The %sub instruction didn't have the efficent implementation that
the %add instructions used. Update subtraction to use the array
method, so that it gets the same performance benefits.
The vvp_vector4_t often receives the results of vector arithmetic.
Add an optimized method for setting that data into the vector. Take
into account that arithmetic results have no X/Z bits, etc.
Logical and/or take as inputs condition expressions, which are scalar
expressions. Be sure to reduce vectors using proper logic to get the
right condition value.
This patch adds check to determine if an always block has delay
in it or not. If there is no delay a runtime infinite loop will
occur. For the indeterminate case it will print a warning message
if the new -Winfloop flag is given. This flag is not part of the
-Wall check!
When generating a real expression you can have bits of the
expression that use vector only operands. When this happens
evaluate that part of the expression as a vector and then
convert it to a real value.
On some systems, 1UL<<X will make a mess if X is the size of
an unsigned long. This especially seems to be a problem on i386
systems. Protect those shifts in the vvp_net.cc.
When left-shifting unsized constants in self-determined contexts, the
constant value is normally pared down to its minimum required width.
But this practically guarantees loss of bits. Instead, detect this
special case and give the unsized constant a width of an integer.
Still allow for the super-special case that the shifted value and the
shift amount are constants. In that case, the result width (and value)
can be calculated precisely and there is no need to resort to default
widths.
This patch uses the true delay expression count not the truncated
one to check that the number of delay expressions is correct.
It also prints the actual number of expressions it found when
printing the error message.
By slightly altering the vvp_bit4_t encoding, a few simple
optimizations become possible. By making Z==2 and X==3, the
conversion from X/Z to X is a simple shift-or, and this can
be used to reduce the size of some of the bit4 operators.
In previous incarnations of the vvp runtime, bit vectors were passed
around as arrays of unsigned char that charried bit4 vectors. That
is no longer used. Remove the last vestiges of that dead code.
Remove dependencies on vvp_bit4_encoding outside of the vvp_net
core types. The table_functor_s class was the worst offfender and
was barely used, so it is now removed completely. There are a few
opcodes in vhtread.cc that also make vvvp_bit4_t encoding
assumptions (and used casts) and those have been fixed. There
were also various VPI interface functions that are fixed.
The vvp_vector4_t holds 4-value logic. This patch changes the encoding
of 4-value bits in the vector to use separate A- and B bit vectors,
with the B- vector signaling the A- bits that are not 0/1. This
allows rapid conversion to 2-value logic, and rapid tests for X
and Z values.
Update the rules for parsing user function definitions to allow
Verilog-2001 ANSI style port declarations. In the process, also
unify with the user task port declaration so that the types don't
diverge. The rules are the same for both, with the extra constraint
that function ports must all be input. This latter rule is checked
later, during elaboration, so that the task/function pform code
can be shared, and better error messages can be generated.
This patch fixes deassign to allow it to unlink from a driver.
It also zeros the cassign_link and force_link pointers after
they have been unlinked. Not doing this will cause an assert
if deassign/release are called multiple times (variable only).
commonly, the make install is run in a compiled directory by a
different user (i.e. an administrator) that doesn't necessarily
have write access to the build directory. This patch fixes it so
that the test that the version.h is up to date doesn't need to
write a temporary file in the build directory.
It also makes sure that if there is a real need to update the
verion.h, and it is not writable, then properly fail the build.
Passing preprocessor definitions forward into library cells was broken
by this bug in processing the precompiled macro values that were written
by the main preprocessor.
Detect thread bit allocation failures and fail gracefully. Print an
error message that points at the expression in question, and return
with an error code so that the compiler exits with an error.
When constant values are added to get another constant value, and the
expression is not otherwise a fixed size, then trim the result to
prevent unbounded expansion of unsized expression with.
In the process, find and fix a bug in the vtrim function that caused
an assert if trimming were not possible for an unsigned value.
This patch fixes the elaboration of parameters in a continuous
assignment to only pad the constants to their defined width.
Previously they were padded to the l-value width which resulted
in a vvp runtime error. This appears to be because the width
for padding is the defined width, but the constant is printed
using its internal width which previously could be larger than
its defined width.
These constants are local nets so I added that flag as well.
This patch adds the ability to assign/deassign a bit or part select.
It also cleans up the code and fixes some problem in the forcing of
strength aware nets.
When printing the strength information for a multi bit net this patch
adds an underscore between the individual bit strength values. This
makes it easier to see the individual bit values.
A patch to insert the version string from git broke compilation when
the source was not a git repository or when building in a read-only
source tree. This patch avoids breaking compilation by using a
graceful failure mechanism for generating the version string and does
not write to the source tree.
Rework the MUXZ and MUXR code to use an enum instead of plain
integers for the select input state. This makes it more obvious
what is actually going on.
This patch adds a flag to the MUXZ object to make sure that it will
run at time zero if needed. If this is not done the default Z result
may not be overridden by an X result.
This patch adds a %assign/av/d opcode. This is a version of %assign/av
that allows a delay expression. Ultimately this allows a dynamically
indexed array to have a delay expression (non-constant delay value).
This patch removes the overly optimistic lookaside save for a signal
that has been set (%set/v). This is incorrect because if a force or
assign are active the value will not be set as expected.
Parameters with vector descriptions that are not zero based and
are used in net contexts should generate the properly ranged
temporary signals. This causes subsequent part selects to work
out properly.
During elaborate_sig, the code to detect implicit wires did not
properly account for the possibility that the name is that of an
explicitly declared parameter.
This patch add (I believe back in) the < and > characters to the
general T_SYMBOL regular expression. The match was also moved after
the special T_SYMBOL cases so that flex would match them correctly.
Flex matching rules are longest or if a tie the first.
This patch adds code to prevent the broken synthesis code in
the development branch from core dumping. Broken code here
refers to the Icarus code not a Verilog file.
This patch fixes a delete[] vs free problem in the NexusSet
class. The items_ array was being allocated with malloc/realloc
and freed with delete[]. The quick fix was to replace delete[]
with a call to free(). A better fix would probably be to rework
the class to use a vector.
The default nettype was not always being set. This patch
modifies the NetScope constructor to get the default
nettype from a parent if it exists. It is set to NONE if
a parent does not exist.
Stephen Williams
Cary R
thiede
Larry Doolittle
J Varshney
Michael