Checks
Commit Message
Hi,
This patch cleans up by_pieces_ninsns and does following things.
1. Do the length and alignment adjustment for by pieces compare when
overlap operation is enabled.
2. Remove unnecessary mov_optab checks.
Bootstrapped and tested on x86 and powerpc64-linux BE and LE with
no regressions. Is this OK for trunk?
Thanks
Gui Haochen
ChangeLog
Clean up by_pieces_ninsns
The by pieces compare can be implemented by overlapped operations. So
it should be taken into consideration when doing the adjustment for
overlap operations. The mode returned from
widest_fixed_size_mode_for_size is already checked with mov_optab in
by_pieces_mode_supported_p called by widest_fixed_size_mode_for_size.
So there is no need to check mov_optab again in by_pieces_ninsns.
The patch fixes these issues.
gcc/
* expr.cc (by_pieces_ninsns): Include by pieces compare when
do the adjustment for overlap operations. Remove unnecessary
mov_optab check.
patch.diff
@@ -1090,18 +1090,15 @@ by_pieces_ninsns (unsigned HOST_WIDE_INT l, unsigned int align,
unsigned HOST_WIDE_INT n_insns = 0;
fixed_size_mode mode;
- if (targetm.overlap_op_by_pieces_p () && op != COMPARE_BY_PIECES)
+ if (targetm.overlap_op_by_pieces_p ())
{
/* NB: Round up L and ALIGN to the widest integer mode for
MAX_SIZE. */
mode = widest_fixed_size_mode_for_size (max_size, op);
- if (optab_handler (mov_optab, mode) != CODE_FOR_nothing)
- {
- unsigned HOST_WIDE_INT up = ROUND_UP (l, GET_MODE_SIZE (mode));
- if (up > l)
- l = up;
- align = GET_MODE_ALIGNMENT (mode);
- }
+ unsigned HOST_WIDE_INT up = ROUND_UP (l, GET_MODE_SIZE (mode));
+ if (up > l)
+ l = up;
+ align = GET_MODE_ALIGNMENT (mode);
}
align = alignment_for_piecewise_move (MOVE_MAX_PIECES, align);
@@ -1109,12 +1106,10 @@ by_pieces_ninsns (unsigned HOST_WIDE_INT l, unsigned int align,
while (max_size > 1 && l > 0)
{
mode = widest_fixed_size_mode_for_size (max_size, op);
- enum insn_code icode;
unsigned int modesize = GET_MODE_SIZE (mode);
- icode = optab_handler (mov_optab, mode);
- if (icode != CODE_FOR_nothing && align >= GET_MODE_ALIGNMENT (mode))
+ if (align >= GET_MODE_ALIGNMENT (mode))
{
unsigned HOST_WIDE_INT n_pieces = l / modesize;
l %= modesize;