From 60c48e4c8d74d72e45418c5c6348c91f5c6aeafa Mon Sep 17 00:00:00 2001 From: Alexandre Oliva Date: Sat, 9 Jan 2010 14:41:35 +0000 Subject: [PATCH] re PR debug/42630 ("-fcompare-debug failure (length)" with "-O1 -fvariable-expansion-in-unroller -funroll-loops") gcc/ChangeLog: PR debug/42630 * loop-unroll.c (referenced_in_one_insn_in_loop_p): Count debug uses in new incoming argument. Free body. (reset_debug_uses_in_loop): New. (analyze_insn_to_expand_var): Call the latter if the former found anything. Fix whitespace. Reject invalid dest overlaps before going through all insns in the loop. gcc/testsuite/ChangeLog: PR debug/42630 * gcc.dg/pr42630.c: New. From-SVN: r155764 --- gcc/ChangeLog | 10 +++++ gcc/loop-unroll.c | 70 ++++++++++++++++++++++++++++------ gcc/testsuite/ChangeLog | 5 +++ gcc/testsuite/gcc.dg/pr42630.c | 9 +++++ 4 files changed, 82 insertions(+), 12 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/pr42630.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index e93c9f1ac22..b38662212de 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,13 @@ +2010-01-09 Alexandre Oliva + + PR debug/42630 + * loop-unroll.c (referenced_in_one_insn_in_loop_p): Count debug + uses in new incoming argument. Free body. + (reset_debug_uses_in_loop): New. + (analyze_insn_to_expand_var): Call the latter if the former found + anything. Fix whitespace. Reject invalid dest overlaps before + going through all insns in the loop. + 2010-01-09 Alexandre Oliva PR debug/42629 diff --git a/gcc/loop-unroll.c b/gcc/loop-unroll.c index 6b7fe8ad091..231d12db9eb 100644 --- a/gcc/loop-unroll.c +++ b/gcc/loop-unroll.c @@ -1,5 +1,5 @@ /* Loop unrolling and peeling. - Copyright (C) 2002, 2003, 2004, 2005, 2007, 2008 + Copyright (C) 2002, 2003, 2004, 2005, 2007, 2008, 2010 Free Software Foundation, Inc. This file is part of GCC. @@ -142,7 +142,7 @@ static void opt_info_start_duplication (struct opt_info *); static void apply_opt_in_copies (struct opt_info *, unsigned, bool, bool); static void free_opt_info (struct opt_info *); static struct var_to_expand *analyze_insn_to_expand_var (struct loop*, rtx); -static bool referenced_in_one_insn_in_loop_p (struct loop *, rtx); +static bool referenced_in_one_insn_in_loop_p (struct loop *, rtx, int *); static struct iv_to_split *analyze_iv_to_split_insn (rtx); static void expand_var_during_unrolling (struct var_to_expand *, rtx); static void insert_var_expansion_initialization (struct var_to_expand *, @@ -1525,10 +1525,13 @@ ve_info_eq (const void *ivts1, const void *ivts2) return i1->insn == i2->insn; } -/* Returns true if REG is referenced in one insn in LOOP. */ +/* Returns true if REG is referenced in one nondebug insn in LOOP. + Set *DEBUG_USES to the number of debug insns that reference the + variable. */ bool -referenced_in_one_insn_in_loop_p (struct loop *loop, rtx reg) +referenced_in_one_insn_in_loop_p (struct loop *loop, rtx reg, + int *debug_uses) { basic_block *body, bb; unsigned i; @@ -1541,14 +1544,45 @@ referenced_in_one_insn_in_loop_p (struct loop *loop, rtx reg) bb = body[i]; FOR_BB_INSNS (bb, insn) - { - if (rtx_referenced_p (reg, insn)) - count_ref++; - } + if (!rtx_referenced_p (reg, insn)) + continue; + else if (DEBUG_INSN_P (insn)) + ++*debug_uses; + else if (++count_ref > 1) + break; } + free (body); return (count_ref == 1); } +/* Reset the DEBUG_USES debug insns in LOOP that reference REG. */ + +static void +reset_debug_uses_in_loop (struct loop *loop, rtx reg, int debug_uses) +{ + basic_block *body, bb; + unsigned i; + rtx insn; + + body = get_loop_body (loop); + for (i = 0; debug_uses && i < loop->num_nodes; i++) + { + bb = body[i]; + + FOR_BB_INSNS (bb, insn) + if (!DEBUG_INSN_P (insn) || !rtx_referenced_p (reg, insn)) + continue; + else + { + validate_change (insn, &INSN_VAR_LOCATION_LOC (insn), + gen_rtx_UNKNOWN_VAR_LOC (), 0); + if (!--debug_uses) + break; + } + } + free (body); +} + /* Determine whether INSN contains an accumulator which can be expanded into separate copies, one for each copy of the LOOP body. @@ -1579,6 +1613,7 @@ analyze_insn_to_expand_var (struct loop *loop, rtx insn) struct var_to_expand *ves; enum machine_mode mode1, mode2; unsigned accum_pos; + int debug_uses = 0; set = single_set (insn); if (!set) @@ -1624,15 +1659,15 @@ analyze_insn_to_expand_var (struct loop *loop, rtx insn) the expansions at the end of the computation will yield wrong results for (x = something - x) thus avoid using it in that case. */ if (accum_pos == 1 - && GET_CODE (src) == MINUS) + && GET_CODE (src) == MINUS) return NULL; - something = (accum_pos == 0)? op2 : op1; + something = (accum_pos == 0) ? op2 : op1; - if (!referenced_in_one_insn_in_loop_p (loop, dest)) + if (rtx_referenced_p (dest, something)) return NULL; - if (rtx_referenced_p (dest, something)) + if (!referenced_in_one_insn_in_loop_p (loop, dest, &debug_uses)) return NULL; mode1 = GET_MODE (dest); @@ -1650,6 +1685,17 @@ analyze_insn_to_expand_var (struct loop *loop, rtx insn) fprintf (dump_file, "\n"); } + if (debug_uses) + /* Instead of resetting the debug insns, we could replace each + debug use in the loop with the sum or product of all expanded + accummulators. Since we'll only know of all expansions at the + end, we'd have to keep track of which vars_to_expand a debug + insn in the loop references, take note of each copy of the + debug insn during unrolling, and when it's all done, compute + the sum or product of each variable and adjust the original + debug insn and each copy thereof. What a pain! */ + reset_debug_uses_in_loop (loop, dest, debug_uses); + /* Record the accumulator to expand. */ ves = XNEW (struct var_to_expand); ves->insn = insn; diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 4d62e328962..f9074e3ab60 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2010-01-09 Alexandre Oliva + + PR debug/42630 + * gcc.dg/pr42630.c: New. + 2010-01-09 Alexandre Oliva PR debug/42629 diff --git a/gcc/testsuite/gcc.dg/pr42630.c b/gcc/testsuite/gcc.dg/pr42630.c new file mode 100644 index 00000000000..34543dab5e9 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr42630.c @@ -0,0 +1,9 @@ +/* { dg-do compile } */ +/* { dg-options "-O1 -fvariable-expansion-in-unroller -funroll-loops -fcompare-debug" } */ + +int sum(int *buf, int len) +{ + int s = 0; + while (--len > 0) s += *buf++; + return s; +} -- 2.30.2