2004-02-29 Kazu Hirata <kazu@cs.umass.edu>
+ * config/h8300/h8300.md: Add comments about peephole2's.
+
+2004-02-29 Kazu Hirata <kazu@cs.umass.edu>
+
* config/h8300/h8300.md: Tweak operand numbers of some
peephole2's.
;; Transform
;;
+;; cmp.w #1,r0
+;; bhi .L1
+;;
+;; into
+;;
+;; shar.w r0
+;; bne .L1
+
+;; TODO: Split the above peephole2.
+
+;; Transform
+;;
;; cmp.w #255,r0
;; bgt .L1
;;
break;
}")
+;; Transform
+;;
+;; cmp.w #255,r0
+;; bhi .L1
+;;
+;; into
+;;
+;; mov.b r0h,r0h
+;; bne .L1
+
+;; TODO: Split the above peephole2.
+
;; (compare (reg:SI) (const_int)) takes 6 bytes, so we try to achieve
;; the equivalent with shorter sequences. Here is the summary. Cases
;; are grouped for each define_peephole2.
;; Transform
;;
;; cmp.l #1,er0
+;; bhi .L1
+;;
+;; into
+;;
+;; mov.l er0,er1
+;; shar.l er1
+;; bne .L1
+
+;; TODO: Split the above peephole2.
+
+;; Transform
+;;
+;; cmp.l #1,er0
;; bgt .L1
;;
;; into
;; Transform
;;
+;; cmp.l #1,er0
+;; bhi .L1
+;;
+;; into
+;;
+;; shar.l er0
+;; bne .L1
+
+;; TODO: Split the above peephole2.
+
+;; Transform
+;;
;; cmp.l #15,er0
;; bgt .L1
;;
;; Transform
;;
+;; cmp.l #15,er0
+;; bhi .L1
+;;
+;; into
+;;
+;; and #240,r0l
+;; mov.l er0,er0
+;; bne .L1
+
+;; TODO: Split the above peephole2.
+
+;; Transform
+;;
;; cmp.l #65535,er0
;; bgt .L1
;;
break;
}")
+;; Transform
+;;
+;; cmp.l #65535,er0
+;; bhi .L1
+;;
+;; into
+;;
+;; mov.l e0,e0
+;; bne .L1
+
+;; TODO: Split the above peephole2.
+
;; For constants like -1, -2, 1, 2, it is still cheaper to make a copy
;; of the register being tested, do the subtraction on the copy, and
;; then test the copy. We avoid this transformation if we see more