| /* Decompose multiword subregs. |
| Copyright (C) 2007-2017 Free Software Foundation, Inc. |
| Contributed by Richard Henderson <rth@redhat.com> |
| Ian Lance Taylor <iant@google.com> |
| |
| This file is part of GCC. |
| |
| GCC is free software; you can redistribute it and/or modify it under |
| the terms of the GNU General Public License as published by the Free |
| Software Foundation; either version 3, or (at your option) any later |
| version. |
| |
| GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
| WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GCC; see the file COPYING3. If not see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include "config.h" |
| #include "system.h" |
| #include "coretypes.h" |
| #include "backend.h" |
| #include "rtl.h" |
| #include "tree.h" |
| #include "cfghooks.h" |
| #include "df.h" |
| #include "memmodel.h" |
| #include "tm_p.h" |
| #include "expmed.h" |
| #include "insn-config.h" |
| #include "emit-rtl.h" |
| #include "recog.h" |
| #include "cfgrtl.h" |
| #include "cfgbuild.h" |
| #include "dce.h" |
| #include "expr.h" |
| #include "tree-pass.h" |
| #include "lower-subreg.h" |
| #include "rtl-iter.h" |
| #include "target.h" |
| |
| |
| /* Decompose multi-word pseudo-registers into individual |
| pseudo-registers when possible and profitable. This is possible |
| when all the uses of a multi-word register are via SUBREG, or are |
| copies of the register to another location. Breaking apart the |
| register permits more CSE and permits better register allocation. |
| This is profitable if the machine does not have move instructions |
| to do this. |
| |
| This pass only splits moves with modes that are wider than |
| word_mode and ASHIFTs, LSHIFTRTs, ASHIFTRTs and ZERO_EXTENDs with |
| integer modes that are twice the width of word_mode. The latter |
| could be generalized if there was a need to do this, but the trend in |
| architectures is to not need this. |
| |
| There are two useful preprocessor defines for use by maintainers: |
| |
| #define LOG_COSTS 1 |
| |
| if you wish to see the actual cost estimates that are being used |
| for each mode wider than word mode and the cost estimates for zero |
| extension and the shifts. This can be useful when port maintainers |
| are tuning insn rtx costs. |
| |
| #define FORCE_LOWERING 1 |
| |
| if you wish to test the pass with all the transformation forced on. |
| This can be useful for finding bugs in the transformations. */ |
| |
| #define LOG_COSTS 0 |
| #define FORCE_LOWERING 0 |
| |
| /* Bit N in this bitmap is set if regno N is used in a context in |
| which we can decompose it. */ |
| static bitmap decomposable_context; |
| |
| /* Bit N in this bitmap is set if regno N is used in a context in |
| which it can not be decomposed. */ |
| static bitmap non_decomposable_context; |
| |
| /* Bit N in this bitmap is set if regno N is used in a subreg |
| which changes the mode but not the size. This typically happens |
| when the register accessed as a floating-point value; we want to |
| avoid generating accesses to its subwords in integer modes. */ |
| static bitmap subreg_context; |
| |
| /* Bit N in the bitmap in element M of this array is set if there is a |
| copy from reg M to reg N. */ |
| static vec<bitmap> reg_copy_graph; |
| |
| struct target_lower_subreg default_target_lower_subreg; |
| #if SWITCHABLE_TARGET |
| struct target_lower_subreg *this_target_lower_subreg |
| = &default_target_lower_subreg; |
| #endif |
| |
| #define twice_word_mode \ |
| this_target_lower_subreg->x_twice_word_mode |
| #define choices \ |
| this_target_lower_subreg->x_choices |
| |
| /* Return true if MODE is a mode we know how to lower. When returning true, |
| store its byte size in *BYTES and its word size in *WORDS. */ |
| |
| static inline bool |
| interesting_mode_p (machine_mode mode, unsigned int *bytes, |
| unsigned int *words) |
| { |
| *bytes = GET_MODE_SIZE (mode); |
| *words = CEIL (*bytes, UNITS_PER_WORD); |
| return true; |
| } |
| |
| /* RTXes used while computing costs. */ |
| struct cost_rtxes { |
| /* Source and target registers. */ |
| rtx source; |
| rtx target; |
| |
| /* A twice_word_mode ZERO_EXTEND of SOURCE. */ |
| rtx zext; |
| |
| /* A shift of SOURCE. */ |
| rtx shift; |
| |
| /* A SET of TARGET. */ |
| rtx set; |
| }; |
| |
| /* Return the cost of a CODE shift in mode MODE by OP1 bits, using the |
| rtxes in RTXES. SPEED_P selects between the speed and size cost. */ |
| |
| static int |
| shift_cost (bool speed_p, struct cost_rtxes *rtxes, enum rtx_code code, |
| machine_mode mode, int op1) |
| { |
| PUT_CODE (rtxes->shift, code); |
| PUT_MODE (rtxes->shift, mode); |
| PUT_MODE (rtxes->source, mode); |
| XEXP (rtxes->shift, 1) = GEN_INT (op1); |
| return set_src_cost (rtxes->shift, mode, speed_p); |
| } |
| |
| /* For each X in the range [0, BITS_PER_WORD), set SPLITTING[X] |
| to true if it is profitable to split a double-word CODE shift |
| of X + BITS_PER_WORD bits. SPEED_P says whether we are testing |
| for speed or size profitability. |
| |
| Use the rtxes in RTXES to calculate costs. WORD_MOVE_ZERO_COST is |
| the cost of moving zero into a word-mode register. WORD_MOVE_COST |
| is the cost of moving between word registers. */ |
| |
| static void |
| compute_splitting_shift (bool speed_p, struct cost_rtxes *rtxes, |
| bool *splitting, enum rtx_code code, |
| int word_move_zero_cost, int word_move_cost) |
| { |
| int wide_cost, narrow_cost, upper_cost, i; |
| |
| for (i = 0; i < BITS_PER_WORD; i++) |
| { |
| wide_cost = shift_cost (speed_p, rtxes, code, twice_word_mode, |
| i + BITS_PER_WORD); |
| if (i == 0) |
| narrow_cost = word_move_cost; |
| else |
| narrow_cost = shift_cost (speed_p, rtxes, code, word_mode, i); |
| |
| if (code != ASHIFTRT) |
| upper_cost = word_move_zero_cost; |
| else if (i == BITS_PER_WORD - 1) |
| upper_cost = word_move_cost; |
| else |
| upper_cost = shift_cost (speed_p, rtxes, code, word_mode, |
| BITS_PER_WORD - 1); |
| |
| if (LOG_COSTS) |
| fprintf (stderr, "%s %s by %d: original cost %d, split cost %d + %d\n", |
| GET_MODE_NAME (twice_word_mode), GET_RTX_NAME (code), |
| i + BITS_PER_WORD, wide_cost, narrow_cost, upper_cost); |
| |
| if (FORCE_LOWERING || wide_cost >= narrow_cost + upper_cost) |
