diff --git a/contrib/btree_gist/btree_cash.c b/contrib/btree_gist/btree_cash.c
index 81131af4dc..18f45f2750 100644
--- a/contrib/btree_gist/btree_cash.c
+++ b/contrib/btree_gist/btree_cash.c
@@ -5,6 +5,7 @@
 
 #include "btree_gist.h"
 #include "btree_utils_num.h"
+#include "common/int.h"
 #include "utils/cash.h"
 
 typedef struct
@@ -99,15 +100,14 @@ cash_dist(PG_FUNCTION_ARGS)
 	Cash		r;
 	Cash		ra;
 
-	r = a - b;
-	ra = Abs(r);
-
-	/* Overflow check. */
-	if (ra < 0 || (!SAMESIGN(a, b) && !SAMESIGN(r, a)))
+	if (pg_sub_s64_overflow(a, b, &r) ||
+		r == INT64_MIN)
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("money out of range")));
 
+	ra = Abs(r);
+
 	PG_RETURN_CASH(ra);
 }
 
diff --git a/contrib/btree_gist/btree_int2.c b/contrib/btree_gist/btree_int2.c
index f343b8615f..c2af4cd566 100644
--- a/contrib/btree_gist/btree_int2.c
+++ b/contrib/btree_gist/btree_int2.c
@@ -5,6 +5,7 @@
 
 #include "btree_gist.h"
 #include "btree_utils_num.h"
+#include "common/int.h"
 
 typedef struct int16key
 {
@@ -98,15 +99,14 @@ int2_dist(PG_FUNCTION_ARGS)
 	int16		r;
 	int16		ra;
 
-	r = a - b;
-	ra = Abs(r);
-
-	/* Overflow check. */
-	if (ra < 0 || (!SAMESIGN(a, b) && !SAMESIGN(r, a)))
+	if (pg_sub_s16_overflow(a, b, &r) ||
+		r == INT16_MIN)
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("smallint out of range")));
 
+	ra = Abs(r);
+
 	PG_RETURN_INT16(ra);
 }
 
diff --git a/contrib/btree_gist/btree_int4.c b/contrib/btree_gist/btree_int4.c
index 35bb442437..f2b6dec660 100644
--- a/contrib/btree_gist/btree_int4.c
+++ b/contrib/btree_gist/btree_int4.c
@@ -5,6 +5,7 @@
 
 #include "btree_gist.h"
 #include "btree_utils_num.h"
+#include "common/int.h"
 
 typedef struct int32key
 {
@@ -99,15 +100,14 @@ int4_dist(PG_FUNCTION_ARGS)
 	int32		r;
 	int32		ra;
 
-	r = a - b;
-	ra = Abs(r);
-
-	/* Overflow check. */
-	if (ra < 0 || (!SAMESIGN(a, b) && !SAMESIGN(r, a)))
+	if (pg_sub_s32_overflow(a, b, &r) ||
+		r == INT32_MIN)
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("integer out of range")));
 
+	ra = Abs(r);
+
 	PG_RETURN_INT32(ra);
 }
 
diff --git a/contrib/btree_gist/btree_int8.c b/contrib/btree_gist/btree_int8.c
index 91f2d032d1..16db0028b7 100644
--- a/contrib/btree_gist/btree_int8.c
+++ b/contrib/btree_gist/btree_int8.c
@@ -5,6 +5,7 @@
 
 #include "btree_gist.h"
 #include "btree_utils_num.h"
+#include "common/int.h"
 
 typedef struct int64key
 {
@@ -99,15 +100,14 @@ int8_dist(PG_FUNCTION_ARGS)
 	int64		r;
 	int64		ra;
 
-	r = a - b;
-	ra = Abs(r);
-
-	/* Overflow check. */
-	if (ra < 0 || (!SAMESIGN(a, b) && !SAMESIGN(r, a)))
+	if (pg_sub_s64_overflow(a, b, &r) ||
+		r == INT64_MIN)
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("bigint out of range")));
 
+	ra = Abs(r);
+
 	PG_RETURN_INT64(ra);
 }
 
diff --git a/contrib/btree_gist/btree_utils_num.h b/contrib/btree_gist/btree_utils_num.h
index 17561fa9e4..d7945f856c 100644
--- a/contrib/btree_gist/btree_utils_num.h
+++ b/contrib/btree_gist/btree_utils_num.h
@@ -89,8 +89,6 @@ typedef struct
 
 #define GET_FLOAT_DISTANCE(t, arg1, arg2)	Abs( ((float8) *((const t *) (arg1))) - ((float8) *((const t *) (arg2))) )
 
-#define SAMESIGN(a,b)	(((a) < 0) == ((b) < 0))
-
 /*
  * check to see if a float4/8 val has underflowed or overflowed
  * borrowed from src/backend/utils/adt/float.c
diff --git a/src/backend/utils/adt/array_userfuncs.c b/src/backend/utils/adt/array_userfuncs.c
index 87d79f3f98..bb70cba171 100644
--- a/src/backend/utils/adt/array_userfuncs.c
+++ b/src/backend/utils/adt/array_userfuncs.c
@@ -13,6 +13,7 @@
 #include "postgres.h"
 
 #include "catalog/pg_type.h"
+#include "common/int.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/lsyscache.h"
@@ -118,15 +119,11 @@ array_append(PG_FUNCTION_ARGS)
 	if (eah->ndims == 1)
 	{
 		/* append newelem */
-		int			ub;
-
 		lb = eah->lbound;
 		dimv = eah->dims;
-		ub = dimv[0] + lb[0] - 1;
-		indx = ub + 1;
 
-		/* overflow? */
-		if (indx < ub)
+		/* index of added elem is at lb[0] + (dimv[0] - 1) + 1 */
+		if (pg_add_s32_overflow(lb[0], dimv[0], &indx))
 			ereport(ERROR,
 					(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 					 errmsg("integer out of range")));
@@ -176,11 +173,9 @@ array_prepend(PG_FUNCTION_ARGS)
 	{
 		/* prepend newelem */
 		lb = eah->lbound;
-		indx = lb[0] - 1;
 		lb0 = lb[0];
 
-		/* overflow? */
-		if (indx > lb[0])
+		if (pg_sub_s32_overflow(lb0, 1, &indx))
 			ereport(ERROR,
 					(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 					 errmsg("integer out of range")));
diff --git a/src/backend/utils/adt/cash.c b/src/backend/utils/adt/cash.c
index 7bbc634bd2..c787dd3419 100644
--- a/src/backend/utils/adt/cash.c
+++ b/src/backend/utils/adt/cash.c
@@ -22,6 +22,7 @@
 #include <ctype.h>
 #include <math.h>
 
+#include "common/int.h"
 #include "libpq/pqformat.h"
 #include "utils/builtins.h"
 #include "utils/cash.h"
@@ -199,20 +200,21 @@ cash_in(PG_FUNCTION_ARGS)
 
 	for (; *s; s++)
 	{
-		/* we look for digits as long as we have found less */
-		/* than the required number of decimal places */
+		/*
+		 * We look for digits as long as we have found less than the required
+		 * number of decimal places.
+		 */
 		if (isdigit((unsigned char) *s) && (!seen_dot || dec < fpoint))
 		{
-			Cash		newvalue = (value * 10) - (*s - '0');
+			int8		digit = *s - '0';
 
