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Commit 82916e7e by Vladimir Makarov Committed by Vladimir Makarov
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re PR middle-end/45312 (GCC 4.4.4 miscompiles the Linux kernel) 

2010-09-09  Vladimir Makarov  <vmakarov@redhat.com>

	PR middle-end/45312
	* reload1.c (merge_assigned_reloads): Remove.
	(reload_as_needed): Don't call it.

From-SVN: r164116
parent b9be2842
Showing with 6 additions and 154 deletions
gcc/ChangeLog
2010-09-09 Vladimir Makarov <vmakarov@redhat.com>
PR middle-end/45312
* reload1.c (merge_assigned_reloads): Remove.
(reload_as_needed): Don't call it.
2010-09-09 Anatoly Sokolov <aesok@post.ru>
* config/m32r/m32r.c (m32r_mode_dependent_address_p): New functions.
......
gcc/reload1.c
......@@ -435,7 +435,6 @@ static void failed_reload (rtx, int);
static int set_reload_reg (int, int);
static void choose_reload_regs_init (struct insn_chain *, rtx *);
static void choose_reload_regs (struct insn_chain *);
static void merge_assigned_reloads (rtx);
static void emit_input_reload_insns (struct insn_chain *, struct reload *,
rtx, int);
static void emit_output_reload_insns (struct insn_chain *, struct reload *,
......@@ -4596,12 +4595,6 @@ reload_as_needed (int live_known)
Record the choices of reload reg in reload_reg_rtx. */
choose_reload_regs (chain);
/* Merge any reloads that we didn't combine for fear of
increasing the number of spill registers needed but now
discover can be safely merged. */
if (targetm.small_register_classes_for_mode_p (VOIDmode))
merge_assigned_reloads (insn);
/* Generate the insns to reload operands into or out of
their reload regs. */
emit_reload_insns (chain);
......@@ -6994,153 +6987,6 @@ deallocate_reload_reg (int r)
reload_spill_index[r] = -1;
}
/* If the small_register_classes_for_mode_p target hook returns true for
some machine modes, we may not have merged two reloads of the same item
for fear that we might not have enough reload registers. However,
normally they will get the same reload register and hence actually need
not be loaded twice.
Here we check for the most common case of this phenomenon: when we have
a number of reloads for the same object, each of which were allocated
the same reload_reg_rtx, that reload_reg_rtx is not used for any other
reload, and is not modified in the insn itself. If we find such,
merge all the reloads and set the resulting reload to RELOAD_OTHER.
This will not increase the number of spill registers needed and will
prevent redundant code. */
static void
merge_assigned_reloads (rtx insn)
{
int i, j;
/* Scan all the reloads looking for ones that only load values and
are not already RELOAD_OTHER and ones whose reload_reg_rtx are
assigned and not modified by INSN. */
for (i = 0; i < n_reloads; i++)
{
int conflicting_input = 0;
int max_input_address_opnum = -1;
int min_conflicting_input_opnum = MAX_RECOG_OPERANDS;
if (rld[i].in == 0 || rld[i].when_needed == RELOAD_OTHER
|| rld[i].out != 0 || rld[i].reg_rtx == 0
|| reg_set_p (rld[i].reg_rtx, insn))
continue;
/* Look at all other reloads. Ensure that the only use of this
reload_reg_rtx is in a reload that just loads the same value
as we do. Note that any secondary reloads must be of the identical
class since the values, modes, and result registers are the
same, so we need not do anything with any secondary reloads. */
for (j = 0; j < n_reloads; j++)
{
if (i == j || rld[j].reg_rtx == 0
|| ! reg_overlap_mentioned_p (rld[j].reg_rtx,