| splitting[i] = true; |
| } |
| } |
| |
| /* Compute what we should do when optimizing for speed or size; SPEED_P |
| selects which. Use RTXES for computing costs. */ |
| |
| static void |
| compute_costs (bool speed_p, struct cost_rtxes *rtxes) |
| { |
| unsigned int i; |
| int word_move_zero_cost, word_move_cost; |
| |
| PUT_MODE (rtxes->target, word_mode); |
| SET_SRC (rtxes->set) = CONST0_RTX (word_mode); |
| word_move_zero_cost = set_rtx_cost (rtxes->set, speed_p); |
| |
| SET_SRC (rtxes->set) = rtxes->source; |
| word_move_cost = set_rtx_cost (rtxes->set, speed_p); |
| |
| if (LOG_COSTS) |
| fprintf (stderr, "%s move: from zero cost %d, from reg cost %d\n", |
| GET_MODE_NAME (word_mode), word_move_zero_cost, word_move_cost); |
| |
| for (i = 0; i < MAX_MACHINE_MODE; i++) |
| { |
| machine_mode mode = (machine_mode) i; |
| unsigned int size, factor; |
| if (interesting_mode_p (mode, &size, &factor) && factor > 1) |
| { |
| unsigned int mode_move_cost; |
| |
| PUT_MODE (rtxes->target, mode); |
| PUT_MODE (rtxes->source, mode); |
| mode_move_cost = set_rtx_cost (rtxes->set, speed_p); |
| |
| if (LOG_COSTS) |
| fprintf (stderr, "%s move: original cost %d, split cost %d * %d\n", |
| GET_MODE_NAME (mode), mode_move_cost, |
| word_move_cost, factor); |
| |
| if (FORCE_LOWERING || mode_move_cost >= word_move_cost * factor) |
| { |
| choices[speed_p].move_modes_to_split[i] = true; |
| choices[speed_p].something_to_do = true; |
| } |
| } |
| } |
| |
| /* For the moves and shifts, the only case that is checked is one |
| where the mode of the target is an integer mode twice the width |
| of the word_mode. |
| |
| If it is not profitable to split a double word move then do not |
| even consider the shifts or the zero extension. */ |
| if (choices[speed_p].move_modes_to_split[(int) twice_word_mode]) |
| { |
| int zext_cost; |
| |
| /* The only case here to check to see if moving the upper part with a |
| zero is cheaper than doing the zext itself. */ |
| PUT_MODE (rtxes->source, word_mode); |
| zext_cost = set_src_cost (rtxes->zext, twice_word_mode, speed_p); |
| |
| if (LOG_COSTS) |
| fprintf (stderr, "%s %s: original cost %d, split cost %d + %d\n", |
| GET_MODE_NAME (twice_word_mode), GET_RTX_NAME (ZERO_EXTEND), |
| zext_cost, word_move_cost, word_move_zero_cost); |
| |
| if (FORCE_LOWERING || zext_cost >= word_move_cost + word_move_zero_cost) |
| choices[speed_p].splitting_zext = true; |
| |
| compute_splitting_shift (speed_p, rtxes, |
| choices[speed_p].splitting_ashift, ASHIFT, |
| word_move_zero_cost, word_move_cost); |
| compute_splitting_shift (speed_p, rtxes, |
| choices[speed_p].splitting_lshiftrt, LSHIFTRT, |
| word_move_zero_cost, word_move_cost); |
| compute_splitting_shift (speed_p, rtxes, |
| choices[speed_p].splitting_ashiftrt, ASHIFTRT, |
| word_move_zero_cost, word_move_cost); |
| } |
| } |
| |
| /* Do one-per-target initialisation. This involves determining |
| which operations on the machine are profitable. If none are found, |
| then the pass just returns when called. */ |
| |
| void |
| init_lower_subreg (void) |
| { |
| struct cost_rtxes rtxes; |
| |
| memset (this_target_lower_subreg, 0, sizeof (*this_target_lower_subreg)); |
| |
| twice_word_mode = GET_MODE_2XWIDER_MODE (word_mode).require (); |
| |
| rtxes.target = gen_rtx_REG (word_mode, LAST_VIRTUAL_REGISTER + 1); |
| rtxes.source = gen_rtx_REG (word_mode, LAST_VIRTUAL_REGISTER + 2); |
| rtxes.set = gen_rtx_SET (rtxes.target, rtxes.source); |
| rtxes.zext = gen_rtx_ZERO_EXTEND (twice_word_mode, rtxes.source); |
| rtxes.shift = gen_rtx_ASHIFT (twice_word_mode, rtxes.source, const0_rtx); |
| |
| if (LOG_COSTS) |
| fprintf (stderr, "\nSize costs\n==========\n\n"); |
| compute_costs (false, &rtxes); |
| |
| if (LOG_COSTS) |
| fprintf (stderr, "\nSpeed costs\n===========\n\n"); |
| compute_costs (true, &rtxes); |
| } |
| |
| static bool |
| simple_move_operand (rtx x) |
| { |
| if (GET_CODE (x) == SUBREG) |
| x = SUBREG_REG (x); |
| |
| if (!OBJECT_P (x)) |
| return false; |
| |
| if (GET_CODE (x) == LABEL_REF |
| || GET_CODE (x) == SYMBOL_REF |
| || GET_CODE (x) == HIGH |
| || GET_CODE (x) == CONST) |
| return false; |
| |
| if (MEM_P (x) |
| && (MEM_VOLATILE_P (x) |
| || mode_dependent_address_p (XEXP (x, 0), MEM_ADDR_SPACE (x)))) |
| return false; |
| |
| return true; |
| } |
| |
| /* If INSN is a single set between two objects that we want to split, |
| return the single set. SPEED_P says whether we are optimizing |
| INSN for speed or size. |
| |
| INSN should have been passed to recog and extract_insn before this |
| is called. */ |
| |
| static rtx |
| simple_move (rtx_insn *insn, bool speed_p) |
| { |
| rtx x; |
| rtx set; |
| machine_mode mode; |
| |
| if (recog_data.n_operands != 2) |
| return NULL_RTX; |
| |
| set = single_set (insn); |
| if (!set) |
| return NULL_RTX; |
| |
| x = SET_DEST (set); |
| if (x != recog_data.operand[0] && x != recog_data.operand[1]) |
| return NULL_RTX; |
| if (!simple_move_operand (x)) |
| return NULL_RTX; |
| |
| x = SET_SRC (set); |
| if (x != recog_data.operand[0] && x != recog_data.operand[1]) |
| return NULL_RTX; |
| /* For the src we can handle ASM_OPERANDS, and it is beneficial for |
| things like x86 rdtsc which returns a DImode value. */ |
| if (GET_CODE (x) != ASM_OPERANDS |
| && !simple_move_operand (x)) |
| return NULL_RTX; |
| |
| /* We try to decompose in integer modes, to avoid generating |
| inefficient code copying between integer and floating point |
| registers. That means that we can't decompose if this is a |
| non-integer mode for which there is no integer mode of the same |
| size. */ |
| mode = GET_MODE (SET_DEST (set)); |
| if (!SCALAR_INT_MODE_P (mode) |
| && !int_mode_for_size (GET_MODE_BITSIZE (mode), 0).exists ()) |
| return NULL_RTX; |
| |
| /* Reject PARTIAL_INT modes. They are used for processor specific |
| purposes and it's probably best not to tamper with them. */ |
| if (GET_MODE_CLASS (mode) == MODE_PARTIAL_INT) |
| return NULL_RTX; |
| |
| if (!choices[speed_p].move_modes_to_split[(int) mode]) |
| return NULL_RTX; |
| |
| return set; |
| } |
| |
| /* If SET is a copy from one multi-word pseudo-register to another, |
| record that in reg_copy_graph. Return whether it is such a |
| copy. */ |
| |
| static bool |
