/* If ARG2 is const0_rtx, see what ARG1 is equivalent to. */
- while (arg2 == const0_rtx)
+ while (arg2 == CONST0_RTX (GET_MODE (arg1)))
{
/* Set non-zero when we find something of interest. */
rtx x = 0;
op1_elt = lookup (op1, op1_hash_code, mode);
/* If we aren't setting two things equal all we can do is save this
- comparison. */
- if (code != EQ)
+ comparison. Similarly if this is floating-point. In the latter
+ case, OP1 might be zero and both -0.0 and 0.0 are equal to it.
+ If we record the equality, we might inadvertently delete code
+ whose intent was to change -0 to +0. */
+
+ if (code != EQ || GET_MODE_CLASS (GET_MODE (op0)) == MODE_FLOAT)
{
/* If we reversed a floating-point comparison, if OP0 is not a
register, or if OP1 is neither a register or constant, we can't