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Re: big slowdown in egcs-1.1.2->gcc-2.95 on alpha
- To: Brad Lucier <lucier at math dot purdue dot edu>
- Subject: Re: big slowdown in egcs-1.1.2->gcc-2.95 on alpha
- From: Richard Henderson <rth at cygnus dot com>
- Date: Sat, 7 Aug 1999 01:04:14 -0700
- Cc: Joern Rennecke <amylaar at cygnus dot co dot uk>, gcc at gcc dot gnu dot org, gcc-bugs at gcc dot gnu dot org, staff at math dot purdue dot edu, hosking at cs dot purdue dot edu, wilker at math dot purdue dot edu, bernds at cygnus dot com, gcc-patches at gcc dot gnu dot org
- References: <199908070139.CAA18804@phal.cygnus.co.uk> <199908070427.XAA00675@polya.math.purdue.edu>
On Fri, Aug 06, 1999 at 11:27:32PM -0500, Brad Lucier wrote:
> Each sample counts as 0.000976562 seconds.
> % cumulative self self total
> time seconds seconds calls ms/call ms/call name
> 35.63 55.32 55.32 16 3457.52 3458.44 prune_preferences
> 12.51 74.75 19.43 391960848 0.00 0.00 bitmap_bit_p
The following should kill bitmap_bit_p from the interesting
functions.
r~
* global.c (build_insn_chain): Use EXECUTE_IF_SET_IN_REG_SET
to invert loops. Simplify block scanning.
Index: global.c
===================================================================
RCS file: /egcs/carton/cvsfiles/egcs/gcc/global.c,v
retrieving revision 1.28
diff -u -p -d -r1.28 global.c
--- global.c 1999/08/04 07:50:08 1.28
+++ global.c 1999/08/07 07:58:44
@@ -271,7 +271,7 @@ static void set_preference PROTO((rtx, r
static void dump_conflicts PROTO((FILE *));
static void reg_becomes_live PROTO((rtx, rtx));
static void reg_dies PROTO((int, enum machine_mode));
-static void build_insn_chain PROTO((rtx));
+static void build_insn_chain PROTO((void));
/* Perform allocation of pseudo-registers not allocated by local_alloc.
FILE is a file to output debugging information on,
@@ -578,7 +578,7 @@ global_alloc (file)
if (n_basic_blocks > 0)
#endif
{
- build_insn_chain (get_insns ());
+ build_insn_chain ();
retval = reload (get_insns (), 1, file);
}
@@ -1667,96 +1667,88 @@ reg_dies (regno, mode)
/* Walk the insns of the current function and build reload_insn_chain,
and record register life information. */
static void
-build_insn_chain (first)
- rtx first;
+build_insn_chain ()
{
struct insn_chain **p = &reload_insn_chain;
struct insn_chain *prev = 0;
- int b = 0;
+ int b;
live_relevant_regs = ALLOCA_REG_SET ();
- for (; first; first = NEXT_INSN (first))
+ for (b = n_basic_blocks - 1; b >= 0; --b)
{
- struct insn_chain *c;
-
- if (first == BLOCK_HEAD (b))
- {
- int i;
- CLEAR_REG_SET (live_relevant_regs);
- for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
- if (REGNO_REG_SET_P (BASIC_BLOCK (b)->global_live_at_start, i)
- && ! TEST_HARD_REG_BIT (eliminable_regset, i))
- SET_REGNO_REG_SET (live_relevant_regs, i);
+ basic_block bb = BASIC_BLOCK (b);
+ rtx insn, end;
+ int i;
- for (; i < max_regno; i++)
- if (reg_renumber[i] >= 0
- && REGNO_REG_SET_P (BASIC_BLOCK (b)->global_live_at_start, i))
- SET_REGNO_REG_SET (live_relevant_regs, i);
- }
+ CLEAR_REG_SET (live_relevant_regs);
- if (GET_CODE (first) != NOTE && GET_CODE (first) != BARRIER)
+ EXECUTE_IF_SET_IN_REG_SET (bb->global_live_at_start, 0, i,
