diff --git a/contrib/file_fdw/file_fdw.c b/contrib/file_fdw/file_fdw.c
index 70564a68b13..50d65418ee8 100644
--- a/contrib/file_fdw/file_fdw.c
+++ b/contrib/file_fdw/file_fdw.c
@@ -1294,7 +1294,7 @@ file_acquire_sample_rows(Relation onerel, int elevel,
 				 * Found a suitable tuple, so save it, replacing one old tuple
 				 * at random
 				 */
-				int			k = (int) (targrows * sampler_random_fract(&rstate.randstate));
+				int			k = (targrows * sampler_random_fract(&rstate.randstate));
 
 				Assert(k >= 0 && k < targrows);
 				heap_freetuple(rows[k]);
diff --git a/contrib/hstore/hstore_gist.c b/contrib/hstore/hstore_gist.c
index 69515dc3d3f..5dc065bcc40 100644
--- a/contrib/hstore/hstore_gist.c
+++ b/contrib/hstore/hstore_gist.c
@@ -37,7 +37,7 @@ typedef char *BITVECP;
 			for (i = 0; i < SIGLENBIT(siglen); i++)
 
 /* beware of multiple evaluation of arguments to these macros! */
-#define GETBYTE(x,i) ( *( (BITVECP)(x) + (int)( (i) / BITBYTE ) ) )
+#define GETBYTE(x,i) ( *( (BITVECP)(x) + ( (i) / BITBYTE ) ) )
 #define GETBITBYTE(x,i) ( (*((char*)(x)) >> (i)) & 0x01 )
 #define CLRBIT(x,i)   GETBYTE(x,i) &= ~( 0x01 << ( (i) % BITBYTE ) )
 #define SETBIT(x,i)   GETBYTE(x,i) |=  ( 0x01 << ( (i) % BITBYTE ) )
@@ -74,7 +74,7 @@ typedef struct
 
 #define GETENTRY(vec,pos) ((GISTTYPE *) DatumGetPointer((vec)->vector[(pos)].key))
 
-#define WISH_F(a,b,c) (double)( -(double)(((a)-(b))*((a)-(b))*((a)-(b)))*(c) )
+#define WISH_F(a,b,c) ( -(double)(((a)-(b))*((a)-(b))*((a)-(b)))*(c) )
 
 /* shorthand for calculating CRC-32 of a single chunk of data. */
 static pg_crc32
@@ -258,7 +258,7 @@ sizebitvec(BITVECP sign, int siglen)
 	LOOPBYTE(siglen)
 	{
 		size += SUMBIT(sign);
-		sign = (BITVECP) (((char *) sign) + 1);
+		sign = ((sign) + 1);
 	}
 	return size;
 }
diff --git a/contrib/ltree/_ltree_gist.c b/contrib/ltree/_ltree_gist.c
index 30d516e60bc..c2d89f24dff 100644
--- a/contrib/ltree/_ltree_gist.c
+++ b/contrib/ltree/_ltree_gist.c
@@ -28,7 +28,7 @@ PG_FUNCTION_INFO_V1(_ltree_gist_options);
 #define GETENTRY(vec,pos) ((ltree_gist *) DatumGetPointer((vec)->vector[(pos)].key))
 #define NEXTVAL(x) ( (ltree*)( (char*)(x) + INTALIGN( VARSIZE(x) ) ) )
 
-#define WISH_F(a,b,c) (double)( -(double)(((a)-(b))*((a)-(b))*((a)-(b)))*(c) )
+#define WISH_F(a,b,c) ( -(double)(((a)-(b))*((a)-(b))*((a)-(b)))*(c) )
 
 
 static void
diff --git a/contrib/ltree/ltree_gist.c b/contrib/ltree/ltree_gist.c
index 932f69bff2d..ba6b46a9d5a 100644
--- a/contrib/ltree/ltree_gist.c
+++ b/contrib/ltree/ltree_gist.c
@@ -225,7 +225,7 @@ ltree_union(PG_FUNCTION_ARGS)
 				BITVECP		sc = LTG_SIGN(cur);
 
 				LOOPBYTE(siglen)
-					((unsigned char *) base)[i] |= sc[i];
+					(base)[i] |= sc[i];
 			}
 
 			curtree = LTG_LNODE(cur, siglen);
@@ -242,7 +242,7 @@ ltree_union(PG_FUNCTION_ARGS)
 		isalltrue = true;
 		LOOPBYTE(siglen)
 		{
-			if (((unsigned char *) base)[i] != 0xff)
+			if ((base)[i] != 0xff)
 			{
 				isalltrue = false;
 				break;
@@ -352,7 +352,7 @@ ltree_picksplit(PG_FUNCTION_ARGS)
 					BITVECP		sc = LTG_SIGN(lu);
 
 					LOOPBYTE(siglen)
-						((unsigned char *) ls)[i] |= sc[i];
+						(ls)[i] |= sc[i];
 				}
 			}
 		}
@@ -373,7 +373,7 @@ ltree_picksplit(PG_FUNCTION_ARGS)
 					BITVECP		sc = LTG_SIGN(lu);
 
