/* Try to unroll loops, and split induction variables.
- Copyright (C) 1992, 1993, 1994, 1995, 1997, 1998, 1999, 2000, 2001
+ Copyright (C) 1992, 1993, 1994, 1995, 1997, 1998, 1999, 2000, 2001, 2002
Free Software Foundation, Inc.
Contributed by James E. Wilson, Cygnus Support/UC Berkeley.
moving the insn back into the loop, or perhaps replicate the insn before
the loop, one copy for each time the loop is unrolled. */
+#include "config.h"
+#include "system.h"
+#include "rtl.h"
+#include "tm_p.h"
+#include "insn-config.h"
+#include "integrate.h"
+#include "regs.h"
+#include "recog.h"
+#include "flags.h"
+#include "function.h"
+#include "expr.h"
+#include "loop.h"
+#include "toplev.h"
+#include "hard-reg-set.h"
+#include "basic-block.h"
+#include "predict.h"
+
/* The prime factors looked for when trying to unroll a loop by some
number which is modulo the total number of iterations. Just checking
for these 4 prime factors will find at least one factor for 75% of
#define NUM_FACTORS 4
-struct _factor { int factor, count; }
+static struct _factor { const int factor; int count; }
factors[NUM_FACTORS] = { {2, 0}, {3, 0}, {5, 0}, {7, 0}};
/* Describes the different types of loop unrolling performed. */
UNROLL_NAIVE
};
-#include "config.h"
-#include "system.h"
-#include "rtl.h"
-#include "tm_p.h"
-#include "insn-config.h"
-#include "integrate.h"
-#include "regs.h"
-#include "recog.h"
-#include "flags.h"
-#include "function.h"
-#include "expr.h"
-#include "loop.h"
-#include "toplev.h"
-#include "hard-reg-set.h"
-#include "basic-block.h"
-#include "predict.h"
-
/* This controls which loops are unrolled, and by how much we unroll
them. */
start_sequence ();
+ /* Final value may have form of (PLUS val1 const1_rtx). We need
+ to convert it into general operand, so compute the real value. */
+
+ if (GET_CODE (final_value) == PLUS)
+ {
+ final_value = expand_simple_binop (mode, PLUS,
+ copy_rtx (XEXP (final_value, 0)),
+ copy_rtx (XEXP (final_value, 1)),
+ NULL_RTX, 0, OPTAB_LIB_WIDEN);
+ }
+ if (!nonmemory_operand (final_value, VOIDmode))
+ final_value = force_reg (mode, copy_rtx (final_value));
+
/* Calculate the difference between the final and initial values.
Final value may be a (plus (reg x) (const_int 1)) rtx.
Let the following cse pass simplify this if initial value is
so we can pretend that the overflow value is 0/~0. */
if (cc == NE || less_p != neg_inc)
- diff = expand_simple_binop (mode, MINUS, copy_rtx (final_value),
+ diff = expand_simple_binop (mode, MINUS, final_value,
copy_rtx (initial_value), NULL_RTX, 0,
OPTAB_LIB_WIDEN);
else
less_p ? GE : LE, NULL_RTX,
mode, unsigned_p, labels[1]);
predict_insn_def (get_last_insn (), PRED_LOOP_CONDITION,
- NOT_TAKEN);
+ TAKEN);
JUMP_LABEL (get_last_insn ()) = labels[1];
LABEL_NUSES (labels[1])++;
}
if (loop_info->n_iterations > 0)
{
- *initial_value = const0_rtx;
- *increment = const1_rtx;
- *final_value = GEN_INT (loop_info->n_iterations);
+ if (INTVAL (loop_info->increment) > 0)
+ {
+ *initial_value = const0_rtx;
+ *increment = const1_rtx;
+ *final_value = GEN_INT (loop_info->n_iterations);
+ }
+ else
+ {
+ *initial_value = GEN_INT (loop_info->n_iterations);
+ *increment = constm1_rtx;
+ *final_value = const0_rtx;
+ }
*mode = word_mode;
if (loop_dump_stream)
{
rtx insn = map->insn_map[INSN_UID (XEXP (note, 0))];
- /* If we failed to remap the note, something is awry. */
+ /* If we failed to remap the note, something is awry.
+ Allow REG_LABEL as it may reference label outside
+ the unrolled loop. */
if (!insn)
- abort ();
-
- XEXP (note, 0) = insn;
+ {
+ if (REG_NOTE_KIND (note) != REG_LABEL)
+ abort ();
+ }
+ else
+ XEXP (note, 0) = insn;
}
}
copy = emit_jump_insn (pattern);
REG_NOTES (copy) = initial_reg_note_copy (REG_NOTES (insn), map);
- if (JUMP_LABEL (insn) == start_label && insn == copy_end
- && ! last_iteration)
+ if (JUMP_LABEL (insn))
{
- /* Update JUMP_LABEL make invert_jump work correctly. */
JUMP_LABEL (copy) = get_label_from_map (map,
CODE_LABEL_NUMBER
(JUMP_LABEL (insn)));
LABEL_NUSES (JUMP_LABEL (copy))++;
+ }
+ if (JUMP_LABEL (insn) == start_label && insn == copy_end
+ && ! last_iteration)
+ {
/* This is a branch to the beginning of the loop; this is the
last insn being copied; and this is not the last iteration.
do
{
- if (GET_CODE (temp) == JUMP_INSN
- /* Previous unrolling may have generated new insns not covered
- by the uid_luid array. */
- && INSN_UID (JUMP_LABEL (temp)) < max_uid_for_loop
- /* Check if we jump back into the loop body. */
- && INSN_LUID (JUMP_LABEL (temp)) > INSN_LUID (loop->top)
- && INSN_LUID (JUMP_LABEL (temp)) < INSN_LUID (loop->cont))
+ if (GET_CODE (temp) == JUMP_INSN)
{
- if (loop_dump_stream)
- fprintf (loop_dump_stream,
- "Loop iterations: Loop has multiple back edges.\n");
- return 0;
+ /* There are some kinds of jumps we can't deal with easily. */
+ if (JUMP_LABEL (temp) == 0)
+ {
+ if (loop_dump_stream)
+ fprintf
+ (loop_dump_stream,
+ "Loop iterations: Jump insn has null JUMP_LABEL.\n");
+ return 0;
+ }
+
+ if (/* Previous unrolling may have generated new insns not
+ covered by the uid_luid array. */
+ INSN_UID (JUMP_LABEL (temp)) < max_uid_for_loop
+ /* Check if we jump back into the loop body. */
+ && INSN_LUID (JUMP_LABEL (temp)) > INSN_LUID (loop->top)
+ && INSN_LUID (JUMP_LABEL (temp)) < INSN_LUID (loop->cont))
+ {
+ if (loop_dump_stream)
+ fprintf
+ (loop_dump_stream,
+ "Loop iterations: Loop has multiple back edges.\n");
+ return 0;
+ }
}
}
while ((temp = PREV_INSN (temp)) != loop->cont);
not HOST_WIDE_INT, disregard higher bits that might have come
into the picture due to sign extension of initial and final
values. */
- abs_diff &= ((unsigned HOST_WIDE_INT)1
+ abs_diff &= ((unsigned HOST_WIDE_INT) 1
<< (GET_MODE_BITSIZE (GET_MODE (iteration_var)) - 1)
<< 1) - 1;
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