diff options
Diffstat (limited to 'gcc/optabs.cc')
| -rw-r--r-- | gcc/optabs.cc | 47 |
1 files changed, 26 insertions, 21 deletions
diff --git a/gcc/optabs.cc b/gcc/optabs.cc index e1898da..f0a048a 100644 --- a/gcc/optabs.cc +++ b/gcc/optabs.cc @@ -533,15 +533,13 @@ expand_subword_shift (scalar_int_mode op1_mode, optab binoptab, has unknown behavior. Do a single shift first, then shift by the remainder. It's OK to use ~OP1 as the remainder if shift counts are truncated to the mode size. */ - carries = expand_binop (word_mode, reverse_unsigned_shift, - outof_input, const1_rtx, 0, unsignedp, methods); - if (shift_mask == BITS_PER_WORD - 1) - { - tmp = immed_wide_int_const - (wi::minus_one (GET_MODE_PRECISION (op1_mode)), op1_mode); - tmp = simplify_expand_binop (op1_mode, xor_optab, op1, tmp, - 0, true, methods); - } + carries = simplify_expand_binop (word_mode, reverse_unsigned_shift, + outof_input, const1_rtx, 0, + unsignedp, methods); + if (carries == const0_rtx) + tmp = const0_rtx; + else if (shift_mask == BITS_PER_WORD - 1) + tmp = expand_unop (op1_mode, one_cmpl_optab, op1, 0, true); else { tmp = immed_wide_int_const (wi::shwi (BITS_PER_WORD - 1, @@ -552,22 +550,29 @@ expand_subword_shift (scalar_int_mode op1_mode, optab binoptab, } if (tmp == 0 || carries == 0) return false; - carries = expand_binop (word_mode, reverse_unsigned_shift, - carries, tmp, 0, unsignedp, methods); + if (carries != const0_rtx && tmp != const0_rtx) + carries = simplify_expand_binop (word_mode, reverse_unsigned_shift, + carries, tmp, 0, unsignedp, methods); if (carries == 0) return false; - /* Shift INTO_INPUT logically by OP1. This is the last use of INTO_INPUT - so the result can go directly into INTO_TARGET if convenient. */ - tmp = expand_binop (word_mode, unsigned_shift, into_input, op1, - into_target, unsignedp, methods); - if (tmp == 0) - return false; + if (into_input != const0_rtx) + { + /* Shift INTO_INPUT logically by OP1. This is the last use of + INTO_INPUT so the result can go directly into INTO_TARGET if + convenient. */ + tmp = simplify_expand_binop (word_mode, unsigned_shift, into_input, + op1, into_target, unsignedp, methods); + if (tmp == 0) + return false; - /* Now OR in the bits carried over from OUTOF_INPUT. */ - if (!force_expand_binop (word_mode, ior_optab, tmp, carries, - into_target, unsignedp, methods)) - return false; + /* Now OR in the bits carried over from OUTOF_INPUT. */ + if (!force_expand_binop (word_mode, ior_optab, tmp, carries, + into_target, unsignedp, methods)) + return false; + } + else + emit_move_insn (into_target, carries); /* Use a standard word_mode shift for the out-of half. */ if (outof_target != 0) |