-			if (newvalue / 10 != value)
+			if (pg_mul_s64_overflow(value, 10, &value) ||
+				pg_sub_s64_overflow(value, digit, &value))
 				ereport(ERROR,
 						(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 						 errmsg("value \"%s\" is out of range for type %s",
 								str, "money")));
 
-			value = newvalue;
-
 			if (seen_dot)
 				dec++;
 		}
@@ -230,26 +232,23 @@ cash_in(PG_FUNCTION_ARGS)
 
 	/* round off if there's another digit */
 	if (isdigit((unsigned char) *s) && *s >= '5')
-		value--;				/* remember we build the value in the negative */
-
-	if (value > 0)
-		ereport(ERROR,
-				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
-				 errmsg("value \"%s\" is out of range for type %s",
-						str, "money")));
-
-	/* adjust for less than required decimal places */
-	for (; dec < fpoint; dec++)
 	{
-		Cash		newvalue = value * 10;
-
-		if (newvalue / 10 != value)
+		/* remember we build the value in the negative */
+		if (pg_sub_s64_overflow(value, 1, &value))
 			ereport(ERROR,
 					(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 					 errmsg("value \"%s\" is out of range for type %s",
 							str, "money")));
+	}
 
-		value = newvalue;
+	/* adjust for less than required decimal places */
+	for (; dec < fpoint; dec++)
+	{
+		if (pg_mul_s64_overflow(value, 10, &value))
+			ereport(ERROR,
+					(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+					 errmsg("value \"%s\" is out of range for type %s",
+							str, "money")));
 	}
 
 	/*
@@ -285,12 +284,12 @@ cash_in(PG_FUNCTION_ARGS)
 	 */
 	if (sgn > 0)
 	{
-		result = -value;
-		if (result < 0)
+		if (value == PG_INT64_MIN)
 			ereport(ERROR,
 					(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 					 errmsg("value \"%s\" is out of range for type %s",
 							str, "money")));
+		result = -value;
 	}
 	else
 		result = value;
diff --git a/src/backend/utils/adt/float.c b/src/backend/utils/adt/float.c
index 18b3b949ac..be65aab1c9 100644
--- a/src/backend/utils/adt/float.c
+++ b/src/backend/utils/adt/float.c
@@ -20,6 +20,7 @@
 #include <limits.h>
 
 #include "catalog/pg_type.h"
+#include "common/int.h"
 #include "libpq/pqformat.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
@@ -3548,9 +3549,7 @@ width_bucket_float8(PG_FUNCTION_ARGS)
 			result = 0;
 		else if (operand >= bound2)
 		{
-			result = count + 1;
-			/* check for overflow */
-			if (result < count)
+			if (pg_add_s32_overflow(count, 1, &result))
 				ereport(ERROR,
 						(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 						 errmsg("integer out of range")));
@@ -3564,9 +3563,7 @@ width_bucket_float8(PG_FUNCTION_ARGS)
 			result = 0;
 		else if (operand <= bound2)
 		{
-			result = count + 1;
-			/* check for overflow */
-			if (result < count)
+			if (pg_add_s32_overflow(count, 1, &result))
 				ereport(ERROR,
 						(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 						 errmsg("integer out of range")));
diff --git a/src/backend/utils/adt/int.c b/src/backend/utils/adt/int.c
index 4cd8960b3f..36ba86ca73 100644
--- a/src/backend/utils/adt/int.c
+++ b/src/backend/utils/adt/int.c
@@ -32,14 +32,12 @@
 #include <limits.h>
 
 #include "catalog/pg_type.h"
+#include "common/int.h"
 #include "funcapi.h"
 #include "libpq/pqformat.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
 
-
-#define SAMESIGN(a,b)	(((a) < 0) == ((b) < 0))
-
 #define Int2VectorSize(n)	(offsetof(int2vector, values) + (n) * sizeof(int16))
 
 typedef struct
@@ -328,7 +326,7 @@ i4toi2(PG_FUNCTION_ARGS)
 {
 	int32		arg1 = PG_GETARG_INT32(0);
 
-	if (arg1 < SHRT_MIN || arg1 > SHRT_MAX)
+	if (unlikely(arg1 < SHRT_MIN) || unlikely(arg1 > SHRT_MAX))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("smallint out of range")));
@@ -598,15 +596,12 @@ Datum
 int4um(PG_FUNCTION_ARGS)
 {
 	int32		arg = PG_GETARG_INT32(0);
-	int32		result;
 
-	result = -arg;
-	/* overflow check (needed for INT_MIN) */
-	if (arg != 0 && SAMESIGN(result, arg))
+	if (unlikely(arg == PG_INT32_MIN))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("integer out of range")));
-	PG_RETURN_INT32(result);
+	PG_RETURN_INT32(-arg);
 }
 
 Datum
@@ -624,14 +619,7 @@ int4pl(PG_FUNCTION_ARGS)
 	int32		arg2 = PG_GETARG_INT32(1);
 	int32		result;
 
-	result = arg1 + arg2;
-
-	/*
-	 * Overflow check.  If the inputs are of different signs then their sum
-	 * cannot overflow.  If the inputs are of the same sign, their sum had
-	 * better be that sign too.
-	 */
-	if (SAMESIGN(arg1, arg2) && !SAMESIGN(result, arg1))
+	if (unlikely(pg_add_s32_overflow(arg1, arg2, &result)))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("integer out of range")));
@@ -645,14 +633,7 @@ int4mi(PG_FUNCTION_ARGS)
 	int32		arg2 = PG_GETARG_INT32(1);
 	int32		result;
 
-	result = arg1 - arg2;
-
-	/*
-	 * Overflow check.  If the inputs are of the same sign then their
-	 * difference cannot overflow.  If they are of different signs then the
-	 * result should be of the same sign as the first input.
-	 */
-	if (!SAMESIGN(arg1, arg2) && !SAMESIGN(result, arg1))
+	if (unlikely(pg_sub_s32_overflow(arg1, arg2, &result)))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("integer out of range")));
@@ -666,24 +647,7 @@ int4mul(PG_FUNCTION_ARGS)
 	int32		arg2 = PG_GETARG_INT32(1);
 	int32		result;
 
-	result = arg1 * arg2;
-
-	/*
-	 * Overflow check.  We basically check to see if result / arg2 gives arg1
-	 * again.  There are two cases where this fails: arg2 = 0 (which cannot
-	 * overflow) and arg1 = INT_MIN, arg2 = -1 (where the division itself will
-	 * overflow and thus incorrectly match).
-	 *
-	 * Since the division is likely much more expensive than the actual
-	 * multiplication, we'd like to skip it where possible.  The best bang for
-	 * the buck seems to be to check whether both inputs are in the int16
-	 * range; if so, no overflow is possible.
-	 */
-	if (!(arg1 >= (int32) SHRT_MIN && arg1 <= (int32) SHRT_MAX &&
-		  arg2 >= (int32) SHRT_MIN && arg2 <= (int32) SHRT_MAX) &&
-		arg2 != 0 &&
-		((arg2 == -1 && arg1 < 0 && result < 0) ||
-		 result / arg2 != arg1))
+	if (unlikely(pg_mul_s32_overflow(arg1, arg2, &result)))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("integer out of range")));
@@ -714,12 +678,11 @@ int4div(PG_FUNCTION_ARGS)
 	 */
 	if (arg2 == -1)
 	{
-		result = -arg1;
-		/* overflow check (needed for INT_MIN) */
-		if (arg1 != 0 && SAMESIGN(result, arg1))
+		if (unlikely(arg1 == PG_INT32_MIN))
 			ereport(ERROR,
 					(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 					 errmsg("integer out of range")));
+		result = -arg1;
 		PG_RETURN_INT32(result);
 	}
 