| find_pseudo_copy (rtx set) |
| { |
| rtx dest = SET_DEST (set); |
| rtx src = SET_SRC (set); |
| unsigned int rd, rs; |
| bitmap b; |
| |
| if (!REG_P (dest) || !REG_P (src)) |
| return false; |
| |
| rd = REGNO (dest); |
| rs = REGNO (src); |
| if (HARD_REGISTER_NUM_P (rd) || HARD_REGISTER_NUM_P (rs)) |
| return false; |
| |
| b = reg_copy_graph[rs]; |
| if (b == NULL) |
| { |
| b = BITMAP_ALLOC (NULL); |
| reg_copy_graph[rs] = b; |
| } |
| |
| bitmap_set_bit (b, rd); |
| |
| return true; |
| } |
| |
| /* Look through the registers in DECOMPOSABLE_CONTEXT. For each case |
| where they are copied to another register, add the register to |
| which they are copied to DECOMPOSABLE_CONTEXT. Use |
| NON_DECOMPOSABLE_CONTEXT to limit this--we don't bother to track |
| copies of registers which are in NON_DECOMPOSABLE_CONTEXT. */ |
| |
| static void |
| propagate_pseudo_copies (void) |
| { |
| auto_bitmap queue, propagate; |
| |
| bitmap_copy (queue, decomposable_context); |
| do |
| { |
| bitmap_iterator iter; |
| unsigned int i; |
| |
| bitmap_clear (propagate); |
| |
| EXECUTE_IF_SET_IN_BITMAP (queue, 0, i, iter) |
| { |
| bitmap b = reg_copy_graph[i]; |
| if (b) |
| bitmap_ior_and_compl_into (propagate, b, non_decomposable_context); |
| } |
| |
| bitmap_and_compl (queue, propagate, decomposable_context); |
| bitmap_ior_into (decomposable_context, propagate); |
| } |
| while (!bitmap_empty_p (queue)); |
| } |
| |
| /* A pointer to one of these values is passed to |
| find_decomposable_subregs. */ |
| |
| enum classify_move_insn |
| { |
| /* Not a simple move from one location to another. */ |
| NOT_SIMPLE_MOVE, |
| /* A simple move we want to decompose. */ |
| DECOMPOSABLE_SIMPLE_MOVE, |
| /* Any other simple move. */ |
| SIMPLE_MOVE |
| }; |
| |
| /* If we find a SUBREG in *LOC which we could use to decompose a |
| pseudo-register, set a bit in DECOMPOSABLE_CONTEXT. If we find an |
| unadorned register which is not a simple pseudo-register copy, |
| DATA will point at the type of move, and we set a bit in |
| DECOMPOSABLE_CONTEXT or NON_DECOMPOSABLE_CONTEXT as appropriate. */ |
| |
| static void |
| find_decomposable_subregs (rtx *loc, enum classify_move_insn *pcmi) |
| { |
| subrtx_var_iterator::array_type array; |
| FOR_EACH_SUBRTX_VAR (iter, array, *loc, NONCONST) |
| { |
| rtx x = *iter; |
| if (GET_CODE (x) == SUBREG) |
| { |
| rtx inner = SUBREG_REG (x); |
| unsigned int regno, outer_size, inner_size, outer_words, inner_words; |
| |
| if (!REG_P (inner)) |
| continue; |
| |
| regno = REGNO (inner); |
| if (HARD_REGISTER_NUM_P (regno)) |
| { |
| iter.skip_subrtxes (); |
| continue; |
| } |
| |
| if (!interesting_mode_p (GET_MODE (x), &outer_size, &outer_words) |
| || !interesting_mode_p (GET_MODE (inner), &inner_size, |
| &inner_words)) |
| continue; |
| |
| /* We only try to decompose single word subregs of multi-word |
| registers. When we find one, we return -1 to avoid iterating |
| over the inner register. |
| |
| ??? This doesn't allow, e.g., DImode subregs of TImode values |
| on 32-bit targets. We would need to record the way the |
| pseudo-register was used, and only decompose if all the uses |
| were the same number and size of pieces. Hopefully this |
| doesn't happen much. */ |
| |
| if (outer_words == 1 && inner_words > 1) |
| { |
| bitmap_set_bit (decomposable_context, regno); |
| iter.skip_subrtxes (); |
| continue; |
| } |
| |
| /* If this is a cast from one mode to another, where the modes |
| have the same size, and they are not tieable, then mark this |
| register as non-decomposable. If we decompose it we are |
| likely to mess up whatever the backend is trying to do. */ |
| if (outer_words > 1 |
| && outer_size == inner_size |
| && !targetm.modes_tieable_p (GET_MODE (x), GET_MODE (inner))) |
| { |
| bitmap_set_bit (non_decomposable_context, regno); |
| bitmap_set_bit (subreg_context, regno); |
| iter.skip_subrtxes (); |
| continue; |
| } |
| } |
| else if (REG_P (x)) |
| { |
| unsigned int regno, size, words; |
| |
| /* We will see an outer SUBREG before we see the inner REG, so |
| when we see a plain REG here it means a direct reference to |
| the register. |
| |
| If this is not a simple copy from one location to another, |
| then we can not decompose this register. If this is a simple |
| copy we want to decompose, and the mode is right, |
| then we mark the register as decomposable. |
| Otherwise we don't say anything about this register -- |
| it could be decomposed, but whether that would be |
| profitable depends upon how it is used elsewhere. |
| |
| We only set bits in the bitmap for multi-word |
| pseudo-registers, since those are the only ones we care about |
| and it keeps the size of the bitmaps down. */ |
| |
| regno = REGNO (x); |
| if (!HARD_REGISTER_NUM_P (regno) |
| && interesting_mode_p (GET_MODE (x), &size, &words) |
| && words > 1) |
| { |
| switch (*pcmi) |
| { |
| case NOT_SIMPLE_MOVE: |
| bitmap_set_bit (non_decomposable_context, regno); |
| break; |
| case DECOMPOSABLE_SIMPLE_MOVE: |
| if (targetm.modes_tieable_p (GET_MODE (x), word_mode)) |
| bitmap_set_bit (decomposable_context, regno); |
| break; |
| case SIMPLE_MOVE: |
| break; |
| default: |
| gcc_unreachable (); |
| } |
| } |
| } |
| else if (MEM_P (x)) |
| { |
| enum classify_move_insn cmi_mem = NOT_SIMPLE_MOVE; |
| |
| /* Any registers used in a MEM do not participate in a |
| SIMPLE_MOVE or DECOMPOSABLE_SIMPLE_MOVE. Do our own recursion |
| here, and return -1 to block the parent's recursion. */ |
| find_decomposable_subregs (&XEXP (x, 0), &cmi_mem); |
| iter.skip_subrtxes (); |
| } |
| } |
| } |
| |
| /* Decompose REGNO into word-sized components. We smash the REG node |
| in place. This ensures that (1) something goes wrong quickly if we |
| fail to make some replacement, and (2) the debug information inside |
| the symbol table is automatically kept up to date. */ |
| |
| static void |
| decompose_register (unsigned int regno) |
| { |
| rtx reg; |
| unsigned int size, words, i; |
| rtvec v; |
| |
| reg = regno_reg_rtx[regno]; |
| |
| regno_reg_rtx[regno] = NULL_RTX; |
| |
| if (!interesting_mode_p (GET_MODE (reg), &size, &words)) |
| gcc_unreachable (); |
| |
| v = rtvec_alloc (words); |
| for (i = 0; i < words; ++i) |
