gcc/gcc ChangeLog fold-const.c simplify-rtx.c ...

[sayle@gcc.gnu.org]

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	sayle@gcc.gnu.org	2004-03-11 17:45:03

Modified files:
	gcc            : ChangeLog fold-const.c simplify-rtx.c 
	gcc/testsuite  : ChangeLog 
Added files:
	gcc/testsuite/gcc.c-torture/execute: 20040311-1.c 

Log message:
	* fold-const.c (negate_expr_p) <RSHIFT_EXPR>: We can optimize
	-((int)X>>C) where C is an integer constant one bit less than the
	size of X into (unsigned)X>>C.  Similarly for unsigned->signed.
	(negate_expr) <RSHIFT_EXPR>: Implement the above transformations.
	
	* simplify-rtx.c (simplify_unary_operation): Also implement the
	above transformations at the RTL level.
	
	* gcc.c-torture/execute/20040311-1.c: New test case.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&r1=2.3135&r2=2.3136
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/fold-const.c.diff?cvsroot=gcc&r1=1.343&r2=1.344
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/simplify-rtx.c.diff?cvsroot=gcc&r1=1.181&r2=1.182
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&r1=1.3595&r2=1.3596
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.c-torture/execute/20040311-1.c.diff?cvsroot=gcc&r1=NONE&r2=1.1