 					LOOPBYTE(siglen)
-						((unsigned char *) rs)[i] |= sc[i];
+						(rs)[i] |= sc[i];
 				}
 			}
 		}
@@ -384,7 +384,7 @@ ltree_picksplit(PG_FUNCTION_ARGS)
 		lisat = true;
 		LOOPBYTE(siglen)
 		{
-			if (((unsigned char *) ls)[i] != 0xff)
+			if ((ls)[i] != 0xff)
 			{
 				lisat = false;
 				break;
@@ -397,7 +397,7 @@ ltree_picksplit(PG_FUNCTION_ARGS)
 		risat = true;
 		LOOPBYTE(siglen)
 		{
-			if (((unsigned char *) rs)[i] != 0xff)
+			if ((rs)[i] != 0xff)
 			{
 				risat = false;
 				break;
diff --git a/contrib/pg_trgm/trgm_gist.c b/contrib/pg_trgm/trgm_gist.c
index 5ba895217b0..a41fe269c0b 100644
--- a/contrib/pg_trgm/trgm_gist.c
+++ b/contrib/pg_trgm/trgm_gist.c
@@ -727,7 +727,7 @@ gtrgm_penalty(PG_FUNCTION_ARGS)
 			cache = newcache;
 		}
 
-		sign = (BITVECP) cache;
+		sign = cache;
 
 		if (ISALLTRUE(origval))
 			*penalty = ((float) (SIGLENBIT(siglen) - sizebitvec(sign, siglen))) / (float) (SIGLENBIT(siglen) + 1);
@@ -758,7 +758,7 @@ fillcache(CACHESIGN *item, TRGM *key, BITVECP sign, int siglen)
 		memcpy(item->sign, GETSIGN(key), siglen);
 }
 
-#define WISH_F(a,b,c) (double)( -(double)(((a)-(b))*((a)-(b))*((a)-(b)))*(c) )
+#define WISH_F(a,b,c) ( -(double)(((a)-(b))*((a)-(b))*((a)-(b)))*(c) )
 typedef struct
 {
 	OffsetNumber pos;
diff --git a/contrib/pg_trgm/trgm_regexp.c b/contrib/pg_trgm/trgm_regexp.c
index 149f9eb259c..9ab251d8878 100644
--- a/contrib/pg_trgm/trgm_regexp.c
+++ b/contrib/pg_trgm/trgm_regexp.c
@@ -2277,7 +2277,7 @@ printTrgmColor(StringInfo buf, TrgmColor co)
 	else if (co == COLOR_BLANK)
 		appendStringInfoChar(buf, 'b');
 	else
-		appendStringInfo(buf, "%d", (int) co);
+		appendStringInfo(buf, "%d", co);
 }
 
 /*
diff --git a/contrib/postgres_fdw/postgres_fdw.c b/contrib/postgres_fdw/postgres_fdw.c
index 06b52c65300..2ffe836867d 100644
--- a/contrib/postgres_fdw/postgres_fdw.c
+++ b/contrib/postgres_fdw/postgres_fdw.c
@@ -5334,7 +5334,7 @@ analyze_row_processor(PGresult *res, int row, PgFdwAnalyzeState *astate)
 		if (astate->rowstoskip <= 0)
 		{
 			/* Choose a random reservoir element to replace. */
-			pos = (int) (targrows * sampler_random_fract(&astate->rstate.randstate));
+			pos = (targrows * sampler_random_fract(&astate->rstate.randstate));
 			Assert(pos >= 0 && pos < targrows);
 			heap_freetuple(astate->rows[pos]);
 		}
diff --git a/contrib/tsm_system_rows/tsm_system_rows.c b/contrib/tsm_system_rows/tsm_system_rows.c
index f401efa2131..1ebcd1d86d6 100644
--- a/contrib/tsm_system_rows/tsm_system_rows.c
+++ b/contrib/tsm_system_rows/tsm_system_rows.c
@@ -335,7 +335,7 @@ random_relative_prime(uint32 n, pg_prng_state *randstate)
 	do
 	{
 		CHECK_FOR_INTERRUPTS();
-		r = (uint32) (sampler_random_fract(randstate) * n);
+		r = (sampler_random_fract(randstate) * n);
 	} while (r == 0 || gcd(r, n) > 1);
 
 	return r;
diff --git a/contrib/tsm_system_time/tsm_system_time.c b/contrib/tsm_system_time/tsm_system_time.c
index c9c71d8c3af..361c92267a0 100644
--- a/contrib/tsm_system_time/tsm_system_time.c
+++ b/contrib/tsm_system_time/tsm_system_time.c
@@ -348,7 +348,7 @@ random_relative_prime(uint32 n, pg_prng_state *randstate)
 	do
 	{
 		CHECK_FOR_INTERRUPTS();
-		r = (uint32) (sampler_random_fract(randstate) * n);
+		r = (sampler_random_fract(randstate) * n);
 	} while (r == 0 || gcd(r, n) > 1);
 
 	return r;
diff --git a/src/backend/access/nbtree/nbtcompare.c b/src/backend/access/nbtree/nbtcompare.c
index 188c27b4925..bcd3b24de7f 100644
--- a/src/backend/access/nbtree/nbtcompare.c
+++ b/src/backend/access/nbtree/nbtcompare.c
@@ -545,7 +545,7 @@ char_decrement(Relation rel, Datum existing, bool *underflow)
 	}
 
