From: Kyrylo Tkachov <kyrylo.tkachov@arm.com>
Date: Fri, 26 Aug 2016 10:23:20 +0000 (+0000)
Subject: [ARM] PR target/70473: Reduce size of Cortex-A8 automaton
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=83c7402aa5d210a822e025f353c8f9bce027a4a7;p=gcc.git

[ARM] PR target/70473: Reduce size of Cortex-A8 automaton

	PR target/70473
	* config/arm/cortex-a8-neon.md (cortex_a8_vfp_muld): Reduce
	reservation duration to 15 cycles.
	(cortex_a8_vfp_macs): Likewise.
	(cortex_a8_vfp_macd): Likewise.
	(cortex_a8_vfp_divs): Likewise.
	(cortex_a8_vfp_divd): Likewise.

From-SVN: r239772
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 9c82debc2f4..dc3cb732c88 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,13 @@
+2016-08-26  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
+
+	PR target/70473
+	* config/arm/cortex-a8-neon.md (cortex_a8_vfp_muld): Reduce
+	reservation duration to 15 cycles.
+	(cortex_a8_vfp_macs): Likewise.
+	(cortex_a8_vfp_macd): Likewise.
+	(cortex_a8_vfp_divs): Likewise.
+	(cortex_a8_vfp_divd): Likewise.
+
 2016-08-26  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
 
 	* config/arm/arm.c (arm_sets_movw_movt_fusible_p): New function.
diff --git a/gcc/config/arm/cortex-a8-neon.md b/gcc/config/arm/cortex-a8-neon.md
index 45f861f6c6f..b16c29974a7 100644
--- a/gcc/config/arm/cortex-a8-neon.md
+++ b/gcc/config/arm/cortex-a8-neon.md
@@ -357,30 +357,34 @@
        (eq_attr "type" "fmuls"))
   "cortex_a8_vfp,cortex_a8_vfplite*11")
 
+;; Don't model a reservation for more than 15 cycles as this explodes the
+;; state space of the automaton for little gain.  It is unlikely that the
+;; scheduler will find enough instructions to hide the full latency of the
+;; instructions.
 (define_insn_reservation "cortex_a8_vfp_muld" 17
   (and (eq_attr "tune" "cortexa8")
        (eq_attr "type" "fmuld"))
-  "cortex_a8_vfp,cortex_a8_vfplite*16")
+  "cortex_a8_vfp,cortex_a8_vfplite*15")
 
 (define_insn_reservation "cortex_a8_vfp_macs" 21
   (and (eq_attr "tune" "cortexa8")
        (eq_attr "type" "fmacs,ffmas"))
-  "cortex_a8_vfp,cortex_a8_vfplite*20")
+  "cortex_a8_vfp,cortex_a8_vfplite*15")
 
 (define_insn_reservation "cortex_a8_vfp_macd" 26
   (and (eq_attr "tune" "cortexa8")
        (eq_attr "type" "fmacd,ffmad"))
-  "cortex_a8_vfp,cortex_a8_vfplite*25")
+  "cortex_a8_vfp,cortex_a8_vfplite*15")
 
 (define_insn_reservation "cortex_a8_vfp_divs" 37
   (and (eq_attr "tune" "cortexa8")
        (eq_attr "type" "fdivs, fsqrts"))
-  "cortex_a8_vfp,cortex_a8_vfplite*36")
+  "cortex_a8_vfp,cortex_a8_vfplite*15")
 
 (define_insn_reservation "cortex_a8_vfp_divd" 65
   (and (eq_attr "tune" "cortexa8")
        (eq_attr "type" "fdivd, fsqrtd"))
-  "cortex_a8_vfp,cortex_a8_vfplite*64")
+  "cortex_a8_vfp,cortex_a8_vfplite*15")
 
 ;; Comparisons can actually take 7 cycles sometimes instead of four,
 ;; but given all the other instructions lumped into type=ffarith that