This patch adds a bitmap_view<X> class that creates a read-only,
on-stack bitmap representation of an array-like object X. The main
use case is to allow HARD_REG_SETs to be used in REG_SET (i.e. bitmap)
operations.
For now it only handles constant-sized arrays, but I've tried to
define the types in a way that could handle variable-sized arrays
in future (although less efficiently). E.g. this might be useful
for combining bitmaps and sbitmaps.
For the read-only view to work as intended, I needed to make
bitmap_bit_p take a const_bitmap instead of a bitmap. Logically
the bitmap really is read-only, but we update the "current" and
"indx" fields of the bitmap_head after doing a search.
2019-09-09 Richard Sandiford <richard.sandiford@arm.com>
gcc/
* array-traits.h: New file.
* coretypes.h (array_traits, bitmap_view): New types.
* bitmap.h: Include "array-traits.h"
(bitmap_bit_p): Take a const_bitmap instead of a bitmap.
(base_bitmap_view, bitmap_view): New classes.
* bitmap.c (bitmap_bit_p): Take a const_bitmap instead of a bitmap.
* hard-reg-set.h: Include array-traits.h.
(array_traits<HARD_REG_SET>): New struct.
* regset.h (IOR_REG_SET_HRS): New macro.
* loop-iv.c (simplify_using_initial_values): Use IOR_REG_SET_HRS
rather than iterating over each hard register.
* sched-deps.c (sched_analyze_insn): Likewise.
* sel-sched-ir.c (setup_id_implicit_regs): Likewise.
From-SVN: r275536
