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From: ghouston@arglist.com To: gcc-gnats@gcc.gnu.org Subject: optimization/7728: Invalid statement reordering gcc 3.2 -O2 Date: Mon, 26 Aug 2002 12:26:00 -0000 [thread overview] Message-ID: <20020826182028.3210.qmail@arglist.com> (raw) >Number: 7728 >Category: optimization >Synopsis: Invalid statement reordering gcc 3.2 -O2 >Confidential: no >Severity: critical >Priority: medium >Responsible: unassigned >State: open >Class: wrong-code >Submitter-Id: net >Arrival-Date: Mon Aug 26 11:26:00 PDT 2002 >Closed-Date: >Last-Modified: >Originator: Gary Houston >Release: 3.2 >Organization: >Environment: System: Linux x.localnet 2.4.18 #1 Sat Apr 6 12:54:37 BST 2002 i686 unknown Architecture: i686 host: i686-pc-linux-gnu build: i686-pc-linux-gnu target: i686-pc-linux-gnu configured with: ../gcc-3.2/configure --prefix=/usr --enable-threads=posix --enable-shared >Description: Output of program below, compiled with gcc -O: 154 153 153 153 153 153 9 64 Output when compiled with gcc -O2: 0 0 0 0 153 153 9 64 >How-To-Repeat: #include <stdlib.h> #include <string.h> typedef struct { unsigned long * type; unsigned long * pad; double real; } x_double; void * make_z (double x) { void *z = malloc (50); memset (z, 0, 50); ((unsigned long *) z) [2] = 0; ((x_double *) z)->real = x; return z; } main () { void *z = make_z (3.2); double d = ((x_double *) z)->real; int i; for (i = 0; i < sizeof (double); i++) { printf ("%d\n", ((unsigned char *) &d)[i]); } return 0; } >Fix: reduce optimization >Release-Note: >Audit-Trail: >Unformatted:
next reply other threads:[~2002-08-26 18:26 UTC|newest] Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top 2002-08-26 12:26 ghouston [this message] 2002-10-02 13:43 rth
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