| RTVEC_ELT (v, i) = gen_reg_rtx_offset (reg, word_mode, i * UNITS_PER_WORD); |
| |
| PUT_CODE (reg, CONCATN); |
| XVEC (reg, 0) = v; |
| |
| if (dump_file) |
| { |
| fprintf (dump_file, "; Splitting reg %u ->", regno); |
| for (i = 0; i < words; ++i) |
| fprintf (dump_file, " %u", REGNO (XVECEXP (reg, 0, i))); |
| fputc ('\n', dump_file); |
| } |
| } |
| |
| /* Get a SUBREG of a CONCATN. */ |
| |
| static rtx |
| simplify_subreg_concatn (machine_mode outermode, rtx op, |
| unsigned int byte) |
| { |
| unsigned int outer_size, outer_words, inner_size, inner_words; |
| machine_mode innermode, partmode; |
| rtx part; |
| unsigned int final_offset; |
| |
| innermode = GET_MODE (op); |
| if (!interesting_mode_p (outermode, &outer_size, &outer_words) |
| || !interesting_mode_p (innermode, &inner_size, &inner_words)) |
| gcc_unreachable (); |
| |
| gcc_assert (GET_CODE (op) == CONCATN); |
| gcc_assert (byte % outer_size == 0); |
| |
| gcc_assert (byte < inner_size); |
| if (outer_size > inner_size) |
| return NULL_RTX; |
| |
| inner_size /= XVECLEN (op, 0); |
| part = XVECEXP (op, 0, byte / inner_size); |
| partmode = GET_MODE (part); |
| |
| final_offset = byte % inner_size; |
| if (final_offset + outer_size > inner_size) |
| return NULL_RTX; |
| |
| /* VECTOR_CSTs in debug expressions are expanded into CONCATN instead of |
| regular CONST_VECTORs. They have vector or integer modes, depending |
| on the capabilities of the target. Cope with them. */ |
| if (partmode == VOIDmode && VECTOR_MODE_P (innermode)) |
| partmode = GET_MODE_INNER (innermode); |
| else if (partmode == VOIDmode) |
| partmode = mode_for_size (inner_size * BITS_PER_UNIT, |
| GET_MODE_CLASS (innermode), 0).require (); |
| |
| return simplify_gen_subreg (outermode, part, partmode, final_offset); |
| } |
| |
| /* Wrapper around simplify_gen_subreg which handles CONCATN. */ |
| |
| static rtx |
| simplify_gen_subreg_concatn (machine_mode outermode, rtx op, |
| machine_mode innermode, unsigned int byte) |
| { |
| rtx ret; |
| |
| /* We have to handle generating a SUBREG of a SUBREG of a CONCATN. |
| If OP is a SUBREG of a CONCATN, then it must be a simple mode |
| change with the same size and offset 0, or it must extract a |
| part. We shouldn't see anything else here. */ |
| if (GET_CODE (op) == SUBREG && GET_CODE (SUBREG_REG (op)) == CONCATN) |
| { |
| rtx op2; |
| |
| if ((GET_MODE_SIZE (GET_MODE (op)) |
| == GET_MODE_SIZE (GET_MODE (SUBREG_REG (op)))) |
| && SUBREG_BYTE (op) == 0) |
| return simplify_gen_subreg_concatn (outermode, SUBREG_REG (op), |
| GET_MODE (SUBREG_REG (op)), byte); |
| |
| op2 = simplify_subreg_concatn (GET_MODE (op), SUBREG_REG (op), |
| SUBREG_BYTE (op)); |
| if (op2 == NULL_RTX) |
| { |
| /* We don't handle paradoxical subregs here. */ |
| gcc_assert (!paradoxical_subreg_p (outermode, GET_MODE (op))); |
| gcc_assert (!paradoxical_subreg_p (op)); |
| op2 = simplify_subreg_concatn (outermode, SUBREG_REG (op), |
| byte + SUBREG_BYTE (op)); |
| gcc_assert (op2 != NULL_RTX); |
| return op2; |
| } |
| |
| op = op2; |
| gcc_assert (op != NULL_RTX); |
| gcc_assert (innermode == GET_MODE (op)); |
| } |
| |
| if (GET_CODE (op) == CONCATN) |
| return simplify_subreg_concatn (outermode, op, byte); |
| |
| ret = simplify_gen_subreg (outermode, op, innermode, byte); |
| |
| /* If we see an insn like (set (reg:DI) (subreg:DI (reg:SI) 0)) then |
| resolve_simple_move will ask for the high part of the paradoxical |
| subreg, which does not have a value. Just return a zero. */ |
| if (ret == NULL_RTX |
| && paradoxical_subreg_p (op)) |
| return CONST0_RTX (outermode); |
| |
| gcc_assert (ret != NULL_RTX); |
| return ret; |
| } |
| |
| /* Return whether we should resolve X into the registers into which it |
| was decomposed. */ |
| |
| static bool |
| resolve_reg_p (rtx x) |
| { |
| return GET_CODE (x) == CONCATN; |
| } |
| |
| /* Return whether X is a SUBREG of a register which we need to |
| resolve. */ |
| |
| static bool |
| resolve_subreg_p (rtx x) |
| { |
| if (GET_CODE (x) != SUBREG) |
| return false; |
| return resolve_reg_p (SUBREG_REG (x)); |
| } |
| |
| /* Look for SUBREGs in *LOC which need to be decomposed. */ |
| |
| static bool |
| resolve_subreg_use (rtx *loc, rtx insn) |
| { |
| subrtx_ptr_iterator::array_type array; |
| FOR_EACH_SUBRTX_PTR (iter, array, loc, NONCONST) |
| { |
| rtx *loc = *iter; |
| rtx x = *loc; |
| if (resolve_subreg_p (x)) |
| { |
| x = simplify_subreg_concatn (GET_MODE (x), SUBREG_REG (x), |
| SUBREG_BYTE (x)); |
| |
| /* It is possible for a note to contain a reference which we can |
| decompose. In this case, return 1 to the caller to indicate |
| that the note must be removed. */ |
| if (!x) |
| { |
| gcc_assert (!insn); |
| return true; |
| } |
| |
| validate_change (insn, loc, x, 1); |
| iter.skip_subrtxes (); |
| } |
| else if (resolve_reg_p (x)) |
| /* Return 1 to the caller to indicate that we found a direct |
| reference to a register which is being decomposed. This can |
| happen inside notes, multiword shift or zero-extend |
| instructions. */ |
| return true; |
| } |
| |
| return false; |
| } |
| |
| /* Resolve any decomposed registers which appear in register notes on |
| INSN. */ |
| |
| static void |
| resolve_reg_notes (rtx_insn *insn) |
| { |
| rtx *pnote, note; |
| |
| note = find_reg_equal_equiv_note (insn); |
| if (note) |
| { |
| int old_count = num_validated_changes (); |
| if (resolve_subreg_use (&XEXP (note, 0), NULL_RTX)) |
| remove_note (insn, note); |
| else |
| if (old_count != num_validated_changes ()) |
| df_notes_rescan (insn); |
| } |
| |
| pnote = ®_NOTES (insn); |
| while (*pnote != NULL_RTX) |
| { |
| bool del = false; |
| |
| note = *pnote; |
| switch (REG_NOTE_KIND (note)) |
| { |
| case REG_DEAD: |
| case REG_UNUSED: |
| if (resolve_reg_p (XEXP (note, 0))) |
| del = true; |
| break; |
| |
| default: |
| break; |
| } |
| |
| if (del) |
| *pnote = XEXP (note, 1); |
| else |
| pnote = &XEXP (note, 1); |
| } |
| } |
| |
| /* Return whether X can be decomposed into subwords. */ |
| |
| static bool |
| can_decompose_p (rtx x) |
| { |
| if (REG_P (x)) |
| { |
| unsigned int regno = REGNO (x); |
| |
| if (HARD_REGISTER_NUM_P (regno)) |
| { |
| unsigned int byte, num_bytes, num_words; |
| |
| if (!interesting_mode_p (GET_MODE (x), &num_bytes, &num_words)) |