@@ -736,9 +699,7 @@ int4inc(PG_FUNCTION_ARGS)
 	int32		arg = PG_GETARG_INT32(0);
 	int32		result;
 
-	result = arg + 1;
-	/* Overflow check */
-	if (arg > 0 && result < 0)
+	if (unlikely(pg_add_s32_overflow(arg, 1, &result)))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("integer out of range")));
@@ -750,15 +711,12 @@ Datum
 int2um(PG_FUNCTION_ARGS)
 {
 	int16		arg = PG_GETARG_INT16(0);
-	int16		result;
 
-	result = -arg;
-	/* overflow check (needed for SHRT_MIN) */
-	if (arg != 0 && SAMESIGN(result, arg))
+	if (unlikely(arg == PG_INT16_MIN))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("smallint out of range")));
-	PG_RETURN_INT16(result);
+	PG_RETURN_INT16(-arg);
 }
 
 Datum
@@ -776,14 +734,7 @@ int2pl(PG_FUNCTION_ARGS)
 	int16		arg2 = PG_GETARG_INT16(1);
 	int16		result;
 
-	result = arg1 + arg2;
-
-	/*
-	 * Overflow check.  If the inputs are of different signs then their sum
-	 * cannot overflow.  If the inputs are of the same sign, their sum had
-	 * better be that sign too.
-	 */
-	if (SAMESIGN(arg1, arg2) && !SAMESIGN(result, arg1))
+	if (unlikely(pg_add_s16_overflow(arg1, arg2, &result)))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("smallint out of range")));
@@ -797,14 +748,7 @@ int2mi(PG_FUNCTION_ARGS)
 	int16		arg2 = PG_GETARG_INT16(1);
 	int16		result;
 
-	result = arg1 - arg2;
-
-	/*
-	 * Overflow check.  If the inputs are of the same sign then their
-	 * difference cannot overflow.  If they are of different signs then the
-	 * result should be of the same sign as the first input.
-	 */
-	if (!SAMESIGN(arg1, arg2) && !SAMESIGN(result, arg1))
+	if (unlikely(pg_sub_s16_overflow(arg1, arg2, &result)))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("smallint out of range")));
@@ -816,20 +760,14 @@ int2mul(PG_FUNCTION_ARGS)
 {
 	int16		arg1 = PG_GETARG_INT16(0);
 	int16		arg2 = PG_GETARG_INT16(1);
-	int32		result32;
+	int16		result;
 
-	/*
-	 * The most practical way to detect overflow is to do the arithmetic in
-	 * int32 (so that the result can't overflow) and then do a range check.
-	 */
-	result32 = (int32) arg1 * (int32) arg2;
-
-	if (result32 < SHRT_MIN || result32 > SHRT_MAX)
+	if (unlikely(pg_mul_s16_overflow(arg1, arg2, &result)))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("smallint out of range")));
 
-	PG_RETURN_INT16((int16) result32);
+	PG_RETURN_INT16(result);
 }
 
 Datum
@@ -856,12 +794,11 @@ int2div(PG_FUNCTION_ARGS)
 	 */
 	if (arg2 == -1)
 	{
-		result = -arg1;
-		/* overflow check (needed for SHRT_MIN) */
-		if (arg1 != 0 && SAMESIGN(result, arg1))
+		if (unlikely(arg1 == INT16_MIN))
 			ereport(ERROR,
 					(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 					 errmsg("smallint out of range")));
+		result = -arg1;
 		PG_RETURN_INT16(result);
 	}
 
@@ -879,14 +816,7 @@ int24pl(PG_FUNCTION_ARGS)
 	int32		arg2 = PG_GETARG_INT32(1);
 	int32		result;
 
-	result = arg1 + arg2;
-
-	/*
-	 * Overflow check.  If the inputs are of different signs then their sum
-	 * cannot overflow.  If the inputs are of the same sign, their sum had
-	 * better be that sign too.
-	 */
-	if (SAMESIGN(arg1, arg2) && !SAMESIGN(result, arg1))
+	if (unlikely(pg_add_s32_overflow((int32) arg1, arg2, &result)))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("integer out of range")));
@@ -900,14 +830,7 @@ int24mi(PG_FUNCTION_ARGS)
 	int32		arg2 = PG_GETARG_INT32(1);
 	int32		result;
 
-	result = arg1 - arg2;
-
-	/*
-	 * Overflow check.  If the inputs are of the same sign then their
-	 * difference cannot overflow.  If they are of different signs then the
-	 * result should be of the same sign as the first input.
-	 */
-	if (!SAMESIGN(arg1, arg2) && !SAMESIGN(result, arg1))
+	if (unlikely(pg_sub_s32_overflow((int32) arg1, arg2, &result)))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("integer out of range")));
@@ -921,20 +844,7 @@ int24mul(PG_FUNCTION_ARGS)
 	int32		arg2 = PG_GETARG_INT32(1);
 	int32		result;
 
-	result = arg1 * arg2;
-
-	/*
-	 * Overflow check.  We basically check to see if result / arg2 gives arg1
-	 * again.  There is one case where this fails: arg2 = 0 (which cannot
-	 * overflow).
-	 *
-	 * Since the division is likely much more expensive than the actual
-	 * multiplication, we'd like to skip it where possible.  The best bang for
-	 * the buck seems to be to check whether both inputs are in the int16
-	 * range; if so, no overflow is possible.
-	 */
-	if (!(arg2 >= (int32) SHRT_MIN && arg2 <= (int32) SHRT_MAX) &&
-		result / arg2 != arg1)
+	if (unlikely(pg_mul_s32_overflow((int32) arg1, arg2, &result)))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("integer out of range")));
@@ -947,7 +857,7 @@ int24div(PG_FUNCTION_ARGS)
 	int16		arg1 = PG_GETARG_INT16(0);
 	int32		arg2 = PG_GETARG_INT32(1);
 
-	if (arg2 == 0)
+	if (unlikely(arg2 == 0))
 	{
 		ereport(ERROR,
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
@@ -967,14 +877,7 @@ int42pl(PG_FUNCTION_ARGS)
 	int16		arg2 = PG_GETARG_INT16(1);
 	int32		result;
 
-	result = arg1 + arg2;
-
-	/*
-	 * Overflow check.  If the inputs are of different signs then their sum
-	 * cannot overflow.  If the inputs are of the same sign, their sum had
-	 * better be that sign too.
-	 */
-	if (SAMESIGN(arg1, arg2) && !SAMESIGN(result, arg1))
+	if (unlikely(pg_add_s32_overflow(arg1, (int32) arg2, &result)))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("integer out of range")));
@@ -988,14 +891,7 @@ int42mi(PG_FUNCTION_ARGS)
 	int16		arg2 = PG_GETARG_INT16(1);
 	int32		result;
 
-	result = arg1 - arg2;
-
-	/*
-	 * Overflow check.  If the inputs are of the same sign then their
-	 * difference cannot overflow.  If they are of different signs then the
-	 * result should be of the same sign as the first input.
-	 */
-	if (!SAMESIGN(arg1, arg2) && !SAMESIGN(result, arg1))
+	if (unlikely(pg_sub_s32_overflow(arg1, (int32) arg2, &result)))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("integer out of range")));
@@ -1009,20 +905,7 @@ int42mul(PG_FUNCTION_ARGS)
 	int16		arg2 = PG_GETARG_INT16(1);
 	int32		result;
 
