When generating code for a condition expression, i.e. directly
before a %jmp/X statement, try to generate the result into the
flag bit without passing through the vec4 stack. For example, the
%cmpX/X instructions generate results into the flag bits, so it
makes no sense to push these bits into the vec4 stack then pop
them back into the flag bit. So try to handle this case.
These bypass the vec4 stack in some common cases, saving instructions
and vec4 manipulations.
Also, minor improvement to the %flag/set/vec4 statement.
Kill a few warnings.
- Have %pushi/vec4 handle some special cases optimally.
- Eliminate some duplicated method calls in %load/vec4.
- Optimize the vvp_vector4_t::copy_from_ method by inlining
some parts.
Added various error/warning messages for behaviour not supported
in synthesis. Also give correct behaviour when multiple case item
expressions evaluate to the same constant value.
When unsized literals are used in case item expressions, it is likely
that the calculated expression width will be larger than necessary to
unambiguously select the correct case item (particularly when using
"strict" expression elaboration). This patch adds an optimisation
step that prunes the expressions to the minimum necessary width.
If an error is found whilst elaborating a range expression in a signal
declaration, create a dummy range and continue elaboration. This stops
the compiler reporting an error every time that signal is referenced.
When checking that an enumeration value is in range we need to cast it to
a 2-state value so that when we compare it we get a true or false value
instead of an undefined value. Undefined bits in the comparison return
undefined which is not logically false.
If elaboration of the msb or lsb expression in the range of a vector
type specification failed (due to an error in the Verilog code being
compiled), an assertion failure was being triggered when the compiler
attempted to evaluate the expressions. Bypassing the evaluation (and
using a default value) should allow us to recover from the error.
Stephen Williams
Martin Whitaker
Cary R