+
+/* Knowing that ARG0 and ARG1 are both RDIV_EXPRs, simplify a binary operation
+ with code CODE. This optimization is unsafe. */
+static tree
+distribute_real_division (enum tree_code code, tree type, tree arg0, tree arg1)
+{
+ bool mul0 = TREE_CODE (arg0) == MULT_EXPR;
+ bool mul1 = TREE_CODE (arg1) == MULT_EXPR;
+
+ /* (A / C) +- (B / C) -> (A +- B) / C. */
+ if (mul0 == mul1
+ && operand_equal_p (TREE_OPERAND (arg0, 1),
+ TREE_OPERAND (arg1, 1), 0))
+ return fold_build2 (mul0 ? MULT_EXPR : RDIV_EXPR, type,
+ fold_build2 (code, type,
+ TREE_OPERAND (arg0, 0),
+ TREE_OPERAND (arg1, 0)),
+ TREE_OPERAND (arg0, 1));
+
+ /* (A / C1) +- (A / C2) -> A * (1 / C1 +- 1 / C2). */
+ if (operand_equal_p (TREE_OPERAND (arg0, 0),
+ TREE_OPERAND (arg1, 0), 0)
+ && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
+ && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
+ {
+ REAL_VALUE_TYPE r0, r1;
+ r0 = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
+ r1 = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
+ if (!mul0)
+ real_arithmetic (&r0, RDIV_EXPR, &dconst1, &r0);
+ if (!mul1)
+ real_arithmetic (&r1, RDIV_EXPR, &dconst1, &r1);
+ real_arithmetic (&r0, code, &r0, &r1);
+ return fold_build2 (MULT_EXPR, type,
+ TREE_OPERAND (arg0, 0),
+ build_real (type, r0));
+ }
+
+ return NULL_TREE;
+}