| return false; |
| for (byte = 0; byte < num_bytes; byte += UNITS_PER_WORD) |
| if (simplify_subreg_regno (regno, GET_MODE (x), byte, word_mode) < 0) |
| return false; |
| return true; |
| } |
| else |
| return !bitmap_bit_p (subreg_context, regno); |
| } |
| |
| return true; |
| } |
| |
| /* Decompose the registers used in a simple move SET within INSN. If |
| we don't change anything, return INSN, otherwise return the start |
| of the sequence of moves. */ |
| |
| static rtx_insn * |
| resolve_simple_move (rtx set, rtx_insn *insn) |
| { |
| rtx src, dest, real_dest; |
| rtx_insn *insns; |
| machine_mode orig_mode, dest_mode; |
| unsigned int orig_size, words; |
| bool pushing; |
| |
| src = SET_SRC (set); |
| dest = SET_DEST (set); |
| orig_mode = GET_MODE (dest); |
| |
| if (!interesting_mode_p (orig_mode, &orig_size, &words)) |
| gcc_unreachable (); |
| gcc_assert (words > 1); |
| |
| start_sequence (); |
| |
| /* We have to handle copying from a SUBREG of a decomposed reg where |
| the SUBREG is larger than word size. Rather than assume that we |
| can take a word_mode SUBREG of the destination, we copy to a new |
| register and then copy that to the destination. */ |
| |
| real_dest = NULL_RTX; |
| |
| if (GET_CODE (src) == SUBREG |
| && resolve_reg_p (SUBREG_REG (src)) |
| && (SUBREG_BYTE (src) != 0 |
| || (GET_MODE_SIZE (orig_mode) |
| != GET_MODE_SIZE (GET_MODE (SUBREG_REG (src)))))) |
| { |
| real_dest = dest; |
| dest = gen_reg_rtx (orig_mode); |
| if (REG_P (real_dest)) |
| REG_ATTRS (dest) = REG_ATTRS (real_dest); |
| } |
| |
| /* Similarly if we are copying to a SUBREG of a decomposed reg where |
| the SUBREG is larger than word size. */ |
| |
| if (GET_CODE (dest) == SUBREG |
| && resolve_reg_p (SUBREG_REG (dest)) |
| && (SUBREG_BYTE (dest) != 0 |
| || (GET_MODE_SIZE (orig_mode) |
| != GET_MODE_SIZE (GET_MODE (SUBREG_REG (dest)))))) |
| { |
| rtx reg, smove; |
| rtx_insn *minsn; |
| |
| reg = gen_reg_rtx (orig_mode); |
| minsn = emit_move_insn (reg, src); |
| smove = single_set (minsn); |
| gcc_assert (smove != NULL_RTX); |
| resolve_simple_move (smove, minsn); |
| src = reg; |
| } |
| |
| /* If we didn't have any big SUBREGS of decomposed registers, and |
| neither side of the move is a register we are decomposing, then |
| we don't have to do anything here. */ |
| |
| if (src == SET_SRC (set) |
| && dest == SET_DEST (set) |
| && !resolve_reg_p (src) |
| && !resolve_subreg_p (src) |
| && !resolve_reg_p (dest) |
| && !resolve_subreg_p (dest)) |
| { |
| end_sequence (); |
| return insn; |
| } |
| |
| /* It's possible for the code to use a subreg of a decomposed |
| register while forming an address. We need to handle that before |
| passing the address to emit_move_insn. We pass NULL_RTX as the |
| insn parameter to resolve_subreg_use because we can not validate |
| the insn yet. */ |
| if (MEM_P (src) || MEM_P (dest)) |
| { |
| int acg; |
| |
| if (MEM_P (src)) |
| resolve_subreg_use (&XEXP (src, 0), NULL_RTX); |
| if (MEM_P (dest)) |
| resolve_subreg_use (&XEXP (dest, 0), NULL_RTX); |
| acg = apply_change_group (); |
| gcc_assert (acg); |
| } |
| |
| /* If SRC is a register which we can't decompose, or has side |
| effects, we need to move via a temporary register. */ |
| |
| if (!can_decompose_p (src) |
| || side_effects_p (src) |
| || GET_CODE (src) == ASM_OPERANDS) |
| { |
| rtx reg; |
| |
| reg = gen_reg_rtx (orig_mode); |
| |
| if (AUTO_INC_DEC) |
| { |
| rtx_insn *move = emit_move_insn (reg, src); |
| if (MEM_P (src)) |
| { |
| rtx note = find_reg_note (insn, REG_INC, NULL_RTX); |
| if (note) |
| add_reg_note (move, REG_INC, XEXP (note, 0)); |
| } |
| } |
| else |
| emit_move_insn (reg, src); |
| |
| src = reg; |
| } |
| |
| /* If DEST is a register which we can't decompose, or has side |
| effects, we need to first move to a temporary register. We |
| handle the common case of pushing an operand directly. We also |
| go through a temporary register if it holds a floating point |
| value. This gives us better code on systems which can't move |
| data easily between integer and floating point registers. */ |
| |
| dest_mode = orig_mode; |
| pushing = push_operand (dest, dest_mode); |
| if (!can_decompose_p (dest) |
| || (side_effects_p (dest) && !pushing) |
| || (!SCALAR_INT_MODE_P (dest_mode) |
| && !resolve_reg_p (dest) |
| && !resolve_subreg_p (dest))) |
| { |
| if (real_dest == NULL_RTX) |
| real_dest = dest; |
| if (!SCALAR_INT_MODE_P (dest_mode)) |
| dest_mode = int_mode_for_mode (dest_mode).require (); |
| dest = gen_reg_rtx (dest_mode); |
| if (REG_P (real_dest)) |
| REG_ATTRS (dest) = REG_ATTRS (real_dest); |
| } |
| |
| if (pushing) |
| { |
| unsigned int i, j, jinc; |
| |
| gcc_assert (orig_size % UNITS_PER_WORD == 0); |
| gcc_assert (GET_CODE (XEXP (dest, 0)) != PRE_MODIFY); |
| gcc_assert (GET_CODE (XEXP (dest, 0)) != POST_MODIFY); |
| |
| if (WORDS_BIG_ENDIAN == STACK_GROWS_DOWNWARD) |
| { |
| j = 0; |
| jinc = 1; |
| } |
| else |
| { |
| j = words - 1; |
| jinc = -1; |
| } |
| |
| for (i = 0; i < words; ++i, j += jinc) |
| { |
| rtx temp; |
| |
| temp = copy_rtx (XEXP (dest, 0)); |
| temp = adjust_automodify_address_nv (dest, word_mode, temp, |
| j * UNITS_PER_WORD); |
| emit_move_insn (temp, |
| simplify_gen_subreg_concatn (word_mode, src, |
| orig_mode, |
| j * UNITS_PER_WORD)); |
| } |
| } |
| else |
| { |
| unsigned int i; |
| |
| if (REG_P (dest) && !HARD_REGISTER_NUM_P (REGNO (dest))) |
| emit_clobber (dest); |
| |
| for (i = 0; i < words; ++i) |
| emit_move_insn (simplify_gen_subreg_concatn (word_mode, dest, |
| dest_mode, |
| i * UNITS_PER_WORD), |
| simplify_gen_subreg_concatn (word_mode, src, |
| orig_mode, |
| i * UNITS_PER_WORD)); |
| } |
| |
| if (real_dest != NULL_RTX) |
| { |
| rtx mdest, smove; |
| rtx_insn *minsn; |
| |
| if (dest_mode == orig_mode) |
| mdest = dest; |
| else |
| mdest = simplify_gen_subreg (orig_mode, dest, GET_MODE (dest), 0); |
| minsn = emit_move_insn (real_dest, mdest); |
| |
| if (AUTO_INC_DEC && MEM_P (real_dest) |
| && !(resolve_reg_p (real_dest) || resolve_subreg_p (real_dest))) |
| { |
| rtx note = find_reg_note (insn, REG_INC, NULL_RTX); |
| if (note) |
| add_reg_note (minsn, REG_INC, XEXP (note, 0)); |
| } |
| |
| smove = single_set (minsn); |