 	*underflow = false;
-	return CharGetDatum((uint8) cexisting - 1);
+	return CharGetDatum(cexisting - 1);
 }
 
 static Datum
@@ -561,7 +561,7 @@ char_increment(Relation rel, Datum existing, bool *overflow)
 	}
 
 	*overflow = false;
-	return CharGetDatum((uint8) cexisting + 1);
+	return CharGetDatum(cexisting + 1);
 }
 
 Datum
diff --git a/src/backend/access/spgist/spgtextproc.c b/src/backend/access/spgist/spgtextproc.c
index 91f4ab260c2..e5796fb479d 100644
--- a/src/backend/access/spgist/spgtextproc.c
+++ b/src/backend/access/spgist/spgtextproc.c
@@ -67,7 +67,7 @@
  * choosing a max prefix size of 32 bytes when BLCKSZ is configured smaller
  * than default.
  */
-#define SPGIST_MAX_PREFIX_LENGTH	Max((int) (BLCKSZ - 258 * 16 - 100), 32)
+#define SPGIST_MAX_PREFIX_LENGTH	Max((BLCKSZ - 258 * 16 - 100), 32)
 
 /*
  * Strategy for collation aware operator on text is equal to btree strategy
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index 25089fae3e0..8dc7c9398bf 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -1287,7 +1287,7 @@ acquire_sample_rows(Relation onerel, int elevel,
 					 * Found a suitable tuple, so save it, replacing one old
 					 * tuple at random
 					 */
-					int			k = (int) (targrows * sampler_random_fract(&rstate.randstate));
+					int			k = (targrows * sampler_random_fract(&rstate.randstate));
 
 					Assert(k >= 0 && k < targrows);
 					heap_freetuple(rows[k]);
diff --git a/src/backend/executor/execGrouping.c b/src/backend/executor/execGrouping.c
index 8b64a625ca5..c295dd94801 100644
--- a/src/backend/executor/execGrouping.c
+++ b/src/backend/executor/execGrouping.c
@@ -360,7 +360,7 @@ EstimateTupleHashTableSpace(double nentries,
 		return SIZE_MAX;
 
 	/* We don't bother estimating size of the miscellaneous overhead data */
-	return (Size) (sh_space + tuples_space);
+	return (sh_space + tuples_space);
 }
 
 /*
diff --git a/src/backend/libpq/pqcomm.c b/src/backend/libpq/pqcomm.c
index 25f739a6a17..170b6b9e3c1 100644
--- a/src/backend/libpq/pqcomm.c
+++ b/src/backend/libpq/pqcomm.c
@@ -456,7 +456,7 @@ ListenServerPort(int family, const char *hostName, unsigned short portNumber,
 			ereport(LOG,
 					(errmsg("Unix-domain socket path \"%s\" is too long (maximum %d bytes)",
 							unixSocketPath,
-							(int) (UNIXSOCK_PATH_BUFLEN - 1))));
+							(UNIXSOCK_PATH_BUFLEN - 1))));
 			return STATUS_ERROR;
 		}
 		if (Lock_AF_UNIX(unixSocketDir, unixSocketPath) != STATUS_OK)
diff --git a/src/backend/nodes/bitmapset.c b/src/backend/nodes/bitmapset.c
index b4ecf0b0390..d6de78482c7 100644
--- a/src/backend/nodes/bitmapset.c
+++ b/src/backend/nodes/bitmapset.c
@@ -1073,13 +1073,13 @@ bms_add_range(Bitmapset *a, int lower, int upper)
 	 */
 	if (lwordnum == uwordnum)
 	{
-		a->words[lwordnum] |= ~(bitmapword) (((bitmapword) 1 << lbitnum) - 1)
+		a->words[lwordnum] |= ~(((bitmapword) 1 << lbitnum) - 1)
 			& (~(bitmapword) 0) >> ushiftbits;
 	}
 	else
 	{
 		/* turn on lbitnum and all bits left of it */
-		a->words[wordnum++] |= ~(bitmapword) (((bitmapword) 1 << lbitnum) - 1);
+		a->words[wordnum++] |= ~(((bitmapword) 1 << lbitnum) - 1);
 
 		/* turn on all bits for any intermediate words */
 		while (wordnum < uwordnum)
diff --git a/src/backend/optimizer/geqo/geqo_main.c b/src/backend/optimizer/geqo/geqo_main.c
index 0064556087a..be65da2b002 100644
--- a/src/backend/optimizer/geqo/geqo_main.c
+++ b/src/backend/optimizer/geqo/geqo_main.c
@@ -244,7 +244,7 @@ geqo(PlannerInfo *root, int number_of_rels, List *initial_rels)
 #if defined(GEQO_DEBUG)
 	if (edge_failures != 0)
 		elog(LOG, "[GEQO] failures: %d, average: %d",
-			 edge_failures, (int) number_generations / edge_failures);
+			 edge_failures, number_generations / edge_failures);
 	else
 		elog(LOG, "[GEQO] no edge failures detected");
 #else
diff --git a/src/backend/postmaster/syslogger.c b/src/backend/postmaster/syslogger.c
index 50c2edec1f6..1b17c69b4d2 100644
--- a/src/backend/postmaster/syslogger.c
+++ b/src/backend/postmaster/syslogger.c
@@ -883,7 +883,7 @@ process_pipe_input(char *logbuffer, int *bytes_in_logbuffer)
 	int			dest = LOG_DESTINATION_STDERR;
 
