024/03/20 07:07]
rajit [Expressions in CHP]
+++ language:expressions [2024/03/20 07:19] (current)
rajit [External circuit functions]
@@ Line 19: / Line 19: @@
    * ''bool(x)'': ''x'' must be an integer expression. This returns false if the integer is zero, and true otherwise.
+Syntactic replication is also supported for the operators ''&'', ''|'', ''^'', ''+'', and ''*''. This means the following expression is valid
+<code act>
+  (+ i : 3 : p[i] + 2*i)
+</code>
+and is equivalent to
+<code act>
+  p[0] + 2*0 + p[1] + 2*1 + p[2] + 2*2
+</code>
 ===== Parameters and constant expressions =====
@@ Line 95: / Line 103: @@
 </code>
-Now the right hand side of the first assignment takes ''x'' and ''1'' and does the subtraction that was expected. The second assignment, on the other hand, takes the bit-pattern for ''-1'' (which is ''1''), and adds it to ''y''!
+Now the right hand side of the first assignment takes ''x'' and ''1'' and does the subtraction that was expected. The second assignment, on the other hand, takes the bit-pattern for ''-1'' (this turns out to be ''1''), and adds it to ''y''! In other words, ''x-1'' and ''x+(-1)'' are not the same because of the way the bit-width rules operate. If you have any doubts, the ''int(...)'' operator can be used to specify the bit-width.
@@ Line 240: / Line 248: @@
 An example of file I/O implemented with external functions can be found in the ''actsim'' [[https://github.com/asyncvlsi/actsim|git repository]] in the ''simlib/'' directory.
+===== Operator Precedence =====
+The operators have the following precedence, from the highest to lowest:
+   - ''~'', ''!''
+   - ''*'', ''/'', ''%''
+   - ''+'', ''-''
+   - ''<<'', ''>>'', ''>>>'', ''<'', ''>'', ''<='', ''>='', ''='', ''!=''
+   - ''&''
+   - ''^''
+   - ''|''
+   - ''?''