re PR fortran/31120 ([4.1/4.2 only] ICE with integer_exponentiation_1.f90 and -ffast-math)

	PR fortran/31120

	* trans-expr.c (gfc_conv_powi): Make n argument unsigned hwi.
	(gfc_conv_cst_int_power): Handle integer exponent with care,
	since it might be too large for us.

	* gfortran.dg/integer_exponentiation_2.f90: New test.

From-SVN: r123028

gcc/fortran/ChangeLog

 2007-03-17  Francois-Xavier Coudert  <coudert@clipper.ens.fr>
 
+	PR fortran/31120
+	* trans-expr.c (gfc_conv_powi): Make n argument unsigned hwi.
+	(gfc_conv_cst_int_power): Handle integer exponent with care,
+	since it might be too large for us.
+
+2007-03-17  Francois-Xavier Coudert  <coudert@clipper.ens.fr>
+
 	PR fortran/31184
 	* invoke.texi: Fix typo.
 

gcc/fortran/trans-expr.c

@@ -634,7 +634,7 @@ static const unsigned char powi_table[POWI_TABLE_SIZE] =
 /* Recursive function to expand the power operator. The temporary 
    values are put in tmpvar. The function returns tmpvar[1] ** n.  */
 static tree
-gfc_conv_powi (gfc_se * se, int n, tree * tmpvar)
+gfc_conv_powi (gfc_se * se, unsigned HOST_WIDE_INT n, tree * tmpvar)
 {
   tree op0;
   tree op1;
@@ -681,15 +681,25 @@ gfc_conv_cst_int_power (gfc_se * se, tree lhs, tree rhs)
   tree tmp;
   tree type;
   tree vartmp[POWI_TABLE_SIZE];
-  int n;
+  HOST_WIDE_INT m;
+  unsigned HOST_WIDE_INT n;
   int sgn;
 
+  /* If exponent is too large, we won't expand it anyway, so don't bother
+     with large integer values.  */
+  if (!double_int_fits_in_shwi_p (TREE_INT_CST (rhs)))
+    return 0;
+
+  m = double_int_to_shwi (TREE_INT_CST (rhs));
+  /* There's no ABS for HOST_WIDE_INT, so here we go. It also takes care
+     of the asymmetric range of the integer type.  */
+  n = (unsigned HOST_WIDE_INT) (m < 0 ? -m : m);
+  
   type = TREE_TYPE (lhs);
-  n = abs (TREE_INT_CST_LOW (rhs));
   sgn = tree_int_cst_sgn (rhs);
 
-  if (((FLOAT_TYPE_P (type) && !flag_unsafe_math_optimizations) || optimize_size)
-      && (n > 2 || n < -1))
+  if (((FLOAT_TYPE_P (type) && !flag_unsafe_math_optimizations)
+       || optimize_size) && (m > 2 || m < -1))
     return 0;
 
   /* rhs == 0  */
@@ -698,6 +708,7 @@ gfc_conv_cst_int_power (gfc_se * se, tree lhs, tree rhs)
       se->expr = gfc_build_const (type, integer_one_node);
       return 1;
     }
+
   /* If rhs < 0 and lhs is an integer, the result is -1, 0 or 1.  */
   if ((sgn == -1) && (TREE_CODE (type) == INTEGER_TYPE))
     {

gcc/testsuite/ChangeLog

+2007-03-17  Francois-Xavier Coudert  <coudert@clipper.ens.fr>
+
+	PR fortran/31120
+	* gfortran.dg/integer_exponentiation_2.f90: New test.
+
 2007-03-17  Dorit Nuzman  <dorit@il.ibm.com>
 
