This works by translating it to a $size() system function call.
The $size function is already implemented for dynamic queues and
it is easy enough to expand it for queues.
The root cause was that NetESignal::dup_exr() was not copying the calculated
type (signed/unsigned) of the expression.
In passing, found and fixed a similar issue when calculating a blended value
for a constant ternary expression.
For shift operations evaluated at compile time, the compiler was converting
the right operand to a native unsigned long value. If the operand exceeded
the size of an unsigned long, excess bits were discarded, which could lead
to an incorrect result.
The fix I've chosen is to add an as_unsigned() function to the verinum class
which returns the maximum unsigned value if the internal verinum value is
wider than the native unsigned type. This then naturally gives the correct
result for shifts, as the verinum bit width is also an unsigned value.
I've changed the as_ulong() and as_ulong64() functions to do likewise, as
this is more likely to either give the correct behaviour or to give some
indication that an overflow has occurred where these functions are used.
The verinum arithmetic operators now observe the standard Verilog
rules for calculating the result width if all operands are sized.
If any operand is unsized, the result is lossless, as before.
They also now all observe the standard rules for handling partially
undefined operands (if any operand bit is 'x', the entire result is
'x').
I've also added the unary '-' operator, and renamed v_not() to be
the unary '~' operator. This has allowed some simplification in
other parts of the compiler.
During expression evaluation, the compiler attempts to optimise away
relational operations when one side is constant and all possible values
of the other side would result in the relation being true. This is not
a valid optimisation if the other side is a 4-state variable, as an
'x' or 'z' will result in the relation being unknown.
This patchs adds support for the $dimensions() and $unpacked_dimensions()
array functions. Since the argument is only used to get the type information
these functions can always be evaluated at compile time.
For the following functions if the dimension argument is constant or omitted
and the first argument is not dynamic (a string or dynamic array) they will
return the specified information.
$left(), $right(), $high(), $low(), $increment() and $size()
Dynamic information and a variable second argument will be implement in a
future patch.
This patch implements the evaluate_function method for the NetDisable
and NetSTask classes. It also makes the checks for a function being
constant work when the function contains nested scopes (named blocks).
Pure functions with constant operands can be evaluated at compile
time rather than at run time. This patch provides a global control
to enable this optimisation. Until constant function support is
complete, by default it is disabled.
IVL_VT_NO_TYPE is now used to signal an untyped LHS in a parameter
declaration. The parser function that handles specparam declarations
needs to do this too. Also, although it should never happen, make
sure we don't set the expression width in a NetECast object to a
negative number. Make constant evaluation of NetECast objects
observe the expression width.
This patch fixes a few issues/bugs that showed up when testing the
fixes for implicit casts:
1. Make the compile-time implementation of $abs, $min, and $max match
the run-time behaviour (system functions can't be polymorphic).
2. Correctly set the type (signed/unsigned) of the result of an
assignment inside a constant user function (the LHS should not
inherit the type of the RHS).
3. Fix a bug in the verinum(double) constructor (insufficient bits
were allocated in the case where the double value rounded up to
the next power of two).
This patch adds support for implicit casts to the elaborate_rval_expr()
function. This will handle the majority of cases where an implicit cast
can occur.
This patch implements the evaluate_function method for the NetEBBits,
NetEBDiv, NetEBLogic, NetEBMinMax, and NetEBPow classes. It also
factors out some common code into the NetEBinary class.
This involves working out the code to get the base type of a select
expression of a darray. Also added the runtime support for darrays
with real value elements.
This patch allows the compiler to perform early elaboration
of functions if they are encountered in expressions that are
elaborated before the function would normally be elaborated.
This makes the function available for constant evaluation.
Suitable error messages are generated if a function that is
used in a constant expression is not a valid constant function.
This patch changes the method used to signal that a constant expression
is being elaborated from flags stored in global variables to flags
passed down the call chain. It also generates more informative error
messages when variable references are found in a constant expression.
This patch ensures that the result of a shift is an undefined value
if the right operand is an undefined value. It also improves the
code generated for right shifts where the right operand is constant
and optimises away shifts where the right operand is a constant 0.
It also fixes a few places where the expression type (signed/unsigned)
was not being set correctly.
The compiler currently performs parameter expression elaboration before
performing parameter overrides. This means that the information needed
to correctly determine the expression type and width may not be available
at the time elaboration is performed. This patch reworks the code to
delay elaboration until after all overrides have been performed. It
also provides a new -g option that controls how the width of parameter
expressions is calculated when the parameter itself is unsized.
This patch adds asserts after new to verify that memory was allocated
correctly and adds a warning if some of the routines are called with
an invalid function name.
This patch covers more than it should. It removes many of the -Wextra
warnings in the main ivl directory. It also makes some minor code
improvements, adds support for constant logicals in eval_tree (&&/||),
adds support for correctly sign extending === and !==, it starts to
standardize the eval_tree debug messages and fixes a strength bug
in the target interface (found with -Wextra). The rest of the warnings
and eval_tree() rework will need to come as a second patch.
This patch avoids a crash when trying to use a parameter/localparam that
has been assigned a value from a constant user function. Icarus does not
currently support constant user functions so it creates a parameter with
a NULL value. This patch fixes a few places where this could crash the
compiler.
The functions (malloc, free, etc.) that used to be provided in
malloc.h are now provided in cstdlib for C++ files and stdlib.h for
C files. Since we require a C99 compliant compiler it makes sense
that malloc.h is no longer needed.
This patch also modifies all the C++ files to use the <c...>
version of the standard C header files (e.g. <cstdlib> vs
<stdlib.h>). Some of the files used the C++ version and others did
not. There are still a few other header changes that could be done,
but this takes care of much of it.
This patch remove the old VAMS $log function. It could create confusion
with the Verilog $log task. Recent versions of VAMS and 1364-2005 use
$log10 for the base 10 logarithm.
The Cygwin compiler is a bit picky. This patch adds some casts
to remove compilation warnings. In the past I have had warnings
off because of problems with the STL, but for this directory we
mas as well remove the warnings we can. It also does not
recognize that an assert(0) or assert(false) ends a routine so
it complains about no return at end of function or variables
not being defined.
Martin Whitaker
Maciej Suminski
Stephen Williams
Clifford Wolf
Cary R
Arun Persaud
Martin Whitaker
Larry Doolittle