Mercurial > hg > CbC > CbC_gcc
diff gcc/cfgbuild.c @ 55:77e2b8dfacca gcc-4.4.5
update it from 4.4.3 to 4.5.0
author | ryoma <e075725@ie.u-ryukyu.ac.jp> |
---|---|
date | Fri, 12 Feb 2010 23:39:51 +0900 |
parents | a06113de4d67 |
children | b7f97abdc517 |
line wrap: on
line diff
--- a/gcc/cfgbuild.c Sun Feb 07 18:28:00 2010 +0900 +++ b/gcc/cfgbuild.c Fri Feb 12 23:39:51 2010 +0900 @@ -19,16 +19,6 @@ along with GCC; see the file COPYING3. If not see <http://www.gnu.org/licenses/>. */ -/* find_basic_blocks divides the current function's rtl into basic - blocks and constructs the CFG. The blocks are recorded in the - basic_block_info array; the CFG exists in the edge structures - referenced by the blocks. - - find_basic_blocks also finds any unreachable loops and deletes them. - - Available functionality: - - CFG construction - find_basic_blocks */ #include "config.h" #include "system.h" @@ -43,11 +33,10 @@ #include "output.h" #include "function.h" #include "except.h" +#include "expr.h" #include "toplev.h" #include "timevar.h" -static int count_basic_blocks (const_rtx); -static void find_basic_blocks_1 (rtx); static void make_edges (basic_block, basic_block, int); static void make_label_edge (sbitmap, basic_block, rtx, int); static void find_bb_boundaries (basic_block); @@ -74,6 +63,7 @@ case CALL_INSN: case INSN: + case DEBUG_INSN: return true; case BARRIER: @@ -91,12 +81,11 @@ bool control_flow_insn_p (const_rtx insn) { - rtx note; - switch (GET_CODE (insn)) { case NOTE: case CODE_LABEL: + case DEBUG_INSN: return false; case JUMP_INSN: @@ -111,21 +100,20 @@ || find_reg_note (insn, REG_NORETURN, 0)) && GET_CODE (PATTERN (insn)) != COND_EXEC) return true; + /* Call insn may return to the nonlocal goto handler. */ - return ((nonlocal_goto_handler_labels - && (0 == (note = find_reg_note (insn, REG_EH_REGION, - NULL_RTX)) - || INTVAL (XEXP (note, 0)) >= 0)) - /* Or may trap. */ - || can_throw_internal (insn)); + if (can_nonlocal_goto (insn)) + return true; + break; case INSN: /* Treat trap instructions like noreturn calls (same provision). */ if (GET_CODE (PATTERN (insn)) == TRAP_IF && XEXP (PATTERN (insn), 0) == const1_rtx) return true; - - return (flag_non_call_exceptions && can_throw_internal (insn)); + if (!flag_non_call_exceptions) + return false; + break; case BARRIER: /* It is nonsense to reach barrier when looking for the @@ -136,47 +124,10 @@ default: gcc_unreachable (); } + + return can_throw_internal (insn); } -/* Count the basic blocks of the function. */ - -static int -count_basic_blocks (const_rtx f) -{ - int count = NUM_FIXED_BLOCKS; - bool saw_insn = false; - const_rtx insn; - - for (insn = f; insn; insn = NEXT_INSN (insn)) - { - /* Code labels and barriers causes current basic block to be - terminated at previous real insn. */ - if ((LABEL_P (insn) || BARRIER_P (insn)) - && saw_insn) - count++, saw_insn = false; - - /* Start basic block if needed. */ - if (!saw_insn && inside_basic_block_p (insn)) - saw_insn = true; - - /* Control flow insn causes current basic block to be terminated. */ - if (saw_insn && control_flow_insn_p (insn)) - count++, saw_insn = false; - } - - if (saw_insn) - count++; - - /* The rest of the compiler works a bit smoother when we don't have to - check for the edge case of do-nothing functions with no basic blocks. */ - if (count == NUM_FIXED_BLOCKS) - { - emit_use (const0_rtx); - count = NUM_FIXED_BLOCKS + 1; - } - - return count; -} /* Create an edge between two basic blocks. FLAGS are auxiliary information about the edge that is accumulated between calls. */ @@ -204,16 +155,23 @@ void rtl_make_eh_edge (sbitmap edge_cache, basic_block src, rtx insn) { - int is_call = CALL_P (insn) ? EDGE_ABNORMAL_CALL : 0; - rtx handlers, i; + eh_landing_pad lp = get_eh_landing_pad_from_rtx (insn); - handlers = reachable_handlers (insn); + if (lp) + { + rtx label = lp->landing_pad; - for (i = handlers; i; i = XEXP (i, 1)) - make_label_edge (edge_cache, src, XEXP (i, 0), - EDGE_ABNORMAL | EDGE_EH | is_call); + /* During initial rtl generation, use the post_landing_pad. */ + if (label == NULL) + { + gcc_assert (lp->post_landing_pad); + label = label_rtx (lp->post_landing_pad); + } - free_INSN_LIST_list (&handlers); + make_label_edge (edge_cache, src, label, + EDGE_ABNORMAL | EDGE_EH + | (CALL_P (insn) ? EDGE_ABNORMAL_CALL : 0)); + } } /* States of basic block as seen by find_many_sub_basic_blocks. */ @@ -302,13 +260,9 @@ { rtx tmp; - /* Recognize exception handling placeholders. */ - if (GET_CODE (PATTERN (insn)) == RESX) - rtl_make_eh_edge (edge_cache, bb, insn); - /* Recognize a non-local goto as a branch outside the current function. */ - else if (find_reg_note (insn, REG_NON_LOCAL_GOTO, NULL_RTX)) + if (find_reg_note (insn, REG_NON_LOCAL_GOTO, NULL_RTX)) ; /* Recognize a tablejump and do the right thing. */ @@ -349,6 +303,15 @@ else if (returnjump_p (insn)) cached_make_edge (edge_cache, bb, EXIT_BLOCK_PTR, 0); + /* Recognize asm goto and do the right thing. */ + else if ((tmp = extract_asm_operands (PATTERN (insn))) != NULL) + { + int i, n = ASM_OPERANDS_LABEL_LENGTH (tmp); + for (i = 0; i < n; ++i) + make_label_edge (edge_cache, bb, + XEXP (ASM_OPERANDS_LABEL (tmp, i), 0), 0); + } + /* Otherwise, we have a plain conditional or unconditional jump. */ else { @@ -382,12 +345,7 @@ gotos do not have their addresses taken, then only calls to those functions or to other nested functions that use them could possibly do nonlocal gotos. */ - - /* We do know that a REG_EH_REGION note with a value less - than 0 is guaranteed not to perform a non-local goto. */ - rtx note = find_reg_note (insn, REG_EH_REGION, NULL_RTX); - - if (!note || INTVAL (XEXP (note, 0)) >= 0) + if (can_nonlocal_goto (insn)) for (x = nonlocal_goto_handler_labels; x; x = XEXP (x, 1)) make_label_edge (edge_cache, bb, XEXP (x, 0), EDGE_ABNORMAL | EDGE_ABNORMAL_CALL); @@ -418,157 +376,6 @@ sbitmap_vector_free (edge_cache); } -/* Find all basic blocks of the function whose first insn is F. - - Collect and return a list of labels whose addresses are taken. This - will be used in make_edges for use with computed gotos. */ - -static void -find_basic_blocks_1 (rtx f) -{ - rtx insn, next; - rtx bb_note = NULL_RTX; - rtx head = NULL_RTX; - rtx end = NULL_RTX; - basic_block prev = ENTRY_BLOCK_PTR; - - /* We process the instructions in a slightly different way than we did - previously. This is so that we see a NOTE_BASIC_BLOCK after we have - closed out the previous block, so that it gets attached at the proper - place. Since this form should be equivalent to the previous, - count_basic_blocks continues to use the old form as a check. */ - - for (insn = f; insn; insn = next) - { - enum rtx_code code = GET_CODE (insn); - - next = NEXT_INSN (insn); - - if ((LABEL_P (insn) || BARRIER_P (insn)) - && head) - { - prev = create_basic_block_structure (head, end, bb_note, prev); - head = end = NULL_RTX; - bb_note = NULL_RTX; - } - - if (inside_basic_block_p (insn)) - { - if (head == NULL_RTX) - head = insn; - end = insn; - } - - if (head && control_flow_insn_p (insn)) - { - prev = create_basic_block_structure (head, end, bb_note, prev); - head = end = NULL_RTX; - bb_note = NULL_RTX; - } - - switch (code) - { - case NOTE: - /* Look for basic block notes with which to keep the - basic_block_info pointers stable. Unthread the note now; - we'll put it back at the right place in create_basic_block. - Or not at all if we've already found a note in this block. */ - if (NOTE_INSN_BASIC_BLOCK_P (insn)) - { - if (bb_note == NULL_RTX) - bb_note = insn; - else - next = delete_insn (insn); - } - break; - - case CODE_LABEL: - case JUMP_INSN: - case CALL_INSN: - case INSN: - case BARRIER: - break; - - default: - gcc_unreachable (); - } - } - - if (head != NULL_RTX) - create_basic_block_structure (head, end, bb_note, prev); - else if (bb_note) - delete_insn (bb_note); - - gcc_assert (last_basic_block == n_basic_blocks); - - clear_aux_for_blocks (); -} - - -/* Find basic blocks of the current function. - F is the first insn of the function. */ - -void -find_basic_blocks (rtx f) -{ - basic_block bb; - - timevar_push (TV_CFG); - - /* Flush out existing data. */ - if (basic_block_info != NULL) - { - clear_edges (); - - /* Clear bb->aux on all extant basic blocks. We'll use this as a - tag for reuse during create_basic_block, just in case some pass - copies around basic block notes improperly. */ - FOR_EACH_BB (bb) - bb->aux = NULL; - - basic_block_info = NULL; - } - - n_basic_blocks = count_basic_blocks (f); - last_basic_block = NUM_FIXED_BLOCKS; - ENTRY_BLOCK_PTR->next_bb = EXIT_BLOCK_PTR; - EXIT_BLOCK_PTR->prev_bb = ENTRY_BLOCK_PTR; - - - /* Size the basic block table. The actual structures will be allocated - by find_basic_blocks_1, since we want to keep the structure pointers - stable across calls to find_basic_blocks. */ - /* ??? This whole issue would be much simpler if we called find_basic_blocks - exactly once, and thereafter we don't have a single long chain of - instructions at all until close to the end of compilation when we - actually lay them out. */ - - basic_block_info = VEC_alloc (basic_block, gc, n_basic_blocks); - VEC_safe_grow_cleared (basic_block, gc, basic_block_info, n_basic_blocks); - SET_BASIC_BLOCK (ENTRY_BLOCK, ENTRY_BLOCK_PTR); - SET_BASIC_BLOCK (EXIT_BLOCK, EXIT_BLOCK_PTR); - - find_basic_blocks_1 (f); - - profile_status = PROFILE_ABSENT; - - /* Tell make_edges to examine every block for out-going edges. */ - FOR_EACH_BB (bb) - SET_STATE (bb, BLOCK_NEW); - - /* Discover the edges of our cfg. */ - make_edges (ENTRY_BLOCK_PTR->next_bb, EXIT_BLOCK_PTR->prev_bb, 0); - - /* Do very simple cleanup now, for the benefit of code that runs between - here and cleanup_cfg, e.g. thread_prologue_and_epilogue_insns. */ - tidy_fallthru_edges (); - -#ifdef ENABLE_CHECKING - verify_flow_info (); -#endif - timevar_pop (TV_CFG); -} - static void mark_tablejump_edge (rtx label) { @@ -646,8 +453,10 @@ { enum rtx_code code = GET_CODE (insn); - /* On code label, split current basic block. */ - if (code == CODE_LABEL) + /* In case we've previously seen an insn that effects a control + flow transfer, split the block. */ + if ((flow_transfer_insn || code == CODE_LABEL) + && inside_basic_block_p (insn)) { fallthru = split_block (bb, PREV_INSN (insn)); if (flow_transfer_insn) @@ -665,27 +474,16 @@ bb = fallthru->dest; remove_edge (fallthru); flow_transfer_insn = NULL_RTX; - if (LABEL_ALT_ENTRY_P (insn)) + if (code == CODE_LABEL && LABEL_ALT_ENTRY_P (insn)) make_edge (ENTRY_BLOCK_PTR, bb, 0); } - - /* In case we've previously seen an insn that effects a control - flow transfer, split the block. */ - if (flow_transfer_insn && inside_basic_block_p (insn)) + else if (code == BARRIER) { - fallthru = split_block (bb, PREV_INSN (insn)); - BB_END (bb) = flow_transfer_insn; - - /* Clean up the bb field for the insns between the blocks. */ - for (x = NEXT_INSN (flow_transfer_insn); - x != BB_HEAD (fallthru->dest); - x = NEXT_INSN (x)) - if (!BARRIER_P (x)) - set_block_for_insn (x, NULL); - - bb = fallthru->dest; - remove_edge (fallthru); - flow_transfer_insn = NULL_RTX; + /* __builtin_unreachable () may cause a barrier to be emitted in + the middle of a BB. We need to split it in the same manner as + if the barrier were preceded by a control_flow_insn_p insn. */ + if (!flow_transfer_insn) + flow_transfer_insn = prev_nonnote_insn_bb (insn); } if (control_flow_insn_p (insn))