markus@x4 mplayer % cat subassconvert.i struct bstr { long len; } fn1(); struct microdvd_tag { int key; int data1; struct bstr data_string; } fn2() { struct microdvd_tag *a; int i = sizeof "cfshyYpo"; for (;; i--) switch (a[i].key) case 'y': if (a[i].data1) fn1(); } markus@x4 mplayer % UBSAN_OPTIONS=print_stacktrace=1 /var/tmp/gcc_ubsan/usr/local/bin/gcc -O3 -march=amdfam10 -c subassconvert.i ../../gcc/gcc/tree-ssa-loop-prefetch.c:835:16: runtime error: signed integer overflow: 288230376151711743 * 64 cannot be represented in type 'long int' #0 0x232e7bd in prune_ref_by_group_reuse ../../gcc/gcc/tree-ssa-loop-prefetch.c:835 #1 0x232e7bd in prune_ref_by_reuse ../../gcc/gcc/tree-ssa-loop-prefetch.c:923 #2 0x232e7bd in prune_group_by_reuse ../../gcc/gcc/tree-ssa-loop-prefetch.c:936 #3 0x232e7bd in prune_by_reuse ../../gcc/gcc/tree-ssa-loop-prefetch.c:975 #4 0x232e7bd in loop_prefetch_arrays ../../gcc/gcc/tree-ssa-loop-prefetch.c:1879 #5 0x232e7bd in tree_ssa_prefetch_arrays() ../../gcc/gcc/tree-ssa-loop-prefetch.c:1989 #6 0x195ad78 in execute_one_pass(opt_pass*) ../../gcc/gcc/passes.c:2370 #7 0x195cc0b in execute_pass_list_1 ../../gcc/gcc/passes.c:2459 #8 0x195cc34 in execute_pass_list_1 ../../gcc/gcc/passes.c:2460 #9 0x195cc34 in execute_pass_list_1 ../../gcc/gcc/passes.c:2460 #10 0x195ccc4 in execute_pass_list(function*, opt_pass*) ../../gcc/gcc/passes.c:2470 #11 0xc75e4b in cgraph_node::expand() ../../gcc/gcc/cgraphunit.c:2001 #12 0xc7b35a in expand_all_functions ../../gcc/gcc/cgraphunit.c:2137 #13 0xc7b35a in symbol_table::compile() ../../gcc/gcc/cgraphunit.c:2494 #14 0xc85517 in symbol_table::compile() ../../gcc/gcc/cgraphunit.c:2587 #15 0xc85517 in symbol_table::finalize_compilation_unit() ../../gcc/gcc/cgraphunit.c:2584 #16 0x1d3ead0 in compile_file ../../gcc/gcc/toplev.c:488 #17 0x629a34 in do_compile ../../gcc/gcc/toplev.c:1983 #18 0x629a34 in toplev::main(int, char**) ../../gcc/gcc/toplev.c:2117 #19 0x62c066 in main ../../gcc/gcc/main.c:39 #20 0x7f60d01cf310 in __libc_start_main ../csu/libc-start.c:286 #21 0x62c489 in _start (/var/tmp/gcc_ubsan/usr/local/libexec/gcc/x86_64-pc-linux-gnu/7.0.0/cc1+0x62c489)
Author: trippels Date: Thu Dec 1 14:59:03 2016 New Revision: 243113 URL: https://gcc.gnu.org/viewcvs?rev=243113&root=gcc&view=rev Log: Fix PR tree-optimization/78598 - tree-ssa-loop-prefetch.c:835:16: runtime error: signed integer overflow Using bootstrap-ubsan gcc to build mplayer shows: tree-ssa-loop-prefetch.c:835:16: runtime error: signed integer overflow: 288230376151711743 * 64 cannot be represented in type 'long int' Here signed und unsigned integers are mixed in a division resulting in bogus values: (-83 + 64ULL -1) / 64ULL) == 288230376151711743 Fixed by casting the unsigned parameter to signed. PR tree-optimization/78598 * tree-ssa-loop-prefetch.c (ddown): Cast to signed to avoid overflows. Modified: trunk/gcc/ChangeLog trunk/gcc/tree-ssa-loop-prefetch.c
Fixed.