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RE: [PATCH] Add support for a helper with 7 arguments
From: |
Taylor Simpson |
Subject: |
RE: [PATCH] Add support for a helper with 7 arguments |
Date: |
Fri, 7 Feb 2020 12:43:48 +0000 |
> -----Original Message-----
> From: Richard Henderson <address@hidden>
>
> But I encourage you to re-think your purely mechanical approach to the
> hexagon
> port. It seems to me that you should be doing much more during the
> translation
> phase so that you can minimize the number of helpers that you require.
>
There are a couple of things we could do
- Short term: Add #ifdef's to the generated code so that the helper isn't
compiled when there is a fWRAP_<tag> defined. There are currently ~500
instructions where this is the case.
- Long term: Integrate rev.ng's approach that uses flex/bison to parse the
semantics and generate TCG code.
- Long long term: A much more general approach will be to turn the C semantics
code into LLVM IR and generate TCG from the IR.
Also, note that being able to use either a helper or TCG code is extremely
useful for debugging qemu-hexagon. When a test is failing and you suspect a
bug in TCG generation, you can switch to the helper version and see if the test
passes. There have been cases where I used binary search over the fWRAP
definitions to figure out which one of them has the bug. Also, it can be very
handy to be able to set a breakpoint inside the helper and examine the CPU
state in the middle of TCG execution.
Taylor
- Re: [PATCH] Add support for a helper with 7 arguments, (continued)
- Re: [PATCH] Add support for a helper with 7 arguments, Richard Henderson, 2020/02/06
- Re: [PATCH] Add support for a helper with 7 arguments, Richard Henderson, 2020/02/06
- RE: [PATCH] Add support for a helper with 7 arguments, Taylor Simpson, 2020/02/06
- Re: [PATCH] Add support for a helper with 7 arguments, Richard Henderson, 2020/02/06
- RE: [PATCH] Add support for a helper with 7 arguments, Taylor Simpson, 2020/02/06
- Re: [PATCH] Add support for a helper with 7 arguments, Richard Henderson, 2020/02/06
- RE: [PATCH] Add support for a helper with 7 arguments, Taylor Simpson, 2020/02/06
- Re: [PATCH] Add support for a helper with 7 arguments, Richard Henderson, 2020/02/07
- RE: [PATCH] Add support for a helper with 7 arguments, Taylor Simpson, 2020/02/07
Re: [PATCH] Add support for a helper with 7 arguments, Richard Henderson, 2020/02/07
- RE: [PATCH] Add support for a helper with 7 arguments,
Taylor Simpson <=
- Re: [PATCH] Add support for a helper with 7 arguments, Richard Henderson, 2020/02/07
- RE: [PATCH] Add support for a helper with 7 arguments, Taylor Simpson, 2020/02/09
- Re: [PATCH] Add support for a helper with 7 arguments, Richard Henderson, 2020/02/09
- RE: [PATCH] Add support for a helper with 7 arguments, Taylor Simpson, 2020/02/09
- RE: [PATCH] Add support for a helper with 7 arguments, Taylor Simpson, 2020/02/09
- Re: [PATCH] Add support for a helper with 7 arguments, Richard Henderson, 2020/02/10