[PATCH, i386]: Remove unneeded truncations to DImode in x86_64{,_zext}_immediate_operand predicates.

[Uros Bizjak]

The immediate is checked that it fits SImode just below the unneeded
truncation to DImode.

2016-07-12  Uros Bizjak  <ubiz...@gmail.com>

    * config/i386/predicates.md (x86_64_immediate_operand)
    <case CONST_INT>: Remove unneeded truncation to DImode.
    <case CONST>: Ditto.
    (x86_64_zext_immediate_operand) <case CONST>: Ditto.

Bootstrapped and regression tested on x86_64-linux-gnu {,-m32}.

Committed to mainline SVN.

Uros.

diff --git a/gcc/config/i386/predicates.md b/gcc/config/i386/predicates.md
index 6854c37..219674e 100644
--- a/gcc/config/i386/predicates.md
+++ b/gcc/config/i386/predicates.md
@@ -156,7 +156,7 @@
     {
     case CONST_INT:
       {
-        HOST_WIDE_INT val = trunc_int_for_mode (INTVAL (op), DImode);
+        HOST_WIDE_INT val = INTVAL (op);
         return trunc_int_for_mode (val, SImode) == val;
       }
     case SYMBOL_REF:
@@ -199,14 +199,13 @@
        {
          rtx op1 = XEXP (XEXP (op, 0), 0);
          rtx op2 = XEXP (XEXP (op, 0), 1);
-         HOST_WIDE_INT offset;
 
          if (ix86_cmodel == CM_LARGE)
            return false;
          if (!CONST_INT_P (op2))
            return false;
 
-         offset = trunc_int_for_mode (INTVAL (op2), DImode);
+         HOST_WIDE_INT offset = INTVAL (op2);
          if (trunc_int_for_mode (offset, SImode) != offset)
            return false;
 
@@ -306,14 +305,13 @@
        {
          rtx op1 = XEXP (XEXP (op, 0), 0);
          rtx op2 = XEXP (XEXP (op, 0), 1);
-         HOST_WIDE_INT offset;
 
          if (ix86_cmodel == CM_LARGE)
            return false;
          if (!CONST_INT_P (op2))
            return false;
 
-         offset = trunc_int_for_mode (INTVAL (op2), DImode);
+         HOST_WIDE_INT offset = INTVAL (op2);
          if (trunc_int_for_mode (offset, SImode) != offset)
            return false;