| gcc_assert (smove != NULL_RTX); |
| |
| resolve_simple_move (smove, minsn); |
| } |
| |
| insns = get_insns (); |
| end_sequence (); |
| |
| copy_reg_eh_region_note_forward (insn, insns, NULL_RTX); |
| |
| emit_insn_before (insns, insn); |
| |
| /* If we get here via self-recursion, then INSN is not yet in the insns |
| chain and delete_insn will fail. We only want to remove INSN from the |
| current sequence. See PR56738. */ |
| if (in_sequence_p ()) |
| remove_insn (insn); |
| else |
| delete_insn (insn); |
| |
| return insns; |
| } |
| |
| /* Change a CLOBBER of a decomposed register into a CLOBBER of the |
| component registers. Return whether we changed something. */ |
| |
| static bool |
| resolve_clobber (rtx pat, rtx_insn *insn) |
| { |
| rtx reg; |
| machine_mode orig_mode; |
| unsigned int orig_size, words, i; |
| int ret; |
| |
| reg = XEXP (pat, 0); |
| if (!resolve_reg_p (reg) && !resolve_subreg_p (reg)) |
| return false; |
| |
| orig_mode = GET_MODE (reg); |
| if (!interesting_mode_p (orig_mode, &orig_size, &words)) |
| gcc_unreachable (); |
| |
| ret = validate_change (NULL_RTX, &XEXP (pat, 0), |
| simplify_gen_subreg_concatn (word_mode, reg, |
| orig_mode, 0), |
| 0); |
| df_insn_rescan (insn); |
| gcc_assert (ret != 0); |
| |
| for (i = words - 1; i > 0; --i) |
| { |
| rtx x; |
| |
| x = simplify_gen_subreg_concatn (word_mode, reg, orig_mode, |
| i * UNITS_PER_WORD); |
| x = gen_rtx_CLOBBER (VOIDmode, x); |
| emit_insn_after (x, insn); |
| } |
| |
| resolve_reg_notes (insn); |
| |
| return true; |
| } |
| |
| /* A USE of a decomposed register is no longer meaningful. Return |
| whether we changed something. */ |
| |
| static bool |
| resolve_use (rtx pat, rtx_insn *insn) |
| { |
| if (resolve_reg_p (XEXP (pat, 0)) || resolve_subreg_p (XEXP (pat, 0))) |
| { |
| delete_insn (insn); |
| return true; |
| } |
| |
| resolve_reg_notes (insn); |
| |
| return false; |
| } |
| |
| /* A VAR_LOCATION can be simplified. */ |
| |
| static void |
| resolve_debug (rtx_insn *insn) |
| { |
| subrtx_ptr_iterator::array_type array; |
| FOR_EACH_SUBRTX_PTR (iter, array, &PATTERN (insn), NONCONST) |
| { |
| rtx *loc = *iter; |
| rtx x = *loc; |
| if (resolve_subreg_p (x)) |
| { |
| x = simplify_subreg_concatn (GET_MODE (x), SUBREG_REG (x), |
| SUBREG_BYTE (x)); |
| |
| if (x) |
| *loc = x; |
| else |
| x = copy_rtx (*loc); |
| } |
| if (resolve_reg_p (x)) |
| *loc = copy_rtx (x); |
| } |
| |
| df_insn_rescan (insn); |
| |
| resolve_reg_notes (insn); |
| } |
| |
| /* Check if INSN is a decomposable multiword-shift or zero-extend and |
| set the decomposable_context bitmap accordingly. SPEED_P is true |
| if we are optimizing INSN for speed rather than size. Return true |
| if INSN is decomposable. */ |
| |
| static bool |
| find_decomposable_shift_zext (rtx_insn *insn, bool speed_p) |
| { |
| rtx set; |
| rtx op; |
| rtx op_operand; |
| |
| set = single_set (insn); |
| if (!set) |
| return false; |
| |
| op = SET_SRC (set); |
| if (GET_CODE (op) != ASHIFT |
| && GET_CODE (op) != LSHIFTRT |
| && GET_CODE (op) != ASHIFTRT |
| && GET_CODE (op) != ZERO_EXTEND) |
| return false; |
| |
| op_operand = XEXP (op, 0); |
| if (!REG_P (SET_DEST (set)) || !REG_P (op_operand) |
| || HARD_REGISTER_NUM_P (REGNO (SET_DEST (set))) |
| || HARD_REGISTER_NUM_P (REGNO (op_operand)) |
| || GET_MODE (op) != twice_word_mode) |
| return false; |
| |
| if (GET_CODE (op) == ZERO_EXTEND) |
| { |
| if (GET_MODE (op_operand) != word_mode |
| || !choices[speed_p].splitting_zext) |
| return false; |
| } |
| else /* left or right shift */ |
| { |
| bool *splitting = (GET_CODE (op) == ASHIFT |
| ? choices[speed_p].splitting_ashift |
| : GET_CODE (op) == ASHIFTRT |
| ? choices[speed_p].splitting_ashiftrt |
| : choices[speed_p].splitting_lshiftrt); |
| if (!CONST_INT_P (XEXP (op, 1)) |
| || !IN_RANGE (INTVAL (XEXP (op, 1)), BITS_PER_WORD, |
| 2 * BITS_PER_WORD - 1) |
| || !splitting[INTVAL (XEXP (op, 1)) - BITS_PER_WORD]) |
| return false; |
| |
| bitmap_set_bit (decomposable_context, REGNO (op_operand)); |
| } |
| |
| bitmap_set_bit (decomposable_context, REGNO (SET_DEST (set))); |
| |
| return true; |
| } |
| |
| /* Decompose a more than word wide shift (in INSN) of a multiword |
| pseudo or a multiword zero-extend of a wordmode pseudo into a move |
| and 'set to zero' insn. Return a pointer to the new insn when a |
| replacement was done. */ |
| |
| static rtx_insn * |
| resolve_shift_zext (rtx_insn *insn) |
| { |
| rtx set; |
| rtx op; |
| rtx op_operand; |
| rtx_insn *insns; |
| rtx src_reg, dest_reg, dest_upper, upper_src = NULL_RTX; |
| int src_reg_num, dest_reg_num, offset1, offset2, src_offset; |
| scalar_int_mode inner_mode; |
| |
| set = single_set (insn); |
| if (!set) |
| return NULL; |
| |
| op = SET_SRC (set); |
| if (GET_CODE (op) != ASHIFT |
| && GET_CODE (op) != LSHIFTRT |
| && GET_CODE (op) != ASHIFTRT |
| && GET_CODE (op) != ZERO_EXTEND) |
| return NULL; |
| |
| op_operand = XEXP (op, 0); |
| if (!is_a <scalar_int_mode> (GET_MODE (op_operand), &inner_mode)) |
| return NULL; |
| |
| /* We can tear this operation apart only if the regs were already |
| torn apart. */ |
| if (!resolve_reg_p (SET_DEST (set)) && !resolve_reg_p (op_operand)) |
| return NULL; |
| |
| /* src_reg_num is the number of the word mode register which we |
| are operating on. For a left shift and a zero_extend on little |
| endian machines this is register 0. */ |
| src_reg_num = (GET_CODE (op) == LSHIFTRT || GET_CODE (op) == ASHIFTRT) |
| ? 1 : 0; |
| |
| if (WORDS_BIG_ENDIAN && GET_MODE_SIZE (inner_mode) > UNITS_PER_WORD) |
| src_reg_num = 1 - src_reg_num; |
| |
| if (GET_CODE (op) == ZERO_EXTEND) |
| dest_reg_num = WORDS_BIG_ENDIAN ? 1 : 0; |
| else |
| dest_reg_num = 1 - src_reg_num; |
| |
| offset1 = UNITS_PER_WORD * dest_reg_num; |
| offset2 = UNITS_PER_WORD * (1 - dest_reg_num); |
| src_offset = UNITS_PER_WORD * src_reg_num; |
| |
| start_sequence (); |
| |
| dest_reg = simplify_gen_subreg_concatn (word_mode, SET_DEST (set), |
| GET_MODE (SET_DEST (set)), |
| offset1); |
| dest_upper = simplify_gen_subreg_concatn (word_mode, SET_DEST (set), |
| GET_MODE (SET_DEST (set)), |
| offset2); |
| src_reg = simplify_gen_subreg_concatn (word_mode, op_operand, |
| GET_MODE (op_operand), |
| src_offset); |
