return 1;
}
+/* Emit a potentially record-form instruction, setting DST from SRC.
+ If DOT is 0, that is all; otherwise, set CCREG to the result of the
+ signed comparison of DST with zero. If DOT is 1, the generated RTL
+ doesn't care about the DST result; if DOT is 2, it does. If CCREG
+ is CR0 do a single dot insn (as a PARALLEL); otherwise, do a SET and
+ a separate COMPARE. */
+
+static void
+rs6000_emit_dot_insn (rtx dst, rtx src, int dot, rtx ccreg)
+{
+ if (dot == 0)
+ {
+ emit_move_insn (dst, src);
+ return;
+ }
+
+ if (cc_reg_not_cr0_operand (ccreg, CCmode))
+ {
+ emit_move_insn (dst, src);
+ emit_move_insn (ccreg, gen_rtx_COMPARE (CCmode, dst, const0_rtx));
+ return;
+ }
+
+ rtx ccset = gen_rtx_SET (ccreg, gen_rtx_COMPARE (CCmode, src, const0_rtx));
+ if (dot == 1)
+ {
+ rtx clobber = gen_rtx_CLOBBER (VOIDmode, dst);
+ emit_insn (gen_rtx_PARALLEL (VOIDmode, gen_rtvec (2, ccset, clobber)));
+ }
+ else
+ {
+ rtx set = gen_rtx_SET (dst, src);
+ emit_insn (gen_rtx_PARALLEL (VOIDmode, gen_rtvec (2, ccset, set)));
+ }
+}
+
+\f
+/* Figure out the correct instructions to generate to load data for
+ block compare. MODE is used for the read from memory, and
+ data is zero extended if REG is wider than MODE. If LE code
+ is being generated, bswap loads are used.
+
+ REG is the destination register to move the data into.
+ MEM is the memory block being read.
+ MODE is the mode of memory to use for the read. */
+static void
+do_load_for_compare (rtx reg, rtx mem, machine_mode mode)
+{
+ switch (GET_MODE (reg))
+ {
+ case DImode:
+ switch (mode)
+ {
+ case QImode:
+ emit_insn (gen_zero_extendqidi2 (reg, mem));
+ break;
+ case HImode:
+ {
+ rtx src = mem;
+ if (TARGET_LITTLE_ENDIAN)
+ {
+ src = gen_reg_rtx (HImode);
+ emit_insn (gen_bswaphi2 (src, mem));
+ }
+ emit_insn (gen_zero_extendhidi2 (reg, src));
+ break;
+ }
+ case SImode:
+ {
+ rtx src = mem;
+ if (TARGET_LITTLE_ENDIAN)
+ {
+ src = gen_reg_rtx (SImode);
+ emit_insn (gen_bswapsi2 (src, mem));
+ }
+ emit_insn (gen_zero_extendsidi2 (reg, src));
+ }
+ break;
+ case DImode:
+ if (TARGET_LITTLE_ENDIAN)
+ emit_insn (gen_bswapdi2 (reg, mem));
+ else
+ emit_insn (gen_movdi (reg, mem));
+ break;
+ default:
+ gcc_unreachable ();
+ }
+ break;
+
+ case SImode:
+ switch (mode)
+ {
+ case QImode:
+ emit_insn (gen_zero_extendqisi2 (reg, mem));
+ break;
+ case HImode:
+ {
+ rtx src = mem;
+ if (TARGET_LITTLE_ENDIAN)
+ {
+ src = gen_reg_rtx (HImode);
+ emit_insn (gen_bswaphi2 (src, mem));
+ }
+ emit_insn (gen_zero_extendhisi2 (reg, src));
+ break;
+ }
+ case SImode:
+ if (TARGET_LITTLE_ENDIAN)
+ emit_insn (gen_bswapsi2 (reg, mem));
+ else
+ emit_insn (gen_movsi (reg, mem));
+ break;
+ case DImode:
+ /* DImode is larger than the destination reg so is not expected. */
+ gcc_unreachable ();
+ break;
+ default:
+ gcc_unreachable ();
+ }
+ break;
+ default:
+ gcc_unreachable ();
+ break;
+ }
+}
+
+/* Select the mode to be used for reading the next chunk of bytes
+ in the compare.
