From f1f02557f7f4d694f0e3b4d62a6bdfad8e746b03 Mon Sep 17 00:00:00 2001 From: Kyotaro Horiguchi Date: Mon, 12 Sep 2016 16:36:37 +0900 Subject: [PATCH] Use __builtin_expect to optimize branches __builtin_expect can minimize the cost of failure of branch prediction for certain cases. It seems to work very fine here. --- src/backend/executor/execProcnode.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/src/backend/executor/execProcnode.c b/src/backend/executor/execProcnode.c index cef262b..c247fa3 100644 --- a/src/backend/executor/execProcnode.c +++ b/src/backend/executor/execProcnode.c @@ -585,13 +585,22 @@ ExecExecuteNode(PlanState *node) * execution subtree and every subtree should have an individual context. * ---------------------------------------------------------------- */ +#define MY_USE_LIKELY +#if defined MY_USE_LIKELY +#define my_likely(x) __builtin_expect((x),1) +#define my_unlikely(x) __builtin_expect((x),0) +#else +#define my_likely(x) (x) +#define my_unlikely(x) (x) +#endif + TupleTableSlot * ExecProcNode(PlanState *node) { CHECK_FOR_INTERRUPTS(); /* Return unconsumed result if any */ - if (node->result_ready) + if (my_unlikely(node->result_ready)) return ExecConsumeResult(node); if (node->chgParam != NULL) /* something changed */ @@ -599,7 +608,7 @@ ExecProcNode(PlanState *node) ExecDispatchNode(node); - if (!node->result_ready) + if (my_unlikely(!node->result_ready)) ExecAsyncWaitForNode(node); return ExecConsumeResult(node); -- 2.9.2