| if (GET_CODE (op) == ASHIFTRT |
| && INTVAL (XEXP (op, 1)) != 2 * BITS_PER_WORD - 1) |
| upper_src = expand_shift (RSHIFT_EXPR, word_mode, copy_rtx (src_reg), |
| BITS_PER_WORD - 1, NULL_RTX, 0); |
| |
| if (GET_CODE (op) != ZERO_EXTEND) |
| { |
| int shift_count = INTVAL (XEXP (op, 1)); |
| if (shift_count > BITS_PER_WORD) |
| src_reg = expand_shift (GET_CODE (op) == ASHIFT ? |
| LSHIFT_EXPR : RSHIFT_EXPR, |
| word_mode, src_reg, |
| shift_count - BITS_PER_WORD, |
| dest_reg, GET_CODE (op) != ASHIFTRT); |
| } |
| |
| if (dest_reg != src_reg) |
| emit_move_insn (dest_reg, src_reg); |
| if (GET_CODE (op) != ASHIFTRT) |
| emit_move_insn (dest_upper, CONST0_RTX (word_mode)); |
| else if (INTVAL (XEXP (op, 1)) == 2 * BITS_PER_WORD - 1) |
| emit_move_insn (dest_upper, copy_rtx (src_reg)); |
| else |
| emit_move_insn (dest_upper, upper_src); |
| insns = get_insns (); |
| |
| end_sequence (); |
| |
| emit_insn_before (insns, insn); |
| |
| if (dump_file) |
| { |
| rtx_insn *in; |
| fprintf (dump_file, "; Replacing insn: %d with insns: ", INSN_UID (insn)); |
| for (in = insns; in != insn; in = NEXT_INSN (in)) |
| fprintf (dump_file, "%d ", INSN_UID (in)); |
| fprintf (dump_file, "\n"); |
| } |
| |
| delete_insn (insn); |
| return insns; |
| } |
| |
| /* Print to dump_file a description of what we're doing with shift code CODE. |
| SPLITTING[X] is true if we are splitting shifts by X + BITS_PER_WORD. */ |
| |
| static void |
| dump_shift_choices (enum rtx_code code, bool *splitting) |
| { |
| int i; |
| const char *sep; |
| |
| fprintf (dump_file, |
| " Splitting mode %s for %s lowering with shift amounts = ", |
| GET_MODE_NAME (twice_word_mode), GET_RTX_NAME (code)); |
| sep = ""; |
| for (i = 0; i < BITS_PER_WORD; i++) |
| if (splitting[i]) |
| { |
| fprintf (dump_file, "%s%d", sep, i + BITS_PER_WORD); |
| sep = ","; |
| } |
| fprintf (dump_file, "\n"); |
| } |
| |
| /* Print to dump_file a description of what we're doing when optimizing |
| for speed or size; SPEED_P says which. DESCRIPTION is a description |
| of the SPEED_P choice. */ |
| |
| static void |
| dump_choices (bool speed_p, const char *description) |
| { |
| unsigned int size, factor, i; |
| |
| fprintf (dump_file, "Choices when optimizing for %s:\n", description); |
| |
| for (i = 0; i < MAX_MACHINE_MODE; i++) |
| if (interesting_mode_p ((machine_mode) i, &size, &factor) |
| && factor > 1) |
| fprintf (dump_file, " %s mode %s for copy lowering.\n", |
| choices[speed_p].move_modes_to_split[i] |
| ? "Splitting" |
| : "Skipping", |
| GET_MODE_NAME ((machine_mode) i)); |
| |
| fprintf (dump_file, " %s mode %s for zero_extend lowering.\n", |
| choices[speed_p].splitting_zext ? "Splitting" : "Skipping", |
| GET_MODE_NAME (twice_word_mode)); |
| |
| dump_shift_choices (ASHIFT, choices[speed_p].splitting_ashift); |
| dump_shift_choices (LSHIFTRT, choices[speed_p].splitting_lshiftrt); |
| dump_shift_choices (ASHIFTRT, choices[speed_p].splitting_ashiftrt); |
| fprintf (dump_file, "\n"); |
| } |
| |
| /* Look for registers which are always accessed via word-sized SUBREGs |
| or -if DECOMPOSE_COPIES is true- via copies. Decompose these |
| registers into several word-sized pseudo-registers. */ |
| |
| static void |
| decompose_multiword_subregs (bool decompose_copies) |
| { |
| unsigned int max; |
| basic_block bb; |
| bool speed_p; |
| |
| if (dump_file) |
| { |
| dump_choices (false, "size"); |
| dump_choices (true, "speed"); |
| } |
| |
| /* Check if this target even has any modes to consider lowering. */ |
| if (!choices[false].something_to_do && !choices[true].something_to_do) |
| { |
| if (dump_file) |
| fprintf (dump_file, "Nothing to do!\n"); |
| return; |
| } |
| |
| max = max_reg_num (); |
| |
| /* First see if there are any multi-word pseudo-registers. If there |
| aren't, there is nothing we can do. This should speed up this |
| pass in the normal case, since it should be faster than scanning |
| all the insns. */ |
| { |
| unsigned int i; |
| bool useful_modes_seen = false; |
| |
| for (i = FIRST_PSEUDO_REGISTER; i < max; ++i) |
| if (regno_reg_rtx[i] != NULL) |
| { |
| machine_mode mode = GET_MODE (regno_reg_rtx[i]); |
| if (choices[false].move_modes_to_split[(int) mode] |
| || choices[true].move_modes_to_split[(int) mode]) |
| { |
| useful_modes_seen = true; |
| break; |
| } |
| } |
| |
| if (!useful_modes_seen) |
| { |
| if (dump_file) |
| fprintf (dump_file, "Nothing to lower in this function.\n"); |
| return; |
| } |
| } |
| |
| if (df) |
| { |
| df_set_flags (DF_DEFER_INSN_RESCAN); |
| run_word_dce (); |
| } |
| |
| /* FIXME: It may be possible to change this code to look for each |
| multi-word pseudo-register and to find each insn which sets or |
| uses that register. That should be faster than scanning all the |
| insns. */ |
| |
| decomposable_context = BITMAP_ALLOC (NULL); |
| non_decomposable_context = BITMAP_ALLOC (NULL); |
| subreg_context = BITMAP_ALLOC (NULL); |
| |
| reg_copy_graph.create (max); |
| reg_copy_graph.safe_grow_cleared (max); |
| memset (reg_copy_graph.address (), 0, sizeof (bitmap) * max); |
| |
| speed_p = optimize_function_for_speed_p (cfun); |
| FOR_EACH_BB_FN (bb, cfun) |
| { |
| rtx_insn *insn; |
| |
| FOR_BB_INSNS (bb, insn) |
| { |
| rtx set; |
| enum classify_move_insn cmi; |
| int i, n; |
| |
| if (!INSN_P (insn) |
| || GET_CODE (PATTERN (insn)) == CLOBBER |
| || GET_CODE (PATTERN (insn)) == USE) |
| continue; |
| |
| recog_memoized (insn); |
| |
| if (find_decomposable_shift_zext (insn, speed_p)) |
| continue; |
| |
| extract_insn (insn); |
| |
| set = simple_move (insn, speed_p); |
| |
| if (!set) |
| cmi = NOT_SIMPLE_MOVE; |
| else |
| { |
| /* We mark pseudo-to-pseudo copies as decomposable during the |
| second pass only. The first pass is so early that there is |
| good chance such moves will be optimized away completely by |
| subsequent optimizations anyway. |
| |
| However, we call find_pseudo_copy even during the first pass |
| so as to properly set up the reg_copy_graph. */ |
| if (find_pseudo_copy (set)) |
| cmi = decompose_copies? DECOMPOSABLE_SIMPLE_MOVE : SIMPLE_MOVE; |
| else |
| cmi = SIMPLE_MOVE; |
| } |
| |
| n = recog_data.n_operands; |
| for (i = 0; i < n; ++i) |
| { |
| find_decomposable_subregs (&recog_data.operand[i], &cmi); |
