From: Wilco Dijkstra <wdijkstr@arm.com>
Date: Wed, 21 Jun 2017 10:40:21 +0000 (+0000)
Subject: Mark symbols as constant
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=f28e54bd06f3733ff147128107a8da6d3e6d428e;p=gcc.git

Mark symbols as constant

Aarch64_legitimate_constant_p currently returns false for symbols,
eventhough they are always valid constants.  This means LOSYM isn't
CSEd correctly.  If we return true CSE works better, resulting in
smaller/faster code (0.3% smaller code on SPEC2006).  Avoid this
for TLS symbols since their sequence is complex.

    gcc/
	* config/aarch64/aarch64.c (aarch64_legitimate_constant_p):
	Return true for non-tls symbols.

From-SVN: r249442
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index e08150c612c..1aaaf61a073 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2017-06-21  Wilco Dijkstra  <wdijkstr@arm.com>
+
+	* config/aarch64/aarch64.c (aarch64_legitimate_constant_p):
+	Return true for non-tls symbols.
+
 2017-06-21  James Greenhalgh  <james.greenhalgh@arm.com>
 
 	* config/aarch64/aarch64-cores.def (cortex-a55): New.
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index 04417dcd609..ba6b45fcb3d 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -10129,6 +10129,11 @@ aarch64_legitimate_constant_p (machine_mode mode, rtx x)
       && aarch64_valid_symref (XEXP (x, 0), GET_MODE (XEXP (x, 0))))
     return true;
 
+  /* Treat symbols as constants.  Avoid TLS symbols as they are complex,
+     so spilling them is better than rematerialization.  */
+  if (SYMBOL_REF_P (x) && !SYMBOL_REF_TLS_MODEL (x))
+    return true;
+
   return aarch64_constant_address_p (x);
 }