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Re: How can I write a builtin func?
On 12/10/2010 02:17 PM, Liu wrote:
Hi all,
I'm porting gcc to a MIPS-based DSP, I need write some builtin
func for some insns, but I can't find a doc., any one should help me?
Show me a example please? Thanks very much.
Liu.
Maybe you should at least implement the following two hooks:
TARGET_INIT_BUILTINS
---> to do some initialization
TARGET_EXPAND_BUILTIN
---> to expand builtin related tree to rtl
I suggest you *define some UNSPEC rtl*, like:
(define_insn "xxx"
[set (match_operand: .....)
(unspec:.... [...] UNSPEC_XXX)]
......
)
and then expand builtin tree to these rtl by calling the
related *gen_xxx*
Suggest you to see s390's related hook implementation.
---
Best,
Wong