File unwind-ia64-2.patch of Package gcc33
From nobody Tue Apr 5 14:18:17 2005 From: James E Wilson <wilson@specifixinc.com> Subject: [3.3/3.4/4.0/4.1] IA-64 FP register file corruption on unwind To: gcc-patches@gcc.gnu.org Cc: gdr@integrable-solutions.net, mark@codesourcery.com Date: Mon, 04 Apr 2005 21:43:10 -0700 --=-AxpUGYhFcHDnkCjv8/Dg Content-Type: text/plain Content-Transfer-Encoding: 7bit This is for PR 20670, which reports a problem that turned up in Ada code. When installing an unwind context, the FP registers from f29 to f31 get reloaded with the wrong values. This was reported without a testcase, but I managed to write a C++ one that shows the problem. The fix is fairly simple. There is some hand written assembly code in the unwind-ia64.c file for restoring registers that accidentally missed one instruction to load the address register r27 before using it to reload f29. This is turn causes the later FP registers to also get the wrong value. I consider this a serious problem with no easy workaround, and would like to install it in as many places as possible. Since this has always been broken, this is not a regression, and thus does not qualify under the normal rules for branches. I believe I can self approve it for the gcc-4.0 branch, but I believe I need permission for the gcc-3.4 and gcc-3.3 branches. This patch has been tested on ia64-linux with gcc-3.4 and gcc-4.0 bootstraps and make checks, with no regressions. gcc-3.3 testing is in progress, and mainline testing will follow. I am not very familiar with the C++ testsuite, but I assume I can just drop it into g++.dg/eh/fp-regs.C with some appropriate dg comments. I haven't tried to do this yet. -- Jim Wilson, GNU Tools Support, http://www.SpecifixInc.com --=-AxpUGYhFcHDnkCjv8/Dg Content-Disposition: attachment; filename=patch.unwind.r27 Content-Type: text/plain; name=patch.unwind.r27; charset=UTF-8 Content-Transfer-Encoding: 7bit 2005-04-01 James E. Wilson <wilson@specifixinc.com> PR target/20670 * unwind-ia64.c (uw_intall_context): Add missing load of r27. Index: gcc/config/ia64/unwind-ia64.c =================================================================== --- gcc/config/ia64/unwind-ia64.c.orig 2009-11-20 13:06:05.000000000 +0100 +++ gcc/config/ia64/unwind-ia64.c 2009-11-20 13:06:34.000000000 +0100 @@ -2272,6 +2272,8 @@ uw_install_context (struct _Unwind_Conte "(p6) ldf.fill f22 = [r28] \n\t" "cmp.ne p7, p0 = r0, r29 \n\t" ";; \n\t" + "ld8 r27 = [r20], 8 \n\t" + ";; \n\t" "ld8 r28 = [r20], 8 \n\t" "(p7) ldf.fill f23 = [r29] \n\t" "cmp.ne p6, p0 = r0, r22 \n\t"
