expr.c (expand_expr_real_1): handle misaligned scalar reads from memory through MEM_REFs by calling...

2012-03-16  Martin Jambor  <mjambor@suse.cz>

	* expr.c (expand_expr_real_1): handle misaligned scalar reads from
	memory through MEM_REFs by calling extract_bit_field.

	* testsuite/gcc.dg/misaligned-expand-1.c: New test.
	* testsuite/gcc.dg/misaligned-expand-3.c: Likewise.

From-SVN: r185470

gcc/ChangeLog

@@ -1,3 +1,8 @@
+2012-03-16  Martin Jambor  <mjambor@suse.cz>
+
+	* expr.c (expand_expr_real_1): handle misaligned scalar reads from
+	memory through MEM_REFs by calling extract_bit_field.
+
 2012-03-16  Richard Guenther  <rguenther@suse.de>
 
 	* fold-const.c (native_interpret_expr): Also support POINTER_TYPE

gcc/expr.c

@@ -9347,21 +9347,27 @@ expand_expr_real_1 (tree exp, rtx target, enum machine_mode tmode,
 	  MEM_VOLATILE_P (temp) = 1;
 	if (modifier != EXPAND_WRITE
 	    && mode != BLKmode
-	    && align < GET_MODE_ALIGNMENT (mode)
-	    /* If the target does not have special handling for unaligned
-	       loads of mode then it can use regular moves for them.  */
-	    && ((icode = optab_handler (movmisalign_optab, mode))
-		!= CODE_FOR_nothing))
+	    && align < GET_MODE_ALIGNMENT (mode))
 	  {
-	    struct expand_operand ops[2];
+	    if ((icode = optab_handler (movmisalign_optab, mode))
+		!= CODE_FOR_nothing)
+	      {
+		struct expand_operand ops[2];
 
-	    /* We've already validated the memory, and we're creating a
-	       new pseudo destination.  The predicates really can't fail,
-	       nor can the generator.  */
-	    create_output_operand (&ops[0], NULL_RTX, mode);
-	    create_fixed_operand (&ops[1], temp);
-	    expand_insn (icode, 2, ops);
-	    return ops[0].value;
+		/* We've already validated the memory, and we're creating a
+		   new pseudo destination.  The predicates really can't fail,
+		   nor can the generator.  */
+		create_output_operand (&ops[0], NULL_RTX, mode);
+		create_fixed_operand (&ops[1], temp);
+		expand_insn (icode, 2, ops);
+		return ops[0].value;
+	      }
+	    else if (SLOW_UNALIGNED_ACCESS (mode, align))
+	      temp = extract_bit_field (temp, GET_MODE_BITSIZE (mode),
+					0, TYPE_UNSIGNED (TREE_TYPE (exp)),
+					true, (modifier == EXPAND_STACK_PARM
+					       ? NULL_RTX : target),
+					mode, mode);
 	  }
 	return temp;
       }

gcc/testsuite/ChangeLog

@@ -1,3 +1,8 @@
+2012-03-16  Martin Jambor  <mjambor@suse.cz>
+
+	* gcc.dg/misaligned-expand-1.c: New test.
+	* gcc.dg/misaligned-expand-3.c: Likewise.
+
 2012-03-16  Richard Guenther  <rguenther@suse.de>
 	Kai Tietz  <ktietz@redhat.com>
 

gcc/testsuite/gcc.dg/misaligned-expand-1.c

@@ -0,0 +1,41 @@
+/* Test that expand can generate correct loads of misaligned data even on
+   strict alignment platforms.  */
+
+/* { dg-do run } */
+/* { dg-options "-O0" } */
+
+extern void abort ();
+
+typedef unsigned int myint __attribute__((aligned(1)));
+
+unsigned int
+foo (myint *p)
+{
+  return *p;
+}
+
+#define cst 0xdeadbeef
+#define NUM 8
+
+struct blah
+{
+  char c;
+  myint i[NUM];
+};
+
+struct blah g;
+
+int
+main (int argc, char **argv)
+{
+  int i, k;
+  for (k = 0; k < NUM; k++)
+    {
+      g.i[k] = cst;
+      i = foo (&g.i[k]);
+
+      if (i != cst)
+	abort ();
+    }
+  return 0;
+}

gcc/testsuite/gcc.dg/misaligned-expand-3.c

@@ -0,0 +1,43 @@
+/* Test that expand can generate correct stores to misaligned data of complex
+   type even on strict alignment platforms.  */
+
+/* { dg-do run } */
+/* { dg-options "-O0" } */
+
+extern void abort ();
+
+typedef _Complex float mycmplx __attribute__((aligned(1)));
+
+void
+foo (mycmplx *p, float r, float i)
+{
+  __real__ *p = r;
+  __imag__ *p = i;
+}
+
+#define cvr 3.2f
+#define cvi 2.5f
+#define NUM 8
+
+struct blah
+{
+  char c;
+  mycmplx x[NUM];
+} __attribute__((packed));
+
+struct blah g;
+
+int
+main (int argc, char **argv)
+{
+  int k;
+
+  for (k = 0; k < NUM; k++)
+    {
+      foo (&g.x[k], cvr, cvi);
+      if (__real__ g.x[k] != cvr
+	  || __imag__ g.x[k] != cvi)
+	abort ();
+    }
+  return 0;
+}