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.
The constant $clog2() was returning a value that had an integer
width, but it did not have the sign bit set. This could result
in incorrect math expressions. This patch sets the sign bit for
the constant $clog2() result.
This patch evaluates the whole concatenation expression and
makes the concatenation padding sign aware. This is needed
when $signed({...}) is passed as an argument.
A repetition is just N copies of the base expression not N
evaluations of the base expression. This is only a problem
when functions have side effects. It's also faster to copy.
The evaluation must also be done when the replication count
is zero (see 1364-2005).
This patch adds messages in various places to warn that constant
user functions are not supported. It uses a global variable to
indicate when we are in a constant context. This is a bit of a
kludge, but works well without needing to change a bunch of code.
It is interesting to note that ports are elaborated late enough
that if we had the constant function evaluation code they would
evaluate correctly. This also applies to the function return
range, the concatenation repeat, specparams and initial values.
Signal definitions are early enough that elaboration is what is
failing because the function body is not available (has not been
elaborated). The same thing applies to both parameters and
localparms.
Verireal had hooks for this, but had an assert(0). This patch
replaces the assert(0) with assert(gn_icarus_misc_flag) and
then used fmod() to calculate the modulus. It is the callers
responsibility to verify and report a message to the user
if the current state should not support real modulus.
This fixes up the elaboration of binary expressions found in
parameter expressions. Parameter expressions are special because
they elaborate early, before all the other parameters are necessarily
completed.
The NetEBAdd::eval_tree method is able to use the associative property
of addition to reduce some constants, but it is picky about widths.
Make it a little bit more resilient to expression widths.
The operands of divide need to be at least the width of the expression
when calculating a constant divide. The only matters for the special
case where the result is x, because the verinum implementation of
divide will get the result width from the left expression width.
It is possible, via the use of the $signed() function, for concatenation
expressions to be signed. Make sure the evaluated constant had the
proper sign by checking explicitly.
Continue cleaning up shadowed variables, flagged by turning on -Wshadow.
No intended change in functionality. Patch looks right, and is tested
to compile and run on my machine. No regressions in test suite.
This patch pushes the evaluation of constant system functions into
normal elaboration vs doing them in the preliminary parameter
elaboration.
It also fixes the compiler version of clog2 to return integer_width
vs a fixed 32 bits.
Nothing to do with tab width! Eliminates useless
trailing spaces and tabs, and nearly all <space><tab>
pairings. No change to derived files (e.g., .vvp),
non-master files (e.g., lxt2_write.c) or the new tgt-vhdl
directory.
Low priority, simple entropy reduction. Please apply
unless it deletes some steganographic content you want
to keep.
Add "include" to fix error with abort() in dup_expr.cc
Add "include" to AStatement.h so usage of struct PExpr works
Get rid of eval_tree.cc:577: warning: suggest parentheses around comparison in operand of ^
This patch adds the constant system functions for Verilog-2005
and Verilog-AMS. These are evaluated at compile time. $abs(),
$min() and $max() support their polymorphic behavior in the
compiler where it really matters. They are always evaluated
as reals in the run time and the result/argument(s) will be
converted as needed.
The Verilog-2005 functions are available if using the 2005
generation (default) and if either the icarus-misc (also on
by default) or verilog-ams flags are set.
The Verilog-AMS functions are available if either the
icarus-misc or verilog-ams flags are set.
If the argument to $clog2() is unsized constant, then trim it to the
smallest representation that doesn't lose the sign, then do the $clog2
on that.
Also, use integer_width instead of 32 for the minimum $clog2() result
for a negative value.
If the argument to $clog2() is unsized constant, then trim it to the
smallest representation that doesn't lose the sign, then do the $clog2
on that.
Also, use integer_width instead of 32 for the minimum $clog2() result
for a negative value.
GCC 4.3 has tightened up header dependencies so that
`strcmp' is no longer declared if <cstdlib> is included
(which it was in prior versions). This causes the changes
in 5e512e6570 to fail to
build with 4.3.
This patch includes <cstring> in the files that are failing.
This patch adds the $clog2 system function. It also makes this
function work as a constant function. The runtime version still
needs to be updated to use an integer based version instead of
the current double based method. The double method suffers from
rounding errors.
Logical (in)equality needs to look at all the bits of both operands,
and cannot short circuit the test unless defined bits differ. If there
are undefined bits, the equality is undefined at that point, but return
x only if there are not other bits that make the results clearly
unequal.
Cary R
Martin Whitaker
Larry Doolittle
Stephen Williams
Nick Gasson