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From: "amodra at bigpond dot net dot au" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug middle-end/17052] [3.5 Regression] altivec varargs failure if no optimization Date: Mon, 23 Aug 2004 07:58:00 -0000 [thread overview] Message-ID: <20040823075857.16761.qmail@sourceware.org> (raw) In-Reply-To: <20040816201040.17052.janis187@us.ibm.com> ------- Additional Comments From amodra at bigpond dot net dot au 2004-08-23 07:58 ------- static int varargsn001(vector float p1, ...) { va_list ap; vector float i1; vector float i2; int i3; va_start(ap, p1); i1 = p1; The real problem occurs with the above assignment to i1. 0x10000508 <varargsn001+120>: li r0,176 0x1000050c <varargsn001+124>: lvx v0,r31,r0 0x10000510 <varargsn001+128>: li r0,136 0x10000514 <varargsn001+132>: stvx v0,r31,r0 Notice that the stack slot for i1 isn't 16 byte aligned. VMX load and store insns silently ignore the bottom 4 bits of the address, so this stores to sp+128 instead of sp+136. It so happens that one element of our va_list is at sp+128... Bottom line: This is a problem with vector stack slot alignment. -- What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Ever Confirmed| |1 Last reconfirmed|0000-00-00 00:00:00 |2004-08-23 07:58:56 date| | http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17052
next prev parent reply other threads:[~2004-08-23 7:58 UTC|newest] Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top 2004-08-16 20:10 [Bug middle-end/17052] New: " janis187 at us dot ibm dot com 2004-08-16 20:11 ` [Bug middle-end/17052] " janis187 at us dot ibm dot com 2004-08-16 20:52 ` [Bug middle-end/17052] [3.5 Regression] " pinskia at gcc dot gnu dot org 2004-08-16 21:08 ` janis187 at us dot ibm dot com 2004-08-23 7:58 ` amodra at bigpond dot net dot au [this message] 2004-08-23 8:47 ` amodra at bigpond dot net dot au 2004-08-24 14:38 ` [Bug target/17052] " amodra at bigpond dot net dot au 2004-08-25 3:40 ` cvs-commit at gcc dot gnu dot org 2004-08-25 3:46 ` amodra at bigpond dot net dot au
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