Following on from the patch for PR61136, this patch avoids some other
uses of const_binop in which we know both operands are INTEGER_CSTs
and where a wi:: routine would do. As before, the idea is to avoid
creating an INTEGER_CST only to test whether it's zero.
Tested on x86_64-linux-gnu. OK to install?
Thanks,
Richard
gcc/
* fold-const.c (optimize_bit_field_compare): Use wi:: operations
instead of const_binop.
(fold_binary_loc): Likewise.
Index: gcc/fold-const.c
===================================================================
--- gcc/fold-const.c 2014-05-10 14:13:50.222904190 +0100
+++ gcc/fold-const.c 2014-05-10 15:48:29.505451808 +0100
@@ -3444,7 +3444,7 @@ optimize_bit_field_compare (location_t l
{
HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
tree type = TREE_TYPE (lhs);
- tree signed_type, unsigned_type;
+ tree unsigned_type;
int const_p = TREE_CODE (rhs) == INTEGER_CST;
enum machine_mode lmode, rmode, nmode;
int lunsignedp, runsignedp;
@@ -3489,7 +3489,6 @@ optimize_bit_field_compare (location_t l
/* Set signed and unsigned types of the precision of this mode for the
shifts below. */
- signed_type = lang_hooks.types.type_for_mode (nmode, 0);
unsigned_type = lang_hooks.types.type_for_mode (nmode, 1);
/* Compute the bit position and size for the new reference and our offset
@@ -3538,10 +3537,7 @@ optimize_bit_field_compare (location_t l
if (lunsignedp)
{
- if (! integer_zerop (const_binop (RSHIFT_EXPR,
- fold_convert_loc (loc,
- unsigned_type, rhs),
- size_int (lbitsize))))
+ if (wi::lrshift (rhs, lbitsize) != 0)
{
warning (0, "comparison is always %d due to width of bit-field",
code == NE_EXPR);
@@ -3550,10 +3546,8 @@ optimize_bit_field_compare (location_t l
}
else
{
- tree tem = const_binop (RSHIFT_EXPR,
- fold_convert_loc (loc, signed_type, rhs),
- size_int (lbitsize - 1));
- if (! integer_zerop (tem) && ! integer_all_onesp (tem))
+ wide_int tem = wi::arshift (rhs, lbitsize - 1);
+ if (tem != 0 && tem != -1)
{
warning (0, "comparison is always %d due to width of bit-field",
code == NE_EXPR);
@@ -10356,9 +10350,8 @@ fold_binary_loc (location_t loc,
&& TREE_CODE (arg1) == BIT_AND_EXPR
&& TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
&& TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
- && integer_zerop (const_binop (BIT_AND_EXPR,
- TREE_OPERAND (arg0, 1),
- TREE_OPERAND (arg1, 1))))
+ && wi::bit_and (TREE_OPERAND (arg0, 1),
+ TREE_OPERAND (arg1, 1)) == 0)
{
code = BIT_IOR_EXPR;
goto bit_ior;
@@ -11478,9 +11471,8 @@ fold_binary_loc (location_t loc,
&& TREE_CODE (arg1) == BIT_AND_EXPR
&& TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
&& TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
- && integer_zerop (const_binop (BIT_AND_EXPR,
- TREE_OPERAND (arg0, 1),
- TREE_OPERAND (arg1, 1))))
+ && wi::bit_and (TREE_OPERAND (arg0, 1),
+ TREE_OPERAND (arg1, 1)) == 0)
{
code = BIT_IOR_EXPR;
goto bit_ior;
