From c3d3862950f5708af0db77c76b5db4db5e65740c Mon Sep 17 00:00:00 2001 From: Marek Polacek Date: Wed, 26 Jul 2017 11:53:17 +0000 Subject: re PR middle-end/70992 (Infinite recursion between fold_build2_stat_loc and fold_binary_loc w/ -fwrapv) PR middle-end/70992 * tree.c (build2_stat): Don't set TREE_CONSTANT on divisions by zero. * gcc.dg/overflow-warn-1.c: Adjust dg-error. * gcc.dg/overflow-warn-2.c: Likewise. * gcc.dg/overflow-warn-3.c: Likewise. * gcc.dg/overflow-warn-4.c: Likewise. * gcc.dg/torture/pr70992-2.c: New test. * gcc.dg/torture/pr70992.c: New test. From-SVN: r250566 --- gcc/tree.c | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-) (limited to 'gcc/tree.c') diff --git a/gcc/tree.c b/gcc/tree.c index b7de284..48fb2ce 100644 --- a/gcc/tree.c +++ b/gcc/tree.c @@ -4456,7 +4456,7 @@ build1_stat (enum tree_code code, tree type, tree node MEM_STAT_DECL) tree build2_stat (enum tree_code code, tree tt, tree arg0, tree arg1 MEM_STAT_DECL) { - bool constant, read_only, side_effects; + bool constant, read_only, side_effects, div_by_zero; tree t; gcc_assert (TREE_CODE_LENGTH (code) == 2); @@ -4489,6 +4489,23 @@ build2_stat (enum tree_code code, tree tt, tree arg0, tree arg1 MEM_STAT_DECL) read_only = 1; side_effects = TREE_SIDE_EFFECTS (t); + switch (code) + { + case TRUNC_DIV_EXPR: + case CEIL_DIV_EXPR: + case FLOOR_DIV_EXPR: + case ROUND_DIV_EXPR: + case EXACT_DIV_EXPR: + case CEIL_MOD_EXPR: + case FLOOR_MOD_EXPR: + case ROUND_MOD_EXPR: + case TRUNC_MOD_EXPR: + div_by_zero = integer_zerop (arg1); + break; + default: + div_by_zero = false; + } + PROCESS_ARG (0); PROCESS_ARG (1); @@ -4505,7 +4522,8 @@ build2_stat (enum tree_code code, tree tt, tree arg0, tree arg1 MEM_STAT_DECL) else { TREE_READONLY (t) = read_only; - TREE_CONSTANT (t) = constant; + /* Don't mark X / 0 as constant. */ + TREE_CONSTANT (t) = constant && !div_by_zero; TREE_THIS_VOLATILE (t) = (TREE_CODE_CLASS (code) == tcc_reference && arg0 && TREE_THIS_VOLATILE (arg0)); -- cgit v1.1