From: Jakub Jelinek <jakub@redhat.com>
Date: Fri, 11 Mar 2016 12:07:01 +0000 (+0100)
Subject: re PR rtl-optimization/70174 (ICE at -O1 and above on x86_64-linux-gnu in gen_lowpart... 
X-Git-Tag: basepoints/gcc-7~478
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=686d390a8fc1c0f72122910844e86d4a412c4e34;p=thirdparty%2Fgcc.git

re PR rtl-optimization/70174 (ICE at -O1 and above on x86_64-linux-gnu in gen_lowpart_general, at rtlhooks.c:63)

	PR rtl-optimization/70174
	* expmed.c (store_bit_field_using_insv): Use gen_lowpart_if_possible
	followed by gen_lowpart on force_reg instead of just gen_lowpart.

	* gcc.dg/pr70174.c: New test.

From-SVN: r234137
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 171a52d1ec8c..09ea7f7bd7a2 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,9 @@
 2016-03-11  Jakub Jelinek  <jakub@redhat.com>
 
+	PR rtl-optimization/70174
+	* expmed.c (store_bit_field_using_insv): Use gen_lowpart_if_possible
+	followed by gen_lowpart on force_reg instead of just gen_lowpart.
+
 	PR tree-optimization/70169
 	* tree-ssa-loop.c (gen_lsm_tmp_name): Handle FUNCTION_DECL and
 	LABEL_DECL like VAR_DECL.  Emit nothing instead of gcc_unreachable
diff --git a/gcc/expmed.c b/gcc/expmed.c
index 829b967b3ca2..31d905bd3d57 100644
--- a/gcc/expmed.c
+++ b/gcc/expmed.c
@@ -658,24 +658,28 @@ store_bit_field_using_insv (const extraction_insn *insv, rtx op0,
     {
       if (GET_MODE_BITSIZE (GET_MODE (value)) >= bitsize)
 	{
+	  rtx tmp;
 	  /* Optimization: Don't bother really extending VALUE
 	     if it has all the bits we will actually use.  However,
 	     if we must narrow it, be sure we do it correctly.  */
 
 	  if (GET_MODE_SIZE (GET_MODE (value)) < GET_MODE_SIZE (op_mode))
 	    {
-	      rtx tmp;
-
 	      tmp = simplify_subreg (op_mode, value1, GET_MODE (value), 0);
 	      if (! tmp)
 		tmp = simplify_gen_subreg (op_mode,
 					   force_reg (GET_MODE (value),
 						      value1),
 					   GET_MODE (value), 0);
-	      value1 = tmp;
 	    }
 	  else
-	    value1 = gen_lowpart (op_mode, value1);
+	    {
+	      tmp = gen_lowpart_if_possible (op_mode, value1);
+	      if (! tmp)
+		tmp = gen_lowpart (op_mode, force_reg (GET_MODE (value),
+						       value1));
+	    }
+	  value1 = tmp;
 	}
       else if (CONST_INT_P (value))
 	value1 = gen_int_mode (INTVAL (value), op_mode);
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 75fe4ac519b8..a1035ef7a46d 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,8 @@
 2016-03-11  Jakub Jelinek  <jakub@redhat.com>
 
+	PR rtl-optimization/70174
+	* gcc.dg/pr70174.c: New test.
+
 	PR tree-optimization/70169
 	* gcc.dg/pr70169.c: New test.
 
diff --git a/gcc/testsuite/gcc.dg/pr70174.c b/gcc/testsuite/gcc.dg/pr70174.c
new file mode 100644
index 000000000000..8a3bc904fad4
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr70174.c
@@ -0,0 +1,11 @@
+/* PR rtl-optimization/70174 */
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+struct S { int f : 4; } a;
+  
+void
+foo (void)
+{ 
+  a.f = foo;	/* { dg-warning "assignment makes integer from pointer without a cast" } */
+}