From e62817edaecb4c8cb5a4f3c608f0ea52276449a1 Mon Sep 17 00:00:00 2001 From: Richard Biener Date: Thu, 18 Apr 2019 12:02:40 +0000 Subject: [PATCH] re PR debug/90131 (wrong debug info at -O3) 2019-04-18 Richard Biener PR debug/90131 * tree-cfgcleanup.c (move_debug_stmts_from_forwarder): Split out from ... (remove_forwarder_block): ... here. (remove_forwarder_block_with_phi): Also move debug stmts here. * gcc.dg/guality/pr90131.c: New testcase. From-SVN: r270441 --- gcc/ChangeLog | 8 +++ gcc/testsuite/ChangeLog | 5 ++ gcc/testsuite/gcc.dg/guality/pr90131.c | 35 +++++++++++ gcc/tree-cfgcleanup.c | 81 ++++++++++++++------------ 4 files changed, 92 insertions(+), 37 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/guality/pr90131.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 783ae7adc93..e589a9e7517 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,11 @@ +2019-04-18 Richard Biener + + PR debug/90131 + * tree-cfgcleanup.c (move_debug_stmts_from_forwarder): Split + out from ... + (remove_forwarder_block): ... here. + (remove_forwarder_block_with_phi): Also move debug stmts here. + 2019-04-18 Jakub Jelinek PR translation/79183 diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 11580f2d006..ee03b5e9b55 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2019-04-18 Richard Biener + + PR debug/90131 + * gcc.dg/guality/pr90131.c: New testcase. + 2019-04-17 Jakub Jelinek PR c++/89325 diff --git a/gcc/testsuite/gcc.dg/guality/pr90131.c b/gcc/testsuite/gcc.dg/guality/pr90131.c new file mode 100644 index 00000000000..2b89aaae24f --- /dev/null +++ b/gcc/testsuite/gcc.dg/guality/pr90131.c @@ -0,0 +1,35 @@ +/* { dg-do run } */ +/* { dg-options "-g" } */ + +void __attribute__((noinline)) +optimize_me_not () +{ + __asm__ volatile ("" : : : "memory"); +} +volatile long a; +int b[9][1]; +static short c[2][1] = {3}; +int main() +{ + int i, d, e; + i = 0; + for (; i < 9; i++) + a = b[i][0]; + i = 0; + for (; i < 2; i++) + { + d = 0; + for (; d < 1; d++) + { + e = 0; + for (; e < 1; e++) + a = c[i][e]; + /* i may very well be optimized out, so we cannot test for i == 0. + Instead test i + 1 which will make the test UNSUPPORTED if i + is optimized out. Since the test previously had wrong debug + with i == 9 this is acceptable. */ + optimize_me_not(); /* { dg-final { gdb-test . "i + 1" "1" } } */ + } + } + return 0; +} diff --git a/gcc/tree-cfgcleanup.c b/gcc/tree-cfgcleanup.c index 3c291f5473b..0a79a6a658f 100644 --- a/gcc/tree-cfgcleanup.c +++ b/gcc/tree-cfgcleanup.c @@ -444,6 +444,45 @@ phi_alternatives_equal (basic_block dest, edge e1, edge e2) return true; } +/* Move debug stmts from the forwarder block SRC to DEST. */ + +static void +move_debug_stmts_from_forwarder (basic_block src, basic_block dest) +{ + if (!MAY_HAVE_DEBUG_STMTS) + return; + + bool can_move_debug_stmts = single_pred_p (dest); + gimple_stmt_iterator gsi_to = gsi_after_labels (dest); + for (gimple_stmt_iterator gsi = gsi_after_labels (src); !gsi_end_p (gsi);) + { + gimple *debug = gsi_stmt (gsi); + gcc_assert (is_gimple_debug (debug)); + /* Move debug binds anyway, but not anything else like begin-stmt + markers unless they are always valid at the destination. */ + if (can_move_debug_stmts + || gimple_debug_bind_p (debug)) + { + gsi_move_before (&gsi, &gsi_to); + /* Reset debug-binds that are not always valid at the destination. + Simply dropping them can cause earlier values to become live, + generating wrong debug information. + ??? There are several things we could improve here. For + one we might be able to move stmts to the predecessor. + For anther, if the debug stmt is immediately followed by a + (debug) definition in the destination (on a post-dominated path?) + we can elide it without any bad effects. */ + if (!can_move_debug_stmts) + { + gimple_debug_bind_reset_value (debug); + update_stmt (debug); + } + } + else + gsi_next (&gsi); + } +} + /* Removes forwarder block BB. Returns false if this failed. */ static bool @@ -454,7 +493,6 @@ remove_forwarder_block (basic_block bb) gimple *stmt; edge_iterator ei; gimple_stmt_iterator gsi, gsi_to; - bool can_move_debug_stmts; /* We check for infinite loops already in tree_forwarder_block_p. However it may happen that the infinite loop is created @@ -503,8 +541,6 @@ remove_forwarder_block (basic_block bb) } } - can_move_debug_stmts = MAY_HAVE_DEBUG_STMTS && single_pred_p (dest); - basic_block pred = NULL; if (single_pred_p (bb)) pred = single_pred (bb); @@ -566,40 +602,7 @@ remove_forwarder_block (basic_block bb) /* Move debug statements. Reset them if the destination does not have a single predecessor. */ - if (!gsi_end_p (gsi)) - { - gsi_to = gsi_after_labels (dest); - do - { - gimple *debug = gsi_stmt (gsi); - gcc_assert (is_gimple_debug (debug)); - /* Move debug binds anyway, but not anything else - like begin-stmt markers unless they are always - valid at the destination. */ - if (can_move_debug_stmts - || gimple_debug_bind_p (debug)) - { - gsi_move_before (&gsi, &gsi_to); - /* Reset debug-binds that are not always valid at the - destination. Simply dropping them can cause earlier - values to become live, generating wrong debug information. - ??? There are several things we could improve here. For - one we might be able to move stmts to the predecessor. - For anther, if the debug stmt is immediately followed - by a (debug) definition in the destination (on a - post-dominated path?) we can elide it without any bad - effects. */ - if (!can_move_debug_stmts) - { - gimple_debug_bind_reset_value (debug); - update_stmt (debug); - } - } - else - gsi_next (&gsi); - } - while (!gsi_end_p (gsi)); - } + move_debug_stmts_from_forwarder (bb, dest); bitmap_set_bit (cfgcleanup_altered_bbs, dest->index); @@ -1282,6 +1285,10 @@ remove_forwarder_block_with_phi (basic_block bb) redirect_edge_var_map_clear (e); } + /* Move debug statements. Reset them if the destination does not + have a single predecessor. */ + move_debug_stmts_from_forwarder (bb, dest); + /* Update the dominators. */ dombb = get_immediate_dominator (CDI_DOMINATORS, bb); domdest = get_immediate_dominator (CDI_DOMINATORS, dest); -- 2.30.2