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Why GCC 4.1.2 casting "short int" to "short unsigned int" ?
- From: 梁? <liangkun1983 at gmail dot com>
- To: gcc at gcc dot gnu dot org
- Date: Tue, 14 Apr 2009 15:20:10 +0800
- Subject: Why GCC 4.1.2 casting "short int" to "short unsigned int" ?
GCC4.1.2 on a Intel Xeon CPU
The test program is test.c:
extern int bar(short);
int foo(short arg1, short arg2)
{
short res;
res = arg1 + arg2;
return bar(res);
}
Compiled with : gcc -fdump-tree-all -S test.c
The resulting test.c.t02.original is :
;; Function foo (foo)
;; enabled by -tree-original
{
short int res;
short int res;
res = (short int) ((short unsigned int) arg1 + (short unsigned int) arg2);
return bar ((int) res);
}
So, my question is : why gcc casted "short" to "short unsigned int"
before addition and casted back after?
--
此致
敬礼！
梁?