-	result = arg1 * arg2;
-
-	/*
-	 * Overflow check.  We basically check to see if result / arg1 gives arg2
-	 * again.  There is one case where this fails: arg1 = 0 (which cannot
-	 * overflow).
-	 *
-	 * Since the division is likely much more expensive than the actual
-	 * multiplication, we'd like to skip it where possible.  The best bang for
-	 * the buck seems to be to check whether both inputs are in the int16
-	 * range; if so, no overflow is possible.
-	 */
-	if (!(arg1 >= (int32) SHRT_MIN && arg1 <= (int32) SHRT_MAX) &&
-		result / arg1 != arg2)
+	if (unlikely(pg_mul_s32_overflow(arg1, (int32) arg2, &result)))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("integer out of range")));
@@ -1036,7 +919,7 @@ int42div(PG_FUNCTION_ARGS)
 	int16		arg2 = PG_GETARG_INT16(1);
 	int32		result;
 
-	if (arg2 == 0)
+	if (unlikely(arg2 == 0))
 	{
 		ereport(ERROR,
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
@@ -1053,12 +936,11 @@ int42div(PG_FUNCTION_ARGS)
 	 */
 	if (arg2 == -1)
 	{
-		result = -arg1;
-		/* overflow check (needed for INT_MIN) */
-		if (arg1 != 0 && SAMESIGN(result, arg1))
+		if (unlikely(arg1 == PG_INT32_MIN))
 			ereport(ERROR,
 					(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 					 errmsg("integer out of range")));
+		result = -arg1;
 		PG_RETURN_INT32(result);
 	}
 
@@ -1075,7 +957,7 @@ int4mod(PG_FUNCTION_ARGS)
 	int32		arg1 = PG_GETARG_INT32(0);
 	int32		arg2 = PG_GETARG_INT32(1);
 
-	if (arg2 == 0)
+	if (unlikely(arg2 == 0))
 	{
 		ereport(ERROR,
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
@@ -1103,7 +985,7 @@ int2mod(PG_FUNCTION_ARGS)
 	int16		arg1 = PG_GETARG_INT16(0);
 	int16		arg2 = PG_GETARG_INT16(1);
 
-	if (arg2 == 0)
+	if (unlikely(arg2 == 0))
 	{
 		ereport(ERROR,
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
@@ -1136,12 +1018,11 @@ int4abs(PG_FUNCTION_ARGS)
 	int32		arg1 = PG_GETARG_INT32(0);
 	int32		result;
 
-	result = (arg1 < 0) ? -arg1 : arg1;
-	/* overflow check (needed for INT_MIN) */
-	if (result < 0)
+	if (unlikely(arg1 == INT32_MIN))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("integer out of range")));
+	result = (arg1 < 0) ? -arg1 : arg1;
 	PG_RETURN_INT32(result);
 }
 
@@ -1151,12 +1032,11 @@ int2abs(PG_FUNCTION_ARGS)
 	int16		arg1 = PG_GETARG_INT16(0);
 	int16		result;
 
-	result = (arg1 < 0) ? -arg1 : arg1;
-	/* overflow check (needed for SHRT_MIN) */
-	if (result < 0)
+	if (unlikely(arg1 == INT16_MIN))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("smallint out of range")));
+	result = (arg1 < 0) ? -arg1 : arg1;
 	PG_RETURN_INT16(result);
 }
 
@@ -1381,11 +1261,11 @@ generate_series_step_int4(PG_FUNCTION_ARGS)
 	if ((fctx->step > 0 && fctx->current <= fctx->finish) ||
 		(fctx->step < 0 && fctx->current >= fctx->finish))
 	{
-		/* increment current in preparation for next iteration */
-		fctx->current += fctx->step;
-
-		/* if next-value computation overflows, this is the final result */
-		if (SAMESIGN(result, fctx->step) && !SAMESIGN(result, fctx->current))
+		/*
+		 * Increment current in preparation for next iteration. If next-value
+		 * computation overflows, this is the final result.
+		 */
+		if (pg_add_s32_overflow(fctx->current, fctx->step, &fctx->current))
 			fctx->step = 0;
 
 		/* do when there is more left to send */
diff --git a/src/backend/utils/adt/int8.c b/src/backend/utils/adt/int8.c
index afa434cfee..bc8dad5c5d 100644
--- a/src/backend/utils/adt/int8.c
+++ b/src/backend/utils/adt/int8.c
@@ -17,6 +17,7 @@
 #include <limits.h>
 #include <math.h>
 
+#include "common/int.h"
 #include "funcapi.h"
 #include "libpq/pqformat.h"
 #include "utils/int8.h"
@@ -25,8 +26,6 @@
 
 #define MAXINT8LEN		25
 
-#define SAMESIGN(a,b)	(((a) < 0) == ((b) < 0))
-
 typedef struct
 {
 	int64		current;
@@ -56,11 +55,14 @@ scanint8(const char *str, bool errorOK, int64 *result)
 {
 	const char *ptr = str;
 	int64		tmp = 0;
-	int			sign = 1;
+	bool		neg = false;
 
 	/*
 	 * Do our own scan, rather than relying on sscanf which might be broken
 	 * for long long.
+	 *
+	 * As INT64_MIN can't be stored as a positive 64 bit integer, accumulate
+	 * value as a negative number.
 	 */
 
 	/* skip leading spaces */
@@ -71,72 +73,60 @@ scanint8(const char *str, bool errorOK, int64 *result)
 	if (*ptr == '-')
 	{
 		ptr++;
-
-		/*
-		 * Do an explicit check for INT64_MIN.  Ugly though this is, it's
-		 * cleaner than trying to get the loop below to handle it portably.
-		 */
-		if (strncmp(ptr, "9223372036854775808", 19) == 0)
-		{
-			tmp = PG_INT64_MIN;
-			ptr += 19;
-			goto gotdigits;
-		}
-		sign = -1;
+		neg = true;
 	}
 	else if (*ptr == '+')
 		ptr++;
 
 	/* require at least one digit */
-	if (!isdigit((unsigned char) *ptr))
+	if (unlikely(!isdigit((unsigned char) *ptr)))
 	{
-		if (errorOK)
-			return false;
-		else
-			ereport(ERROR,
-					(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
-					 errmsg("invalid input syntax for integer: \"%s\"",
-							str)));
+		goto invalid_syntax;
 	}
 
 	/* process digits */
 	while (*ptr && isdigit((unsigned char) *ptr))
 	{
-		int64		newtmp = tmp * 10 + (*ptr++ - '0');
+		int8		digit = (*ptr++ - '0');
 
-		if ((newtmp / 10) != tmp)	/* overflow? */
-		{
-			if (errorOK)
-				return false;
-			else
-				ereport(ERROR,
-						(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
-						 errmsg("value \"%s\" is out of range for type %s",
-								str, "bigint")));
-		}
-		tmp = newtmp;
+		if (unlikely(pg_mul_s64_overflow(tmp, 10, &tmp)) ||
+			unlikely(pg_sub_s64_overflow(tmp, digit, &tmp)))
+			goto out_of_range;
 	}
 
