40 lines
1.6 KiB
C
40 lines
1.6 KiB
C
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#ifndef _CODEGEN_ALLOCATOR_H_
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#define _CODEGEN_ALLOCATOR_H_
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/*The allocator handles all allocation of executable memory. Since the two-pass
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recompiler design makes applying hard limits to codeblock size difficult, the
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allocator allows memory to be provided as and when required.
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The allocator provides a block size of a little under 1 kB (slightly lower to
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limit cache aliasing). Each generated codeblock is allocated one block by default,
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and will allocate additional block(s) once the existing memory is sorted. Blocks
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are chained together by jump instructions.
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Due to the chaining, the total memory size is limited by the range of a jump
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instruction. ARMv7 is restricted to +/- 32 MB, ARMv8 to +/- 128 MB, x86 to
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+/- 2GB. As a result, total memory size is limited to 32 MB on ARMv7*/
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#ifdef __ARM_EABI__
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#define MEM_BLOCK_NR 32768
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#else
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#define MEM_BLOCK_NR 131072
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#endif
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#define MEM_BLOCK_MASK (MEM_BLOCK_NR-1)
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#define MEM_BLOCK_SIZE 0x3c0
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void codegen_allocator_init();
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/*Allocate a mem_block_t, and the associated backing memory.
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If parent is non-NULL, then the new block will be added to the list in
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parent->next*/
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struct mem_block_t *codegen_allocator_allocate(struct mem_block_t *parent, int code_block);
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/*Free a mem_block_t, and any subsequent blocks in the list at block->next*/
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void codegen_allocator_free(struct mem_block_t *block);
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/*Get a pointer to the backing memory associated with block*/
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uint8_t *codeblock_allocator_get_ptr(struct mem_block_t *block);
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/*Cache clean memory block list*/
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void codegen_allocator_clean_blocks(struct mem_block_t *block);
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extern int codegen_allocator_usage;
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#endif
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