diff mbox

[AArch64] Implement TARGET_SCHED_MACRO_FUSION_PAIR_P

Message ID 5461F924.3000304@arm.com
State New
Headers show

Commit Message

Kyrylo Tkachov Nov. 11, 2014, 11:55 a.m. UTC 
Hi all,

This is the aarch64 implementation of the macro fusion hook, used to 
fuse mov+movk instructions together.

A new field is declared in the tuning struct and as we add more fuseable 
ops in the future we will fill in more bits in the fuseable_ops field.

Bootstrapped and tested on aarch64-none-linux-gnu.

Ok for trunk?

2014-11-11  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>

     * config/aarch64/aarch64-protos.h (struct tune_params): Add
     fuseable_ops field.
     * config/aarch64/aarch64.c (generic_tunings): Specify fuseable_ops.
     (cortexa53_tunings): Likewise.
     (cortexa57_tunings): Likewise.
     (thunderx_tunings): Likewise.
     (aarch64_macro_fusion_p): New function.
     (aarch_macro_fusion_pair_p): Likewise.
     (TARGET_SCHED_MACRO_FUSION_P): Define.
     (TARGET_SCHED_MACRO_FUSION_PAIR_P): Likewise.
     (AARCH64_FUSE_MOV_MOVK): Likewise.
     (AARCH64_FUSE_NOTHING): Likewise.

Comments

Andrew Pinski Nov. 13, 2014, 7:24 a.m. UTC | #1 
On Tue, Nov 11, 2014 at 3:55 AM, Kyrill Tkachov <kyrylo.tkachov@arm.com> wrote:
> Hi all,
>
> This is the aarch64 implementation of the macro fusion hook, used to fuse
> mov+movk instructions together.
>
> A new field is declared in the tuning struct and as we add more fuseable ops
> in the future we will fill in more bits in the fuseable_ops field.
>
> Bootstrapped and tested on aarch64-none-linux-gnu.
>
> Ok for trunk?

I have a few comments about this patch as I have a patch which depends
on this for ThunderX.

Each new function should have a comment before it saying what the function does.
The checks inside aarch_macro_fusion_pair_p for single_set and
any_condjump_p seems a little too restrictive to add more fusion
without major changes to the code.
In the fusion case I am adding is about fusing any single cycle
arithmetic instruction (on ThunderX) that produces flags and the
branch that consumes it.

Thanks,
Andrew

>
> 2014-11-11  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
>
>     * config/aarch64/aarch64-protos.h (struct tune_params): Add
>     fuseable_ops field.
>     * config/aarch64/aarch64.c (generic_tunings): Specify fuseable_ops.
>     (cortexa53_tunings): Likewise.
>     (cortexa57_tunings): Likewise.
>     (thunderx_tunings): Likewise.
>     (aarch64_macro_fusion_p): New function.
>     (aarch_macro_fusion_pair_p): Likewise.
>     (TARGET_SCHED_MACRO_FUSION_P): Define.
>     (TARGET_SCHED_MACRO_FUSION_PAIR_P): Likewise.
>     (AARCH64_FUSE_MOV_MOVK): Likewise.
>     (AARCH64_FUSE_NOTHING): Likewise.
diff mbox

Patch

commit 3181b0988eed091c8b1ead7a6381c6f9aee7774e
Author: Kyrylo Tkachov <kyrylo.tkachov@arm.com>
Date:   Tue Oct 21 10:36:48 2014 +0100

    [AArch64] Implement TARGET_MACRO_FUSION

diff --git a/gcc/config/aarch64/aarch64-protos.h b/gcc/config/aarch64/aarch64-protos.h
index 810644c..d3d295d 100644
--- a/gcc/config/aarch64/aarch64-protos.h
+++ b/gcc/config/aarch64/aarch64-protos.h
@@ -170,6 +170,7 @@  struct tune_params
   const struct cpu_vector_cost *const vec_costs;
   const int memmov_cost;
   const int issue_rate;
+  const unsigned int fuseable_ops;
 };
 
 HOST_WIDE_INT aarch64_initial_elimination_offset (unsigned, unsigned);
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index 9aeac7c..96f6c47 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -299,6 +299,9 @@  static const struct cpu_vector_cost cortexa57_vector_cost =
   NAMED_PARAM (cond_not_taken_branch_cost, 1)
 };
 
