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authorLuis Machado <luis.machado@linaro.org>2018-05-23 16:23:11 +0000
committerLuis Machado <luisgpm@gcc.gnu.org>2018-05-23 16:23:11 +0000
commitd2ff35c0913539a31782fbc05bb6d4c2ce74f2ce (patch)
tree36f27cdd1a5fcc65a32d45f16e798bdd393b5cb3 /gcc/params.h
parent59100dfc42bbe92caff61bca1560da4a30f99906 (diff)
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[Patch 02/02] Introduce prefetch-dynamic-strides option
The following patch adds an option to control software prefetching of memory references with non-constant/unknown strides. Currently we prefetch these references if the pass thinks there is benefit to doing so. But, since this is all based on heuristics, it's not always the case that we end up with better performance. For Falkor there is also the problem of conflicts with the hardware prefetcher, so we need to be more conservative in terms of what we issue software prefetch hints for. This also aligns GCC with what LLVM does for Falkor. Similarly to the previous patch, the defaults guarantee no change in behavior for other targets and architectures. gcc/ChangeLog: 2018-05-23 Luis Machado <luis.machado@linaro.org> * config/aarch64/aarch64-protos.h (cpu_prefetch_tune) <prefetch_dynamic_strides>: New const bool field. * config/aarch64/aarch64.c (generic_prefetch_tune): Update to include prefetch_dynamic_strides. (exynosm1_prefetch_tune): Likewise. (thunderxt88_prefetch_tune): Likewise. (thunderx_prefetch_tune): Likewise. (thunderx2t99_prefetch_tune): Likewise. (qdf24xx_prefetch_tune): Likewise. Set prefetch_dynamic_strides to false. (aarch64_override_options_internal): Update to set PARAM_PREFETCH_DYNAMIC_STRIDES. * doc/invoke.texi (prefetch-dynamic-strides): Document new option. * params.def (PARAM_PREFETCH_DYNAMIC_STRIDES): New. * params.h (PARAM_PREFETCH_DYNAMIC_STRIDES): Define. * tree-ssa-loop-prefetch.c (should_issue_prefetch_p): Account for prefetch-dynamic-strides setting. From-SVN: r260618
Diffstat (limited to 'gcc/params.h')
-rw-r--r--gcc/params.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/gcc/params.h b/gcc/params.h
index 96012db..8aa960a 100644
--- a/gcc/params.h
+++ b/gcc/params.h
@@ -196,6 +196,8 @@ extern void init_param_values (int *params);
PARAM_VALUE (PARAM_L1_CACHE_LINE_SIZE)
#define L2_CACHE_SIZE \
PARAM_VALUE (PARAM_L2_CACHE_SIZE)
+#define PREFETCH_DYNAMIC_STRIDES \
+ PARAM_VALUE (PARAM_PREFETCH_DYNAMIC_STRIDES)
#define PREFETCH_MINIMUM_STRIDE \
PARAM_VALUE (PARAM_PREFETCH_MINIMUM_STRIDE)
#define USE_CANONICAL_TYPES \