-gotdigits:
-
 	/* allow trailing whitespace, but not other trailing chars */
 	while (*ptr != '\0' && isspace((unsigned char) *ptr))
 		ptr++;
 
-	if (*ptr != '\0')
-	{
-		if (errorOK)
-			return false;
-		else
-			ereport(ERROR,
-					(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
-					 errmsg("invalid input syntax for integer: \"%s\"",
-							str)));
-	}
+	if (unlikely(*ptr != '\0'))
+		goto invalid_syntax;
 
-	*result = (sign < 0) ? -tmp : tmp;
+	if (!neg)
+	{
+		if (unlikely(tmp == INT64_MIN))
+			goto out_of_range;
+		tmp = -tmp;
+	}
+	*result = tmp;
 
 	return true;
+
+out_of_range:
+	if (errorOK)
+		return false;
+	else
+		ereport(ERROR,
+				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+				 errmsg("value \"%s\" is out of range for type %s",
+						str, "bigint")));
+invalid_syntax:
+	if (errorOK)
+		return false;
+	else
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+				 errmsg("invalid input syntax for integer: \"%s\"",
+						str)));
 }
 
 /* int8in()
@@ -492,12 +482,11 @@ int8um(PG_FUNCTION_ARGS)
 	int64		arg = PG_GETARG_INT64(0);
 	int64		result;
 
-	result = -arg;
-	/* overflow check (needed for INT64_MIN) */
-	if (arg != 0 && SAMESIGN(result, arg))
+	if (unlikely(arg == PG_INT64_MIN))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("bigint out of range")));
+	result = -arg;
 	PG_RETURN_INT64(result);
 }
 
@@ -516,14 +505,7 @@ int8pl(PG_FUNCTION_ARGS)
 	int64		arg2 = PG_GETARG_INT64(1);
 	int64		result;
 
-	result = arg1 + arg2;
-
-	/*
-	 * Overflow check.  If the inputs are of different signs then their sum
-	 * cannot overflow.  If the inputs are of the same sign, their sum had
-	 * better be that sign too.
-	 */
-	if (SAMESIGN(arg1, arg2) && !SAMESIGN(result, arg1))
+	if (unlikely(pg_add_s64_overflow(arg1, arg2, &result)))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("bigint out of range")));
@@ -537,14 +519,7 @@ int8mi(PG_FUNCTION_ARGS)
 	int64		arg2 = PG_GETARG_INT64(1);
 	int64		result;
 
-	result = arg1 - arg2;
-
-	/*
-	 * Overflow check.  If the inputs are of the same sign then their
-	 * difference cannot overflow.  If they are of different signs then the
-	 * result should be of the same sign as the first input.
-	 */
-	if (!SAMESIGN(arg1, arg2) && !SAMESIGN(result, arg1))
+	if (unlikely(pg_sub_s64_overflow(arg1, arg2, &result)))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("bigint out of range")));
@@ -558,28 +533,10 @@ int8mul(PG_FUNCTION_ARGS)
 	int64		arg2 = PG_GETARG_INT64(1);
 	int64		result;
 
-	result = arg1 * arg2;
-
-	/*
-	 * Overflow check.  We basically check to see if result / arg2 gives arg1
-	 * again.  There are two cases where this fails: arg2 = 0 (which cannot
-	 * overflow) and arg1 = INT64_MIN, arg2 = -1 (where the division itself
-	 * will overflow and thus incorrectly match).
-	 *
-	 * Since the division is likely much more expensive than the actual
-	 * multiplication, we'd like to skip it where possible.  The best bang for
-	 * the buck seems to be to check whether both inputs are in the int32
-	 * range; if so, no overflow is possible.
-	 */
-	if (arg1 != (int64) ((int32) arg1) || arg2 != (int64) ((int32) arg2))
-	{
-		if (arg2 != 0 &&
-			((arg2 == -1 && arg1 < 0 && result < 0) ||
-			 result / arg2 != arg1))
-			ereport(ERROR,
-					(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
-					 errmsg("bigint out of range")));
-	}
+	if (unlikely(pg_mul_s64_overflow(arg1, arg2, &result)))
+		ereport(ERROR,
+				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+				 errmsg("bigint out of range")));
 	PG_RETURN_INT64(result);
 }
 
@@ -607,12 +564,11 @@ int8div(PG_FUNCTION_ARGS)
 	 */
 	if (arg2 == -1)
 	{
-		result = -arg1;
-		/* overflow check (needed for INT64_MIN) */
-		if (arg1 != 0 && SAMESIGN(result, arg1))
+		if (unlikely(arg1 == INT64_MIN))
 			ereport(ERROR,
 					(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 					 errmsg("bigint out of range")));
+		result = -arg1;
 		PG_RETURN_INT64(result);
 	}
 
@@ -632,12 +588,11 @@ int8abs(PG_FUNCTION_ARGS)
 	int64		arg1 = PG_GETARG_INT64(0);
 	int64		result;
 
-	result = (arg1 < 0) ? -arg1 : arg1;
-	/* overflow check (needed for INT64_MIN) */
-	if (result < 0)
+	if (unlikely(arg1 == INT64_MIN))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("bigint out of range")));
+	result = (arg1 < 0) ? -arg1 : arg1;
 	PG_RETURN_INT64(result);
 }
 
@@ -650,7 +605,7 @@ int8mod(PG_FUNCTION_ARGS)
 	int64		arg1 = PG_GETARG_INT64(0);
 	int64		arg2 = PG_GETARG_INT64(1);
 
-	if (arg2 == 0)
+	if (unlikely(arg2 == 0))
 	{
 		ereport(ERROR,
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
@@ -687,16 +642,12 @@ int8inc(PG_FUNCTION_ARGS)
 	if (AggCheckCallContext(fcinfo, NULL))
 	{
 		int64	   *arg = (int64 *) PG_GETARG_POINTER(0);
-		int64		result;
 
-		result = *arg + 1;
-		/* Overflow check */
-		if (result < 0 && *arg > 0)
+		if (unlikely(pg_add_s64_overflow(*arg, 1, arg)))
 			ereport(ERROR,
 					(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 					 errmsg("bigint out of range")));
 
-		*arg = result;
 		PG_RETURN_POINTER(arg);
 	}
 	else
@@ -706,9 +657,7 @@ int8inc(PG_FUNCTION_ARGS)
 		int64		arg = PG_GETARG_INT64(0);
 		int64		result;
 
-		result = arg + 1;
-		/* Overflow check */
-		if (result < 0 && arg > 0)
+		if (unlikely(pg_add_s64_overflow(arg, 1, &result)))
 			ereport(ERROR,
 					(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 					 errmsg("bigint out of range")));
@@ -731,16 +680,11 @@ int8dec(PG_FUNCTION_ARGS)
 	if (AggCheckCallContext(fcinfo, NULL))
 	{
 		int64	   *arg = (int64 *) PG_GETARG_POINTER(0);
-		int64		result;
 
-		result = *arg - 1;
-		/* Overflow check */
-		if (result > 0 && *arg < 0)
+		if (unlikely(pg_sub_s64_overflow(*arg, 1, arg)))
 			ereport(ERROR,
 					(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 					 errmsg("bigint out of range")));
-
-		*arg = result;
 		PG_RETURN_POINTER(arg);
 	}
 	else
@@ -750,9 +694,7 @@ int8dec(PG_FUNCTION_ARGS)
 		int64		arg = PG_GETARG_INT64(0);
 		int64		result;
 
