From 5c81cf6b035368ac2dc9c4b20881a9e13eff5360 Mon Sep 17 00:00:00 2001
From: Michael Paquier <michael@paquier.xyz>
Date: Tue, 9 Sep 2025 12:40:04 +0900
Subject: [PATCH v3 1/2] Replace callers of dynahash.h's my_log() by equivalent
 in pg_bitutils.h

All these callers use 4-byte signed integers for their variables, hence
they do not require my_log2() maximum based on int64.  This eases an
upcoming removal of my_log2().

ExecChooseHashTableSize(), that calculates the number of buckets to use
for hash tables, is now capped at 2^30, to keep pg_ceil_log2_32() on the
same side.  nodeAgg.c is already capped at 1024, and worker.c relies on
the maximum number of subxacts.
---
 src/backend/executor/nodeAgg.c           |  3 +--
 src/backend/executor/nodeHash.c          | 14 ++++++++++----
 src/backend/replication/logical/worker.c |  3 +--
 3 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/src/backend/executor/nodeAgg.c b/src/backend/executor/nodeAgg.c
index 377e016d7322..a4f3d30f307c 100644
--- a/src/backend/executor/nodeAgg.c
+++ b/src/backend/executor/nodeAgg.c
@@ -267,7 +267,6 @@
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/datum.h"
-#include "utils/dynahash.h"
 #include "utils/expandeddatum.h"
 #include "utils/injection_point.h"
 #include "utils/logtape.h"
@@ -2115,7 +2114,7 @@ hash_choose_num_partitions(double input_groups, double hashentrysize,
 	npartitions = (int) dpartitions;
 
 	/* ceil(log2(npartitions)) */
-	partition_bits = my_log2(npartitions);
+	partition_bits = pg_ceil_log2_32(npartitions);
 
 	/* make sure that we don't exhaust the hash bits */
 	if (partition_bits + used_bits >= 32)
diff --git a/src/backend/executor/nodeHash.c b/src/backend/executor/nodeHash.c
index 8d2201ab67fa..db8f4722ebb2 100644
--- a/src/backend/executor/nodeHash.c
+++ b/src/backend/executor/nodeHash.c
@@ -36,7 +36,6 @@
 #include "executor/nodeHashjoin.h"
 #include "miscadmin.h"
 #include "port/pg_bitutils.h"
-#include "utils/dynahash.h"
 #include "utils/lsyscache.h"
 #include "utils/memutils.h"
 #include "utils/syscache.h"
@@ -340,7 +339,7 @@ MultiExecParallelHash(HashState *node)
 	 */
 	hashtable->curbatch = -1;
 	hashtable->nbuckets = pstate->nbuckets;
-	hashtable->log2_nbuckets = my_log2(hashtable->nbuckets);
+	hashtable->log2_nbuckets = pg_ceil_log2_32(hashtable->nbuckets);
 	hashtable->totalTuples = pstate->total_tuples;
 
 	/*
@@ -480,7 +479,7 @@ ExecHashTableCreate(HashState *state)
 							&nbuckets, &nbatch, &num_skew_mcvs);
 
 	/* nbuckets must be a power of 2 */
-	log2_nbuckets = my_log2(nbuckets);
+	log2_nbuckets = pg_ceil_log2_32(nbuckets);
 	Assert(nbuckets == (1 << log2_nbuckets));
 
 	/*
@@ -935,6 +934,13 @@ ExecChooseHashTableSize(double ntuples, int tupwidth, bool useskew,
 	Assert(nbuckets > 0);
 	Assert(nbatch > 0);
 
+	/*
+	 * Cap nbuckets, for power of 2 calculations.  This maximum is safe
+	 * for pg_ceil_log2_32().
+	 */
+	if (nbuckets > PG_INT32_MAX / 2)
+		nbuckets = PG_INT32_MAX / 2;
+
 	*numbuckets = nbuckets;
 	*numbatches = nbatch;
 }
@@ -3499,7 +3505,7 @@ ExecParallelHashTableSetCurrentBatch(HashJoinTable hashtable, int batchno)
 		dsa_get_address(hashtable->area,
 						hashtable->batches[batchno].shared->buckets);
 	hashtable->nbuckets = hashtable->parallel_state->nbuckets;
-	hashtable->log2_nbuckets = my_log2(hashtable->nbuckets);
+	hashtable->log2_nbuckets = pg_ceil_log2_32(hashtable->nbuckets);
 	hashtable->current_chunk = NULL;
 	hashtable->current_chunk_shared = InvalidDsaPointer;
 	hashtable->batches[batchno].at_least_one_chunk = false;
diff --git a/src/backend/replication/logical/worker.c b/src/backend/replication/logical/worker.c
index c0f6bef5c282..c6d7c1fcde71 100644
--- a/src/backend/replication/logical/worker.c
+++ b/src/backend/replication/logical/worker.c
@@ -276,7 +276,6 @@
 #include "storage/procarray.h"
 #include "tcop/tcopprot.h"
 #include "utils/acl.h"
-#include "utils/dynahash.h"
 #include "utils/guc.h"
 #include "utils/inval.h"
 #include "utils/lsyscache.h"
@@ -5109,7 +5108,7 @@ subxact_info_read(Oid subid, TransactionId xid)
 	len = sizeof(SubXactInfo) * subxact_data.nsubxacts;
 
 	/* we keep the maximum as a power of 2 */
-	subxact_data.nsubxacts_max = 1 << my_log2(subxact_data.nsubxacts);
+	subxact_data.nsubxacts_max = 1 << pg_ceil_log2_32(subxact_data.nsubxacts);
 
 	/*
 	 * Allocate subxact information in the logical streaming context. We need
-- 
2.51.0