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Commit 6865f4cd by Richard Sandiford Committed by Richard Sandiford
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mips.c (mips16_optimize_gp): Delete. 

	* config/mips/mips.c (mips16_optimize_gp): Delete.
	(mips_reorg): Don't call it.

From-SVN: r76623
parent f210a007
Showing with 6 additions and 223 deletions
gcc/ChangeLog
2004-01-26 Richard Sandiford <rsandifo@redhat.com>
* config/mips/mips.c (mips16_optimize_gp): Delete.
(mips_reorg): Don't call it.
2004-01-26 Michael Hayes <m.hayes@elec.canterbury.ac.nz>
* config/c4x/c4x.md (addqi3_noclobber): Move up pecking order.
......
gcc/config/mips/mips.c
......@@ -267,7 +267,6 @@ static rtx mips_return_fpr_pair (enum machine_mode mode,
static rtx mips16_gp_pseudo_reg (void);
static void mips16_fp_args (FILE *, int, int);
static void build_mips16_function_stub (FILE *);
static void mips16_optimize_gp (void);
static rtx add_constant (struct constant **, rtx, enum machine_mode);
static void dump_constants (struct constant *, rtx);
static rtx mips_find_symbol (rtx);
......@@ -8306,223 +8305,6 @@ build_mips16_call_stub (rtx retval, rtx fn, rtx arg_size, int fp_code)
return 0;
}
/* This function looks through the code for a function, and tries to
optimize the usage of the $gp register. We arrange to copy $gp
into a pseudo-register, and then let gcc's normal reload handling
deal with the pseudo-register. Unfortunately, if reload choose to
put the pseudo-register into a call-clobbered register, it will
emit saves and restores for that register around any function
calls. We don't need the saves, and it's faster to copy $gp than
to do an actual restore. ??? This still means that we waste a
stack slot.
This is an optimization, and the code which gcc has actually
generated is correct, so we do not need to catch all cases. */
static void
mips16_optimize_gp (void)
{
rtx gpcopy, slot, insn;
/* Look through the instructions. Set GPCOPY to the register which
holds a copy of $gp. Set SLOT to the stack slot where it is
saved. If we find an instruction which sets GPCOPY to anything
other than $gp or SLOT, then we can't use it. If we find an
instruction which sets SLOT to anything other than GPCOPY, we
can't use it. */
gpcopy = NULL_RTX;
slot = NULL_RTX;
for (insn = get_insns (); insn != NULL_RTX; insn = next_active_insn (insn))
{
rtx set;
if (! INSN_P (insn))
continue;
set = PATTERN (insn);
/* We know that all references to memory will be inside a SET,
because there is no other way to access memory on the mips16.
We don't have to worry about a PARALLEL here, because the
mips.md file will never generate them for memory references. */
if (GET_CODE (set) != SET)
continue;
if (gpcopy == NULL_RTX
&& GET_CODE (SET_SRC (set)) == CONST
&& XEXP (SET_SRC (set), 0) == pic_offset_table_rtx
&& GET_CODE (SET_DEST (set)) == REG)
gpcopy = SET_DEST (set);
else if (slot == NULL_RTX
&& gpcopy != NULL_RTX
&& GET_CODE (SET_DEST (set)) == MEM
&& GET_CODE (SET_SRC (set)) == REG
&& REGNO (SET_SRC (set)) == REGNO (gpcopy))
{
rtx base, offset;
offset = const0_rtx;
base = eliminate_constant_term (XEXP (SET_DEST (set), 0), &offset);
if (GET_CODE (base) == REG
&& (REGNO (base) == STACK_POINTER_REGNUM
|| REGNO (base) == FRAME_POINTER_REGNUM))
slot = SET_DEST (set);
}
else if (gpcopy != NULL_RTX
&& (GET_CODE (SET_DEST (set)) == REG
|| GET_CODE (SET_DEST (set)) == SUBREG)
&& reg_overlap_mentioned_p (SET_DEST (set), gpcopy)
&& (GET_CODE (SET_DEST (set)) != REG
|| REGNO (SET_DEST (set)) != REGNO (gpcopy)
|| ((GET_CODE (SET_SRC (set)) != CONST
|| XEXP (SET_SRC (set), 0) != pic_offset_table_rtx)
&& ! rtx_equal_p (SET_SRC (set), slot))))
break;
else if (slot != NULL_RTX
&& GET_CODE (SET_DEST (set)) == MEM
&& rtx_equal_p (SET_DEST (set), slot)
&& (GET_CODE (SET_SRC (set)) != REG
|| REGNO (SET_SRC (set)) != REGNO (gpcopy)))
break;
}
/* If we couldn't find a unique value for GPCOPY or SLOT, then try a
different optimization. Any time we find a copy of $28 into a
register, followed by an add of a symbol_ref to that register, we
convert it to load the value from the constant table instead.
