IMPALA-4705, IMPALA-4779, IMPALA-4780: Fix some Expr bugs with codegen
This change fixes expr-test.cc to work with codegen as it's
originally intended. Fixing it uncovers a couple of bugs fixed
in this patch:
IMPALA-4705: When an IR function is materialized, its
function body is parsed to find all its callee functions
to be materialized too. However, the old code doesn't
detect callee fnctions referenced indirectly (e.g. a
callee function passed as argument to another function).
This change fixes the problem above inspecting the use
lists of llvm::Function objects. When parsing the bitcode
module into memory, LLVM already establishes a use list
for each llvm::Value object which llvm::Function is a
subclass of. A use list contains all the locations in
the module in which the Value is referenced. For a
llvm::Function object, that would be its call sites and
constant expressions referencing the functions. By using
the use lists of llvm::Function in the module, a global
map is established at Impala initialization time to map
functions to their corresponding callee functions. This
map is then used when materializing a function to ensure
all its callee functions are also materialized recursively.
IMPALA-4779: conditional function isfalse(), istrue(),
isnotfalse(), isnotrue() aren't cross-compiled so they
will lead to unexpected query failure when codegen is enabled.
This change will cross-compile these functions.
IMPALA-4780: next_day() always returns NULL when codegen
is enabled. The bound checks for next_day() use some class
static variables initialized in the global constructors
(@llvm.global_ctors). However, we never execute the global
constructors before calling the JIT compiled functions.
This causes these variables to remain as zero, causing all
executions of next_day() to fail the bound checks. The reason
why these class static variables aren't compiled as global
constants in LLVM IR is that TimestampFunctions::MIN_YEAR is
not a compile time constant. This change fixes the problem
above by setting TimestampFunctions::MIN_YEAR to a known constant
value. A DCHECK is added to verify that it matches the value
defined in the boost library.
Reviewed-by: Michael Ho <email@example.com>
Tested-by: Impala Public Jenkins