 	/* While we have enough for a header, process data... */
-	while (count >= (int) (offsetof(PipeProtoHeader, data) + 1))
+	while (count >= (offsetof(PipeProtoHeader, data) + 1))
 	{
 		PipeProtoHeader p;
 		int			chunklen;
diff --git a/src/backend/storage/smgr/md.c b/src/backend/storage/smgr/md.c
index e3f335a8340..cd19dd7316d 100644
--- a/src/backend/storage/smgr/md.c
+++ b/src/backend/storage/smgr/md.c
@@ -132,7 +132,7 @@ static MemoryContext MdCxt;		/* context for all MdfdVec objects */
 #define MD_PATH_STR_MAXLEN \
 	(\
 		REL_PATH_STR_MAXLEN \
-		+ sizeof((char)'.') \
+		+ sizeof('.') \
 		+ SEGMENT_CHARS \
 	)
 typedef struct MdPathStr
diff --git a/src/backend/storage/sync/sync.c b/src/backend/storage/sync/sync.c
index fc16db90133..e3cab800f5a 100644
--- a/src/backend/storage/sync/sync.c
+++ b/src/backend/storage/sync/sync.c
@@ -374,7 +374,7 @@ ProcessSyncRequests(void)
 			continue;
 
 		/* Else assert we haven't missed it */
-		Assert((CycleCtr) (entry->cycle_ctr + 1) == sync_cycle_ctr);
+		Assert((entry->cycle_ctr + 1) == sync_cycle_ctr);
 
 		/*
 		 * If fsync is off then we don't have to bother opening the file at
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index 7dd75a490aa..702c3d16691 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -303,7 +303,7 @@ InteractiveBackend(StringInfo inBuf)
 	 */
 
 	/* Add '\0' to make it look the same as message case. */
-	appendStringInfoChar(inBuf, (char) '\0');
+	appendStringInfoChar(inBuf, '\0');
 
 	/*
 	 * if the query echo flag was given, print the query..
diff --git a/src/backend/utils/adt/like.c b/src/backend/utils/adt/like.c
index 4216ac17f43..32cfe6310c2 100644
--- a/src/backend/utils/adt/like.c
+++ b/src/backend/utils/adt/like.c
@@ -454,5 +454,5 @@ like_escape_bytea(PG_FUNCTION_ARGS)
 	bytea	   *esc = PG_GETARG_BYTEA_PP(1);
 	bytea	   *result = SB_do_like_escape((text *) pat, (text *) esc);
 
-	PG_RETURN_BYTEA_P((bytea *) result);
+	PG_RETURN_BYTEA_P(result);
 }
diff --git a/src/backend/utils/adt/numutils.c b/src/backend/utils/adt/numutils.c
index 3bf30774a0c..f468bc2cd7e 100644
--- a/src/backend/utils/adt/numutils.c
+++ b/src/backend/utils/adt/numutils.c
@@ -1102,7 +1102,7 @@ pg_ultoa_n(uint32 value, char *a)
 	}
 	else
 	{
-		*a = (char) ('0' + value);
+		*a = ('0' + value);
 	}
 
 	return olength;
@@ -1211,7 +1211,7 @@ pg_ulltoa_n(uint64 value, char *a)
 		memcpy(pos - 2, DIGIT_TABLE + c, 2);
 	}
 	else
-		*a = (char) ('0' + value2);
+		*a = ('0' + value2);
 
 	return olength;
 }
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index 3d98d064a94..7aaf1ee1f16 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -1446,7 +1446,7 @@ pgstat_get_io_time_index(IOOp io_op)
 static inline double
 pg_stat_us_to_ms(PgStat_Counter val_ms)
 {
-	return val_ms * (double) 0.001;
+	return val_ms * 0.001;
 }
 
 /*
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index 540aa9628d7..53d96cbea50 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -5456,7 +5456,7 @@ convert_timevalue_to_scalar(Datum value, Oid typid, bool *failure)
 				TimeTzADT  *timetz = DatumGetTimeTzADTP(value);
 
 				/* use GMT-equivalent time */
-				return (double) (timetz->time + (timetz->zone * 1000000.0));
+				return (timetz->time + (timetz->zone * 1000000.0));
 			}
 	}
 
diff --git a/src/backend/utils/adt/tsgistidx.c b/src/backend/utils/adt/tsgistidx.c
index 935187b37c7..23fca62c199 100644
--- a/src/backend/utils/adt/tsgistidx.c
+++ b/src/backend/utils/adt/tsgistidx.c
@@ -575,7 +575,7 @@ fillcache(CACHESIGN *item, SignTSVector *key, int siglen)
 		memcpy(item->sign, GETSIGN(key), siglen);
 }
 