 	PR tree-optimization/31041

gcc/testsuite/gfortran.dg/integer_exponentiation_2.f90

+! { dg-do run }
+! { dg-options "" }
+! Test various exponentations
+! initially designed for patch to PR31120
+
+program test
+  call run_me (1.0, 1, (1.0,0.0))
+  call run_me (-1.1, -1, (0.0,-1.0))
+  call run_me (42.0, 12, (1.0,7.0))
+end program test
+
+! This subroutine is for runtime tests
+subroutine run_me(a, i, z)
+  implicit none
+
+  real, intent(in) :: a
+  integer, intent(in) :: i
+  complex, intent(in) :: z
+
+  call check_equal_i (i**0, 1)
+  call check_equal_i (i**1, i)
+  call check_equal_i (i**2, i*i)
+  call check_equal_i (i**3, i*(i**2))
+
+  call check_equal_i (int(i**0_8,kind=4), 1)
+  call check_equal_i (int(i**1_8,kind=4), i)
+  call check_equal_i (int(i**2_8,kind=4), i*i)
+  call check_equal_i (int(i**3_8,kind=4), i*i*i)
+
+  call check_equal_r (a**0.0, 1.0)
+  call check_equal_r (a**1.0, a)
+  call check_equal_r (a**2.0, a*a)
+  call check_equal_r (a**3.0, a*(a**2))
+  call check_equal_r (a**-1.0, 1/a)
+  call check_equal_r (a**-2.0, (1/a)*(1/a))
+
+  call check_equal_r (a**0, 1.0)
+  call check_equal_r (a**1, a)
+  call check_equal_r (a**2, a*a)
+  call check_equal_r (a**3, a*(a**2))
+  call check_equal_r (a**-1, 1/a)
+  call check_equal_r (a**-2, (1/a)*(1/a))
+
+  call check_equal_r (a**0_8, 1.0)
+  call check_equal_r (a**1_8, a)
+  call check_equal_r (a**2_8, a*a)
+  call check_equal_r (a**3_8, a*(a**2))
+  call check_equal_r (a**-1_8, 1/a)
+  call check_equal_r (a**-2_8, (1/a)*(1/a))
+
+  call check_equal_c (z**0.0, (1.0,0.0))
+  call check_equal_c (z**1.0, z)
+  call check_equal_c (z**2.0, z*z)
+  call check_equal_c (z**3.0, z*(z**2))
+  call check_equal_c (z**-1.0, 1/z)
+  call check_equal_c (z**-2.0, (1/z)*(1/z))
+
+  call check_equal_c (z**(0.0,0.0), (1.0,0.0))
+  call check_equal_c (z**(1.0,0.0), z)
+  call check_equal_c (z**(2.0,0.0), z*z)
+  call check_equal_c (z**(3.0,0.0), z*(z**2))
+  call check_equal_c (z**(-1.0,0.0), 1/z)
+  call check_equal_c (z**(-2.0,0.0), (1/z)*(1/z))
+
+  call check_equal_c (z**0, (1.0,0.0))
+  call check_equal_c (z**1, z)
+  call check_equal_c (z**2, z*z)
+  call check_equal_c (z**3, z*(z**2))
+  call check_equal_c (z**-1, 1/z)
+  call check_equal_c (z**-2, (1/z)*(1/z))
+
+  call check_equal_c (z**0_8, (1.0,0.0))
+  call check_equal_c (z**1_8, z)
+  call check_equal_c (z**2_8, z*z)
+  call check_equal_c (z**3_8, z*(z**2))
+  call check_equal_c (z**-1_8, 1/z)
+  call check_equal_c (z**-2_8, (1/z)*(1/z))
+
+
+contains
+
+  subroutine check_equal_r (a, b)
+    real, intent(in) :: a, b
+    if (abs(a - b) > 1.e-5 * abs(b)) call abort
+  end subroutine check_equal_r
+
+  subroutine check_equal_c (a, b)
+    complex, intent(in) :: a, b
+    if (abs(a - b) > 1.e-5 * abs(b)) call abort
+  end subroutine check_equal_c
+
+  subroutine check_equal_i (a, b)
+    integer, intent(in) :: a, b
+    if (a /= b) call abort
+  end subroutine check_equal_i
+
+end subroutine run_me
+
+! subroutine foo is used for compilation test only
+subroutine foo(a)
+  implicit none
+
+  real, intent(in) :: a
+  integer :: i
+  complex :: z
+
+  ! Integer
+  call gee_i(i**0_1)
+  call gee_i(i**1_1)
