From patchwork Thu May 23 07:38:08 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [RFA,alpha] : Fix PR 57379, segfault in invalidate_any_buried_refs X-Patchwork-Submitter: Uros Bizjak X-Patchwork-Id: 245832 Message-Id: To: "gcc-patches@gcc.gnu.org" Cc: Richard Henderson Date: Thu, 23 May 2013 09:38:08 +0200 From: Uros Bizjak List-Id: Hello! As explained in the PR [1], alpha constructs a strange REG_EQUAL note for the TFmode xfloating compare call. A recent mainline change that tries to invalidate any buried refs trips on this note and segfaults on null expr_list terminator: (gdb) p debug_rtx (insn) (insn 65 64 66 2 (set (reg:DI 148) (reg:DI 0 $0)) ../../../gcc-svn/trunk/libgcc/libgcc2.c:1882 226 {*movdi} (expr_list:REG_DEAD (reg:DI 0 $0) (expr_list:REG_EQUAL (expr_list:REG_DEP_TRUE (symbol_ref:DI ("_OtsEqlX") [flags 0x41]) (expr_list:REG_DEP_TRUE (reg/v:TF 70 [ x ]) (expr_list:REG_DEP_TRUE (reg/v:TF 70 [ x ]) (nil)))) (nil)))) Proposed patch replaces expr_list sequence inside REG_EQUAL RTX with an unspec RTX. 2013-05-23 Uros Bizjak * config/alpha/alpha.md (unspec): Add UNSPEC_XFLT_COMPARE. * config/alpha/alpha.c (alpha_emit_xfloating_compare): Construct REG_EQUAL note as UNSPEC_XFLT_COMPARE unspec. Patch was bootstrapped and regression tested on alphaev68-linux-gnu. OK for mainline and release branches? [1] http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57379 Uros. Index: config/alpha/alpha.md =================================================================== --- config/alpha/alpha.md (revision 199131) +++ config/alpha/alpha.md (working copy) @@ -23,6 +23,7 @@ ;; Uses of UNSPEC in this file: (define_c_enum "unspec" [ + UNSPEC_XFLT_COMPARE UNSPEC_ARG_HOME UNSPEC_LDGP1 UNSPEC_INSXH Index: config/alpha/alpha.c =================================================================== --- config/alpha/alpha.c (revision 199131) +++ config/alpha/alpha.c (working copy) @@ -3067,12 +3067,8 @@ alpha_emit_xfloating_compare (enum rtx_code *pcode operands[1] = op1; out = gen_reg_rtx (DImode); - /* What's actually returned is -1,0,1, not a proper boolean value, - so use an EXPR_LIST as with a generic libcall instead of a - comparison type expression. */ - note = gen_rtx_EXPR_LIST (VOIDmode, op1, NULL_RTX); - note = gen_rtx_EXPR_LIST (VOIDmode, op0, note); - note = gen_rtx_EXPR_LIST (VOIDmode, func, note); + /* What's actually returned is -1,0,1, not a proper boolean value. */ + note = gen_rtx_UNSPEC (DImode, gen_rtvec (2, op0, op1), UNSPEC_XFLT_COMPARE); alpha_emit_xfloating_libcall (func, out, operands, 2, note); return out;