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Short circuit if upper 128bits are unchanged in the block.

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2010-12-30  H.J. Lu  <hongjiu.lu@intel.com>

	* config/i386/i386.c (upper_128bits_state): Remove comments.
	(block_info_def): Add unchanged.
	(move_or_delete_vzeroupper_2): Short circuit if upper 128bits
	are unchanged in the block.

From-SVN: r168343
This commit is contained in:
H.J. Lu 2010-12-30 13:13:13 +00:00 • committed by H.J. Lu
parent 310a21aa31
commit 720386ac5f
2 changed files with 43 additions and 12 deletions
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7
gcc/ChangeLog
View file

@ -1,3 +1,10 @@
2010-12-30 H.J. Lu <hongjiu.lu@intel.com>
* config/i386/i386.c (upper_128bits_state): Remove comments.
(block_info_def): Add unchanged.
(move_or_delete_vzeroupper_2): Short circuit if upper 128bits
are unchanged in the block.
2010-12-30 H.J. Lu <hongjiu.lu@intel.com>
PR target/46519

48
gcc/config/i386/i386.c
View file

@ -59,15 +59,18 @@ along with GCC; see the file COPYING3. If not see
enum upper_128bits_state
{
unknown = 0, /* Unknown. */
unused, /* Not used or not referenced. */
used /* Used or referenced. */
unknown = 0,
unused,
used
};
typedef struct block_info_def
{
/* State of the upper 128bits of any AVX registers at exit. */
/* State of the upper 128bits of AVX registers at exit. */
enum upper_128bits_state state;
/* TRUE if state of the upper 128bits of AVX registers is unchanged
in this block. */
bool unchanged;
/* TRUE if block has been processed. */
bool processed;
} *block_info;
@ -110,8 +113,7 @@ check_avx256_stores (rtx dest, const_rtx set, void *data)
in basic block BB. Delete it if upper 128bit AVX registers are
unused. If it isn't deleted, move it to just before a jump insn.
UPPER_128BITS_LIVE is TRUE if the upper 128bits of any AVX registers
are live at entry. */
STATE is state of the upper 128bits of AVX registers at entry. */
static void
move_or_delete_vzeroupper_2 (basic_block bb,
@ -121,11 +123,24 @@ move_or_delete_vzeroupper_2 (basic_block bb,
rtx vzeroupper_insn = NULL_RTX;
rtx pat;
int avx256;
bool unchanged;
if (BLOCK_INFO (bb)->unchanged)
{
if (dump_file)
fprintf (dump_file, " [bb %i] unchanged: upper 128bits: %d\n",
bb->index, state);
BLOCK_INFO (bb)->state = state;
return;
}
if (dump_file)
fprintf (dump_file, " [bb %i] entry: upper 128bits: %d\n",
bb->index, state);
unchanged = true;
/* BB_END changes when it is deleted. */
bb_end = BB_END (bb);
insn = BB_HEAD (bb);
@ -179,6 +194,7 @@ move_or_delete_vzeroupper_2 (basic_block bb,
&& XINT (XVECEXP (pat, 0, 0), 1) == UNSPECV_VZEROALL)
{
state = unused;
unchanged = false;
/* Delete pending vzeroupper insertion. */
if (vzeroupper_insn)
@ -189,9 +205,9 @@ move_or_delete_vzeroupper_2 (basic_block bb,
}
else if (state != used)
{
/* No need to call note_stores if the upper 128bits of
AVX registers are never referenced. */
note_stores (pat, check_avx256_stores, &state);
if (state == used)
unchanged = false;
}
continue;
}
@ -205,7 +221,10 @@ move_or_delete_vzeroupper_2 (basic_block bb,
256bit AVX register. We only need to check if callee
returns 256bit AVX register. */
if (avx256 == callee_return_avx256)
state = used;
{
state = used;
unchanged = false;
}
/* Remove unnecessary vzeroupper since upper 128bits are
cleared. */
@ -236,15 +255,20 @@ move_or_delete_vzeroupper_2 (basic_block bb,
delete_insn (insn);
}
else
vzeroupper_insn = insn;
{
vzeroupper_insn = insn;
unchanged = false;
}
}
}
BLOCK_INFO (bb)->state = state;
BLOCK_INFO (bb)->unchanged = unchanged;
if (dump_file)
fprintf (dump_file, " [bb %i] exit: upper 128bits: %d\n",
bb->index, state);
fprintf (dump_file, " [bb %i] exit: %s: upper 128bits: %d\n",
bb->index, unchanged ? "unchanged" : "changed",
state);
}
/* Helper function for move_or_delete_vzeroupper. Process vzeroupper