PR rtl-optimization/27616
* cse.c (table_size): New static variable.
(new_basic_block): Initialize it to 0.
(remove_from_table): Decrement it.
(insert): Increment it.
(fold_rtx_mem_1): New function, renamed from fold_rtx_mem.
(fold_rtx_mem): Enforce a cap on the recursion depth. Call
fold_rtx_mem_1 if under the cap.
(fold_rtx) <RTX_COMM_ARITH>: In the associative case, delay a little
the lookup of the equivalent expression and test for equality of the
first operand of the equivalent expression before in turn looking up
an equivalent constant for the second operand.
From-SVN: r116683
