https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107591
--- Comment #10 from Jakub Jelinek <jakub at gcc dot gnu.org> --- (In reply to Andrew Macleod from comment #9) > you could also test whether op1_range contains + and/or - 0, as well as > op2_range. VREL_EQ is a symbolic equality.. the ranges can still be > distinct and individually testable to see if you have a +0 and -0.. I > guess you could also test for equality of the ranges.. op1_range == op2_range Equality of the ranges doesn't imply equality of the values. int foo (int x, y) { if (x < -13 || x > 26) return -1; if (y < -13 || y > 26) return -1; return x * y; } In the above testcase, both x and y have [-13, 26] ranges, but here the range [-338, 676] is correct, while [0, 676] is right for the #c0 testcase.