From: Ben Elliston Date: Thu, 3 Apr 2008 05:17:11 +0000 (+0000) Subject: * expmed.c (extract_force_align_mem_bit_field): Remove. X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=9e0aebcaeec9fd14355424916ecde132097ee0e9;p=gcc.git * expmed.c (extract_force_align_mem_bit_field): Remove. From-SVN: r133858 --- diff --git a/gcc/ChangeLog b/gcc/ChangeLog index aa78346a55e..e9d13b07981 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,7 @@ +2008-04-03 Ben Elliston + + * expmed.c (extract_force_align_mem_bit_field): Remove. + 2008-04-03 Richard Guenther PR middle-end/35800 diff --git a/gcc/expmed.c b/gcc/expmed.c index 8724258acc1..d5d2d528ca0 100644 --- a/gcc/expmed.c +++ b/gcc/expmed.c @@ -1835,152 +1835,6 @@ lshift_value (enum machine_mode mode, rtx value, int bitpos, int bitsize) return immed_double_const (low, high, mode); } -/* Extract a bit field from a memory by forcing the alignment of the - memory. This efficient only if the field spans at least 4 boundaries. - - OP0 is the MEM. - BITSIZE is the field width; BITPOS is the position of the first bit. - UNSIGNEDP is true if the result should be zero-extended. */ - -static rtx -extract_force_align_mem_bit_field (rtx op0, unsigned HOST_WIDE_INT bitsize, - unsigned HOST_WIDE_INT bitpos, - int unsignedp) -{ - enum machine_mode mode, dmode; - unsigned int m_bitsize, m_size; - unsigned int sign_shift_up, sign_shift_dn; - rtx base, a1, a2, v1, v2, comb, shift, result, start; - - /* Choose a mode that will fit BITSIZE. */ - mode = smallest_mode_for_size (bitsize, MODE_INT); - m_size = GET_MODE_SIZE (mode); - m_bitsize = GET_MODE_BITSIZE (mode); - - /* Choose a mode twice as wide. Fail if no such mode exists. */ - dmode = mode_for_size (m_bitsize * 2, MODE_INT, false); - if (dmode == BLKmode) - return NULL; - - do_pending_stack_adjust (); - start = get_last_insn (); - - /* At the end, we'll need an additional shift to deal with sign/zero - extension. By default this will be a left+right shift of the - appropriate size. But we may be able to eliminate one of them. */ - sign_shift_up = sign_shift_dn = m_bitsize - bitsize; - - if (STRICT_ALIGNMENT) - { - base = plus_constant (XEXP (op0, 0), bitpos / BITS_PER_UNIT); - bitpos %= BITS_PER_UNIT; - - /* We load two values to be concatenate. There's an edge condition - that bears notice -- an aligned value at the end of a page can - only load one value lest we segfault. So the two values we load - are at "base & -size" and "(base + size - 1) & -size". If base - is unaligned, the addresses will be aligned and sequential; if - base is aligned, the addresses will both be equal to base. */ - - a1 = expand_simple_binop (Pmode, AND, force_operand (base, NULL), - GEN_INT (-(HOST_WIDE_INT)m_size), - NULL, true, OPTAB_LIB_WIDEN); - mark_reg_pointer (a1, m_bitsize); - v1 = gen_rtx_MEM (mode, a1); - set_mem_align (v1, m_bitsize); - v1 = force_reg (mode, validize_mem (v1)); - - a2 = plus_constant (base, GET_MODE_SIZE (mode) - 1); - a2 = expand_simple_binop (Pmode, AND, force_operand (a2, NULL), - GEN_INT (-(HOST_WIDE_INT)m_size), - NULL, true, OPTAB_LIB_WIDEN); - v2 = gen_rtx_MEM (mode, a2); - set_mem_align (v2, m_bitsize); - v2 = force_reg (mode, validize_mem (v2)); - - /* Combine these two values into a double-word value. */ - if (m_bitsize == BITS_PER_WORD) - { - comb = gen_reg_rtx (dmode); - emit_insn (gen_rtx_CLOBBER (VOIDmode, comb)); - emit_move_insn (gen_rtx_SUBREG (mode, comb, 0), v1); - emit_move_insn (gen_rtx_SUBREG (mode, comb, m_size), v2); - } - else - { - if (BYTES_BIG_ENDIAN) - comb = v1, v1 = v2, v2 = comb; - v1 = convert_modes (dmode, mode, v1, true); - if (v1 == NULL) - goto fail; - v2 = convert_modes (dmode, mode, v2, true); - v2 = expand_simple_binop (dmode, ASHIFT, v2, GEN_INT (m_bitsize), - NULL, true, OPTAB_LIB_WIDEN); - if (v2 == NULL) - goto fail; - comb = expand_simple_binop (dmode, IOR, v1, v2, NULL, - true, OPTAB_LIB_WIDEN); - if (comb == NULL) - goto fail; - } - - shift = expand_simple_binop (Pmode, AND, base, GEN_INT (m_size - 1), - NULL, true, OPTAB_LIB_WIDEN); - shift = expand_mult (Pmode, shift, GEN_INT (BITS_PER_UNIT), NULL, 1); - - if (bitpos != 0) - { - if (sign_shift_up <= bitpos) - bitpos -= sign_shift_up, sign_shift_up = 0; - shift = expand_simple_binop (Pmode, PLUS, shift, GEN_INT (bitpos), - NULL, true, OPTAB_LIB_WIDEN); - } - } - else - { - unsigned HOST_WIDE_INT offset = bitpos / BITS_PER_UNIT; - bitpos %= BITS_PER_UNIT; - - /* When strict alignment is not required, we can just load directly - from memory without masking. If the remaining BITPOS offset is - small enough, we may be able to do all operations in MODE as - opposed to DMODE. */ - if (bitpos + bitsize <= m_bitsize) - dmode = mode; - comb = adjust_address (op0, dmode, offset); - - if (sign_shift_up <= bitpos) - bitpos -= sign_shift_up, sign_shift_up = 0; - shift = GEN_INT (bitpos); - } - - /* Shift down the double-word such that the requested value is at bit 0. */ - if (shift != const0_rtx) - comb = expand_simple_binop (dmode, unsignedp ? LSHIFTRT : ASHIFTRT, - comb, shift, NULL, unsignedp, OPTAB_LIB_WIDEN); - if (comb == NULL) - goto fail; - - /* If the field exactly matches MODE, then all we need to do is return the - lowpart. Otherwise, shift to get the sign bits set properly. */ - result = force_reg (mode, gen_lowpart (mode, comb)); - - if (sign_shift_up) - result = expand_simple_binop (mode, ASHIFT, result, - GEN_INT (sign_shift_up), - NULL_RTX, 0, OPTAB_LIB_WIDEN); - if (sign_shift_dn) - result = expand_simple_binop (mode, unsignedp ? LSHIFTRT : ASHIFTRT, - result, GEN_INT (sign_shift_dn), - NULL_RTX, 0, OPTAB_LIB_WIDEN); - - return result; - - fail: - delete_insns_since (start); - return NULL; -} - /* Extract a bit field that is split across two words and return an RTX for the result.