DynASM/arm64: Support shifted immediate for add/sub/adds/subs/cmp/cmn #718
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For instructions add/adds/sub/subs/cmp/cmn, optionally-shifted immediate value can be used. Note that only left shift by 0 or 12 is accepted. Example: ``` | add x0, x0, #0x1, lsl LuaJIT#12 | add x0, sp, #0x2, lsl #0 | adds x0, x0, #0x3, lsl #0 | adds w0, w0, #0x4, lsl LuaJIT#12 | cmn sp, #0x5, lsl LuaJIT#12 | cmn w0, #0x6, lsl #0 | sub x0, x1, #0x7, lsl #0 | subs x0, x1, #0x8, lsl LuaJIT#12 | cmp x0, #0x9, lsl #0 | cmp x0, #0x9, lsl LuaJIT#12 ``` Disassembly: ``` 0xffffbc8c734c: add x0, x0, #0x1, lsl LuaJIT#12 0xffffbc8c7350: add x0, sp, #0x2 0xffffbc8c7354: adds x0, x0, #0x3 0xffffbc8c7358: adds w0, w0, #0x4, lsl LuaJIT#12 0xffffbc8c735c: cmn sp, #0x5, lsl LuaJIT#12 0xffffbc8c7360: cmn w0, #0x6 0xffffbc8c7364: sub x0, x1, #0x7 0xffffbc8c7368: subs x0, x1, #0x8, lsl LuaJIT#12 0xffffbc8c736c: cmp x0, #0x9 0xffffbc8c7370: cmp x0, #0x9, lsl LuaJIT#12 ``` Change-Id: I7afc76807d9e7821e92d974aae6ca03ee5f33eff
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As pointed out by MikePall in [1], shifted immediate value is supported. See [2]. For example, `add x0, x1, php#4096` would be encoded by DynASM into `add x0, x1, php#1, lsl php#12` directly. In this patch, a helper is added to check whether an immediate value is in the two allowed ranges: (1) 0 to 4095, and (2) LSL php#12 on all the values from the first range. Note that this helper works for add/adds/sub/subs/cmp/cmn instructions. [1] LuaJIT/LuaJIT#718 [2] https://github.com/LuaJIT/LuaJIT/blob/v2.1/dynasm/dasm_arm64.lua#L342 Change-Id: I4870048b9b8e6c429b73a4803af2a3b2d5ec0fbb
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* JIT/AArch64: Support shifted immediate As pointed out by MikePall in [1], shifted immediate value is supported. See [2]. For example, `add x0, x1, #4096` would be encoded by DynASM into `add x0, x1, #1, lsl #12` directly. In this patch, a helper is added to check whether an immediate value is in the two allowed ranges: (1) 0 to 4095, and (2) LSL #12 on all the values from the first range. Note that this helper works for add/adds/sub/subs/cmp/cmn instructions. [1] LuaJIT/LuaJIT#718 [2] https://github.com/LuaJIT/LuaJIT/blob/v2.1/dynasm/dasm_arm64.lua#L342 Change-Id: I4870048b9b8e6c429b73a4803af2a3b2d5ec0fbb * Deprecatd CMP_IMM/ADD_SUB_IMM and add test cases Macros CMP_IMM and ADD_SUB_IMM are deprecated and instead we use this helper to guard the immediate encoding. Add two 64-bit only test cases, since 64-bit integers are used and tested inside. Change-Id: I0b42d4617b40372e2f4ce5b6ad31a4ddb7d89e49
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For instructions add/adds/sub/subs/cmp/cmn, optionally-shifted immediate
value can be used.
Note that only left shift by 0 or 12 is accepted.
Example:
Disassembly:
Change-Id: I7afc76807d9e7821e92d974aae6ca03ee5f33eff