+
+ OFFSET is the current read offset from the beginning of the block.
+ BYTES is the number of bytes remaining to be read.
+ ALIGN is the minimum alignment of the memory blocks being compared in bytes.
+ WORD_MODE_OK indicates using WORD_MODE is allowed, else SImode is
+ the largest allowable mode. */
+static machine_mode
+select_block_compare_mode (HOST_WIDE_INT offset, HOST_WIDE_INT bytes,
+ HOST_WIDE_INT align, bool word_mode_ok)
+{
+ /* First see if we can do a whole load unit
+ as that will be more efficient than a larger load + shift. */
+
+ /* If big, use biggest chunk.
+ If exactly chunk size, use that size.
+ If remainder can be done in one piece with shifting, do that.
+ Do largest chunk possible without violating alignment rules. */
+
+ /* The most we can read without potential page crossing. */
+ HOST_WIDE_INT maxread = ROUND_UP (bytes, align);
+
+ if (word_mode_ok && bytes >= UNITS_PER_WORD)
+ return word_mode;
+ else if (bytes == GET_MODE_SIZE (SImode))
+ return SImode;
+ else if (bytes == GET_MODE_SIZE (HImode))
+ return HImode;
+ else if (bytes == GET_MODE_SIZE (QImode))
+ return QImode;
+ else if (bytes < GET_MODE_SIZE (SImode)
+ && offset >= GET_MODE_SIZE (SImode) - bytes)
+ /* This matches the case were we have SImode and 3 bytes
+ and offset >= 1 and permits us to move back one and overlap
+ with the previous read, thus avoiding having to shift
+ unwanted bytes off of the input. */
+ return SImode;
+ else if (word_mode_ok && bytes < UNITS_PER_WORD
+ && offset >= UNITS_PER_WORD-bytes)
+ /* Similarly, if we can use DImode it will get matched here and
+ can do an overlapping read that ends at the end of the block. */
+ return word_mode;
+ else if (word_mode_ok && maxread >= UNITS_PER_WORD)
+ /* It is safe to do all remaining in one load of largest size,
+ possibly with a shift to get rid of unwanted bytes. */
+ return word_mode;
+ else if (maxread >= GET_MODE_SIZE (SImode))
+ /* It is safe to do all remaining in one SImode load,
+ possibly with a shift to get rid of unwanted bytes. */
+ return SImode;
+ else if (bytes > GET_MODE_SIZE (SImode))
+ return SImode;
+ else if (bytes > GET_MODE_SIZE (HImode))
+ return HImode;
+
+ /* final fallback is do one byte */
+ return QImode;
+}
+
+/* Compute the alignment of pointer+OFFSET where the original alignment
+ of pointer was BASE_ALIGN. */
+static HOST_WIDE_INT
+compute_current_alignment (HOST_WIDE_INT base_align, HOST_WIDE_INT offset)
+{
+ if (offset == 0)
+ return base_align;
+ return min (base_align, offset & -offset);
+}
+
+/* Expand a block compare operation, and return true if successful.
+ Return false if we should let the compiler generate normal code,
+ probably a memcmp call.
+
+ OPERANDS[0] is the target (result).
+ OPERANDS[1] is the first source.
+ OPERANDS[2] is the second source.
+ OPERANDS[3] is the length.