-		result = arg - 1;
-		/* Overflow check */
-		if (result > 0 && arg < 0)
+		if (unlikely(pg_sub_s64_overflow(arg, 1, &result)))
 			ereport(ERROR,
 					(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 					 errmsg("bigint out of range")));
@@ -821,14 +763,7 @@ int84pl(PG_FUNCTION_ARGS)
 	int32		arg2 = PG_GETARG_INT32(1);
 	int64		result;
 
-	result = arg1 + arg2;
-
-	/*
-	 * Overflow check.  If the inputs are of different signs then their sum
-	 * cannot overflow.  If the inputs are of the same sign, their sum had
-	 * better be that sign too.
-	 */
-	if (SAMESIGN(arg1, arg2) && !SAMESIGN(result, arg1))
+	if (unlikely(pg_add_s64_overflow(arg1, (int64) arg2, &result)))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("bigint out of range")));
@@ -842,14 +777,7 @@ int84mi(PG_FUNCTION_ARGS)
 	int32		arg2 = PG_GETARG_INT32(1);
 	int64		result;
 
-	result = arg1 - arg2;
-
-	/*
-	 * Overflow check.  If the inputs are of the same sign then their
-	 * difference cannot overflow.  If they are of different signs then the
-	 * result should be of the same sign as the first input.
-	 */
-	if (!SAMESIGN(arg1, arg2) && !SAMESIGN(result, arg1))
+	if (unlikely(pg_sub_s64_overflow(arg1, (int64) arg2, &result)))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("bigint out of range")));
@@ -863,20 +791,7 @@ int84mul(PG_FUNCTION_ARGS)
 	int32		arg2 = PG_GETARG_INT32(1);
 	int64		result;
 
-	result = arg1 * arg2;
-
-	/*
-	 * Overflow check.  We basically check to see if result / arg1 gives arg2
-	 * again.  There is one case where this fails: arg1 = 0 (which cannot
-	 * overflow).
-	 *
-	 * Since the division is likely much more expensive than the actual
-	 * multiplication, we'd like to skip it where possible.  The best bang for
-	 * the buck seems to be to check whether both inputs are in the int32
-	 * range; if so, no overflow is possible.
-	 */
-	if (arg1 != (int64) ((int32) arg1) &&
-		result / arg1 != arg2)
+	if (unlikely(pg_mul_s64_overflow(arg1, (int64) arg2, &result)))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("bigint out of range")));
@@ -907,12 +822,11 @@ int84div(PG_FUNCTION_ARGS)
 	 */
 	if (arg2 == -1)
 	{
-		result = -arg1;
-		/* overflow check (needed for INT64_MIN) */
-		if (arg1 != 0 && SAMESIGN(result, arg1))
+		if (unlikely(arg1 == INT64_MIN))
 			ereport(ERROR,
 					(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 					 errmsg("bigint out of range")));
+		result = -arg1;
 		PG_RETURN_INT64(result);
 	}
 
@@ -930,14 +844,7 @@ int48pl(PG_FUNCTION_ARGS)
 	int64		arg2 = PG_GETARG_INT64(1);
 	int64		result;
 
-	result = arg1 + arg2;
-
-	/*
-	 * Overflow check.  If the inputs are of different signs then their sum
-	 * cannot overflow.  If the inputs are of the same sign, their sum had
-	 * better be that sign too.
-	 */
-	if (SAMESIGN(arg1, arg2) && !SAMESIGN(result, arg1))
+	if (unlikely(pg_add_s64_overflow((int64) arg1, arg2, &result)))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("bigint out of range")));
@@ -951,14 +858,7 @@ int48mi(PG_FUNCTION_ARGS)
 	int64		arg2 = PG_GETARG_INT64(1);
 	int64		result;
 
-	result = arg1 - arg2;
-
-	/*
-	 * Overflow check.  If the inputs are of the same sign then their
-	 * difference cannot overflow.  If they are of different signs then the
-	 * result should be of the same sign as the first input.
-	 */
-	if (!SAMESIGN(arg1, arg2) && !SAMESIGN(result, arg1))
+	if (unlikely(pg_sub_s64_overflow((int64) arg1, arg2, &result)))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("bigint out of range")));
@@ -972,20 +872,7 @@ int48mul(PG_FUNCTION_ARGS)
 	int64		arg2 = PG_GETARG_INT64(1);
 	int64		result;
 
-	result = arg1 * arg2;
-
-	/*
-	 * Overflow check.  We basically check to see if result / arg2 gives arg1
-	 * again.  There is one case where this fails: arg2 = 0 (which cannot
-	 * overflow).
-	 *
-	 * Since the division is likely much more expensive than the actual
-	 * multiplication, we'd like to skip it where possible.  The best bang for
-	 * the buck seems to be to check whether both inputs are in the int32
-	 * range; if so, no overflow is possible.
-	 */
-	if (arg2 != (int64) ((int32) arg2) &&
-		result / arg2 != arg1)
+	if (unlikely(pg_mul_s64_overflow((int64) arg1, arg2, &result)))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("bigint out of range")));
@@ -998,7 +885,7 @@ int48div(PG_FUNCTION_ARGS)
 	int32		arg1 = PG_GETARG_INT32(0);
 	int64		arg2 = PG_GETARG_INT64(1);
 
-	if (arg2 == 0)
+	if (unlikely(arg2 == 0))
 	{
 		ereport(ERROR,
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
@@ -1018,14 +905,7 @@ int82pl(PG_FUNCTION_ARGS)
 	int16		arg2 = PG_GETARG_INT16(1);
 	int64		result;
 
-	result = arg1 + arg2;
-
-	/*
-	 * Overflow check.  If the inputs are of different signs then their sum
-	 * cannot overflow.  If the inputs are of the same sign, their sum had
-	 * better be that sign too.
-	 */
-	if (SAMESIGN(arg1, arg2) && !SAMESIGN(result, arg1))
+	if (unlikely(pg_add_s64_overflow(arg1, (int64) arg2, &result)))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("bigint out of range")));
@@ -1039,14 +919,7 @@ int82mi(PG_FUNCTION_ARGS)
 	int16		arg2 = PG_GETARG_INT16(1);
 	int64		result;
 
-	result = arg1 - arg2;
-
-	/*
-	 * Overflow check.  If the inputs are of the same sign then their
-	 * difference cannot overflow.  If they are of different signs then the
-	 * result should be of the same sign as the first input.
-	 */
-	if (!SAMESIGN(arg1, arg2) && !SAMESIGN(result, arg1))
+	if (unlikely(pg_sub_s64_overflow(arg1, (int64) arg2, &result)))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("bigint out of range")));
@@ -1060,20 +933,7 @@ int82mul(PG_FUNCTION_ARGS)
 	int16		arg2 = PG_GETARG_INT16(1);
 	int64		result;
 
-	result = arg1 * arg2;
-
-	/*
-	 * Overflow check.  We basically check to see if result / arg1 gives arg2
-	 * again.  There is one case where this fails: arg1 = 0 (which cannot
-	 * overflow).
-	 *
-	 * Since the division is likely much more expensive than the actual
-	 * multiplication, we'd like to skip it where possible.  The best bang for
-	 * the buck seems to be to check whether both inputs are in the int32
-	 * range; if so, no overflow is possible.
-	 */
-	if (arg1 != (int64) ((int32) arg1) &&
-		result / arg1 != arg2)
+	if (unlikely(pg_mul_s64_overflow(arg1, (int64) arg2, &result)))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("bigint out of range")));
@@ -1087,7 +947,7 @@ int82div(PG_FUNCTION_ARGS)
 	int16		arg2 = PG_GETARG_INT16(1);
 	int64		result;
 