-#define WISH_F(a,b,c) (double)( -(double)(((a)-(b))*((a)-(b))*((a)-(b)))*(c) )
+#define WISH_F(a,b,c) ( -(double)(((a)-(b))*((a)-(b))*((a)-(b)))*(c) )
 typedef struct
 {
 	OffsetNumber pos;
diff --git a/src/backend/utils/adt/tsquery_gist.c b/src/backend/utils/adt/tsquery_gist.c
index f7f94c1c760..ec7da50fc67 100644
--- a/src/backend/utils/adt/tsquery_gist.c
+++ b/src/backend/utils/adt/tsquery_gist.c
@@ -161,7 +161,7 @@ comparecost(const void *a, const void *b)
 					  ((const SPLITCOST *) b)->cost);
 }
 
-#define WISH_F(a,b,c) (double)( -(double)(((a)-(b))*((a)-(b))*((a)-(b)))*(c) )
+#define WISH_F(a,b,c) ( -(double)(((a)-(b))*((a)-(b))*((a)-(b)))*(c) )
 
 Datum
 gtsquery_picksplit(PG_FUNCTION_ARGS)
diff --git a/src/backend/utils/error/elog.c b/src/backend/utils/error/elog.c
index 29643c51439..bd86de0a293 100644
--- a/src/backend/utils/error/elog.c
+++ b/src/backend/utils/error/elog.c
@@ -2703,7 +2703,7 @@ get_formatted_log_time(void)
 				pg_localtime(&stamp_time, log_timezone));
 
 	/* 'paste' milliseconds into place... */
-	sprintf(msbuf, ".%03d", (int) (saved_timeval.tv_usec / 1000));
+	sprintf(msbuf, ".%03d", (saved_timeval.tv_usec / 1000));
 	memcpy(formatted_log_time + 19, msbuf, 4);
 
 	return formatted_log_time;
@@ -3046,7 +3046,7 @@ log_status_format(StringInfo buf, const char *format, ErrorData *edata)
 
 					snprintf(strfbuf, sizeof(strfbuf), "%ld.%03d",
 							 (long) saved_timeval.tv_sec,
-							 (int) (saved_timeval.tv_usec / 1000));
+							 (saved_timeval.tv_usec / 1000));
 
 					if (padding != 0)
 						appendStringInfo(buf, "%*s", padding, strfbuf);
diff --git a/src/backend/utils/mb/conversion_procs/euc_tw_and_big5/big5.c b/src/backend/utils/mb/conversion_procs/euc_tw_and_big5/big5.c
index 68f76aa8cb8..abef1f22bb4 100644
--- a/src/backend/utils/mb/conversion_procs/euc_tw_and_big5/big5.c
+++ b/src/backend/utils/mb/conversion_procs/euc_tw_and_big5/big5.c
@@ -264,7 +264,7 @@ static unsigned short BinarySearchRange
 				 * Its radix is 0x5e. But there is no distance bias like big5.
 				 */
 				distance = tmp * 0x5e
-					+ ((int) (code & 0x00ff) - (int) (array[mid].code & 0x00ff));
+					+ ((code & 0x00ff) - (array[mid].code & 0x00ff));
 
 				/*
 				 * NOTE: Similar to big5 to cns conversion, we extract
diff --git a/src/backend/utils/mb/wstrcmp.c b/src/backend/utils/mb/wstrcmp.c
index dad3ae023a3..f16a2d47252 100644
--- a/src/backend/utils/mb/wstrcmp.c
+++ b/src/backend/utils/mb/wstrcmp.c
@@ -43,5 +43,5 @@ pg_char_and_wchar_strcmp(const char *s1, const pg_wchar *s2)
 	while ((pg_wchar) *s1 == *s2++)
 		if (*s1++ == 0)
 			return 0;
-	return *(const unsigned char *) s1 - *(const pg_wchar *) (s2 - 1);
+	return *(const unsigned char *) s1 - *(s2 - 1);
 }
diff --git a/src/backend/utils/mmgr/aset.c b/src/backend/utils/mmgr/aset.c
index bcd09c07533..bce86fcd304 100644
--- a/src/backend/utils/mmgr/aset.c
+++ b/src/backend/utils/mmgr/aset.c
@@ -517,7 +517,7 @@ AllocSetContextCreateInternal(MemoryContext parent,
 	 */
 	set->allocChunkLimit = ALLOC_CHUNK_LIMIT;
 	while ((Size) (set->allocChunkLimit + ALLOC_CHUNKHDRSZ) >
-		   (Size) ((maxBlockSize - ALLOC_BLOCKHDRSZ) / ALLOC_CHUNK_FRACTION))
+		   ((maxBlockSize - ALLOC_BLOCKHDRSZ) / ALLOC_CHUNK_FRACTION))
 		set->allocChunkLimit >>= 1;
 