+ OPERANDS[4] is the alignment. */
+bool
+expand_block_compare (rtx operands[])
+{
+ rtx target = operands[0];
+ rtx orig_src1 = operands[1];
+ rtx orig_src2 = operands[2];
+ rtx bytes_rtx = operands[3];
+ rtx align_rtx = operands[4];
+ HOST_WIDE_INT cmp_bytes = 0;
+ rtx src1 = orig_src1;
+ rtx src2 = orig_src2;
+
+ /* If this is not a fixed size compare, just call memcmp */
+ if (!CONST_INT_P (bytes_rtx))
+ return false;
+
+ /* This must be a fixed size alignment */
+ if (!CONST_INT_P (align_rtx))
+ return false;
+
+ int base_align = INTVAL (align_rtx) / BITS_PER_UNIT;
+
+ /* SLOW_UNALIGNED_ACCESS -- don't do unaligned stuff */
+ if (SLOW_UNALIGNED_ACCESS (word_mode, MEM_ALIGN (orig_src1))
+ || SLOW_UNALIGNED_ACCESS (word_mode, MEM_ALIGN (orig_src2)))
+ return false;
+
+ gcc_assert (GET_MODE (target) == SImode);
+
+ /* Anything to move? */
+ HOST_WIDE_INT bytes = INTVAL (bytes_rtx);
+ if (bytes <= 0)
+ return true;
+
+ rtx tmp_reg_src1 = gen_reg_rtx (word_mode);
+ rtx tmp_reg_src2 = gen_reg_rtx (word_mode);
+
+ /* If we have an LE target without ldbrx and word_mode is DImode,
+ then we must avoid using word_mode. */
+ int word_mode_ok = !(TARGET_LITTLE_ENDIAN && !TARGET_LDBRX
+ && word_mode == DImode);
+
+ /* Strategy phase. How many ops will this take and should we expand it? */
+
+ int offset = 0;
+ machine_mode load_mode =
+ select_block_compare_mode (offset, bytes, base_align, word_mode_ok);
+ int load_mode_size = GET_MODE_SIZE (load_mode);
+
+ /* We don't want to generate too much code. */
+ if (ROUND_UP (bytes, load_mode_size) / load_mode_size
+ > rs6000_block_compare_inline_limit)
+ return false;
+
+ bool generate_6432_conversion = false;
+ rtx convert_label = NULL;
+ rtx final_label = NULL;
+
+ /* Example of generated code for 11 bytes aligned 1 byte:
+ .L10:
+ ldbrx 10,6,9
+ ldbrx 9,7,9
+ subf. 9,9,10
+ bne 0,.L8
+ addi 9,4,7
+ lwbrx 10,0,9
+ addi 9,5,7
+ lwbrx 9,0,9
+ subf 9,9,10
+ b .L9
+ .L8: # convert_label
+ cntlzd 9,9
+ addi 9,9,-1
+ xori 9,9,0x3f
+ .L9: # final_label
+
+ We start off with DImode and have a compare/branch to something
+ with a smaller mode then we will need a block with the DI->SI conversion
+ that may or may not be executed. */
+
+ while (bytes > 0)
+ {
+ int align = compute_current_alignment (base_align, offset);
+ load_mode = select_block_compare_mode(offset, bytes, align, word_mode_ok);
+ load_mode_size = GET_MODE_SIZE (load_mode);
+ if (bytes >= load_mode_size)
+ cmp_bytes = load_mode_size;
+ else
+ {
+ /* Move this load back so it doesn't go past the end. */
+ int extra_bytes = load_mode_size - bytes;
+ cmp_bytes = bytes;
+ if (extra_bytes < offset)
+ {
+ offset -= extra_bytes;
+ cmp_bytes = load_mode_size;
+ bytes = cmp_bytes;
+ }
+ }
+
+ src1 = adjust_address (orig_src1, load_mode, offset);
+ src2 = adjust_address (orig_src2, load_mode, offset);
+
+ if (!REG_P (XEXP (src1, 0)))
+ {
+ rtx src1_reg = copy_addr_to_reg (XEXP (src1, 0));
