diff options
Diffstat (limited to 'gcc/loop.c')
| -rw-r--r-- | gcc/loop.c | 14 |
1 files changed, 9 insertions, 5 deletions
@@ -824,7 +824,7 @@ scan_loop (loop, flags) && (maybe_never || loop_reg_used_before_p (loop, set, p))) /* It is unsafe to move the set. However, it may be OK to - move the source into a new psuedo, and subsitute a + move the source into a new pseudo, and substitute a reg-to-reg copy for the original insn. This code used to consider it OK to move a set of a variable @@ -839,11 +839,15 @@ scan_loop (loop, flags) the benefit. */ if (REGNO (SET_DEST (set)) >= max_reg_before_loop) ; - /* Don't move the source and add a reg-to-reg copy with -Os - (this certainly increases size) or if the source is - already a reg (the motion will gain nothing). */ + /* Don't move the source and add a reg-to-reg copy: + - with -Os (this certainly increases size), + - if the mode doesn't support copy operations (obviously), + - if the source is already a reg (the motion will gain nothing), + - if the source is a legitimate constant (likewise). */ else if (insert_temp - && (optimize_size || GET_CODE (SET_SRC (set)) == REG + && (optimize_size + || ! can_copy_p (GET_MODE (SET_SRC (set))) + || GET_CODE (SET_SRC (set)) == REG || (CONSTANT_P (SET_SRC (set)) && LEGITIMATE_CONSTANT_P (SET_SRC (set))))) ; |