This patch removes bogus debug info left around by shrink-wrapping, which on some powerpc targets with just the right register allocation led to assembly errors.
Bootstrapped and regression tested powerpc64-linux and x86_64-linux. I did see some regressions, but completely unrelated to this patch. See pr65810 for the powerpc64 regressions. x86_64-linux showed fails of +FAIL: c-c++-common/ubsan/object-size-10.c -O2 execution test +FAIL: c-c++-common/ubsan/object-size-10.c -O2 -flto -fno-use-linker-plugin -flto-partition=none execution test +FAIL: c-c++-common/ubsan/object-size-10.c -O2 -flto -fuse-linker-plugin -fno-fat-lto-objects execution test +FAIL: gfortran.dg/class_allocate_18.f90 -O0 execution test +FAIL: gfortran.dg/class_allocate_18.f90 -O1 execution test FAIL: gfortran.dg/class_allocate_18.f90 -O3 -fomit-frame-pointer -funroll-all-loops -finline-functions execution test -FAIL: gfortran.dg/class_allocate_18.f90 -Os execution test +FAIL: gfortran.dg/class_allocate_18.f90 -O3 -g execution test with the log for the ubsan fails /src/gcc-5/gcc/testsuite/c-c++-common/ubsan/object-size-10.c:19:11: runtime error: index 128 out of bounds for type 'char [128]' /src/gcc-5/gcc/testsuite/c-c++-common/ubsan/object-size-10.c:19:11: runtime error: load of address 0x0804a000 with insufficient space for an object of type 'char' 0x0804a000: note: pointer points here <memory cannot be printed> I assume I was thrashing my ubuntu 14.10 x86_64 box too hard and just ran out of memory. Running the test by hand resulted in the expected output. The class_allocate_18.f90 failure are intermittent, and occur occasionally when running the testcase by hand. :-( gcc/ PR debug/65779 * shrink-wrap.c (insn_uses_reg): New function. (move_insn_for_shrink_wrap): Remove debug insns using regs set by the moved insn. gcc/testsuite/ * gcc.dg/pr65779.c: New. Index: gcc/shrink-wrap.c =================================================================== --- gcc/shrink-wrap.c (revision 222160) +++ gcc/shrink-wrap.c (working copy) @@ -182,6 +182,21 @@ live_edge_for_reg (basic_block bb, int regno, int return live_edge; } +static bool +insn_uses_reg (rtx_insn *insn, unsigned int regno, unsigned int end_regno) +{ + df_ref use; + + FOR_EACH_INSN_USE (use, insn) + { + rtx reg = DF_REF_REG (use); + + if (REG_P (reg) && REGNO (reg) >= regno && REGNO (reg) < end_regno) + return true; + } + return false; +} + /* Try to move INSN from BB to a successor. Return true on success. USES and DEFS are the set of registers that are used and defined after INSN in BB. SPLIT_P indicates whether a live edge from BB @@ -340,10 +355,15 @@ move_insn_for_shrink_wrap (basic_block bb, rtx_ins *split_p = true; } + vec<basic_block> live_bbs; + if (MAY_HAVE_DEBUG_INSNS) + live_bbs.create (5); /* At this point we are committed to moving INSN, but let's try to move it as far as we can. */ do { + if (MAY_HAVE_DEBUG_INSNS) + live_bbs.safe_push (bb); live_out = df_get_live_out (bb); live_in = df_get_live_in (next_block); bb = next_block; @@ -426,6 +446,34 @@ move_insn_for_shrink_wrap (basic_block bb, rtx_ins SET_REGNO_REG_SET (bb_uses, i); } + /* Remove debug insns using regs set by the insn we are moving. */ + if (MAY_HAVE_DEBUG_INSNS) + { + while (!live_bbs.is_empty ()) + { + rtx_insn *dinsn; + basic_block tmp_bb = live_bbs.pop (); + + FOR_BB_INSNS_REVERSE (tmp_bb, dinsn) + { + if (dinsn == insn) + break; + if (DEBUG_INSN_P (dinsn) + && insn_uses_reg (dinsn, dregno, end_dregno)) + { + if (*split_p) + /* If split, then we will be moving insn into a + newly created block immediately after the entry + block. Move the debug info there too. */ + emit_debug_insn_after (PATTERN (dinsn), bb_note (bb)); + delete_insn (dinsn); + break; + } + } + } + live_bbs.release (); + } + emit_insn_after (PATTERN (insn), bb_note (bb)); delete_insn (insn); return true; Index: gcc/testsuite/gcc.dg/pr65779.c =================================================================== --- gcc/testsuite/gcc.dg/pr65779.c (revision 0) +++ gcc/testsuite/gcc.dg/pr65779.c (working copy) @@ -0,0 +1,64 @@ +/* { dg-do run } */ +/* { dg-options "-O2 -g" } */ +/* { dg-additional-options "-mrelocatable" { target powerpc-*-rtems* } } */ + +unsigned long __attribute__ ((noinline)) +adler32 (unsigned long adler, unsigned char *buf, unsigned int len) +{ + unsigned long s1 = adler & 0xffff; + unsigned long s2 = (adler >> 16) & 0xffff; + int k; + + if (buf == 0) + return 1L; + + while (len > 0) + { + k = len < 5552 ? len : 5552; + len -= k; + while (k >= 16) + { + s1 += *buf++; s2 += s1; + s1 += *buf++; s2 += s1; + s1 += *buf++; s2 += s1; + s1 += *buf++; s2 += s1; + s1 += *buf++; s2 += s1; + s1 += *buf++; s2 += s1; + s1 += *buf++; s2 += s1; + s1 += *buf++; s2 += s1; + s1 += *buf++; s2 += s1; + s1 += *buf++; s2 += s1; + s1 += *buf++; s2 += s1; + s1 += *buf++; s2 += s1; + s1 += *buf++; s2 += s1; + s1 += *buf++; s2 += s1; + s1 += *buf++; s2 += s1; + s1 += *buf++; s2 += s1; + k -= 16; + } + if (k != 0) + do + { + s1 += *buf++; s2 += s1; + } while (--k); + s1 &= 0xffffffffUL; + s2 &= 0xffffffffUL; + s1 %= 65521L; + s2 %= 65521L; + } + return (s2 << 16) | s1; +} + +unsigned char buf[] = { 0, 1, 2, 3, 4, 5, 6, 7, + 8, 9, 10, 11, 12, 13, 14, 15, + 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, + 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, + 0x55, 0xaa }; +int +main () +{ + unsigned long x = adler32 (0, buf, sizeof buf); + if (x != 0x640409efUL) + __builtin_abort (); + return 0; +} -- Alan Modra Australia Development Lab, IBM