diff --git a/src/devices/cpu/e132xs/e132xs.h b/src/devices/cpu/e132xs/e132xs.h
index 3c27a39d737..51f9c5cc3c1 100644
--- a/src/devices/cpu/e132xs/e132xs.h
+++ b/src/devices/cpu/e132xs/e132xs.h
@@ -337,6 +337,10 @@ private:
 
 	uint32_t get_global_register(uint8_t code);
 
+	// words interpreted as pairs of signed half-words (HS)
+	static int get_lhs(uint32_t val) { return int16_t(val & 0xffff); }
+	static int get_rhs(uint32_t val) { return int16_t(val >> 16); }
+
 	uint32_t get_emu_code_addr(uint8_t num);
 	int32_t get_instruction_length(uint16_t op);
 
diff --git a/src/devices/cpu/e132xs/e132xsop.hxx b/src/devices/cpu/e132xs/e132xsop.hxx
index 953e82f4150..03a35898a9d 100644
--- a/src/devices/cpu/e132xs/e132xsop.hxx
+++ b/src/devices/cpu/e132xs/e132xsop.hxx
@@ -2264,27 +2264,27 @@ void hyperstone_device::hyperstone_extend()
 
 		// signed half-word multiply/add, single word product sum
 		case EHMAC:
-			m_core->global_regs[15] = (int32_t)m_core->global_regs[15] + mul_16x16(vald >> 16, vals >> 16) + mul_16x16(vald & 0xffff, vals & 0xffff);
+			m_core->global_regs[15] = m_core->global_regs[15] + get_lhs(vald) * get_lhs(vals) + get_rhs(vald) * get_rhs(vals);
 			break;
 
 		// signed half-word multiply/add, double word product sum
 		case EHMACD:
 		{
-			int64_t result = get_double_word<GLOBAL>(14, 15) + (int64_t)mul_16x16(vald >> 16, vals >> 16) + (int64_t)mul_16x16(vald & 0xffff, vals & 0xffff);
+			int64_t result = get_double_word<GLOBAL>(14, 15) + int64_t(get_lhs(vald) * get_lhs(vals)) + int64_t(get_rhs(vald) * get_rhs(vals));
 			set_double_word<GLOBAL>(14, 15, result);
 			break;
 		}
 
 		// half-word complex multiply
 		case EHCMULD:
-			m_core->global_regs[14] = mul_16x16(vald >> 16, vals >> 16    ) - mul_16x16(vald & 0xffff, vals & 0xffff);
-			m_core->global_regs[15] = mul_16x16(vald >> 16, vals &  0xffff) + mul_16x16(vald & 0xffff, vals >> 16   );
+			m_core->global_regs[14] = get_lhs(vald) * get_lhs(vals) - get_rhs(vald) * get_rhs(vals);
+			m_core->global_regs[15] = get_lhs(vald) * get_rhs(vals) + get_rhs(vald) * get_lhs(vals);
 			break;
 
 		// half-word complex multiply/add
 		case EHCMACD:
-			m_core->global_regs[14] += mul_16x16(vald >> 16, vals >> 16    ) - mul_16x16(vald & 0xffff, vals &  0xffff);
-			m_core->global_regs[15] += mul_16x16(vald >> 16, vals &  0xffff) + mul_16x16(vald & 0xffff, vals >> 16    );
+			m_core->global_regs[14] += get_lhs(vald) * get_lhs(vals) - get_rhs(vald) * get_rhs(vals);
+			m_core->global_regs[15] += get_lhs(vald) * get_rhs(vals) + get_rhs(vald) * get_lhs(vals);
 			break;
 
 		// half-word (complex) add/subtract
diff --git a/src/osd/eminline.h b/src/osd/eminline.h
index 685025416b9..4d4ccb25237 100644
--- a/src/osd/eminline.h
+++ b/src/osd/eminline.h
@@ -50,19 +50,6 @@
     INLINE MATH FUNCTIONS
 ***************************************************************************/
 
-/*-------------------------------------------------
-    mul_16x16 - perform a signed 16 bit x 16 bit
-    multiply and return the full 32 bit result
--------------------------------------------------*/
-
-#ifndef mul_16x16
-constexpr int32_t mul_16x16(int16_t a, int16_t b)
-{
-	return int32_t(a) * int32_t(b);
-}
-#endif
-
-
 /*-------------------------------------------------
     mul_32x32 - perform a signed 32 bit x 32 bit
     multiply and return the full 64 bit result