+ src1 = replace_equiv_address (src1, src1_reg);
+ }
+ set_mem_size (src1, cmp_bytes);
+
+ if (!REG_P (XEXP (src2, 0)))
+ {
+ rtx src2_reg = copy_addr_to_reg (XEXP (src2, 0));
+ src2 = replace_equiv_address (src2, src2_reg);
+ }
+ set_mem_size (src2, cmp_bytes);
+
+ do_load_for_compare (tmp_reg_src1, src1, load_mode);
+ do_load_for_compare (tmp_reg_src2, src2, load_mode);
+
+ if (cmp_bytes < load_mode_size)
+ {
+ /* Shift unneeded bytes off. */
+ rtx sh = GEN_INT (BITS_PER_UNIT * (load_mode_size - cmp_bytes));
+ if (word_mode == DImode)
+ {
+ emit_insn (gen_lshrdi3 (tmp_reg_src1, tmp_reg_src1, sh));
+ emit_insn (gen_lshrdi3 (tmp_reg_src2, tmp_reg_src2, sh));
+ }
+ else
+ {
+ emit_insn (gen_lshrsi3 (tmp_reg_src1, tmp_reg_src1, sh));
+ emit_insn (gen_lshrsi3 (tmp_reg_src2, tmp_reg_src2, sh));
+ }
+ }
+
+ /* We previously did a block that need 64->32 conversion but
+ the current block does not, so a label is needed to jump
+ to the end. */
+ if (generate_6432_conversion && !final_label
+ && GET_MODE_SIZE (GET_MODE (target)) >= load_mode_size)
+ final_label = gen_label_rtx ();
+
+ /* Do we need a 64->32 conversion block? */
+ int remain = bytes - cmp_bytes;
+ if (GET_MODE_SIZE (GET_MODE (target)) < GET_MODE_SIZE (load_mode))
+ {
+ generate_6432_conversion = true;
+ if (remain > 0 && !convert_label)
+ convert_label = gen_label_rtx ();
+ }
+
+ if (GET_MODE_SIZE (GET_MODE (target)) >= GET_MODE_SIZE (load_mode))
+ {
+ /* Target is larger than load size so we don't need to
+ reduce result size. */
+ if (remain > 0)
+ {
+ /* This is not the last block, branch to the end if the result
+ of this subtract is not zero. */
+ if (!final_label)
+ final_label = gen_label_rtx ();
+ rtx fin_ref = gen_rtx_LABEL_REF (VOIDmode, final_label);
+ rtx cond = gen_reg_rtx (CCmode);
+ rtx tmp = gen_rtx_MINUS (word_mode, tmp_reg_src1, tmp_reg_src2);
+ rs6000_emit_dot_insn (tmp_reg_src2, tmp, 2, cond);
+ emit_insn (gen_movsi (target, gen_lowpart (SImode, tmp_reg_src2)));
+ rtx ne_rtx = gen_rtx_NE (VOIDmode, cond, const0_rtx);
+ rtx ifelse = gen_rtx_IF_THEN_ELSE (VOIDmode, ne_rtx,
+ fin_ref, pc_rtx);
+ rtx j = emit_jump_insn (gen_rtx_SET (pc_rtx, ifelse));
+ JUMP_LABEL (j) = final_label;
+ LABEL_NUSES (final_label) += 1;
+ }
+ else
+ {
+ if (word_mode == DImode)
+ {
+ emit_insn (gen_subdi3 (tmp_reg_src2, tmp_reg_src1,
+ tmp_reg_src2));
+ emit_insn (gen_movsi (target,
+ gen_lowpart (SImode, tmp_reg_src2)));
+ }
+ else
+ emit_insn (gen_subsi3 (target, tmp_reg_src1, tmp_reg_src2));
+
+ if (final_label)
+ {
+ rtx fin_ref = gen_rtx_LABEL_REF (VOIDmode, final_label);
+ rtx j = emit_jump_insn (gen_rtx_SET (pc_rtx, fin_ref));
+ JUMP_LABEL(j) = final_label;
+ LABEL_NUSES (final_label) += 1;
+ emit_barrier ();
+ }
+ }
+ }
+ else
+ {
+ generate_6432_conversion = true;
+ if (remain > 0)
+ {
+ if (!convert_label)
+ convert_label = gen_label_rtx ();
+