+  call gee_i(i**2_1)
+  call gee_i(i**3_1)
+  call gee_i(i**-1_1)
+  call gee_i(i**-2_1)
+  call gee_i(i**-3_1)
+  call gee_i(i**huge(0_1))
+  call gee_i(i**-huge(0_1))
+  call gee_i(i**(-huge(0_1)-1_1))
+
+  call gee_i(i**0_2)
+  call gee_i(i**1_2)
+  call gee_i(i**2_2)
+  call gee_i(i**3_2)
+  call gee_i(i**-1_2)
+  call gee_i(i**-2_2)
+  call gee_i(i**-3_2)
+  call gee_i(i**huge(0_2))
+  call gee_i(i**-huge(0_2))
+  call gee_i(i**(-huge(0_2)-1_2))
+
+  call gee_i(i**0_4)
+  call gee_i(i**1_4)
+  call gee_i(i**2_4)
+  call gee_i(i**3_4)
+  call gee_i(i**-1_4)
+  call gee_i(i**-2_4)
+  call gee_i(i**-3_4)
+  call gee_i(i**huge(0_4))
+  call gee_i(i**-huge(0_4))
+  call gee_i(i**(-huge(0_4)-1_4))
+
+  call gee_i(i**0_8)
+  call gee_i(i**1_8)
+  call gee_i(i**2_8)
+  call gee_i(i**3_8)
+  call gee_i(i**-1_8)
+  call gee_i(i**-2_8)
+  call gee_i(i**-3_8)
+  call gee_i(i**huge(0_8))
+  call gee_i(i**-huge(0_8))
+  call gee_i(i**(-huge(0_8)-1_8))
+
+  ! Real
+  call gee_r(a**0_1)
+  call gee_r(a**1_1)
+  call gee_r(a**2_1)
+  call gee_r(a**3_1)
+  call gee_r(a**-1_1)
+  call gee_r(a**-2_1)
+  call gee_r(a**-3_1)
+  call gee_r(a**huge(0_1))
+  call gee_r(a**-huge(0_1))
+  call gee_r(a**(-huge(0_1)-1_1))
+
+  call gee_r(a**0_2)
+  call gee_r(a**1_2)
+  call gee_r(a**2_2)
+  call gee_r(a**3_2)
+  call gee_r(a**-1_2)
+  call gee_r(a**-2_2)
+  call gee_r(a**-3_2)
+  call gee_r(a**huge(0_2))
+  call gee_r(a**-huge(0_2))
+  call gee_r(a**(-huge(0_2)-1_2))
+
+  call gee_r(a**0_4)
+  call gee_r(a**1_4)
+  call gee_r(a**2_4)
+  call gee_r(a**3_4)
+  call gee_r(a**-1_4)
+  call gee_r(a**-2_4)
+  call gee_r(a**-3_4)
+  call gee_r(a**huge(0_4))
+  call gee_r(a**-huge(0_4))
+  call gee_r(a**(-huge(0_4)-1_4))
+
+  call gee_r(a**0_8)
+  call gee_r(a**1_8)
+  call gee_r(a**2_8)
+  call gee_r(a**3_8)
+  call gee_r(a**-1_8)
+  call gee_r(a**-2_8)
+  call gee_r(a**-3_8)
+  call gee_r(a**huge(0_8))
+  call gee_r(a**-huge(0_8))
+  call gee_r(a**(-huge(0_8)-1_8))
+
+  ! Complex
+  call gee_z(z**0_1)
+  call gee_z(z**1_1)
+  call gee_z(z**2_1)
+  call gee_z(z**3_1)
+  call gee_z(z**-1_1)
+  call gee_z(z**-2_1)
+  call gee_z(z**-3_1)
+  call gee_z(z**huge(0_1))
+  call gee_z(z**-huge(0_1))
+  call gee_z(z**(-huge(0_1)-1_1))
+
+  call gee_z(z**0_2)
+  call gee_z(z**1_2)
+  call gee_z(z**2_2)
+  call gee_z(z**3_2)
+  call gee_z(z**-1_2)
+  call gee_z(z**-2_2)
+  call gee_z(z**-3_2)
+  call gee_z(z**huge(0_2))
+  call gee_z(z**-huge(0_2))
+  call gee_z(z**(-huge(0_2)-1_2))
+
+  call gee_z(z**0_4)
+  call gee_z(z**1_4)
+  call gee_z(z**2_4)
+  call gee_z(z**3_4)
+  call gee_z(z**-1_4)
+  call gee_z(z**-2_4)
+  call gee_z(z**-3_4)
+  call gee_z(z**huge(0_4))
+  call gee_z(z**-huge(0_4))
+  call gee_z(z**(-huge(0_4)-1_4))
+
+  call gee_z(z**0_8)
+  call gee_z(z**1_8)
+  call gee_z(z**2_8)
+  call gee_z(z**3_8)
+  call gee_z(z**-1_8)
+  call gee_z(z**-2_8)
+  call gee_z(z**-3_8)
+  call gee_z(z**huge(0_8))
+  call gee_z(z**-huge(0_8))
+  call gee_z(z**(-huge(0_8)-1_8))
+end subroutine foo
+
+subroutine gee_i(i)
+  integer :: i
+end subroutine gee_i
+
+subroutine gee_r(r)
+  real :: r
+end subroutine gee_r
+
+subroutine gee_z(c)
+  complex :: c
+end subroutine gee_z