expr.c (expand_expr, [...]): Pass constants through immed_double_const to ensure...

        * expr.c (expand_expr, case PLUS_EXPR): Pass constants through
        immed_double_const to ensure they are properly truncated then
        sign extended.

From-SVN: r28066

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 95e80053583cf83f3a314559ca5de0d2c19e9523..fd5d177eb7ac66ac76febf986f13932601b78e07 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+Mon Jul 12 14:29:15 1999  Jeffrey A Law  (law@cygnus.com)
+
+       * expr.c (expand_expr, case PLUS_EXPR): Pass constants through
+       immed_double_const to ensure they are properly truncated then
+       sign extended.
+
 Mon Jul 12 10:40:01 1999  Vladimir Makarov  <vmakarov@tofu.to.cygnus.com>
 
        * config/arm/thumb.c (thumb_reorg): Call replace_symbols_in_block

diff --git a/gcc/expr.c b/gcc/expr.c
index a5c6f887c0d44b40cdff18ad5a3234b4ff177a69..111e6ebe3f1b9b336777c919ade76fe235ae3b09 100644 (file)
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -6968,13 +6968,25 @@ expand_expr (exp, target, tmode, modifier)
       if (modifier == EXPAND_SUM || modifier == EXPAND_INITIALIZER
          || mode == ptr_mode)
        {
+         rtx constant_part;
+
          if (TREE_CODE (TREE_OPERAND (exp, 0)) == INTEGER_CST
              && GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT
              && TREE_CONSTANT (TREE_OPERAND (exp, 1)))
            {
+             rtx constant_part;
+
              op1 = expand_expr (TREE_OPERAND (exp, 1), subtarget, VOIDmode,
                                 EXPAND_SUM);
-             op1 = plus_constant (op1, TREE_INT_CST_LOW (TREE_OPERAND (exp, 0)));
+             /* Use immed_double_const to ensure that the constant is
+                truncated according to the mode of OP1, then sign extended
+                to a HOST_WIDE_INT.  Using the constant directly can result
+                in non-canonical RTL in a 64x32 cross compile.  */
+             constant_part
+               = immed_double_const (TREE_INT_CST_LOW (TREE_OPERAND (exp, 0)),
+                                     (HOST_WIDE_INT) 0,
+                                     GET_MODE (op1));
+             op1 = plus_constant (op1, XINT (constant_part, 0));
              if (modifier != EXPAND_SUM && modifier != EXPAND_INITIALIZER)
                op1 = force_operand (op1, target);
              return op1;
@@ -6984,6 +6996,8 @@ expand_expr (exp, target, tmode, modifier)
                   && GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_INT
                   && TREE_CONSTANT (TREE_OPERAND (exp, 0)))
            {
+             rtx constant_part;
+
              op0 = expand_expr (TREE_OPERAND (exp, 0), subtarget, VOIDmode,
                                 EXPAND_SUM);
              if (! CONSTANT_P (op0))
@@ -6996,7 +7010,15 @@ expand_expr (exp, target, tmode, modifier)
                    goto binop2;
                  goto both_summands;
                }
-             op0 = plus_constant (op0, TREE_INT_CST_LOW (TREE_OPERAND (exp, 1)));
+             /* Use immed_double_const to ensure that the constant is
+                truncated according to the mode of OP1, then sign extended
+                to a HOST_WIDE_INT.  Using the constant directly can result
+                in non-canonical RTL in a 64x32 cross compile.  */
+             constant_part
+               = immed_double_const (TREE_INT_CST_LOW (TREE_OPERAND (exp, 1)),
+                                     (HOST_WIDE_INT) 0,
+                                     GET_MODE (op0));
+             op0 = plus_constant (op0, XINT (constant_part, 0));
              if (modifier != EXPAND_SUM && modifier != EXPAND_INITIALIZER)
                op0 = force_operand (op0, target);
              return op0;