https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67889
Bug ID: 67889 Summary: ICE on valid code at -O1 and above on x86_64-linux-gnu in VN_INFO, at tree-ssa-sccvn.c:384 Product: gcc Version: 6.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: su at cs dot ucdavis.edu Target Milestone: --- The following code causes an ICE when compiled with the current gcc trunk at -O1 and above on x86_64-linux-gnu in both 32-bit and 64-bit modes. It is a regression from 5.2.x. $ gcc-trunk -v Using built-in specs. COLLECT_GCC=gcc-trunk COLLECT_LTO_WRAPPER=/usr/local/gcc-trunk/libexec/gcc/x86_64-pc-linux-gnu/6.0.0/lto-wrapper Target: x86_64-pc-linux-gnu Configured with: ../gcc-trunk/configure --prefix=/usr/local/gcc-trunk --enable-languages=c,c++ --disable-werror --enable-multilib Thread model: posix gcc version 6.0.0 20151007 (experimental) [trunk revision 228566] (GCC) $ $ gcc-trunk -O0 -c small.c $ gcc-5.2 -O1 -c small.c $ $ gcc-trunk -O1 -c small.c small.c: In function ‘fn1’: small.c:11:1: internal compiler error: in VN_INFO, at tree-ssa-sccvn.c:384 } ^ 0xc5710b VN_INFO(tree_node*) ../../gcc-trunk/gcc/tree-ssa-sccvn.c:384 0xc57854 vn_valueize ../../gcc-trunk/gcc/tree-ssa-sccvn.h:236 0xe29afd do_valueize(tree_node* (*)(tree_node*), tree_node*) ../../gcc-trunk/gcc/gimple-match-head.c:802 0xe29afd gimple_simplify_CONVERT_EXPR /tmp/objdir/gcc/gimple-match.c:8085 0xe05b50 gimple_simplify /tmp/objdir/gcc/gimple-match.c:12600 0xe08115 gimple_resimplify1 ../../gcc-trunk/gcc/gimple-match-head.c:123 0xe2a8ee gimple_simplify_CONVERT_EXPR /tmp/objdir/gcc/gimple-match.c:8306 0xe05b50 gimple_simplify /tmp/objdir/gcc/gimple-match.c:12600 0xe08115 gimple_resimplify1 ../../gcc-trunk/gcc/gimple-match-head.c:123 0xe2a66f gimple_simplify_CONVERT_EXPR /tmp/objdir/gcc/gimple-match.c:8355 0xe05b50 gimple_simplify /tmp/objdir/gcc/gimple-match.c:12600 0xe08115 gimple_resimplify1 ../../gcc-trunk/gcc/gimple-match-head.c:123 0xe065b7 gimple_simplify_VIEW_CONVERT_EXPR /tmp/objdir/gcc/gimple-match.c:8570 0xe065b7 gimple_simplify /tmp/objdir/gcc/gimple-match.c:12602 0xe07f71 gimple_simplify(tree_code, tree_node*, tree_node*, gimple**, tree_node* (*)(tree_node*)) ../../gcc-trunk/gcc/gimple-match-head.c:400 0xc5f073 visit_reference_op_load ../../gcc-trunk/gcc/tree-ssa-sccvn.c:3049 0xc5f073 visit_use ../../gcc-trunk/gcc/tree-ssa-sccvn.c:3416 0xc617d4 process_scc ../../gcc-trunk/gcc/tree-ssa-sccvn.c:3636 0xc617d4 extract_and_process_scc_for_name ../../gcc-trunk/gcc/tree-ssa-sccvn.c:3723 0xc617d4 DFS ../../gcc-trunk/gcc/tree-ssa-sccvn.c:3775 Please submit a full bug report, with preprocessed source if appropriate. Please include the complete backtrace with any bug report. See <http://gcc.gnu.org/bugs.html> for instructions. $ ---------------------------- unsigned int a, *b; unsigned short c; int d; void fn1 () { b = &d; *b = c = a; *b = d; }