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//===---------------------------------------------------------------------===//
// Random ideas for the ARM backend (Thumb specific).
//===---------------------------------------------------------------------===//
* Add support for compiling functions in both ARM and Thumb mode, then taking
the smallest.
* Add support for compiling individual basic blocks in thumb mode, when in a
larger ARM function. This can be used for presumed cold code, like paths
to abort (failure path of asserts), EH handling code, etc.
* Thumb doesn't have normal pre/post increment addressing modes, but you can
load/store 32-bit integers with pre/postinc by using load/store multiple
instrs with a single register.
* Make better use of high registers r8, r10, r11, r12 (ip). Some variants of add
and cmp instructions can use high registers. Also, we can use them as
temporaries to spill values into.
* If we know function size is less than (1 << 16) * 2 bytes, we can use 16-bit
jumptable entries (e.g. (L1 - L2) >> 1). Or even smaller entries if the
function is even smaller. This also applies to ARM.
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