+ case UNSPEC_FPATAN:
+ /* These insns operate on the top two stack slots. */
+
+ src1 = get_true_reg (&XVECEXP (pat_src, 0, 0));
+ src2 = get_true_reg (&XVECEXP (pat_src, 0, 1));
+
+ src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1));
+ src2_note = find_regno_note (insn, REG_DEAD, REGNO (*src2));
+
+ {
+ struct stack_def temp_stack;
+ int regno, j, k, temp;
+
+ temp_stack = *regstack;
+
+ /* Place operand 1 at the top of stack. */
+ regno = get_hard_regnum (&temp_stack, *src1);
+ if (regno < 0)
+ abort ();
+ if (regno != FIRST_STACK_REG)
+ {
+ k = temp_stack.top - (regno - FIRST_STACK_REG);
+ j = temp_stack.top;
+
+ temp = temp_stack.reg[k];
+ temp_stack.reg[k] = temp_stack.reg[j];
+ temp_stack.reg[j] = temp;
+ }
+
+ /* Place operand 2 next on the stack. */
+ regno = get_hard_regnum (&temp_stack, *src2);
+ if (regno < 0)
+ abort ();
+ if (regno != FIRST_STACK_REG + 1)
+ {
+ k = temp_stack.top - (regno - FIRST_STACK_REG);
+ j = temp_stack.top - 1;
+
+ temp = temp_stack.reg[k];
+ temp_stack.reg[k] = temp_stack.reg[j];
+ temp_stack.reg[j] = temp;
+ }
+
+ change_stack (insn, regstack, &temp_stack, EMIT_BEFORE);
+ }
+
+ replace_reg (src1, FIRST_STACK_REG);
+ replace_reg (src2, FIRST_STACK_REG + 1);
+
+ if (src1_note)
+ replace_reg (&XEXP (src1_note, 0), FIRST_STACK_REG);
+ if (src2_note)
+ replace_reg (&XEXP (src2_note, 0), FIRST_STACK_REG + 1);
+
+ /* Pop both input operands from the stack. */
+ CLEAR_HARD_REG_BIT (regstack->reg_set,
+ regstack->reg[regstack->top]);
+ CLEAR_HARD_REG_BIT (regstack->reg_set,
+ regstack->reg[regstack->top - 1]);
+ regstack->top -= 2;
+
+ /* Push the result back onto the stack. */
+ regstack->reg[++regstack->top] = REGNO (*dest);
+ SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest));
+ replace_reg (dest, FIRST_STACK_REG);
+ break;
+