 	/* Finally, do the type-independent part of context creation */
diff --git a/src/backend/utils/mmgr/bump.c b/src/backend/utils/mmgr/bump.c
index e60ec94e139..dd4bb93ff81 100644
--- a/src/backend/utils/mmgr/bump.c
+++ b/src/backend/utils/mmgr/bump.c
@@ -228,7 +228,7 @@ BumpContextCreate(MemoryContext parent, const char *name, Size minContextSize,
 	 */
 	set->allocChunkLimit = Min(maxBlockSize, MEMORYCHUNK_MAX_VALUE);
 	while ((Size) (set->allocChunkLimit + Bump_CHUNKHDRSZ) >
-		   (Size) ((Size) (maxBlockSize - Bump_BLOCKHDRSZ) / Bump_CHUNK_FRACTION))
+		   ((maxBlockSize - Bump_BLOCKHDRSZ) / Bump_CHUNK_FRACTION))
 		set->allocChunkLimit >>= 1;
 
 	/* Finally, do the type-independent part of context creation */
@@ -626,10 +626,10 @@ BumpBlockFree(BumpContext *set, BumpBlock *block)
 	/* release the block from the list of blocks */
 	dlist_delete(&block->node);
 
-	((MemoryContext) set)->mem_allocated -= ((char *) block->endptr - (char *) block);
+	((MemoryContext) set)->mem_allocated -= (block->endptr - (char *) block);
 
 #ifdef CLOBBER_FREED_MEMORY
-	wipe_mem(block, ((char *) block->endptr - (char *) block));
+	wipe_mem(block, (block->endptr - (char *) block));
 #endif
 
 	/* As in aset.c, free block-header vchunks explicitly */
diff --git a/src/backend/utils/mmgr/generation.c b/src/backend/utils/mmgr/generation.c
index f6203501956..c9960573ea1 100644
--- a/src/backend/utils/mmgr/generation.c
+++ b/src/backend/utils/mmgr/generation.c
@@ -263,7 +263,7 @@ GenerationContextCreate(MemoryContext parent,
 	 */
 	set->allocChunkLimit = Min(maxBlockSize, MEMORYCHUNK_MAX_VALUE);
 	while ((Size) (set->allocChunkLimit + Generation_CHUNKHDRSZ) >
-		   (Size) ((Size) (maxBlockSize - Generation_BLOCKHDRSZ) / Generation_CHUNK_FRACTION))
+		   ((maxBlockSize - Generation_BLOCKHDRSZ) / Generation_CHUNK_FRACTION))
 		set->allocChunkLimit >>= 1;
 
 	/* Finally, do the type-independent part of context creation */
diff --git a/src/bin/pg_basebackup/walmethods.c b/src/bin/pg_basebackup/walmethods.c
index eaaabc5f374..8a625481aa2 100644
--- a/src/bin/pg_basebackup/walmethods.c
+++ b/src/bin/pg_basebackup/walmethods.c
@@ -644,7 +644,7 @@ CreateWalDirectoryMethod(const char *basedir,
 	DirectoryMethodData *wwmethod;
 
 	wwmethod = pg_malloc0(sizeof(DirectoryMethodData));
-	*((const WalWriteMethodOps **) &wwmethod->base.ops) =
+	*(&wwmethod->base.ops) =
 		&WalDirectoryMethodOps;
 	wwmethod->base.compression_algorithm = compression_algorithm;
 	wwmethod->base.compression_level = compression_level;
@@ -1361,7 +1361,7 @@ CreateWalTarMethod(const char *tarbase,
 		".tar.gz" : ".tar";
 
 	wwmethod = pg_malloc0(sizeof(TarMethodData));
-	*((const WalWriteMethodOps **) &wwmethod->base.ops) =
+	*(&wwmethod->base.ops) =
 		&WalTarMethodOps;
 	wwmethod->base.compression_algorithm = compression_algorithm;
 	wwmethod->base.compression_level = compression_level;
diff --git a/src/bin/pg_upgrade/pg_upgrade.c b/src/bin/pg_upgrade/pg_upgrade.c
index 490e98fa26f..e4be03a3d36 100644
--- a/src/bin/pg_upgrade/pg_upgrade.c
+++ b/src/bin/pg_upgrade/pg_upgrade.c
@@ -295,7 +295,7 @@ make_outputdirs(char *pgdata)
 	strftime(timebuf, sizeof(timebuf), "%Y%m%dT%H%M%S", localtime(&tt));
 	/* append milliseconds */
 	snprintf(timebuf + strlen(timebuf), sizeof(timebuf) - strlen(timebuf),
-			 ".%03d", (int) (time.tv_usec / 1000));
+			 ".%03d", (time.tv_usec / 1000));
 	log_opts.basedir = (char *) pg_malloc0(MAXPGPATH);
 	len = snprintf(log_opts.basedir, MAXPGPATH, "%s/%s", log_opts.rootdir,
 				   timebuf);
diff --git a/src/bin/pgbench/pgbench.c b/src/bin/pgbench/pgbench.c
index 68774a59efd..fb515181a66 100644
--- a/src/bin/pgbench/pgbench.c
+++ b/src/bin/pgbench/pgbench.c
@@ -1120,7 +1120,7 @@ getExponentialRand(pg_prng_state *state, int64 min, int64 max,
 	Assert((1.0 - cut) != 0.0);
 	rand = -log(cut + (1.0 - cut) * uniform) / parameter;
 	/* return int64 random number within between min and max */
-	return min + (int64) ((max - min + 1) * rand);
+	return min + ((max - min + 1) * rand);
 }
 