+ /* Compare to zero and branch to convert_label if not zero. */
+ rtx cvt_ref = gen_rtx_LABEL_REF (VOIDmode, convert_label);
+ rtx cond = gen_reg_rtx (CCmode);
+ rtx tmp = gen_rtx_MINUS (DImode, tmp_reg_src1, tmp_reg_src2);
+ rs6000_emit_dot_insn (tmp_reg_src2, tmp, 2, cond);
+ rtx ne_rtx = gen_rtx_NE (VOIDmode, cond, const0_rtx);
+ rtx ifelse = gen_rtx_IF_THEN_ELSE (VOIDmode, ne_rtx,
+ cvt_ref, pc_rtx);
+ rtx j = emit_jump_insn (gen_rtx_SET (pc_rtx, ifelse));
+ JUMP_LABEL(j) = convert_label;
+ LABEL_NUSES (convert_label) += 1;
+ }
+ else
+ {
+ /* Just do the subtract. Since this is the last block the
+ convert code will be generated immediately following. */
+ emit_insn (gen_subdi3 (tmp_reg_src2, tmp_reg_src1,
+ tmp_reg_src2));
+ }
+ }
+
+ offset += cmp_bytes;
+ bytes -= cmp_bytes;
+ }
+
+ if (generate_6432_conversion)
+ {
+ if (convert_label)
+ emit_label (convert_label);
+
+ /* We need to produce DI result from sub, then convert to target SI
+ while maintaining <0 / ==0 / >0 properties.
+ Segher's sequence: cntlzd 3,3 ; addi 3,3,-1 ; xori 3,3,63 */
+ emit_insn (gen_clzdi2 (tmp_reg_src2, tmp_reg_src2));
+ emit_insn (gen_adddi3 (tmp_reg_src2, tmp_reg_src2, GEN_INT (-1)));
+ emit_insn (gen_xordi3 (tmp_reg_src2, tmp_reg_src2, GEN_INT (63)));
+ emit_insn (gen_movsi (target, gen_lowpart (SImode, tmp_reg_src2)));
+ }
+
+ if (final_label)
+ emit_label (final_label);
+
+ gcc_assert (bytes == 0);
+ return true;
+}
+
\f
/* Expand a block move operation, and return 1 if successful. Return 0
if we should let the compiler generate normal code.
return rs6000_is_valid_and_mask (GEN_INT (val + bit3 - bit2), mode);
}
-/* Emit a potentially record-form instruction, setting DST from SRC.
- If DOT is 0, that is all; otherwise, set CCREG to the result of the
- signed comparison of DST with zero. If DOT is 1, the generated RTL
- doesn't care about the DST result; if DOT is 2, it does. If CCREG
- is CR0 do a single dot insn (as a PARALLEL); otherwise, do a SET and
- a separate COMPARE. */
-
-static void
-rs6000_emit_dot_insn (rtx dst, rtx src, int dot, rtx ccreg)
-{
- if (dot == 0)
- {
- emit_move_insn (dst, src);
- return;
- }
-
- if (cc_reg_not_cr0_operand (ccreg, CCmode))
- {
- emit_move_insn (dst, src);
- emit_move_insn (ccreg, gen_rtx_COMPARE (CCmode, dst, const0_rtx));
- return;
- }
-
- rtx ccset = gen_rtx_SET (ccreg, gen_rtx_COMPARE (CCmode, src, const0_rtx));
- if (dot == 1)
- {
- rtx clobber = gen_rtx_CLOBBER (VOIDmode, dst);
- emit_insn (gen_rtx_PARALLEL (VOIDmode, gen_rtvec (2, ccset, clobber)));
- }
- else
- {
- rtx set = gen_rtx_SET (dst, src);
- emit_insn (gen_rtx_PARALLEL (VOIDmode, gen_rtvec (2, ccset, set)));
- }
-}
-
/* Emit the two insns to do an AND in mode MODE, with operands OPERANDS.
If EXPAND is true, split rotate-and-mask instructions we generate to
their constituent parts as well (this is used during expand); if DOT
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