Hi, Following the discussion about "disable peeling" [1] a few weeks ago, it turned out that the vectorizer cost model needed some implementation for ARM.
The attached patch implements arm_builtin_vectorization_cost and arm_add_stmt_cost, providing default costs when aligned and unaligned loads/stores have the same cost (=1). init_cost and finish_cost still use the default implementation (I noticed that x86 has chosen to duplicate the default implementation without changing it, why?) Benchmarking shows very little variation, expect a noticeable +1.6% on coremark. If this is OK, we can then discuss how to disable peeling completely when aligned and unaligned accesses have the same cost (and thus where peeling is a loss of performance). I think adding a new hook is necessary, since target descriptions may use different models for these costs (eg x86 makes no difference between unaligned loads and unaligned stores). Thanks, Christophe. [1] http://gcc.gnu.org/ml/gcc/2012-12/msg00036.html 2013-02-05 Christophe Lyon <christophe.l...@linaro.org> * config/arm/arm.c (arm_builtin_vectorization_cost) (arm_add_stmt_cost): New functions. (TARGET_VECTORIZE_BUILTIN_VECTORIZATION_COST) (TARGET_VECTORIZE_ADD_STMT_COST): Define. (struct processor_costs): New struct type. (default_arm_cost): New struct of type processor_costs.
vect-cost-model.patch
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