Messages in this thread | | | Subject | Re: [PATCH 1/2] zstd: pass pointer rathen than structure to functions | From | Joe Perches <> | Date | Fri, 10 May 2019 10:39:57 -0700 |
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On Fri, 2019-05-10 at 11:41 +0530, Maninder Singh wrote: > currently params structure is passed in all functions, which increases > stack usage in all the function and lead to stack overflow on target like > ARM with kernel stack size of 8 KB so better to pass pointer. [] > diff --git a/lib/zstd/compress.c b/lib/zstd/compress.c [] > @@ -206,18 +206,18 @@ ZSTD_compressionParameters ZSTD_adjustCParams(ZSTD_compressionParameters cPar, u > return cPar; > } > > -static U32 ZSTD_equivalentParams(ZSTD_parameters param1, ZSTD_parameters param2) > +static U32 ZSTD_equivalentParams(const ZSTD_parameters *param1, const ZSTD_parameters *param2) > { > - return (param1.cParams.hashLog == param2.cParams.hashLog) & (param1.cParams.chainLog == param2.cParams.chainLog) & > - (param1.cParams.strategy == param2.cParams.strategy) & ((param1.cParams.searchLength == 3) == (param2.cParams.searchLength == 3)); > + return (param1->cParams.hashLog == param2->cParams.hashLog) & (param1->cParams.chainLog == param2->cParams.chainLog) & > + (param1->cParams.strategy == param2->cParams.strategy) & ((param1->cParams.searchLength == 3) == (param2->cParams.searchLength == 3)); > }
trivia:
Using & instead of && makes this somewhat difficult to read. It's hard to believe this is a performance optimization.
It might be better as
return param1->cParams.hashLog == param2->cParams.hashLog && param1->cParams.chainLog == param2->cParams.chainLog && param1->cParams.strategy == param2->cParams.strategy && param1->cParams.searchLength == 3 && param1->cParams.searchLength == param2->cParams.searchLength;
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