diff --git a/libgfortran/ChangeLog b/libgfortran/ChangeLog
index 93e9117d9569..15b9f94314be 100644
--- a/libgfortran/ChangeLog
+++ b/libgfortran/ChangeLog
@@ -1,3 +1,21 @@
+2012-04-10  Michael Matz  <matz@suse.de>
+
+	* m4/cshift0.m4 (cshift0_'rtype_code`): Guard use of modulo.
+
+	* generated/cshift0_c10.c: Regenerated.
+	* generated/cshift0_c16.c: Regenerated.
+	* generated/cshift0_c4.c: Regenerated.
+	* generated/cshift0_c8.c: Regenerated.
+	* generated/cshift0_i16.c: Regenerated.
+	* generated/cshift0_i1.c: Regenerated.
+	* generated/cshift0_i2.c: Regenerated.
+	* generated/cshift0_i4.c: Regenerated.
+	* generated/cshift0_i8.c: Regenerated.
+	* generated/cshift0_r10.c: Regenerated.
+	* generated/cshift0_r16.c: Regenerated.
+	* generated/cshift0_r4.c: Regenerated.
+	* generated/cshift0_r8.c: Regenerated.
+
 2012-04-04  Tristan Gingold  <gingold@adacore.com>
 
 	* libgfortran.h: Include complex.h before math.h
diff --git a/libgfortran/generated/cshift0_c10.c b/libgfortran/generated/cshift0_c10.c
index 43e173bf417d..ba27a9ed4aea 100644
--- a/libgfortran/generated/cshift0_c10.c
+++ b/libgfortran/generated/cshift0_c10.c
@@ -97,9 +97,13 @@ cshift0_c10 (gfc_array_c10 *ret, const gfc_array_c10 *array, ptrdiff_t shift,
   rptr = ret->base_addr;
   sptr = array->base_addr;
 
-  shift = len == 0 ? 0 : shift % (ptrdiff_t)len;
-  if (shift < 0)
-    shift += len;
+  /* Avoid the costly modulo for trivially in-bound shifts.  */
+  if (shift < 0 || shift >= len)
+    {
+      shift = len == 0 ? 0 : shift % (ptrdiff_t)len;
+      if (shift < 0)
+	shift += len;
+    }
 
   while (rptr)
     {
diff --git a/libgfortran/generated/cshift0_c16.c b/libgfortran/generated/cshift0_c16.c
index f1f2539bc771..0cdc6dc31e94 100644
--- a/libgfortran/generated/cshift0_c16.c
+++ b/libgfortran/generated/cshift0_c16.c
@@ -97,9 +97,13 @@ cshift0_c16 (gfc_array_c16 *ret, const gfc_array_c16 *array, ptrdiff_t shift,
   rptr = ret->base_addr;
   sptr = array->base_addr;
 
-  shift = len == 0 ? 0 : shift % (ptrdiff_t)len;
-  if (shift < 0)
-    shift += len;
+  /* Avoid the costly modulo for trivially in-bound shifts.  */
+  if (shift < 0 || shift >= len)
+    {
+      shift = len == 0 ? 0 : shift % (ptrdiff_t)len;
+      if (shift < 0)
+	shift += len;
+    }
 
   while (rptr)
     {
diff --git a/libgfortran/generated/cshift0_c4.c b/libgfortran/generated/cshift0_c4.c
index bf8554e1abef..176137770467 100644
--- a/libgfortran/generated/cshift0_c4.c
+++ b/libgfortran/generated/cshift0_c4.c
@@ -97,9 +97,13 @@ cshift0_c4 (gfc_array_c4 *ret, const gfc_array_c4 *array, ptrdiff_t shift,
   rptr = ret->base_addr;
   sptr = array->base_addr;
 
-  shift = len == 0 ? 0 : shift % (ptrdiff_t)len;
-  if (shift < 0)
-    shift += len;
+  /* Avoid the costly modulo for trivially in-bound shifts.  */
+  if (shift < 0 || shift >= len)
+    {
+      shift = len == 0 ? 0 : shift % (ptrdiff_t)len;
+      if (shift < 0)
+	shift += len;
+    }
 
   while (rptr)
     {
diff --git a/libgfortran/generated/cshift0_c8.c b/libgfortran/generated/cshift0_c8.c
index e3fd5b66e22b..e4534885d1b5 100644
--- a/libgfortran/generated/cshift0_c8.c
+++ b/libgfortran/generated/cshift0_c8.c
@@ -97,9 +97,13 @@ cshift0_c8 (gfc_array_c8 *ret, const gfc_array_c8 *array, ptrdiff_t shift,
   rptr = ret->base_addr;
   sptr = array->base_addr;
 
