This splits up the monolithic and confusing vhdl_expr::cast function into
several smaller to_XXX functions which each generate code to cast an
expression to type XXX. This makes it much easier to understand and maintain.
In continuous assignment, the width of the expression needs to come
from the expression itself, and not just from the width of the l-value.
Use the PExpr::test_width method to get the width of the expression
to pass to the elaborate.
the sub_net_from function is used by the ::synthesize method of the
NetEUnary class to make the expression 0-N. By making that function
handle a real-valued net, the NetEUnary suddenly supports real-valued
nets, and this probably helps in other places as well.
When the condition expression of a ternary is constant 1 or 0, we can
short-circuit the elaboration by only processing the clause (true or
false) that we need. This saves compile time and execution time.
This patch adds an error message for the standard system
tasks and functions that are not currently implemented.
These are currently $fmonitor*, $ferror, $fread, the
queue and PLA tasks.
It is possible for the left operand of a left shift to be not known
early during elaborate expression. In that case, make a punt expression
and expect it to be resolved later.
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.
The expr:::synthesize methods need not deal with saturating left or
right shifts if they are dealt with early, in elaborate_expr methods.
So the elaborate_expr for shift takes on much more responsibility.
Mostly this ensures that a recursive call to a function
is made with the correct types (this may involve generating
code to cast expressions to the correct type).
This patch pushes the automatic property for both tasks and
functions to the code generators. The vvp back end does not
currently support this so it will error out during code
generation. The VHDL back end should be able to use this
property and tgt-stub prints the property. Having this will
also make it easier when we do adding this to the runtime.
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.
This patch adds support for vpiScaledRealTime and vpiSuppressTime
to VPI callbacks. It also fixes a bug where the callback data
object was not being copied correctly and adds support for
vpiSuppressVal. This requires adding vpiSuppressVal to a few
other routines. It adds the ability for a callback to return
more than vpiScalarVal (all values supported by the
vpip_vec4_get_value() procedure). It also fixes a bug where
vpip_vec4_get_value() would incorrectly return vpiZ for a BIT4_X
scalar value. It also comments the potentially dangerous
vpiScalarVal calculation in the vvp_fun_signal::get_value()
procedure.
Since NetExpr::synthesize methods were rarely used, then had a lot
of bugs. Now that continuous assign uses these methods, these bugs
must be fixed.
Binary and Unary minus properly pad/extens its arguments,
Case compare generates correct code,
Divide properly takes on signed flag,
Signed right shift sign-extends its argument to prevent loss of sign bits
and uses the NetSignExtend instead of simple padding,
Use the correct target node for reduction NAND,
Properly handle constant arguments of NetESelect
Handle some exressions that were not handled before, include abs()
and POW.
In signed contextx, the right shift and unary minus expressions need
to be sign extended before they operate, otherwise there may be bad
results in the high bits in the greater context.
This patch causes a thread that is created to evaluate a function
to be executed immediately. The parent thread is resumed when the
function thread terminates.
Because Icarus tries to elaborate as much as it can even after
an error has occurred we need to check for these errors during
elaboration. This patch prevent an undefined identifier from
crashing the compiler.
Nick Gasson
Stephen Williams
Cary R
Martin Whitaker