From: Segher Boessenkool <segher@kernel.crashing.org>
Date: Fri, 15 Mar 2019 22:09:15 +0000 (+0100)
Subject: LRA: side_effects_p stmts' output is not invariant (PR89721)
X-Git-Tag: basepoints/gcc-10~604
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=850b8aa3091a2c62200bde93fc61101e4dec45b6;p=thirdparty%2Fgcc.git

LRA: side_effects_p stmts' output is not invariant (PR89721)

PR89721 shows LRA treating an unspec_volatile's result as invariant,
which of course isn't correct.  This patch fixes it.


	PR rtl-optimization/89721
	* lra-constraints (invariant_p): Return false if side_effects_p holds.

From-SVN: r269716
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 55d80e563678..67dc0bfdbb69 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2019-03-15  Segher Boessenkool  <segher@kernel.crashing.org>
+
+	PR rtl-optimization/89721
+	* lra-constraints (invariant_p): Return false if side_effects_p holds.
+
 2019-03-15  Kelvin Nilsen  <kelvin@gcc.gnu.org>
 
 	PR target/87532
diff --git a/gcc/lra-constraints.c b/gcc/lra-constraints.c
index d7d69c6ba50c..ccca1303ec2a 100644
--- a/gcc/lra-constraints.c
+++ b/gcc/lra-constraints.c
@@ -5839,6 +5839,9 @@ invariant_p (const_rtx x)
   enum rtx_code code;
   int i, j;
 
+  if (side_effects_p (x))
+    return false;
+
   code = GET_CODE (x);
   mode = GET_MODE (x);
   if (code == SUBREG)