{
- c = new_insn_chain ();
- c->prev = prev;
- prev = c;
- *p = c;
- p = &c->next;
- c->insn = first;
- c->block = b;
+ if ((i < FIRST_PSEUDO_REGISTER
+ && ! TEST_HARD_REG_BIT (eliminable_regset, i))
+ || (i >= FIRST_PSEUDO_REGISTER
+ && reg_renumber[i] >= 0))
+ SET_REGNO_REG_SET (live_relevant_regs, i);
+ });
- COPY_REG_SET (c->live_before, live_relevant_regs);
+ insn = bb->head, end = bb->end;
+ while (1)
+ {
+ struct insn_chain *c;
- if (GET_RTX_CLASS (GET_CODE (first)) == 'i')
+ if (GET_CODE (insn) != NOTE)
{
- rtx link;
-
- /* Mark the death of everything that dies in this instruction. */
+ c = new_insn_chain ();
+ c->prev = prev;
+ prev = c;
+ *p = c;
+ p = &c->next;
+ c->insn = insn;
+ c->block = b;
- for (link = REG_NOTES (first); link; link = XEXP (link, 1))
- if (REG_NOTE_KIND (link) == REG_DEAD
- && GET_CODE (XEXP (link, 0)) == REG)
- reg_dies (REGNO (XEXP (link, 0)), GET_MODE (XEXP (link, 0)));
+ COPY_REG_SET (c->live_before, live_relevant_regs);
- /* Mark everything born in this instruction as live. */
+ if (GET_RTX_CLASS (GET_CODE (insn)) == 'i')
+ {
+ rtx link;
- note_stores (PATTERN (first), reg_becomes_live);
- }
+ /* Mark the death of everything that dies in this
+ instruction. */
+ for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
+ if (REG_NOTE_KIND (link) == REG_DEAD
+ && GET_CODE (XEXP (link, 0)) == REG)
+ reg_dies (REGNO (XEXP (link, 0)),
+ GET_MODE (XEXP (link, 0)));
- /* Remember which registers are live at the end of the insn, before
- killing those with REG_UNUSED notes. */
- COPY_REG_SET (c->live_after, live_relevant_regs);
+ /* Mark everything born in this instruction as live. */
+ note_stores (PATTERN (insn), reg_becomes_live);
+ }
- if (GET_RTX_CLASS (GET_CODE (first)) == 'i')
- {
- rtx link;
+ /* Remember which registers are live at the end of the insn,
+ before killing those with REG_UNUSED notes. */
+ COPY_REG_SET (c->live_after, live_relevant_regs);
- /* Mark anything that is set in this insn and then unused as dying. */
+ if (GET_RTX_CLASS (GET_CODE (insn)) == 'i')
+ {
+ rtx link;
- for (link = REG_NOTES (first); link; link = XEXP (link, 1))
- if (REG_NOTE_KIND (link) == REG_UNUSED
- && GET_CODE (XEXP (link, 0)) == REG)
- reg_dies (REGNO (XEXP (link, 0)), GET_MODE (XEXP (link, 0)));
+ /* Mark anything that is set in this insn and then unused
+ as dying. */
+ for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
+ if (REG_NOTE_KIND (link) == REG_UNUSED
+ && GET_CODE (XEXP (link, 0)) == REG)
+ reg_dies (REGNO (XEXP (link, 0)),
+ GET_MODE (XEXP (link, 0)));
+ }
}
- }
-
- if (first == BLOCK_END (b))
- b++;
- /* Stop after we pass the end of the last basic block. Verify that
- no real insns are after the end of the last basic block.
-
- We may want to reorganize the loop somewhat since this test should
- always be the right exit test. */
- if (b == n_basic_blocks)
- {
- for (first = NEXT_INSN (first) ; first; first = NEXT_INSN (first))
- if (GET_RTX_CLASS (GET_CODE (first)) == 'i'
- && GET_CODE (PATTERN (first)) != USE)
- abort ();
- break;
+ if (insn == end)
+ break;
+ insn = NEXT_INSN (insn);
}
}
+
FREE_REG_SET (live_relevant_regs);
*p = 0;
}