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author | Richard Kenner <kenner@vlsi1.ultra.nyu.edu> | 2001-02-18 23:56:34 +0000 |
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committer | Richard Kenner <kenner@gcc.gnu.org> | 2001-02-18 18:56:34 -0500 |
commit | fb0c0a1270d945fb86e4abeaddc7e97481822270 (patch) | |
tree | e6a5316cb8b24a370d243ef6570ecc30bce2c4ac /gcc/gcse.c | |
parent | d659de97e72b033dfef264bd3f8d6dfdd8212252 (diff) | |
download | gcc-fb0c0a1270d945fb86e4abeaddc7e97481822270.zip gcc-fb0c0a1270d945fb86e4abeaddc7e97481822270.tar.gz gcc-fb0c0a1270d945fb86e4abeaddc7e97481822270.tar.bz2 |
Makefile.in (gcse.o): Now includes ggc.h.
* Makefile.in (gcse.o): Now includes ggc.h.
* gcse.c: Include ggc.h.
(want_to_gcse_p): Verify expression can be in SET as valid insn.
(try_replace_reg): Remove warning of uninitialize variable.
(process_insert_insn): Call invalid_insn_p to validate insn.
* recog.c (insn_invalid_p): Now global.
See if can make valid by adding CLOBBERs of SCRATCH only and do if so.
* recog.h (insn_invalid_p): New declaration.
From-SVN: r39857
Diffstat (limited to 'gcc/gcse.c')
-rw-r--r-- | gcc/gcse.c | 62 |
1 files changed, 50 insertions, 12 deletions
@@ -159,6 +159,7 @@ Boston, MA 02111-1307, USA. */ #include "output.h" #include "function.h" #include "expr.h" +#include "ggc.h" #include "obstack.h" #define obstack_chunk_alloc gmalloc @@ -1187,13 +1188,17 @@ static int *reg_last_set; static int mem_first_set; static int mem_last_set; -/* Perform a quick check whether X, the source of a set, is something - we want to consider for GCSE. */ +/* See whether X, the source of a set, is something we want to consider for + GCSE. */ static int want_to_gcse_p (x) rtx x; { + static rtx test_insn = 0; + int num_clobbers = 0; + int icode; + switch (GET_CODE (x)) { case REG: @@ -1207,7 +1212,31 @@ want_to_gcse_p (x) break; } - return 1; + /* If this is a valid operand, we are OK. If it's VOIDmode, we aren't. */ + if (general_operand (x, GET_MODE (x))) + return 1; + else if (GET_MODE (x) == VOIDmode) + return 0; + + /* Otherwise, check if we can make a valid insn from it. First initialize + our test insn if we haven't already. */ + if (test_insn == 0) + { + test_insn + = make_insn_raw (gen_rtx_SET (VOIDmode, + gen_rtx_REG (word_mode, + FIRST_PSEUDO_REGISTER * 2), + const0_rtx)); + NEXT_INSN (test_insn) = PREV_INSN (test_insn) = 0; + ggc_add_rtx_root (&test_insn, 1); + } + + /* Now make an insn like the one we would make when GCSE'ing and see if + valid. */ + PUT_MODE (SET_DEST (PATTERN (test_insn)), GET_MODE (x)); + SET_SRC (PATTERN (test_insn)) = x; + return ((icode = recog (PATTERN (test_insn), test_insn, &num_clobbers)) >= 0 + && (num_clobbers == 0 || ! added_clobbers_hard_reg_p (icode))); } /* Return non-zero if the operands of expression X are unchanged from the @@ -3612,7 +3641,7 @@ try_replace_reg (from, to, insn) rtx from, to, insn; { rtx note = find_reg_equal_equiv_note (insn); - rtx src; + rtx src = 0; int success = 0; rtx set = single_set (insn); @@ -3640,10 +3669,10 @@ try_replace_reg (from, to, insn) if (!success) success = validate_replace_src (from, to, insn); - /* We've failed to do replacement, have a single SET, and don't already - have a note, two to add a REG_EQUAL note to not lose information. */ + /* If we've failed to do replacement, have a single SET, and don't already + have a note, add a REG_EQUAL note to not lose information. */ if (!success && note == 0 && set != 0) - note= REG_NOTES (insn) + note = REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_EQUAL, src, REG_NOTES (insn)); /* If there is already a NOTE, update the expression in it with our @@ -4265,13 +4294,22 @@ process_insert_insn (expr) struct expr *expr; { rtx reg = expr->reaching_reg; - rtx pat, copied_expr; - rtx first_new_insn; + rtx exp = copy_rtx (expr->expr); + rtx pat; start_sequence (); - copied_expr = copy_rtx (expr->expr); - emit_move_insn (reg, copied_expr); - first_new_insn = get_insns (); + + /* If the expression is something that's an operand, like a constant, + just copy it to a register. */ + if (general_operand (exp, GET_MODE (reg))) + emit_move_insn (reg, exp); + + /* Otherwise, make a new insn to compute this expression and make sure the + insn will be recognized (this also adds any needed CLOBBERs). Copy the + expression to make sure we don't have any sharing issues. */ + if (insn_invalid_p (emit_insn (gen_rtx_SET (VOIDmode, reg, exp)))) + abort (); + pat = gen_sequence (); end_sequence (); |