[PATCH][AARCH64][5/5] Add macro fusion support for cmp/b.X for ThunderX

[Kyrill Tkachov]

Hi all,

Andrew posted this patch sometime ago (before stage1 closed) and I had 
rebased it on top of the
other macro fusion patches in that series.
This is a respin of that patch with the comment about not calling 
get_attr_type
repeatedly resolved 
(https://gcc.gnu.org/ml/gcc-patches/2014-11/msg02251.html)

Tested aarch64-none-elf.

Is this ok to go in?

Thanks,
Kyrill

2014-12-01  Andrew Pinski  apin...@cavium.com
                    Kyrylo Tkachov  kyrylo.tkac...@arm.com

     * config/aarch64/aarch64.c (AARCH64_FUSE_CMP_BRANCH): New define.
     (thunderx_tunings): Add AARCH64_FUSE_CMP_BRANCH to fuseable_ops.
     (aarch_macro_fusion_pair_p): Handle AARCH64_FUSE_CMP_BRANCH.commit 3035cf0bed7058e45ca70cb33face93d7dc1ce9c
Author: Kyrylo Tkachov <kyrylo.tkac...@arm.com>
Date:   Fri Nov 14 09:16:08 2014 +0000

    [AArch64][apinski] CMP+branch macro fusion

diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index 93932c8..3b76071 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -310,6 +310,7 @@ static const struct cpu_vector_cost cortexa57_vector_cost =
 #define AARCH64_FUSE_ADRP_ADD	(1 << 1)
 #define AARCH64_FUSE_MOVK_MOVK	(1 << 2)
 #define AARCH64_FUSE_ADRP_LDR	(1 << 3)
+#define AARCH64_FUSE_CMP_BRANCH	(1 << 4)
 
 #if HAVE_DESIGNATED_INITIALIZERS && GCC_VERSION >= 2007
 __extension__
@@ -356,7 +357,7 @@ static const struct tune_params thunderx_tunings =
   &generic_vector_cost,
   NAMED_PARAM (memmov_cost, 6),
   NAMED_PARAM (issue_rate, 2),
-  NAMED_PARAM (fuseable_ops, AARCH64_FUSE_NOTHING)
+  NAMED_PARAM (fuseable_ops, AARCH64_FUSE_CMP_BRANCH)
 };
 
 /* A processor implementing AArch64.  */
@@ -10522,6 +10523,20 @@ aarch_macro_fusion_pair_p (rtx_insn *prev, rtx_insn *curr)
         }
     }
 
+  if ((aarch64_tune_params->fuseable_ops & AARCH64_FUSE_CMP_BRANCH)
+      && any_condjump_p (curr))
+    {
+      enum attr_type prev_type = get_attr_type (prev);
+
+      /* FIXME: this misses some which is considered simple arthematic
+         instructions for ThunderX.  Simple shifts are missed here.  */
+      if (prev_type == TYPE_ALUS_SREG
+          || prev_type == TYPE_ALUS_IMM
+          || prev_type == TYPE_LOGICS_REG
+          || prev_type == TYPE_LOGICS_IMM)
+        return true;
+    }
+
   return false;
 }