[PATCH] Fix rotate discovery in fold-const.c (PR tree-optimization/65014)

[Jakub Jelinek]

Hi!

We pass the values after STRIP_NOPS to *ROTATE_EXPR build, which is
undesirable, as the testcase shows, the operand could very well end up being
a pointer rather than integer.
This patch fixes it by passing the original trees instead.
Alternatively we could fold_convert the STRIP_NOPS result to the original
type, but I'd be afraid that in the common case that would just create more
GC garbage.

Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

2015-02-12  Jakub Jelinek  <ja...@redhat.com>

        PR tree-optimization/65014
        * fold-const.c (fold_binary_loc): When creating {L,R}ROTATE_EXPR,
        use original second operand of arg0 or arg1 instead of
        that adjusted by STRIP_NOPS.

        * gcc.c-torture/compile/pr65014.c: New test.

--- gcc/fold-const.c.jj 2015-01-22 19:30:59.000000000 +0100
+++ gcc/fold-const.c    2015-02-11 15:06:52.628078961 +0100
@@ -10261,7 +10261,9 @@ fold_binary_loc (location_t loc,
                tem = build2_loc (loc, LROTATE_EXPR,
                                  TREE_TYPE (TREE_OPERAND (arg0, 0)),
                                  TREE_OPERAND (arg0, 0),
-                                 code0 == LSHIFT_EXPR ? tree01 : tree11);
+                                 code0 == LSHIFT_EXPR
+                                 ? TREE_OPERAND (arg0, 1)
+                                 : TREE_OPERAND (arg1, 1));
                return fold_convert_loc (loc, type, tem);
              }
            else if (code11 == MINUS_EXPR)
@@ -10283,7 +10285,8 @@ fold_binary_loc (location_t loc,
                                               ? LROTATE_EXPR
                                               : RROTATE_EXPR),
                                              TREE_TYPE (TREE_OPERAND (arg0, 
0)),
-                                             TREE_OPERAND (arg0, 0), tree01));
+                                             TREE_OPERAND (arg0, 0),
+                                             TREE_OPERAND (arg0, 1)));
              }
            else if (code01 == MINUS_EXPR)
              {
@@ -10304,7 +10307,7 @@ fold_binary_loc (location_t loc,
                                ? LROTATE_EXPR
                                : RROTATE_EXPR),
                               TREE_TYPE (TREE_OPERAND (arg0, 0)),
-                              TREE_OPERAND (arg0, 0), tree11));
+                              TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1)));
              }
          }
       }
--- gcc/testsuite/gcc.c-torture/compile/pr65014.c.jj    2015-02-11 
15:21:19.175681614 +0100
+++ gcc/testsuite/gcc.c-torture/compile/pr65014.c       2015-02-11 
15:22:18.040703653 +0100
@@ -0,0 +1,10 @@
+/* PR tree-optimization/65014 */
+/* { dg-do compile { target int32plus } } */
+
+extern int x;
+
+unsigned
+foo (unsigned int y)
+{
+  return (y << ((__INTPTR_TYPE__) &x)) | (y >> (32 - ((__INTPTR_TYPE__) &x)));
+}

        Jakub