diff --git a/arch/arm/src/efm32/efm32_irq.c b/arch/arm/src/efm32/efm32_irq.c
index 63a82b194ca..db5992dea7b 100644
--- a/arch/arm/src/efm32/efm32_irq.c
+++ b/arch/arm/src/efm32/efm32_irq.c
@@ -93,10 +93,6 @@ volatile uint32_t *g_current_regs[1];
 
 extern uint32_t _vectors[];
 
-/****************************************************************************
- * Private Data
- ****************************************************************************/
-
 /****************************************************************************
  * Private Functions
  ****************************************************************************/
@@ -261,15 +257,9 @@ static int efm32_irqinfo(int irq, uintptr_t *regaddr, uint32_t *bit,
     {
       if (irq < NR_VECTORS)
         {
-          n = irq - EFM32_IRQ_INTERRUPTS;
+          n        = irq - EFM32_IRQ_INTERRUPTS;
           *regaddr = NVIC_IRQ_ENABLE(n) + offset;
-
-          while (n >= 32)
-            {
-              n -= 32;
-            }
-
-          *bit     = 1 << n;
+          *bit     = (uint32_t)1 << (n & 0x1f);
         }
       else
         {
diff --git a/arch/arm/src/lpc43xx/lpc43_irq.c b/arch/arm/src/lpc43xx/lpc43_irq.c
index 26881472c8d..09680bd9e91 100644
--- a/arch/arm/src/lpc43xx/lpc43_irq.c
+++ b/arch/arm/src/lpc43xx/lpc43_irq.c
@@ -91,10 +91,6 @@ volatile uint32_t *g_current_regs[1];
 
 extern uint32_t _vectors[];
 
-/****************************************************************************
- * Private Data
- ****************************************************************************/
-
 /****************************************************************************
  * Private Functions
  ****************************************************************************/
@@ -250,15 +246,9 @@ static int lpc43_irqinfo(int irq, uintptr_t *regaddr, uint32_t *bit,
 
   if (irq >= LPC43_IRQ_EXTINT)
     {
-      n = irq - LPC43_IRQ_EXTINT;
+      n        = irq - LPC43_IRQ_EXTINT;
       *regaddr = NVIC_IRQ_ENABLE(n) + offset;
-
-      while (n >= 32)
-        {
-          n -= 32;
-        }
-
-      *bit     = 1 << n;
+      *bit     = (uint32_t)1 << (n & 0x1f);
     }
 
   /* Handle processor exceptions.  Only a few can be disabled */
diff --git a/arch/arm/src/stm32/stm32_exti_alarm.c b/arch/arm/src/stm32/stm32_exti_alarm.c
index f38574f2523..2e6d582a4aa 100644
--- a/arch/arm/src/stm32/stm32_exti_alarm.c
+++ b/arch/arm/src/stm32/stm32_exti_alarm.c
@@ -53,10 +53,6 @@
 #include "stm32_gpio.h"
 #include "stm32_exti.h"
 
-/****************************************************************************
- * Pre-processor Definitions
- ****************************************************************************/
-
 /****************************************************************************
  * Private Data
  ****************************************************************************/
@@ -65,10 +61,6 @@
 
 static xcpt_t stm32_exti_callback;
 
-/****************************************************************************
- * Public Data
- ****************************************************************************/
-
 /****************************************************************************
  * Private Functions
  ****************************************************************************/
diff --git a/arch/arm/src/stm32/stm32_irq.c b/arch/arm/src/stm32/stm32_irq.c
index ea7c4ddfcbe..ff40bf8d033 100644
--- a/arch/arm/src/stm32/stm32_irq.c
+++ b/arch/arm/src/stm32/stm32_irq.c
@@ -253,15 +253,9 @@ static int stm32_irqinfo(int irq, uintptr_t *regaddr, uint32_t *bit,
 
   if (irq >= STM32_IRQ_FIRST)
     {
-      n = irq - STM32_IRQ_FIRST;
+      n        = irq - STM32_IRQ_FIRST;
       *regaddr = NVIC_IRQ_ENABLE(n) + offset;
-
-      while (n >= 32)
-        {
-          n -= 32;
-        }
-
-      *bit     = 1 << n;
+      *bit     = (uint32_t)1 << (n & 0x1f);
     }
 
   /* Handle processor exceptions.  Only a few can be disabled */
diff --git a/arch/arm/src/stm32l4/stm32l4_irq.c b/arch/arm/src/stm32l4/stm32l4_irq.c
index 8e90bf0fa8a..7376b146753 100644
--- a/arch/arm/src/stm32l4/stm32l4_irq.c
+++ b/arch/arm/src/stm32l4/stm32l4_irq.c
@@ -1,8 +1,7 @@
 /****************************************************************************
  * arch/arm/src/stm32l4/stm32l4_irq.c
- * arch/arm/src/chip/stm32l4_irq.c
  *
- *   Copyright (C) 2009-2015 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2009-2016 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -90,10 +89,6 @@ volatile uint32_t *g_current_regs[1];
 
 extern uint32_t _vectors[];
 
-/****************************************************************************
- * Private Data
- ****************************************************************************/
-
 /****************************************************************************
  * Private Functions
  ****************************************************************************/
@@ -254,13 +249,7 @@ static int stm32l4_irqinfo(int irq, uintptr_t *regaddr, uint32_t *bit,
     {
       n = irq - STM32L4_IRQ_FIRST;
       *regaddr = NVIC_IRQ_ENABLE(n) + offset;
-
-      while (n >= 32)
-        {
-          n -= 32;
-        }
-
-      *bit     = 1 << n;
+      *bit     = (uint32_t)1 << (n & 0x1f);
     }
 
   /* Handle processor exceptions.  Only a few can be disabled */