@@ -686,13 +686,13 @@ simplify_unary_operation_1 (enum rtx_cod
return simplify_gen_binary (MINUS, mode, temp, XEXP (op, 1));
}
- /* (neg (mult A B)) becomes (mult (neg A) B).
+ /* (neg (mult A B)) becomes (mult A (neg B)).
This works even for floating-point values. */
if (GET_CODE (op) == MULT
&& !HONOR_SIGN_DEPENDENT_ROUNDING (mode))
{
- temp = simplify_gen_unary (NEG, mode, XEXP (op, 0), mode);
- return simplify_gen_binary (MULT, mode, temp, XEXP (op, 1));
+ temp = simplify_gen_unary (NEG, mode, XEXP (op, 1), mode);
+ return simplify_gen_binary (MULT, mode, XEXP (op, 0), temp);
}
/* NEG commutes with ASHIFT since it is multiplication. Only do
@@ -2271,12 +2271,34 @@ simplify_binary_operation_1 (enum rtx_co
if (GET_CODE (op0) == NEG)
{
rtx temp = simplify_unary_operation (NEG, mode, op1, mode);
+ /* If op1 is a MULT as well and simplify_unary_operation
+ just moved the NEG to the second operand, simplify_gen_binary
+ below could through simplify_associative_operation move
+ the NEG around again and recurse endlessly. */
+ if (temp
+ && GET_CODE (op1) == MULT
+ && GET_CODE (temp) == MULT
+ && XEXP (op1, 0) == XEXP (temp, 0)
+ && GET_CODE (XEXP (temp, 1)) == NEG
+ && XEXP (op1, 1) == XEXP (XEXP (temp, 1), 0))
+ temp = NULL_RTX;
if (temp)
return simplify_gen_binary (MULT, mode, XEXP (op0, 0), temp);
}
if (GET_CODE (op1) == NEG)
{
rtx temp = simplify_unary_operation (NEG, mode, op0, mode);
+ /* If op0 is a MULT as well and simplify_unary_operation
+ just moved the NEG to the second operand, simplify_gen_binary
+ below could through simplify_associative_operation move
+ the NEG around again and recurse endlessly. */
+ if (temp
+ && GET_CODE (op0) == MULT
+ && GET_CODE (temp) == MULT
+ && XEXP (op0, 0) == XEXP (temp, 0)
+ && GET_CODE (XEXP (temp, 1)) == NEG
+ && XEXP (op0, 1) == XEXP (XEXP (temp, 1), 0))
+ temp = NULL_RTX;
if (temp)
return simplify_gen_binary (MULT, mode, temp, XEXP (op1, 0));
}
@@ -0,0 +1,15 @@
+! PR rtl-optimization/49472
+! { dg-do compile }
+! { dg-options "-O -fcompare-debug -ffast-math" }
+subroutine pr49472
+ integer, parameter :: n = 3
+ real(8) :: a, b, c, d, e (n+1)
+ integer :: i
+ do i=2, (n+1)
+ b = 1. / ((i - 1.5d0) * 1.)
+ c = b * a
+ d = -b * c / (1. + b * b) ** 1.5d0
+ e(i) = d
+ end do
+ call dummy (e)
+end subroutine