Specifically, stmts and exprs are no longer responsible for first recursively
optimizing their children before doing their own optimization (this turned
out to be error-prone, with children sometimes being forgotten.) They now
are just responsible for their own optimization, when appropriate.
In general, it should just return the original node pointer, but for type checking
and optimization passes, it can return a new value for the node (that will be
assigned where the old one was in the tree.)
Along the way, fixed some bugs in WalkAST() where the postorder callback wouldn't
end up being called for a few expr types (sizeof, dereference, address of,
reference).
For starters, use it for the check to see if code is safe to run with the
mask all off.
This also fixes a bug where we would sometimes incorrectly say that
a whole block of code was unsafe to run with an all off mask because we came
to a NULL AST node during traversal.
Accept 'u' and 'l' suffixes to force the constants to be corresponding types.
Just carry around a single 64-bit int value in yylval rather than having both
32- and 64-bit variants.
Previously, we used an IfStmt to wrap complex functions with the equivalent
of a "cif" to check to see if the mask was all on, all off, or mixed at the
start of executing non-trivial functions. This had the unintended side
effect of suggesting to other parts of the compiler that the entire function
was under varying control flow (which in turn led to some small code
quality issues.)
Now, we emit the equivalent code directly.
We should always use the full mask when storing to a reference, since we
don't in general know what it refers to (and thence the appropriate mask
to use for its target).
The conceptual error was the assumption that not being under varying
control flow implied that the mask was all on; this is not the case
if some of the instances have executed a return earlier in the function's
execution. The error in practice would be that the mask would be
assumed to be all-on for things like memory writes, so there would
be unintended side-effects for the instances that had returned.
(Somehow this wasn't being done before.)
Errors are now issued if too few arguments are used when calling through
a function pointer, too many arguments are used, or if any of them can't be
type converted to the parameter type.
Specifically, we weren't storing the results passed back from when we called
those methods of the start and end exprs. This manifested itself as overloaded
functions there not resolving properly.
Fixes issue #131; because they weren't being marked as internal before, when
compiling to multiple targets these would lead to multiply-defined symbols.
For now this target just uses the same builtins-*.ll files as the
regular AVX1 target. Once the gather intrinsic is available from
LLVM, we'll want to have custom target files that call out to that
for gathers. (The integer min/max intrinsics should be wired up to
the __{min,max}_varying_{int,uint}*() builtins at that point as
well.)