-  shift = len == 0 ? 0 : shift % (ptrdiff_t)len;
-  if (shift < 0)
-    shift += len;
+  /* Avoid the costly modulo for trivially in-bound shifts.  */
+  if (shift < 0 || shift >= len)
+    {
+      shift = len == 0 ? 0 : shift % (ptrdiff_t)len;
+      if (shift < 0)
+	shift += len;
+    }
 
   while (rptr)
     {
diff --git a/libgfortran/generated/cshift0_i1.c b/libgfortran/generated/cshift0_i1.c
index f2315de95fa6..76c30efbd587 100644
--- a/libgfortran/generated/cshift0_i1.c
+++ b/libgfortran/generated/cshift0_i1.c
@@ -97,9 +97,13 @@ cshift0_i1 (gfc_array_i1 *ret, const gfc_array_i1 *array, ptrdiff_t shift,
   rptr = ret->base_addr;
   sptr = array->base_addr;
 
-  shift = len == 0 ? 0 : shift % (ptrdiff_t)len;
-  if (shift < 0)
-    shift += len;
+  /* Avoid the costly modulo for trivially in-bound shifts.  */
+  if (shift < 0 || shift >= len)
+    {
+      shift = len == 0 ? 0 : shift % (ptrdiff_t)len;
+      if (shift < 0)
+	shift += len;
+    }
 
   while (rptr)
     {
diff --git a/libgfortran/generated/cshift0_i16.c b/libgfortran/generated/cshift0_i16.c
index 7566042c8fb6..b11430320213 100644
--- a/libgfortran/generated/cshift0_i16.c
+++ b/libgfortran/generated/cshift0_i16.c
@@ -97,9 +97,13 @@ cshift0_i16 (gfc_array_i16 *ret, const gfc_array_i16 *array, ptrdiff_t shift,
   rptr = ret->base_addr;
   sptr = array->base_addr;
 
-  shift = len == 0 ? 0 : shift % (ptrdiff_t)len;
-  if (shift < 0)
-    shift += len;
+  /* Avoid the costly modulo for trivially in-bound shifts.  */
+  if (shift < 0 || shift >= len)
+    {
+      shift = len == 0 ? 0 : shift % (ptrdiff_t)len;
+      if (shift < 0)
+	shift += len;
+    }
 
   while (rptr)
     {
diff --git a/libgfortran/generated/cshift0_i2.c b/libgfortran/generated/cshift0_i2.c
index 4a8154c4c55c..0f510f854c93 100644
--- a/libgfortran/generated/cshift0_i2.c
+++ b/libgfortran/generated/cshift0_i2.c
@@ -97,9 +97,13 @@ cshift0_i2 (gfc_array_i2 *ret, const gfc_array_i2 *array, ptrdiff_t shift,
   rptr = ret->base_addr;
   sptr = array->base_addr;
 
-  shift = len == 0 ? 0 : shift % (ptrdiff_t)len;
-  if (shift < 0)
-    shift += len;
+  /* Avoid the costly modulo for trivially in-bound shifts.  */
+  if (shift < 0 || shift >= len)
+    {
+      shift = len == 0 ? 0 : shift % (ptrdiff_t)len;
+      if (shift < 0)
+	shift += len;
+    }
 
   while (rptr)
     {
diff --git a/libgfortran/generated/cshift0_i4.c b/libgfortran/generated/cshift0_i4.c
index 7d25b7b0200d..d75b4d6b475f 100644
--- a/libgfortran/generated/cshift0_i4.c
+++ b/libgfortran/generated/cshift0_i4.c
@@ -97,9 +97,13 @@ cshift0_i4 (gfc_array_i4 *ret, const gfc_array_i4 *array, ptrdiff_t shift,
   rptr = ret->base_addr;
   sptr = array->base_addr;
 
-  shift = len == 0 ? 0 : shift % (ptrdiff_t)len;
-  if (shift < 0)
-    shift += len;
+  /* Avoid the costly modulo for trivially in-bound shifts.  */
+  if (shift < 0 || shift >= len)
+    {
+      shift = len == 0 ? 0 : shift % (ptrdiff_t)len;
+      if (shift < 0)
+	shift += len;
+    }
 
   while (rptr)
     {
diff --git a/libgfortran/generated/cshift0_i8.c b/libgfortran/generated/cshift0_i8.c
index 2f565caeedef..4154eb29ef35 100644
--- a/libgfortran/generated/cshift0_i8.c
+++ b/libgfortran/generated/cshift0_i8.c
@@ -97,9 +97,13 @@ cshift0_i8 (gfc_array_i8 *ret, const gfc_array_i8 *array, ptrdiff_t shift,
   rptr = ret->base_addr;
   sptr = array->base_addr;
 