+#define AARCH64_FUSE_NOTHING	(0)
+#define AARCH64_FUSE_MOV_MOVK	(1 << 0)
+
 #if HAVE_DESIGNATED_INITIALIZERS && GCC_VERSION >= 2007
 __extension__
 #endif
@@ -309,7 +312,8 @@  static const struct tune_params generic_tunings =
   &generic_regmove_cost,
   &generic_vector_cost,
   NAMED_PARAM (memmov_cost, 4),
-  NAMED_PARAM (issue_rate, 2)
+  NAMED_PARAM (issue_rate, 2),
+  NAMED_PARAM (fuseable_ops, AARCH64_FUSE_NOTHING)
 };
 
 static const struct tune_params cortexa53_tunings =
@@ -319,7 +323,8 @@  static const struct tune_params cortexa53_tunings =
   &cortexa53_regmove_cost,
   &generic_vector_cost,
   NAMED_PARAM (memmov_cost, 4),
-  NAMED_PARAM (issue_rate, 2)
+  NAMED_PARAM (issue_rate, 2),
+  NAMED_PARAM (fuseable_ops, AARCH64_FUSE_MOV_MOVK)
 };
 
 static const struct tune_params cortexa57_tunings =
@@ -329,7 +334,8 @@  static const struct tune_params cortexa57_tunings =
   &cortexa57_regmove_cost,
   &cortexa57_vector_cost,
   NAMED_PARAM (memmov_cost, 4),
-  NAMED_PARAM (issue_rate, 3)
+  NAMED_PARAM (issue_rate, 3),
+  NAMED_PARAM (fuseable_ops, AARCH64_FUSE_MOV_MOVK)
 };
 
 static const struct tune_params thunderx_tunings =
@@ -339,7 +345,8 @@  static const struct tune_params thunderx_tunings =
   &thunderx_regmove_cost,
   &generic_vector_cost,
   NAMED_PARAM (memmov_cost, 6),
-  NAMED_PARAM (issue_rate, 2)
+  NAMED_PARAM (issue_rate, 2),
+  NAMED_PARAM (fuseable_ops, AARCH64_FUSE_NOTHING)
 };
 
 /* A processor implementing AArch64.  */
@@ -10017,6 +10024,48 @@  aarch64_use_by_pieces_infrastructure_p (unsigned int size,
   return default_use_by_pieces_infrastructure_p (size, align, op, speed_p);
 }
 
+static bool
+aarch64_macro_fusion_p (void)
+{
+  return aarch64_tune_params->fuseable_ops != AARCH64_FUSE_NOTHING;
+}
+
+static bool
+aarch_macro_fusion_pair_p (rtx_insn *prev, rtx_insn *curr)
+{
+  rtx set_dest;
+  rtx prev_set = single_set (prev);
+  rtx curr_set = single_set (curr);
+
+  if (!prev_set
+      || !curr_set)
+    return false;
+
+  if (any_condjump_p (curr))
+    return false;
+
+  if (!aarch64_macro_fusion_p ())
+    return false;
+
+  if (aarch64_tune_params->fuseable_ops & AARCH64_FUSE_MOV_MOVK)
+    {
+      /* We are trying to fuse
+         mov imm / movk imm
+         instructions as a group that gets scheduled together.  */
+
+      set_dest = SET_DEST (curr_set);
+
+      return GET_CODE (set_dest) == ZERO_EXTRACT
+             && CONST_INT_P (SET_SRC (curr_set))
+             && CONST_INT_P (SET_SRC (prev_set))
+             && REG_P (XEXP (set_dest, 0))
+             && REG_P (SET_DEST (prev_set))
+             && REGNO (XEXP (set_dest, 0)) == REGNO (SET_DEST (prev_set));
+    }
+
+  return false;
+}
+
 #undef TARGET_ADDRESS_COST
 #define TARGET_ADDRESS_COST aarch64_address_cost
 
@@ -10273,6 +10322,12 @@  aarch64_use_by_pieces_infrastructure_p (unsigned int size,
 #define TARGET_USE_BY_PIECES_INFRASTRUCTURE_P \
   aarch64_use_by_pieces_infrastructure_p
 
+#undef TARGET_SCHED_MACRO_FUSION_P
+#define TARGET_SCHED_MACRO_FUSION_P aarch64_macro_fusion_p
+
+#undef TARGET_SCHED_MACRO_FUSION_PAIR_P
+#define TARGET_SCHED_MACRO_FUSION_PAIR_P aarch_macro_fusion_pair_p
+
 struct gcc_target targetm = TARGET_INITIALIZER;
 
 #include "gt-aarch64.h"