-	if (arg2 == 0)
+	if (unlikely(arg2 == 0))
 	{
 		ereport(ERROR,
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
@@ -1104,12 +964,11 @@ int82div(PG_FUNCTION_ARGS)
 	 */
 	if (arg2 == -1)
 	{
-		result = -arg1;
-		/* overflow check (needed for INT64_MIN) */
-		if (arg1 != 0 && SAMESIGN(result, arg1))
+		if (unlikely(arg1 == INT64_MIN))
 			ereport(ERROR,
 					(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 					 errmsg("bigint out of range")));
+		result = -arg1;
 		PG_RETURN_INT64(result);
 	}
 
@@ -1127,14 +986,7 @@ int28pl(PG_FUNCTION_ARGS)
 	int64		arg2 = PG_GETARG_INT64(1);
 	int64		result;
 
-	result = arg1 + arg2;
-
-	/*
-	 * Overflow check.  If the inputs are of different signs then their sum
-	 * cannot overflow.  If the inputs are of the same sign, their sum had
-	 * better be that sign too.
-	 */
-	if (SAMESIGN(arg1, arg2) && !SAMESIGN(result, arg1))
+	if (unlikely(pg_add_s64_overflow((int64) arg1, arg2, &result)))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("bigint out of range")));
@@ -1148,14 +1000,7 @@ int28mi(PG_FUNCTION_ARGS)
 	int64		arg2 = PG_GETARG_INT64(1);
 	int64		result;
 
-	result = arg1 - arg2;
-
-	/*
-	 * Overflow check.  If the inputs are of the same sign then their
-	 * difference cannot overflow.  If they are of different signs then the
-	 * result should be of the same sign as the first input.
-	 */
-	if (!SAMESIGN(arg1, arg2) && !SAMESIGN(result, arg1))
+	if (unlikely(pg_sub_s64_overflow((int64) arg1, arg2, &result)))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("bigint out of range")));
@@ -1169,20 +1014,7 @@ int28mul(PG_FUNCTION_ARGS)
 	int64		arg2 = PG_GETARG_INT64(1);
 	int64		result;
 
-	result = arg1 * arg2;
-
-	/*
-	 * Overflow check.  We basically check to see if result / arg2 gives arg1
-	 * again.  There is one case where this fails: arg2 = 0 (which cannot
-	 * overflow).
-	 *
-	 * Since the division is likely much more expensive than the actual
-	 * multiplication, we'd like to skip it where possible.  The best bang for
-	 * the buck seems to be to check whether both inputs are in the int32
-	 * range; if so, no overflow is possible.
-	 */
-	if (arg2 != (int64) ((int32) arg2) &&
-		result / arg2 != arg1)
+	if (unlikely(pg_mul_s64_overflow((int64) arg1, arg2, &result)))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("bigint out of range")));
@@ -1195,7 +1027,7 @@ int28div(PG_FUNCTION_ARGS)
 	int16		arg1 = PG_GETARG_INT16(0);
 	int64		arg2 = PG_GETARG_INT64(1);
 
-	if (arg2 == 0)
+	if (unlikely(arg2 == 0))
 	{
 		ereport(ERROR,
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
@@ -1287,17 +1119,13 @@ Datum
 int84(PG_FUNCTION_ARGS)
 {
 	int64		arg = PG_GETARG_INT64(0);
-	int32		result;
 
-	result = (int32) arg;
-
-	/* Test for overflow by reverse-conversion. */
-	if ((int64) result != arg)
+	if (unlikely(arg < PG_INT32_MIN) || unlikely(arg > PG_INT32_MAX))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("integer out of range")));
 
-	PG_RETURN_INT32(result);
+	PG_RETURN_INT32((int32) arg);
 }
 
 Datum
@@ -1312,17 +1140,13 @@ Datum
 int82(PG_FUNCTION_ARGS)
 {
 	int64		arg = PG_GETARG_INT64(0);
-	int16		result;
 
-	result = (int16) arg;
-
-	/* Test for overflow by reverse-conversion. */
-	if ((int64) result != arg)
+	if (unlikely(arg < PG_INT16_MIN) || unlikely(arg > PG_INT16_MAX))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("smallint out of range")));
 
-	PG_RETURN_INT16(result);
+	PG_RETURN_INT16((int16) arg);
 }
 
 Datum
@@ -1348,18 +1172,15 @@ dtoi8(PG_FUNCTION_ARGS)
 	/* Round arg to nearest integer (but it's still in float form) */
 	arg = rint(arg);
 
-	/*
-	 * Does it fit in an int64?  Avoid assuming that we have handy constants
-	 * defined for the range boundaries, instead test for overflow by
-	 * reverse-conversion.
-	 */
-	result = (int64) arg;
-
-	if ((float8) result != arg)
+	if (unlikely(arg < (double) PG_INT64_MIN) ||
+		unlikely(arg > (double) PG_INT64_MAX) ||
+		unlikely(isnan(arg)))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("bigint out of range")));
 
+	result = (int64) arg;
+
 	PG_RETURN_INT64(result);
 }
 
@@ -1381,42 +1202,32 @@ Datum
 ftoi8(PG_FUNCTION_ARGS)
 {
 	float4		arg = PG_GETARG_FLOAT4(0);
-	int64		result;
 	float8		darg;
 
 	/* Round arg to nearest integer (but it's still in float form) */
 	darg = rint(arg);
 
-	/*
-	 * Does it fit in an int64?  Avoid assuming that we have handy constants
-	 * defined for the range boundaries, instead test for overflow by
-	 * reverse-conversion.
-	 */
-	result = (int64) darg;
-
-	if ((float8) result != darg)
+	if (unlikely(arg < (float4) PG_INT64_MIN) ||
+		unlikely(arg > (float4) PG_INT64_MAX) ||
+		unlikely(isnan(arg)))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("bigint out of range")));
 
-	PG_RETURN_INT64(result);
+	PG_RETURN_INT64((int64) darg);
 }
 
 Datum
 i8tooid(PG_FUNCTION_ARGS)
 {
 	int64		arg = PG_GETARG_INT64(0);
-	Oid			result;
 
-	result = (Oid) arg;
-
-	/* Test for overflow by reverse-conversion. */
-	if ((int64) result != arg)
+	if (unlikely(arg < 0) || unlikely(arg > PG_UINT32_MAX))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("OID out of range")));
 
-	PG_RETURN_OID(result);
+	PG_RETURN_OID((Oid) arg);
 }
 
 Datum
@@ -1494,11 +1305,11 @@ generate_series_step_int8(PG_FUNCTION_ARGS)
 	if ((fctx->step > 0 && fctx->current <= fctx->finish) ||
 		(fctx->step < 0 && fctx->current >= fctx->finish))
 	{
-		/* increment current in preparation for next iteration */
-		fctx->current += fctx->step;
-
-		/* if next-value computation overflows, this is the final result */
-		if (SAMESIGN(result, fctx->step) && !SAMESIGN(result, fctx->current))
+		/*
+		 * Increment current in preparation for next iteration. If next-value
+		 * computation overflows, this is the final result.
+		 */
+		if (pg_add_s64_overflow(fctx->current, fctx->step, &fctx->current))
 			fctx->step = 0;
 