-  shift = len == 0 ? 0 : shift % (ptrdiff_t)len;
-  if (shift < 0)
-    shift += len;
+  /* Avoid the costly modulo for trivially in-bound shifts.  */
+  if (shift < 0 || shift >= len)
+    {
+      shift = len == 0 ? 0 : shift % (ptrdiff_t)len;
+      if (shift < 0)
+	shift += len;
+    }
 
   while (rptr)
     {
diff --git a/libgfortran/generated/cshift0_r10.c b/libgfortran/generated/cshift0_r10.c
index b7f21caffb24..14be68321233 100644
--- a/libgfortran/generated/cshift0_r10.c
+++ b/libgfortran/generated/cshift0_r10.c
@@ -97,9 +97,13 @@ cshift0_r10 (gfc_array_r10 *ret, const gfc_array_r10 *array, ptrdiff_t shift,
   rptr = ret->base_addr;
   sptr = array->base_addr;
 
-  shift = len == 0 ? 0 : shift % (ptrdiff_t)len;
-  if (shift < 0)
-    shift += len;
+  /* Avoid the costly modulo for trivially in-bound shifts.  */
+  if (shift < 0 || shift >= len)
+    {
+      shift = len == 0 ? 0 : shift % (ptrdiff_t)len;
+      if (shift < 0)
+	shift += len;
+    }
 
   while (rptr)
     {
diff --git a/libgfortran/generated/cshift0_r16.c b/libgfortran/generated/cshift0_r16.c
index 320b705f3826..6d351f7bfdd1 100644
--- a/libgfortran/generated/cshift0_r16.c
+++ b/libgfortran/generated/cshift0_r16.c
@@ -97,9 +97,13 @@ cshift0_r16 (gfc_array_r16 *ret, const gfc_array_r16 *array, ptrdiff_t shift,
   rptr = ret->base_addr;
   sptr = array->base_addr;
 
-  shift = len == 0 ? 0 : shift % (ptrdiff_t)len;
-  if (shift < 0)
-    shift += len;
+  /* Avoid the costly modulo for trivially in-bound shifts.  */
+  if (shift < 0 || shift >= len)
+    {
+      shift = len == 0 ? 0 : shift % (ptrdiff_t)len;
+      if (shift < 0)
+	shift += len;
+    }
 
   while (rptr)
     {
diff --git a/libgfortran/generated/cshift0_r4.c b/libgfortran/generated/cshift0_r4.c
index 93ccf529b6d2..939ba6e12cc4 100644
--- a/libgfortran/generated/cshift0_r4.c
+++ b/libgfortran/generated/cshift0_r4.c
@@ -97,9 +97,13 @@ cshift0_r4 (gfc_array_r4 *ret, const gfc_array_r4 *array, ptrdiff_t shift,
   rptr = ret->base_addr;
   sptr = array->base_addr;
 
-  shift = len == 0 ? 0 : shift % (ptrdiff_t)len;
-  if (shift < 0)
-    shift += len;
+  /* Avoid the costly modulo for trivially in-bound shifts.  */
+  if (shift < 0 || shift >= len)
+    {
+      shift = len == 0 ? 0 : shift % (ptrdiff_t)len;
+      if (shift < 0)
+	shift += len;
+    }
 
   while (rptr)
     {
diff --git a/libgfortran/generated/cshift0_r8.c b/libgfortran/generated/cshift0_r8.c
index a3f747993c9c..73afb8a43e00 100644
--- a/libgfortran/generated/cshift0_r8.c
+++ b/libgfortran/generated/cshift0_r8.c
@@ -97,9 +97,13 @@ cshift0_r8 (gfc_array_r8 *ret, const gfc_array_r8 *array, ptrdiff_t shift,
   rptr = ret->base_addr;
   sptr = array->base_addr;
 
-  shift = len == 0 ? 0 : shift % (ptrdiff_t)len;
-  if (shift < 0)
-    shift += len;
+  /* Avoid the costly modulo for trivially in-bound shifts.  */
+  if (shift < 0 || shift >= len)
+    {
+      shift = len == 0 ? 0 : shift % (ptrdiff_t)len;
+      if (shift < 0)
+	shift += len;
+    }
 
   while (rptr)
     {
diff --git a/libgfortran/m4/cshift0.m4 b/libgfortran/m4/cshift0.m4
index 567222b71467..b1966aa5556b 100644
--- a/libgfortran/m4/cshift0.m4
+++ b/libgfortran/m4/cshift0.m4
@@ -98,9 +98,13 @@ cshift0_'rtype_code` ('rtype` *ret, const 'rtype` *array, ptrdiff_t shift,
   rptr = ret->base_addr;
   sptr = array->base_addr;
 
-  shift = len == 0 ? 0 : shift % (ptrdiff_t)len;
-  if (shift < 0)
-    shift += len;
+  /* Avoid the costly modulo for trivially in-bound shifts.  */
+  if (shift < 0 || shift >= len)
+    {
+      shift = len == 0 ? 0 : shift % (ptrdiff_t)len;
+      if (shift < 0)
+	shift += len;
+    }
 
   while (rptr)
     {