 /* random number generator: gaussian distribution from min to max inclusive */
@@ -1156,7 +1156,7 @@ getGaussianRand(pg_prng_state *state, int64 min, int64 max,
 	rand = (stdev + parameter) / (parameter * 2.0);
 
 	/* return int64 random number within between min and max */
-	return min + (int64) ((max - min + 1) * rand);
+	return min + ((max - min + 1) * rand);
 }
 
 /*
diff --git a/src/common/d2s.c b/src/common/d2s.c
index 5322c465d53..e0ac9d36c57 100644
--- a/src/common/d2s.c
+++ b/src/common/d2s.c
@@ -736,7 +736,7 @@ to_chars_df(const floating_decimal_64 v, const uint32 olength, char *const resul
 	}
 	else
 	{
-		result[index] = (char) ('0' + output2);
+		result[index] = ('0' + output2);
 	}
 
 	if (index == 1)
@@ -917,7 +917,7 @@ to_chars(floating_decimal_64 v, const bool sign, char *const result)
 	}
 	else
 	{
-		result[index] = (char) ('0' + output2);
+		result[index] = ('0' + output2);
 	}
 
 	/* Print decimal point if needed. */
@@ -946,7 +946,7 @@ to_chars(floating_decimal_64 v, const bool sign, char *const result)
 		const int32 c = exp % 10;
 
 		memcpy(result + index, DIGIT_TABLE + 2 * (exp / 10), 2);
-		result[index + 2] = (char) ('0' + c);
+		result[index + 2] = ('0' + c);
 		index += 3;
 	}
 	else
diff --git a/src/common/f2s.c b/src/common/f2s.c
index a239a8765b0..c94d2261511 100644
--- a/src/common/f2s.c
+++ b/src/common/f2s.c
@@ -517,7 +517,7 @@ to_chars_f(const floating_decimal_32 v, const uint32 olength, char *const result
 	}
 	else
 	{
-		result[index] = (char) ('0' + output);
+		result[index] = ('0' + output);
 	}
 
 	if (index == 1)
@@ -655,7 +655,7 @@ to_chars(const floating_decimal_32 v, const bool sign, char *const result)
 	}
 	else
 	{
-		result[index] = (char) ('0' + output);
+		result[index] = ('0' + output);
 	}
 
 	/* Print decimal point if needed. */
diff --git a/src/interfaces/ecpg/compatlib/informix.c b/src/interfaces/ecpg/compatlib/informix.c
index ca11a81f1bc..5e546950820 100644
--- a/src/interfaces/ecpg/compatlib/informix.c
+++ b/src/interfaces/ecpg/compatlib/informix.c
@@ -383,7 +383,7 @@ dectoasc(decimal *np, char *cp, int len, int right)
 	char	   *str;
 	numeric    *nres;
 
-	rsetnull(CSTRINGTYPE, (char *) cp);
+	rsetnull(CSTRINGTYPE, cp);
 	if (risnull(CDECIMALTYPE, (char *) np))
 		return 0;
 
@@ -410,7 +410,7 @@ dectoasc(decimal *np, char *cp, int len, int right)
 	 * TODO: have to take care of len here and create exponential notation if
 	 * necessary
 	 */
-	if ((int) (strlen(str) + 1) > len)
+	if ((strlen(str) + 1) > len)
 	{
 		if (len > 1)
 		{
diff --git a/src/interfaces/ecpg/ecpglib/data.c b/src/interfaces/ecpg/ecpglib/data.c
index d5d40f7b654..b5b9dd7412f 100644
--- a/src/interfaces/ecpg/ecpglib/data.c
+++ b/src/interfaces/ecpg/ecpglib/data.c
@@ -390,7 +390,7 @@ ecpg_get_data(const PGresult *results, int act_tuple, int act_field, int lineno,
 							*((int *) (var + offset * act_tuple)) = (int) res;
 							break;
 						case ECPGt_long:
-							*((long *) (var + offset * act_tuple)) = (long) res;
+							*((long *) (var + offset * act_tuple)) = res;
 							break;
 						default:
 							/* Cannot happen */
@@ -419,7 +419,7 @@ ecpg_get_data(const PGresult *results, int act_tuple, int act_field, int lineno,
 							*((unsigned int *) (var + offset * act_tuple)) = (unsigned int) ures;
 							break;
 						case ECPGt_unsigned_long:
-							*((unsigned long *) (var + offset * act_tuple)) = (unsigned long) ures;
+							*((unsigned long *) (var + offset * act_tuple)) = ures;
 							break;
 						default:
 							/* Cannot happen */
@@ -557,7 +557,7 @@ ecpg_get_data(const PGresult *results, int act_tuple, int act_field, int lineno,
 				case ECPGt_unsigned_char:
 				case ECPGt_string:
 					{
-						char	   *str = (char *) (var + offset * act_tuple);
+						char	   *str = (var + offset * act_tuple);
 
