diff options
Diffstat (limited to 'gcc/expr.cc')
| -rw-r--r-- | gcc/expr.cc | 150 |
1 files changed, 149 insertions, 1 deletions
diff --git a/gcc/expr.cc b/gcc/expr.cc index b897b6d..4c892d6 100644 --- a/gcc/expr.cc +++ b/gcc/expr.cc @@ -344,7 +344,11 @@ convert_mode_scalar (rtx to, rtx from, int unsignedp) gcc_assert ((GET_MODE_PRECISION (from_mode) != GET_MODE_PRECISION (to_mode)) || (DECIMAL_FLOAT_MODE_P (from_mode) - != DECIMAL_FLOAT_MODE_P (to_mode))); + != DECIMAL_FLOAT_MODE_P (to_mode)) + || (REAL_MODE_FORMAT (from_mode) == &arm_bfloat_half_format + && REAL_MODE_FORMAT (to_mode) == &ieee_half_format) + || (REAL_MODE_FORMAT (to_mode) == &arm_bfloat_half_format + && REAL_MODE_FORMAT (from_mode) == &ieee_half_format)); if (GET_MODE_PRECISION (from_mode) == GET_MODE_PRECISION (to_mode)) /* Conversion between decimal float and binary float, same size. */ @@ -364,6 +368,150 @@ convert_mode_scalar (rtx to, rtx from, int unsignedp) return; } +#ifdef HAVE_SFmode + if (REAL_MODE_FORMAT (from_mode) == &arm_bfloat_half_format + && REAL_MODE_FORMAT (SFmode) == &ieee_single_format) + { + if (GET_MODE_PRECISION (to_mode) > GET_MODE_PRECISION (SFmode)) + { + /* To cut down on libgcc size, implement + BFmode -> {DF,XF,TF}mode conversions by + BFmode -> SFmode -> {DF,XF,TF}mode conversions. */ + rtx temp = gen_reg_rtx (SFmode); + convert_mode_scalar (temp, from, unsignedp); + convert_mode_scalar (to, temp, unsignedp); + return; + } + if (REAL_MODE_FORMAT (to_mode) == &ieee_half_format) + { + /* Similarly, implement BFmode -> HFmode as + BFmode -> SFmode -> HFmode conversion where SFmode + has superset of BFmode values. We don't need + to handle sNaNs by raising exception and turning + into into qNaN though, as that can be done in the + SFmode -> HFmode conversion too. */ + rtx temp = gen_reg_rtx (SFmode); + int save_flag_finite_math_only = flag_finite_math_only; + flag_finite_math_only = true; + convert_mode_scalar (temp, from, unsignedp); + flag_finite_math_only = save_flag_finite_math_only; + convert_mode_scalar (to, temp, unsignedp); + return; + } + if (to_mode == SFmode + && !HONOR_NANS (from_mode) + && !HONOR_NANS (to_mode) + && optimize_insn_for_speed_p ()) + { + /* If we don't expect sNaNs, for BFmode -> SFmode we can just + shift the bits up. */ + machine_mode fromi_mode, toi_mode; + if (int_mode_for_size (GET_MODE_BITSIZE (from_mode), + 0).exists (&fromi_mode) + && int_mode_for_size (GET_MODE_BITSIZE (to_mode), + 0).exists (&toi_mode)) + { + start_sequence (); + rtx fromi = lowpart_subreg (fromi_mode, from, from_mode); + rtx tof = NULL_RTX; + if (fromi) + { + rtx toi = gen_reg_rtx (toi_mode); + convert_mode_scalar (toi, fromi, 1); + toi + = maybe_expand_shift (LSHIFT_EXPR, toi_mode, toi, + GET_MODE_PRECISION (to_mode) + - GET_MODE_PRECISION (from_mode), + NULL_RTX, 1); + if (toi) + { + tof = lowpart_subreg (to_mode, toi, toi_mode); + if (tof) + emit_move_insn (to, tof); + } + } + insns = get_insns (); + end_sequence (); + if (tof) + { + emit_insn (insns); + return; + } + } + } + } + if (REAL_MODE_FORMAT (from_mode) == &ieee_single_format + && REAL_MODE_FORMAT (to_mode) == &arm_bfloat_half_format + && !HONOR_NANS (from_mode) + && !HONOR_NANS (to_mode) + && !flag_rounding_math + && optimize_insn_for_speed_p ()) + { + /* If we don't expect qNaNs nor sNaNs and can assume rounding + to nearest, we can expand the conversion inline as + (fromi + 0x7fff + ((fromi >> 16) & 1)) >> 16. */ + machine_mode fromi_mode, toi_mode; + if (int_mode_for_size (GET_MODE_BITSIZE (from_mode), + 0).exists (&fromi_mode) + && int_mode_for_size (GET_MODE_BITSIZE (to_mode), + 0).exists (&toi_mode)) + { + start_sequence (); + rtx fromi = lowpart_subreg (fromi_mode, from, from_mode); + rtx tof = NULL_RTX; + do + { + if (!fromi) + break; + int shift = (GET_MODE_PRECISION (from_mode) + - GET_MODE_PRECISION (to_mode)); + rtx temp1 + = maybe_expand_shift (RSHIFT_EXPR, fromi_mode, fromi, + shift, NULL_RTX, 1); + if (!temp1) + break; + rtx temp2 + = expand_binop (fromi_mode, and_optab, temp1, const1_rtx, + NULL_RTX, 1, OPTAB_DIRECT); + if (!temp2) + break; + rtx temp3 + = expand_binop (fromi_mode, add_optab, fromi, + gen_int_mode ((HOST_WIDE_INT_1U + << (shift - 1)) - 1, + fromi_mode), NULL_RTX, + 1, OPTAB_DIRECT); + if (!temp3) + break; + rtx temp4 + = expand_binop (fromi_mode, add_optab, temp3, temp2, + NULL_RTX, 1, OPTAB_DIRECT); + if (!temp4) + break; + rtx temp5 = maybe_expand_shift (RSHIFT_EXPR, fromi_mode, + temp4, shift, NULL_RTX, 1); + if (!temp5) + break; + rtx temp6 = lowpart_subreg (toi_mode, temp5, fromi_mode); + if (!temp6) + break; + tof = lowpart_subreg (to_mode, force_reg (toi_mode, temp6), + toi_mode); + if (tof) + emit_move_insn (to, tof); + } + while (0); + insns = get_insns (); + end_sequence (); + if (tof) + { + emit_insn (insns); + return; + } + } + } +#endif + /* Otherwise use a libcall. */ libcall = convert_optab_libfunc (tab, to_mode, from_mode); |