From 672ec745f97d3ccce3f1d5da67bea3508010cedb Mon Sep 17 00:00:00 2001 From: Jakub Jelinek Date: Fri, 22 Jun 2018 22:53:41 +0200 Subject: [PATCH] backport: re PR debug/84875 (ICE in maybe_record_trace_start, at dwarf2cfi.c:2348 on s390x) Backported from mainline 2018-03-20 Jakub Jelinek PR debug/84875 * dce.c (delete_unmarked_insns): Don't remove frame related noop moves holding REG_CFA_RESTORE notes, instead turn them into a USE. * gcc.dg/pr84875.c: New test. From-SVN: r261932 --- gcc/ChangeLog | 4 ++++ gcc/dce.c | 27 ++++++++++++++++++++++++--- gcc/testsuite/ChangeLog | 3 +++ gcc/testsuite/gcc.dg/pr84875.c | 28 ++++++++++++++++++++++++++++ 4 files changed, 59 insertions(+), 3 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/pr84875.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 83af672bc0d8..c50b4c8c9fc9 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -11,6 +11,10 @@ 2018-03-20 Jakub Jelinek + PR debug/84875 + * dce.c (delete_unmarked_insns): Don't remove frame related noop moves + holding REG_CFA_RESTORE notes, instead turn them into a USE. + PR c/84953 * builtins.c (fold_builtin_strpbrk): For strpbrk(x, "") use type instead of TREE_TYPE (s1) for the return value. diff --git a/gcc/dce.c b/gcc/dce.c index f7f41e8e71ff..91e2f2768a3c 100644 --- a/gcc/dce.c +++ b/gcc/dce.c @@ -566,9 +566,19 @@ delete_unmarked_insns (void) FOR_BB_INSNS_REVERSE_SAFE (bb, insn, next) if (NONDEBUG_INSN_P (insn)) { + rtx turn_into_use = NULL_RTX; + /* Always delete no-op moves. */ if (noop_move_p (insn)) - ; + { + if (RTX_FRAME_RELATED_P (insn)) + turn_into_use + = find_reg_note (insn, REG_CFA_RESTORE, NULL); + if (turn_into_use && REG_P (XEXP (turn_into_use, 0))) + turn_into_use = XEXP (turn_into_use, 0); + else + turn_into_use = NULL_RTX; + } /* Otherwise rely only on the DCE algorithm. */ else if (marked_insn_p (insn)) @@ -608,8 +618,19 @@ delete_unmarked_insns (void) if (CALL_P (insn)) must_clean = true; - /* Now delete the insn. */ - delete_insn_and_edges (insn); + if (turn_into_use) + { + /* Don't remove frame related noop moves if they cary + REG_CFA_RESTORE note, while we don't need to emit any code, + we need it to emit the CFI restore note. */ + PATTERN (insn) + = gen_rtx_USE (GET_MODE (turn_into_use), turn_into_use); + INSN_CODE (insn) = -1; + df_insn_rescan (insn); + } + else + /* Now delete the insn. */ + delete_insn_and_edges (insn); } /* Deleted a pure or const call. */ diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index ce51bb094f77..93b4acee0f3e 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -3,6 +3,9 @@ Backported from mainline 2018-03-20 Jakub Jelinek + PR debug/84875 + * gcc.dg/pr84875.c: New test. + PR c/84953 * gcc.dg/pr84953.c: New test. diff --git a/gcc/testsuite/gcc.dg/pr84875.c b/gcc/testsuite/gcc.dg/pr84875.c new file mode 100644 index 000000000000..257176de205c --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr84875.c @@ -0,0 +1,28 @@ +/* PR debug/84875 */ +/* { dg-do compile } */ +/* { dg-options "-Os" } */ +/* { dg-additional-options "-fpie" { target pie } } */ +/* { dg-additional-options "-march=z196" { target s390*-*-* } } */ + +static long *a[100]; +static int b[100]; +long *c; +int d; +void foo (long *); + +void +bar () +{ + long *g = c; + g--; + d = *g; + if (d) + if (b[d] < 8) + { + *(void **)g = a[d]; + a[d] = g; + b[d]++; + return; + } + foo (g); +} -- 2.47.2