rld[i].reg_rtx))
continue;
if (rld[j].when_needed == RELOAD_FOR_INPUT_ADDRESS
&& rld[j].opnum > max_input_address_opnum)
max_input_address_opnum = rld[j].opnum;
/* If the reload regs aren't exactly the same (e.g, different modes)
or if the values are different, we can't merge this reload.
But if it is an input reload, we might still merge
RELOAD_FOR_INPUT_ADDRESS and RELOAD_FOR_OTHER_ADDRESS reloads. */
if (! rtx_equal_p (rld[i].reg_rtx, rld[j].reg_rtx)
|| rld[j].out != 0 || rld[j].in == 0
|| ! rtx_equal_p (rld[i].in, rld[j].in))
{
if (rld[j].when_needed != RELOAD_FOR_INPUT
|| ((rld[i].when_needed != RELOAD_FOR_INPUT_ADDRESS
|| rld[i].opnum > rld[j].opnum)
&& rld[i].when_needed != RELOAD_FOR_OTHER_ADDRESS))
break;
conflicting_input = 1;
if (min_conflicting_input_opnum > rld[j].opnum)
min_conflicting_input_opnum = rld[j].opnum;
}
}
/* If all is OK, merge the reloads. Only set this to RELOAD_OTHER if
we, in fact, found any matching reloads. */
if (j == n_reloads
&& max_input_address_opnum <= min_conflicting_input_opnum)
{
gcc_assert (rld[i].when_needed != RELOAD_FOR_OUTPUT);
for (j = 0; j < n_reloads; j++)
if (i != j && rld[j].reg_rtx != 0
&& rtx_equal_p (rld[i].reg_rtx, rld[j].reg_rtx)
&& (! conflicting_input
|| rld[j].when_needed == RELOAD_FOR_INPUT_ADDRESS
|| rld[j].when_needed == RELOAD_FOR_OTHER_ADDRESS))
{
rld[i].when_needed = RELOAD_OTHER;
rld[j].in = 0;
reload_spill_index[j] = -1;
transfer_replacements (i, j);
}
/* If this is now RELOAD_OTHER, look for any reloads that
load parts of this operand and set them to
RELOAD_FOR_OTHER_ADDRESS if they were for inputs,
RELOAD_OTHER for outputs. Note that this test is
equivalent to looking for reloads for this operand
number.
We must take special care with RELOAD_FOR_OUTPUT_ADDRESS;
it may share registers with a RELOAD_FOR_INPUT, so we can
not change it to RELOAD_FOR_OTHER_ADDRESS. We should
never need to, since we do not modify RELOAD_FOR_OUTPUT.
It is possible that the RELOAD_FOR_OPERAND_ADDRESS
instruction is assigned the same register as the earlier
RELOAD_FOR_OTHER_ADDRESS instruction. Merging these two
instructions will cause the RELOAD_FOR_OTHER_ADDRESS
instruction to be deleted later on. */
if (rld[i].when_needed == RELOAD_OTHER)
for (j = 0; j < n_reloads; j++)
if (rld[j].in != 0
&& rld[j].when_needed != RELOAD_OTHER
&& rld[j].when_needed != RELOAD_FOR_OTHER_ADDRESS
&& rld[j].when_needed != RELOAD_FOR_OUTPUT_ADDRESS
&& rld[j].when_needed != RELOAD_FOR_OPERAND_ADDRESS
&& (! conflicting_input
|| rld[j].when_needed == RELOAD_FOR_INPUT_ADDRESS
|| rld[j].when_needed == RELOAD_FOR_INPADDR_ADDRESS)
&& reg_overlap_mentioned_for_reload_p (rld[j].in,
rld[i].in))
{
int k;
rld[j].when_needed
= ((rld[j].when_needed == RELOAD_FOR_INPUT_ADDRESS
|| rld[j].when_needed == RELOAD_FOR_INPADDR_ADDRESS)
? RELOAD_FOR_OTHER_ADDRESS : RELOAD_OTHER);
/* Check to see if we accidentally converted two
reloads that use the same reload register with
different inputs to the same type. If so, the
resulting code won't work. */
if (rld[j].reg_rtx)
for (k = 0; k < j; k++)
gcc_assert (rld[k].in == 0 || rld[k].reg_rtx == 0
|| rld[k].when_needed != rld[j].when_needed
|| !rtx_equal_p (rld[k].reg_rtx,
rld[j].reg_rtx)
|| rtx_equal_p (rld[k].in,
rld[j].in));
}
}
}
}
/* These arrays are filled by emit_reload_insns and its subroutines. */
static rtx input_reload_insns[MAX_RECOG_OPERANDS];
static rtx other_input_address_reload_insns = 0;
......
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