| |
| /* We handle ASM_OPERANDS as a special case to support |
| things like x86 rdtsc which returns a DImode value. |
| We can decompose the output, which will certainly be |
| operand 0, but not the inputs. */ |
| |
| if (cmi == SIMPLE_MOVE |
| && GET_CODE (SET_SRC (set)) == ASM_OPERANDS) |
| { |
| gcc_assert (i == 0); |
| cmi = NOT_SIMPLE_MOVE; |
| } |
| } |
| } |
| } |
| |
| bitmap_and_compl_into (decomposable_context, non_decomposable_context); |
| if (!bitmap_empty_p (decomposable_context)) |
| { |
| unsigned int i; |
| sbitmap_iterator sbi; |
| bitmap_iterator iter; |
| unsigned int regno; |
| |
| propagate_pseudo_copies (); |
| |
| auto_sbitmap sub_blocks (last_basic_block_for_fn (cfun)); |
| bitmap_clear (sub_blocks); |
| |
| EXECUTE_IF_SET_IN_BITMAP (decomposable_context, 0, regno, iter) |
| decompose_register (regno); |
| |
| FOR_EACH_BB_FN (bb, cfun) |
| { |
| rtx_insn *insn; |
| |
| FOR_BB_INSNS (bb, insn) |
| { |
| rtx pat; |
| |
| if (!INSN_P (insn)) |
| continue; |
| |
| pat = PATTERN (insn); |
| if (GET_CODE (pat) == CLOBBER) |
| resolve_clobber (pat, insn); |
| else if (GET_CODE (pat) == USE) |
| resolve_use (pat, insn); |
| else if (DEBUG_INSN_P (insn)) |
| resolve_debug (insn); |
| else |
| { |
| rtx set; |
| int i; |
| |
| recog_memoized (insn); |
| extract_insn (insn); |
| |
| set = simple_move (insn, speed_p); |
| if (set) |
| { |
| rtx_insn *orig_insn = insn; |
| bool cfi = control_flow_insn_p (insn); |
| |
| /* We can end up splitting loads to multi-word pseudos |
| into separate loads to machine word size pseudos. |
| When this happens, we first had one load that can |
| throw, and after resolve_simple_move we'll have a |
| bunch of loads (at least two). All those loads may |
| trap if we can have non-call exceptions, so they |
| all will end the current basic block. We split the |
| block after the outer loop over all insns, but we |
| make sure here that we will be able to split the |
| basic block and still produce the correct control |
| flow graph for it. */ |
| gcc_assert (!cfi |
| || (cfun->can_throw_non_call_exceptions |
| && can_throw_internal (insn))); |
| |
| insn = resolve_simple_move (set, insn); |
| if (insn != orig_insn) |
| { |
| recog_memoized (insn); |
| extract_insn (insn); |
| |
| if (cfi) |
| bitmap_set_bit (sub_blocks, bb->index); |
| } |
| } |
| else |
| { |
| rtx_insn *decomposed_shift; |
| |
| decomposed_shift = resolve_shift_zext (insn); |
| if (decomposed_shift != NULL_RTX) |
| { |
| insn = decomposed_shift; |
| recog_memoized (insn); |
| extract_insn (insn); |
| } |
| } |
| |
| for (i = recog_data.n_operands - 1; i >= 0; --i) |
| resolve_subreg_use (recog_data.operand_loc[i], insn); |
| |
| resolve_reg_notes (insn); |
| |
| if (num_validated_changes () > 0) |
| { |
| for (i = recog_data.n_dups - 1; i >= 0; --i) |
| { |
| rtx *pl = recog_data.dup_loc[i]; |
| int dup_num = recog_data.dup_num[i]; |
| rtx *px = recog_data.operand_loc[dup_num]; |
| |
| validate_unshare_change (insn, pl, *px, 1); |
| } |
| |
| i = apply_change_group (); |
| gcc_assert (i); |
| } |
| } |
| } |
| } |
| |
| /* If we had insns to split that caused control flow insns in the middle |
| of a basic block, split those blocks now. Note that we only handle |
| the case where splitting a load has caused multiple possibly trapping |
| loads to appear. */ |
| EXECUTE_IF_SET_IN_BITMAP (sub_blocks, 0, i, sbi) |
| { |
| rtx_insn *insn, *end; |
| edge fallthru; |
| |
| bb = BASIC_BLOCK_FOR_FN (cfun, i); |
| insn = BB_HEAD (bb); |
| end = BB_END (bb); |
| |
| while (insn != end) |
| { |
| if (control_flow_insn_p (insn)) |
| { |
| /* Split the block after insn. There will be a fallthru |
| edge, which is OK so we keep it. We have to create the |
| exception edges ourselves. */ |
| fallthru = split_block (bb, insn); |
| rtl_make_eh_edge (NULL, bb, BB_END (bb)); |
| bb = fallthru->dest; |
| insn = BB_HEAD (bb); |
| } |
| else |
| insn = NEXT_INSN (insn); |
| } |
| } |
| } |
| |
| { |
| unsigned int i; |
| bitmap b; |
| |
| FOR_EACH_VEC_ELT (reg_copy_graph, i, b) |
| if (b) |
| BITMAP_FREE (b); |
| } |
| |
| reg_copy_graph.release (); |
| |
| BITMAP_FREE (decomposable_context); |
| BITMAP_FREE (non_decomposable_context); |
| BITMAP_FREE (subreg_context); |
| } |
| |
| /* Implement first lower subreg pass. */ |
| |
| namespace { |
| |
| const pass_data pass_data_lower_subreg = |
| { |
| RTL_PASS, /* type */ |
| "subreg1", /* name */ |
| OPTGROUP_NONE, /* optinfo_flags */ |
| TV_LOWER_SUBREG, /* tv_id */ |
| 0, /* properties_required */ |
| 0, /* properties_provided */ |
| 0, /* properties_destroyed */ |
| 0, /* todo_flags_start */ |
| 0, /* todo_flags_finish */ |
| }; |
| |
| class pass_lower_subreg : public rtl_opt_pass |
| { |
| public: |
| pass_lower_subreg (gcc::context *ctxt) |
| : rtl_opt_pass (pass_data_lower_subreg, ctxt) |
| {} |
| |
| /* opt_pass methods: */ |
| virtual bool gate (function *) { return flag_split_wide_types != 0; } |
| virtual unsigned int execute (function *) |
| { |
| decompose_multiword_subregs (false); |
| return 0; |
| } |
| |
| }; // class pass_lower_subreg |
| |
| } // anon namespace |
| |
| rtl_opt_pass * |
| make_pass_lower_subreg (gcc::context *ctxt) |
| { |
| return new pass_lower_subreg (ctxt); |
| } |
| |
| /* Implement second lower subreg pass. */ |
| |
| namespace { |
| |
| const pass_data pass_data_lower_subreg2 = |
| { |
| RTL_PASS, /* type */ |
| "subreg2", /* name */ |
| OPTGROUP_NONE, /* optinfo_flags */ |
| TV_LOWER_SUBREG, /* tv_id */ |
| 0, /* properties_required */ |
| 0, /* properties_provided */ |
| 0, /* properties_destroyed */ |
| 0, /* todo_flags_start */ |
| TODO_df_finish, /* todo_flags_finish */ |
| }; |
| |
| class pass_lower_subreg2 : public rtl_opt_pass |
| { |
| public: |
| pass_lower_subreg2 (gcc::context *ctxt) |
| : rtl_opt_pass (pass_data_lower_subreg2, ctxt) |
| {} |
| |
| /* opt_pass methods: */ |
| virtual bool gate (function *) { return flag_split_wide_types != 0; } |
| virtual unsigned int execute (function *) |
| { |
| decompose_multiword_subregs (true); |
| return 0; |
| } |
| |
| }; // class pass_lower_subreg2 |
| |
| } // anon namespace |
| |
| rtl_opt_pass * |
| make_pass_lower_subreg2 (gcc::context *ctxt) |
| { |
| return new pass_lower_subreg2 (ctxt); |
| } |