From: Richard Biener <rguenther@suse.de>
Date: Tue, 19 Nov 2013 09:21:07 +0000 (+0000)
Subject: re PR tree-optimization/57517 (internal compiler error: in eliminate_temp_copies... 
X-Git-Tag: releases/gcc-4.9.0~2666
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=7906dbe42433518f7adef2ca388d7edc0a7fd246;p=thirdparty%2Fgcc.git

re PR tree-optimization/57517 (internal compiler error: in eliminate_temp_copies, at tree-predcom.c:1913)

2013-11-19  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/57517
	* tree-predcom.c (combinable_refs_p): Verify the combination
	is always executed when the refs are.

	* gfortran.fortran-torture/compile/pr57517.f90: New testcase.
	* gcc.dg/torture/pr57517.c: Likewise.

From-SVN: r205010
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index d759d4c5c080..65601e8c7758 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2013-11-19  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/57517
+	* tree-predcom.c (combinable_refs_p): Verify the combination
+	is always executed when the refs are.
+
 2013-11-19  Jeff Law  <law@redhat.com>
 
 	* tree-ssa-threadupdate.c: Include ssa-iterators.h
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 7e28844d2627..06e0bf551b82 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2013-11-19  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/57517
+	* gfortran.fortran-torture/compile/pr57517.f90: New testcase.
+	* gcc.dg/torture/pr57517.c: Likewise.
+
 2013-11-19  Jan Hubicka  <jh@suse.cz>
 
 	* gcc.target/i386/memcpy-3.c: New testcase.
diff --git a/gcc/testsuite/gcc.dg/torture/pr57517.c b/gcc/testsuite/gcc.dg/torture/pr57517.c
new file mode 100644
index 000000000000..2422d8ee64ab
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr57517.c
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+
+int x[1024], y[1024], z[1024], w[1024];
+void foo (void)
+{
+  int i;
+  for (i = 1; i < 1024; ++i)
+    {
+      int a = x[i];
+      int b = y[i];
+      int c = x[i-1];
+      int d = y[i-1];
+      if (w[i])
+	z[i] = (a + b) + (c + d);
+    }
+}
diff --git a/gcc/testsuite/gfortran.fortran-torture/compile/pr57517.f90 b/gcc/testsuite/gfortran.fortran-torture/compile/pr57517.f90
new file mode 100644
index 000000000000..f32698aa3a67
--- /dev/null
+++ b/gcc/testsuite/gfortran.fortran-torture/compile/pr57517.f90
@@ -0,0 +1,13 @@
+SUBROUTINE cal_helicity (uh, ph, phb, wavg, ims, ime, its, ite)
+  INTEGER, INTENT( IN ) :: ims, ime, its, ite
+  REAL, DIMENSION( ims:ime), INTENT( IN ) :: ph, phb, wavg
+  REAL, DIMENSION( ims:ime), INTENT( INOUT ) :: uh
+  INTEGER :: i
+  REAL :: zu
+  DO i = its, ite
+    zu =  (ph(i ) + phb(i)) + (ph(i-1) + phb(i-1))
+    IF (wavg(i) .GT. 0) THEN
+      uh(i) = uh(i) + zu 
+    ENDIF
+  END DO
+END SUBROUTINE cal_helicity
diff --git a/gcc/tree-predcom.c b/gcc/tree-predcom.c
index 77a15ab5523f..a43d19b08a9f 100644
--- a/gcc/tree-predcom.c
+++ b/gcc/tree-predcom.c
@@ -2035,7 +2035,11 @@ combinable_refs_p (dref r1, dref r2,
 
   stmt = find_common_use_stmt (&name1, &name2);
 
-  if (!stmt)
+  if (!stmt
+      /* A simple post-dominance check - make sure the combination
+         is executed under the same condition as the references.  */
+      || (gimple_bb (stmt) != gimple_bb (r1->stmt)
+	  && gimple_bb (stmt) != gimple_bb (r2->stmt)))
     return false;
 
   acode = gimple_assign_rhs_code (stmt);