The copy and add will take six bytes, just as the load and
constant table entry will take six bytes. However, it is
possible that the constant table entry will be shared.
This could be a peephole optimization, but I don't know if the
peephole code can call force_const_mem.
Using the same register for the copy of $28 and the add of the
symbol_ref is actually pretty likely, since the add instruction
requires the destination and the first addend to be the same
register. */
if (insn != NULL_RTX || gpcopy == NULL_RTX || slot == NULL_RTX)
{
#if 0
/* Used below in #if 0 area. */
rtx next;
#endif
/* This optimization is only reasonable if the constant table
entries are only 4 bytes. */
if (Pmode != SImode)
return;
#if 0
/* ??? FIXME. Rewrite for new UNSPEC_RELOC stuff. */
for (insn = get_insns (); insn != NULL_RTX; insn = next)
{
rtx set1, set2;
next = insn;
do
{
next = NEXT_INSN (next);
}
while (next != NULL_RTX
&& (GET_CODE (next) == NOTE
|| (GET_CODE (next) == INSN
&& (GET_CODE (PATTERN (next)) == USE
|| GET_CODE (PATTERN (next)) == CLOBBER))));
if (next == NULL_RTX)
break;
if (! INSN_P (insn))
continue;
if (! INSN_P (next))
continue;
set1 = PATTERN (insn);
if (GET_CODE (set1) != SET)
continue;
set2 = PATTERN (next);
if (GET_CODE (set2) != SET)
continue;
if (GET_CODE (SET_DEST (set1)) == REG
&& GET_CODE (SET_SRC (set1)) == CONST
&& XEXP (SET_SRC (set1), 0) == pic_offset_table_rtx
&& rtx_equal_p (SET_DEST (set1), SET_DEST (set2))
&& GET_CODE (SET_SRC (set2)) == PLUS
&& rtx_equal_p (SET_DEST (set1), XEXP (SET_SRC (set2), 0))
&& mips16_gp_offset_p (XEXP (SET_SRC (set2), 1))
&& GET_CODE (XEXP (XEXP (SET_SRC (set2), 1), 0)) == MINUS)
{
rtx sym;
/* We've found a case we can change to load from the
constant table. */
sym = XEXP (XEXP (XEXP (SET_SRC (set2), 1), 0), 0);
if (GET_CODE (sym) != SYMBOL_REF)
abort ();
emit_insn_after (gen_rtx (SET, VOIDmode, SET_DEST (set1),
force_const_mem (Pmode, sym)),
next);
PUT_CODE (insn, NOTE);
NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
NOTE_SOURCE_FILE (insn) = 0;
PUT_CODE (next, NOTE);
NOTE_LINE_NUMBER (next) = NOTE_INSN_DELETED;
NOTE_SOURCE_FILE (next) = 0;
}
}
#endif
return;
}
/* We can safely remove all assignments to SLOT from GPCOPY, and
replace all assignments from SLOT to GPCOPY with assignments from
$28. */
for (insn = get_insns (); insn != NULL_RTX; insn = next_active_insn (insn))
{
rtx set;
if (! INSN_P (insn))
continue;
set = PATTERN (insn);
if (GET_CODE (set) != SET)
continue;
if (GET_CODE (SET_DEST (set)) == MEM
&& rtx_equal_p (SET_DEST (set), slot)
&& GET_CODE (SET_SRC (set)) == REG
&& REGNO (SET_SRC (set)) == REGNO (gpcopy))
{
PUT_CODE (insn, NOTE);
NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
NOTE_SOURCE_FILE (insn) = 0;
}
else if (GET_CODE (SET_DEST (set)) == REG
&& REGNO (SET_DEST (set)) == REGNO (gpcopy)
&& GET_CODE (SET_SRC (set)) == MEM
&& rtx_equal_p (SET_SRC (set), slot))
{
enum machine_mode mode;
rtx src;
mode = GET_MODE (SET_DEST (set));
src = gen_rtx_CONST (mode, pic_offset_table_rtx);
emit_insn_after (gen_rtx_SET (VOIDmode, SET_DEST (set), src), insn);
PUT_CODE (insn, NOTE);
NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
NOTE_SOURCE_FILE (insn) = 0;
}
}
}
/* We keep a list of constants we which we have to add to internal
constant tables in the middle of large functions. */
......@@ -8971,11 +8753,7 @@ static void
mips_reorg (void)
{
if (TARGET_MIPS16)
{
if (optimize)
mips16_optimize_gp ();
mips16_lay_out_constants ();
}
mips16_lay_out_constants ();
else if (TARGET_EXPLICIT_RELOCS)
{
if (mips_flag_delayed_branch)
......
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