Now index[ptr] works in constant expressions.
Fixed codegen for cast type in constant expressions.
Calls on swapstk in 'i[ptr]' is avoided when possible.
The old broken code defers the count until the end of the (parent function's) argument list. But, a nested function call clears the pointer to the deferred type. That leads to an access violation.
The new code defers only until the end of each argument. Fixes#1320.
When there is an integral constant like `3` in an expression, it has
type `int` according to the C spec, even though it can be represented
as an `unsigned char`. Change codegen (`hie_internal` and `typeadjust`)
to treat it as `unsigned char` instead of `int` so that faster,
unsigned operations can be used.
For the test case in #1298, reduces the cycles per iteration from
4311 to 1884. This is a great improvement, but still much worse than
the 1053 cycles/iter from `c4698df~`, so more work remains to be done.
Further partial fix for #1298 and #1308.
This usually allows faster & smaller code.
Note that deferred operations must still be called at sequence points even if the whole expressions containing them had constant values.
Previously, the following rules were used for binary operators:
* If one of the values is a long, the result is long.
* If one of the values is unsigned, the result is also unsigned.
* Otherwise the result is an int.
C89 specifies the "usual arithmetic conversions" as:
* The integral promotions are performed on both operands.
* Then the following rules are applied:
* If either operand has type unsigned long int, the other operand is
converted to unsigned long int.
* Otherwise, if one operand has type long int and the other has type
unsigned int, if a long int can represent all values of an unsigned int,
the operand of type unsigned int is converted to long int; if a long int
cannot represent all the values of an unsigned int, both operands are
converted to unsigned long int.
* Otherwise, if either operand has type long int, the other operand is
converted to long int.
* Otherwise, if either operand has type unsigned int, the other operand is
converted to unsigned int.
* Otherwise, both operands have type int.
https://port70.net/~nsz/c/c89/c89-draft.html#3.2.1.5
As one example, these rules give a different result for an operator
with one long operand and one unsigned int operand. Previously,
the result type was unsigned long. With C89 semantics, it is just long,
since long can represent all unsigned ints.
Integral promotions convert types shorter than int to int (or unsigned int).
Both char and unsigned char are promoted to int since int can represent
all unsigned chars.
https://port70.net/~nsz/c/c89/c89-draft.html#3.2.1.1
Rename promoteint to ArithmeticConvert, since this is more accurate.
Fixes#170