 						/*
 						 * If varcharsize is unknown and the offset is that of
diff --git a/src/interfaces/ecpg/pgtypeslib/dt_common.c b/src/interfaces/ecpg/pgtypeslib/dt_common.c
index c4119ab7932..fe960edc236 100644
--- a/src/interfaces/ecpg/pgtypeslib/dt_common.c
+++ b/src/interfaces/ecpg/pgtypeslib/dt_common.c
@@ -892,7 +892,7 @@ EncodeDateTime(struct tm *tm, fsec_t fsec, bool print_tz, int tz, const char *tz
 			/* Backward-compatible with traditional Postgres abstime dates */
 
 			day = date2j(tm->tm_year, tm->tm_mon, tm->tm_mday);
-			tm->tm_wday = (int) ((day + date2j(2000, 1, 1) + 1) % 7);
+			tm->tm_wday = ((day + date2j(2000, 1, 1) + 1) % 7);
 
 			memcpy(str, days[tm->tm_wday], 3);
 			strcpy(str + 3, " ");
diff --git a/src/interfaces/ecpg/test/expected/sql-desc.c b/src/interfaces/ecpg/test/expected/sql-desc.c
index bdd12a506be..ecf0bd60e2a 100644
--- a/src/interfaces/ecpg/test/expected/sql-desc.c
+++ b/src/interfaces/ecpg/test/expected/sql-desc.c
@@ -280,7 +280,7 @@ if (sqlca.sqlcode < 0) sqlprint();}
 #line 65 "desc.pgc"
 
 
-	{ ECPGset_desc_header(__LINE__, "indesc", (int)(1));
+	{ ECPGset_desc_header(__LINE__, "indesc", (1));
 
 #line 67 "desc.pgc"
 
diff --git a/src/interfaces/libpq/fe-connect.c b/src/interfaces/libpq/fe-connect.c
index c3a2448dce5..b87774334ce 100644
--- a/src/interfaces/libpq/fe-connect.c
+++ b/src/interfaces/libpq/fe-connect.c
@@ -3096,7 +3096,7 @@ keep_going:						/* We will come back to here until there is
 				{
 					libpq_append_conn_error(conn, "Unix-domain socket path \"%s\" is too long (maximum %d bytes)",
 											portstr,
-											(int) (UNIXSOCK_PATH_BUFLEN - 1));
+											(UNIXSOCK_PATH_BUFLEN - 1));
 					goto keep_going;
 				}
 
diff --git a/src/test/isolation/isolation_main.c b/src/test/isolation/isolation_main.c
index a13f9cdcaf7..f9b165c5cf4 100644
--- a/src/test/isolation/isolation_main.c
+++ b/src/test/isolation/isolation_main.c
@@ -125,7 +125,7 @@ isolation_init(int argc, char **argv)
 	if (argv0_len >= MAXPGPATH)
 	{
 		fprintf(stderr, _("path for isolationtester executable is longer than %d bytes\n"),
-				(int) (MAXPGPATH - 1));
+				(MAXPGPATH - 1));
 		exit(2);
 	}
 
diff --git a/src/test/regress/regress.c b/src/test/regress/regress.c
index 56cc0567b1c..bad6c576b2f 100644
--- a/src/test/regress/regress.c
+++ b/src/test/regress/regress.c
@@ -1082,7 +1082,7 @@ test_enc_conversion(PG_FUNCTION_ARGS)
 					 errdetail("String of %d bytes is too long for encoding conversion.",
 							   (int) srclen)));
 
-		dstsize = (Size) srclen * MAX_CONVERSION_GROWTH + 1;
+		dstsize = srclen * MAX_CONVERSION_GROWTH + 1;
 		dst = MemoryContextAlloc(CurrentMemoryContext, dstsize);
 
 		/* perform conversion */
diff --git a/src/timezone/localtime.c b/src/timezone/localtime.c
index 20147f1a2c2..fb68594b868 100644
--- a/src/timezone/localtime.c
+++ b/src/timezone/localtime.c
@@ -1522,7 +1522,7 @@ timesub(const pg_time_t *timep, int_fast32_t offset,
 	ip = mon_lengths[isleap(y)];
 	for (tmp->tm_mon = 0; idays >= ip[tmp->tm_mon]; ++(tmp->tm_mon))
 		idays -= ip[tmp->tm_mon];
-	tmp->tm_mday = (int) (idays + 1);
+	tmp->tm_mday = (idays + 1);
 	tmp->tm_isdst = 0;
 	tmp->tm_gmtoff = offset;
 	return tmp;
diff --git a/src/timezone/zic.c b/src/timezone/zic.c
index a8c1de9910d..1b4f3017f12 100644
--- a/src/timezone/zic.c
+++ b/src/timezone/zic.c
@@ -3891,7 +3891,7 @@ will not work with pre-2004 versions of zic"));
 		return min_time;
 	if (dayoff > max_time / SECSPERDAY)
 		return max_time;
-	t = (zic_t) dayoff * SECSPERDAY;
+	t = dayoff * SECSPERDAY;
 	return tadd(t, rp->r_tod);
 }