 		/* do when there is more left to send */
diff --git a/src/backend/utils/adt/numeric.c b/src/backend/utils/adt/numeric.c
index 82e6f4483b..e9a6ca3535 100644
--- a/src/backend/utils/adt/numeric.c
+++ b/src/backend/utils/adt/numeric.c
@@ -28,6 +28,7 @@
 
 #include "access/hash.h"
 #include "catalog/pg_type.h"
+#include "common/int.h"
 #include "funcapi.h"
 #include "lib/hyperloglog.h"
 #include "libpq/pqformat.h"
@@ -6169,8 +6170,7 @@ numericvar_to_int64(const NumericVar *var, int64 *result)
 	int			ndigits;
 	int			weight;
 	int			i;
-	int64		val,
-				oldval;
+	int64		val;
 	bool		neg;
 	NumericVar	rounded;
 
@@ -6196,27 +6196,25 @@ numericvar_to_int64(const NumericVar *var, int64 *result)
 	weight = rounded.weight;
 	Assert(weight >= 0 && ndigits <= weight + 1);
 
-	/* Construct the result */
+	/*
+	 * Construct the result. To avoid issues with converting a value
+	 * corresponding to INT64_MIN (which can't be represented as a positive 64
+	 * bit two's complement integer), accumulate value as a negative number.
+	 */
 	digits = rounded.digits;
 	neg = (rounded.sign == NUMERIC_NEG);
-	val = digits[0];
+	val = -digits[0];
 	for (i = 1; i <= weight; i++)
 	{
-		oldval = val;
-		val *= NBASE;
-		if (i < ndigits)
-			val += digits[i];
-
-		/*
-		 * The overflow check is a bit tricky because we want to accept
-		 * INT64_MIN, which will overflow the positive accumulator.  We can
-		 * detect this case easily though because INT64_MIN is the only
-		 * nonzero value for which -val == val (on a two's complement machine,
-		 * anyway).
-		 */
-		if ((val / NBASE) != oldval)	/* possible overflow? */
+		if (unlikely(pg_mul_s64_overflow(val, NBASE, &val)))
 		{
-			if (!neg || (-val) != val || val == 0 || oldval < 0)
+			free_var(&rounded);
+			return false;
+		}
+
+		if (i < ndigits)
+		{
+			if (unlikely(pg_sub_s64_overflow(val, digits[i], &val)))
 			{
 				free_var(&rounded);
 				return false;
@@ -6226,7 +6224,14 @@ numericvar_to_int64(const NumericVar *var, int64 *result)
 
 	free_var(&rounded);
 
-	*result = neg ? -val : val;
+	if (!neg)
+	{
+		if (unlikely(val == INT64_MIN))
+			return false;
+		val = -val;
+	}
+	*result = val;
+
 	return true;
 }
 
diff --git a/src/backend/utils/adt/oracle_compat.c b/src/backend/utils/adt/oracle_compat.c
index b82016500b..a5aa6a95aa 100644
--- a/src/backend/utils/adt/oracle_compat.c
+++ b/src/backend/utils/adt/oracle_compat.c
@@ -15,6 +15,7 @@
  */
 #include "postgres.h"
 
+#include "common/int.h"
 #include "utils/builtins.h"
 #include "utils/formatting.h"
 #include "mb/pg_wchar.h"
@@ -1045,19 +1046,12 @@ repeat(PG_FUNCTION_ARGS)
 		count = 0;
 
 	slen = VARSIZE_ANY_EXHDR(string);
-	tlen = VARHDRSZ + (count * slen);
 
-	/* Check for integer overflow */
-	if (slen != 0 && count != 0)
-	{
-		int			check = count * slen;
-		int			check2 = check + VARHDRSZ;
-
-		if ((check / slen) != count || check2 <= check)
-			ereport(ERROR,
-					(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
-					 errmsg("requested length too large")));
-	}
+	if (unlikely(pg_mul_s32_overflow(count, slen, &tlen)) ||
+		unlikely(pg_add_s32_overflow(tlen, VARHDRSZ, &tlen)))
+		ereport(ERROR,
+				(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+				 errmsg("requested length too large")));
 
 	result = (text *) palloc(tlen);
 
diff --git a/src/backend/utils/adt/varbit.c b/src/backend/utils/adt/varbit.c
index 478fab9bfc..6caa7e9b5e 100644
--- a/src/backend/utils/adt/varbit.c
+++ b/src/backend/utils/adt/varbit.c
@@ -17,6 +17,7 @@
 #include "postgres.h"
 
 #include "access/htup_details.h"
+#include "common/int.h"
 #include "libpq/pqformat.h"
 #include "nodes/nodeFuncs.h"
 #include "utils/array.h"
@@ -1166,8 +1167,7 @@ bit_overlay(VarBit *t1, VarBit *t2, int sp, int sl)
 		ereport(ERROR,
 				(errcode(ERRCODE_SUBSTRING_ERROR),
 				 errmsg("negative substring length not allowed")));
-	sp_pl_sl = sp + sl;
-	if (sp_pl_sl <= sl)
+	if (pg_add_s32_overflow(sp, sl, &sp_pl_sl))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("integer out of range")));
diff --git a/src/backend/utils/adt/varlena.c b/src/backend/utils/adt/varlena.c
index 39b68dbc65..a84e845ad2 100644
--- a/src/backend/utils/adt/varlena.c
+++ b/src/backend/utils/adt/varlena.c
@@ -21,6 +21,7 @@
 #include "access/tuptoaster.h"
 #include "catalog/pg_collation.h"
 #include "catalog/pg_type.h"
+#include "common/int.h"
 #include "common/md5.h"
 #include "lib/hyperloglog.h"
 #include "libpq/pqformat.h"
@@ -1047,8 +1048,7 @@ text_overlay(text *t1, text *t2, int sp, int sl)
 		ereport(ERROR,
 				(errcode(ERRCODE_SUBSTRING_ERROR),
 				 errmsg("negative substring length not allowed")));
-	sp_pl_sl = sp + sl;
-	if (sp_pl_sl <= sl)
+	if (pg_add_s32_overflow(sp, sl, &sp_pl_sl))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("integer out of range")));
@@ -2950,8 +2950,7 @@ bytea_overlay(bytea *t1, bytea *t2, int sp, int sl)
 		ereport(ERROR,
 				(errcode(ERRCODE_SUBSTRING_ERROR),
 				 errmsg("negative substring length not allowed")));
-	sp_pl_sl = sp + sl;
-	if (sp_pl_sl <= sl)
+	if (pg_add_s32_overflow(sp, sl, &sp_pl_sl))
 		ereport(ERROR,
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("integer out of range")));
@@ -5279,13 +5278,13 @@ text_format_parse_digits(const char **ptr, const char *end_ptr, int *value)
 
 	while (*cp >= '0' && *cp <= '9')
 	{
-		int			newval = val * 10 + (*cp - '0');
+		int8		digit = (*cp - '0');
 
-		if (newval / 10 != val) /* overflow? */
+		if (unlikely(pg_mul_s32_overflow(val, 10, &val)) ||
+			unlikely(pg_add_s32_overflow(val, digit, &val)))
 			ereport(ERROR,
 					(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 					 errmsg("number is out of range")));
-		val = newval;
 		ADVANCE_PARSE_POINTER(cp, end_ptr);
 		found = true;
 	}