From 429e3b7d8bf6609ddf7c7b1e49244997e9ac76b8 Mon Sep 17 00:00:00 2001 From: Oracle Public Cloud User Date: Mon, 1 Nov 2021 15:14:26 +0000 Subject: PR 102281 (-ftrivial-auto-var-init=zero causes ice) Do not add call to __builtin_clear_padding when a variable is a gimple register or it might not have padding. gcc/ChangeLog: 2021-11-01 qing zhao * gimplify.c (gimplify_decl_expr): Do not add call to __builtin_clear_padding when a variable is a gimple register or it might not have padding. (gimplify_init_constructor): Likewise. gcc/testsuite/ChangeLog: 2021-11-01 qing zhao * c-c++-common/pr102281.c: New test. * gcc.target/i386/auto-init-2.c: Adjust testing case. * gcc.target/i386/auto-init-4.c: Likewise. * gcc.target/i386/auto-init-6.c: Likewise. * gcc.target/aarch64/auto-init-6.c: Likewise. --- gcc/gimplify.c | 25 +++++++++++++++++++------ 1 file changed, 19 insertions(+), 6 deletions(-) (limited to 'gcc/gimplify.c') diff --git a/gcc/gimplify.c b/gcc/gimplify.c index 8bb54fd..c2ab96e 100644 --- a/gcc/gimplify.c +++ b/gcc/gimplify.c @@ -1784,8 +1784,8 @@ gimple_add_init_for_auto_var (tree decl, that padding is initialized to zero. So, we always initialize paddings to zeroes regardless INIT_TYPE. To do the padding initialization, we insert a call to - __BUILTIN_CLEAR_PADDING (&decl, 0, for_auto_init = true). - Note, we add an additional dummy argument for __BUILTIN_CLEAR_PADDING, + __builtin_clear_padding (&decl, 0, for_auto_init = true). + Note, we add an additional dummy argument for __builtin_clear_padding, 'for_auto_init' to distinguish whether this call is for automatic variable initialization or not. */ @@ -1954,8 +1954,14 @@ gimplify_decl_expr (tree *stmt_p, gimple_seq *seq_p) pattern initialization. In order to make the paddings as zeroes for pattern init, We should add a call to __builtin_clear_padding to clear the - paddings to zero in compatiple with CLANG. */ - if (flag_auto_var_init == AUTO_INIT_PATTERN) + paddings to zero in compatiple with CLANG. + We cannot insert this call if the variable is a gimple register + since __builtin_clear_padding will take the address of the + variable. As a result, if a long double/_Complex long double + variable will spilled into stack later, its padding is 0XFE. */ + if (flag_auto_var_init == AUTO_INIT_PATTERN + && !is_gimple_reg (decl) + && clear_padding_type_may_have_padding_p (TREE_TYPE (decl))) gimple_add_padding_init_for_auto_var (decl, is_vla, seq_p); } } @@ -5384,12 +5390,19 @@ gimplify_init_constructor (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p, /* If the user requests to initialize automatic variables, we should initialize paddings inside the variable. Add a call to - __BUILTIN_CLEAR_PADDING (&object, 0, for_auto_init = true) to + __builtin_clear_pading (&object, 0, for_auto_init = true) to initialize paddings of object always to zero regardless of INIT_TYPE. Note, we will not insert this call if the aggregate variable has be completely cleared already or it's initialized - with an empty constructor. */ + with an empty constructor. We cannot insert this call if the + variable is a gimple register since __builtin_clear_padding will take + the address of the variable. As a result, if a long double/_Complex long + double variable will be spilled into stack later, its padding cannot + be cleared with __builtin_clear_padding. We should clear its padding + when it is spilled into memory. */ if (is_init_expr + && !is_gimple_reg (object) + && clear_padding_type_may_have_padding_p (type) && ((AGGREGATE_TYPE_P (type) && !cleared && !is_empty_ctor) || !AGGREGATE_TYPE_P (type)) && is_var_need_auto_init (object)) -- cgit v1.1