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i386: Update SSE <-> integer move costs 

Since inline_secondary_memory_needed has

  /* ??? This is a lie.  We do have moves between mmx/general, and for
     mmx/sse2.  But by saying we need secondary memory we discourage the
     register allocator from using the mmx registers unless needed.  */
  if (MMX_CLASS_P (class1) != MMX_CLASS_P (class2))
    return true;

moves between MMX and non-MMX units require secondary memory.   There
is no need to check moves between MMX and integer units.

struct processor_costs has:

  const int mmxsse_to_integer;  /* cost of moving mmxsse register to
                                   integer.  */
  const int ssemmx_to_integer;  /* cost of moving integer to mmxsse register. */

This patch also renames mmxsse_to_integer to sse_to_integer and
ssemmx_to_integer to integer_to_sse.

Tested on Linux/x86-64.

	PR target/90877
	* config/i386/i386-features.c
	(dimode_scalar_chain::compute_convert_gain): Replace
	mmxsse_to_integer with sse_to_integer.
	* config/i386/i386.c (ix86_register_move_cost): Verify that
	moves between MMX and non-MMX units require secondary memory.
	Correct costs of moves between SSE and integer units.
	* config/i386/i386.h (processor_costs): Rename cost of moving
	SSE register to integer to sse_to_integer.  Rename cost of
	moving integer register to SSE to integer_to_sse.

From-SVN: r272294
This commit is contained in:
Hongtao Liu 2019-06-14 15:41:43 +00:00 committed by H.J. Lu
parent 9f119e2926
commit 66574c5374
4 changed files with 25 additions and 11 deletions
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12
gcc/ChangeLog
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@ -1,3 +1,15 @@
2019-06-14 Hongtao Liu <hongtao.liu@intel.com>
PR target/90877
* config/i386/i386-features.c
(dimode_scalar_chain::compute_convert_gain): Replace
mmxsse_to_integer with sse_to_integer.
* config/i386/i386.c (ix86_register_move_cost): Verify that
moves between MMX and non-MMX units require secondary memory.
Correct costs of moves between SSE and integer units.
* config/i386/i386.h (processor_costs): Rename cost of moving
SSE register to integer to sse_to_integer. Rename cost of
2019-06-14 Matt Thomas <matt@3am-software.com>
Matthew Green <mrg@eterna.com.au>
Nick Hudson <skrll@netbsd.org>

2
gcc/config/i386/i386-features.c
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@ -554,7 +554,7 @@ dimode_scalar_chain::compute_convert_gain ()
fprintf (dump_file, " Instruction conversion gain: %d\n", gain);
EXECUTE_IF_SET_IN_BITMAP (defs_conv, 0, insn_uid, bi)
cost += DF_REG_DEF_COUNT (insn_uid) * ix86_cost->mmxsse_to_integer;
cost += DF_REG_DEF_COUNT (insn_uid) * ix86_cost->sse_to_integer;
if (dump_file)
fprintf (dump_file, " Registers conversion cost: %d\n", cost);

17
gcc/config/i386/i386.c
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@ -18633,18 +18633,21 @@ ix86_register_move_cost (machine_mode mode, reg_class_t class1_i,
return cost;
}
/* Moves between SSE/MMX and integer unit are expensive. */
if (MMX_CLASS_P (class1) != MMX_CLASS_P (class2)
|| SSE_CLASS_P (class1) != SSE_CLASS_P (class2))
/* Moves between MMX and non-MMX units require secondary memory. */
if (MMX_CLASS_P (class1) != MMX_CLASS_P (class2))
gcc_unreachable ();
/* Moves between SSE and integer units are expensive. */
if (SSE_CLASS_P (class1) != SSE_CLASS_P (class2))
/* ??? By keeping returned value relatively high, we limit the number
of moves between integer and MMX/SSE registers for all targets.
of moves between integer and SSE registers for all targets.
Additionally, high value prevents problem with x86_modes_tieable_p(),
where integer modes in MMX/SSE registers are not tieable
where integer modes in SSE registers are not tieable
because of missing QImode and HImode moves to, from or between
MMX/SSE registers. */
return MAX (8, MMX_CLASS_P (class1) || MMX_CLASS_P (class2)
? ix86_cost->mmxsse_to_integer : ix86_cost->ssemmx_to_integer);
return MAX (8, SSE_CLASS_P (class1)
? ix86_cost->sse_to_integer : ix86_cost->integer_to_sse);
if (MAYBE_FLOAT_CLASS_P (class1))
return ix86_cost->fp_move;

5
gcc/config/i386/i386.h
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@ -276,9 +276,8 @@ struct processor_costs {
const int sse_store[5]; /* cost of storing SSE register
in SImode, DImode and TImode. */
const int sse_unaligned_store[5];/* cost of unaligned store. */
const int mmxsse_to_integer; /* cost of moving mmxsse register to
integer. */
const int ssemmx_to_integer; /* cost of moving integer to mmxsse register. */
const int sse_to_integer; /* cost of moving SSE register to integer. */
const int integer_to_sse; /* cost of moving integer register to SSE. */
const int gather_static, gather_per_elt; /* Cost of gather load is computed
as static + per_item * nelts. */
const int scatter_static, scatter_per_elt; /* Cost of gather store is