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authorphython <phython@138bc75d-0d04-0410-961f-82ee72b054a4>2005-03-04 02:48:30 +0000
committerphython <phython@138bc75d-0d04-0410-961f-82ee72b054a4>2005-03-04 02:48:30 +0000
commitaa8057b43cfc5906f3ec496e182a913613b60a96 (patch)
treec908d67b93dc9a831686bb43afc3806aef6fd260 /gcc/fold-const.c
parent35db3ec168fe37033e35bb171191d3f707af8c0d (diff)
downloadgcc-aa8057b43cfc5906f3ec496e182a913613b60a96.tar.gz
2005-03-03 James A. Morrison <phython@gcc.gnu.org>
PR tree-optimization/15784 * fold-const.c (fold): Fold ~A + 1 to -1. Fold -A - 1 and -1 - A to ~A. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@95870 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/fold-const.c')
-rw-r--r--gcc/fold-const.c15
1 files changed, 15 insertions, 0 deletions
diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 72e557eeb71..2c6d71ec030 100644
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -7223,6 +7223,11 @@ fold (tree expr)
if (TREE_CODE (arg0) == NEGATE_EXPR
&& reorder_operands_p (TREE_OPERAND (arg0, 0), arg1))
return fold (build2 (MINUS_EXPR, type, arg1, TREE_OPERAND (arg0, 0)));
+ /* Convert ~A + 1 to -A. */
+ if (INTEGRAL_TYPE_P (type)
+ && TREE_CODE (arg0) == BIT_NOT_EXPR
+ && integer_onep (arg1))
+ return fold (build1 (NEGATE_EXPR, type, TREE_OPERAND (arg0, 0)));
if (TREE_CODE (type) == COMPLEX_TYPE)
{
@@ -7661,6 +7666,16 @@ fold (tree expr)
&& reorder_operands_p (arg0, arg1))
return fold (build2 (MINUS_EXPR, type, negate_expr (arg1),
TREE_OPERAND (arg0, 0)));
+ /* Convert -A - 1 to ~A. */
+ if (INTEGRAL_TYPE_P (type)
+ && TREE_CODE (arg0) == NEGATE_EXPR
+ && integer_onep (arg1))
+ return fold (build1 (BIT_NOT_EXPR, type, TREE_OPERAND (arg0, 0)));
+
+ /* Convert -1 - A to ~A. */
+ if (INTEGRAL_TYPE_P (type)
+ && integer_all_onesp (arg0))
+ return fold (build1 (BIT_NOT_EXPR, type, arg1));
if (TREE_CODE (type) == COMPLEX_TYPE)
{