OpenE2K/gcc
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

(expand_expr, case MINUS_EXPR): Properly handle case when the NEGATE

Browse Source 
overflows.

From-SVN: r8648
This commit is contained in:
Richard Kenner 1994-12-13 07:50:58 -05:00
parent cd8ce14b50
commit ae4311830e
1 changed files with 23 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
gcc/expr.c
View File

@ -5239,10 +5239,29 @@ expand_expr (exp, target, tmode, modifier)
/* Convert A - const to A + (-const). */
if (TREE_CODE (TREE_OPERAND (exp, 1)) == INTEGER_CST)
{
exp = build (PLUS_EXPR, type, TREE_OPERAND (exp, 0),
fold (build1 (NEGATE_EXPR, type,
TREE_OPERAND (exp, 1))));
goto plus_expr;
tree negated = fold (build1 (NEGATE_EXPR, type,
TREE_OPERAND (exp, 1)));
/* Deal with the case where we can't negate the constant
in TYPE. */
if (TREE_UNSIGNED (type) || TREE_OVERFLOW (negated))
{
tree newtype = signed_type (type);
tree newop0 = convert (newtype, TREE_OPERAND (exp, 0));
tree newop1 = convert (newtype, TREE_OPERAND (exp, 1));
tree newneg = fold (build1 (NEGATE_EXPR, newtype, newop1));
if (! TREE_OVERFLOW (newneg))
return expand_expr (convert (type,
build (PLUS_EXPR, newtype,
newop0, newneg)),
target, tmode, modifier);
}
else
{
exp = build (PLUS_EXPR, type, TREE_OPERAND (exp, 0), negated);
goto plus_expr;
}
}
this_optab = sub_optab;
goto binop;