From b7e61f3668c515f07e5989a98c45d6662767be30 Mon Sep 17 00:00:00 2001 From: Yury Gribov Date: Sat, 12 Nov 2016 16:22:48 +0000 Subject: [PATCH] Optionally treat assertions as optimization hints (draft reincarnation of ancient patch by Paolo Bonzini). --- gcc/Makefile.in | 1 + gcc/c-family/c-common.c | 1 + gcc/c-family/c-common.h | 1 + gcc/c/c-parser.c | 24 ++++++++++++++++++++++++ gcc/cp/parser.c | 23 +++++++++++++++++++++++ gcc/ginclude/assert.h | 12 ++++++++++++ 6 files changed, 62 insertions(+) create mode 100755 gcc/ginclude/assert.h diff --git a/gcc/Makefile.in b/gcc/Makefile.in index 513f9c5..bfbe481 100644 --- a/gcc/Makefile.in +++ b/gcc/Makefile.in @@ -416,6 +416,7 @@ USER_H = $(srcdir)/ginclude/float.h \ $(srcdir)/ginclude/stdnoreturn.h \ $(srcdir)/ginclude/stdalign.h \ $(srcdir)/ginclude/stdatomic.h \ + $(srcdir)/ginclude/assert.h \ $(EXTRA_HEADERS) USER_H_INC_NEXT_PRE = @user_headers_inc_next_pre@ diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c index d2e3ad4..f7140b3 100644 --- a/gcc/c-family/c-common.c +++ b/gcc/c-family/c-common.c @@ -458,6 +458,7 @@ const struct c_common_resword c_common_reswords[] = { "__builtin_shuffle", RID_BUILTIN_SHUFFLE, 0 }, { "__builtin_offsetof", RID_OFFSETOF, 0 }, { "__builtin_types_compatible_p", RID_TYPES_COMPATIBLE_P, D_CONLY }, + { "__builtin_has_side_effects_p", RID_HAS_SIDE_EFFECTS_P, 0 }, { "__builtin_va_arg", RID_VA_ARG, 0 }, { "__complex", RID_COMPLEX, 0 }, { "__complex__", RID_COMPLEX, 0 }, diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h index dd74d0d..dfb5b37 100644 --- a/gcc/c-family/c-common.h +++ b/gcc/c-family/c-common.h @@ -101,6 +101,7 @@ enum rid RID_ASM, RID_TYPEOF, RID_ALIGNOF, RID_ATTRIBUTE, RID_VA_ARG, RID_EXTENSION, RID_IMAGPART, RID_REALPART, RID_LABEL, RID_CHOOSE_EXPR, RID_TYPES_COMPATIBLE_P, RID_BUILTIN_COMPLEX, RID_BUILTIN_SHUFFLE, + RID_HAS_SIDE_EFFECTS_P, RID_DFLOAT32, RID_DFLOAT64, RID_DFLOAT128, RID_FRACT, RID_ACCUM, RID_AUTO_TYPE, RID_BUILTIN_CALL_WITH_STATIC_CHAIN, diff --git a/gcc/c/c-parser.c b/gcc/c/c-parser.c index c9eb8dd..161702a 100644 --- a/gcc/c/c-parser.c +++ b/gcc/c/c-parser.c @@ -7407,6 +7407,7 @@ c_parser_generic_selection (c_parser *parser) __builtin_shuffle ( assignment-expression , assignment-expression , assignment-expression, ) + __builtin_has_side_effects_p ( assignment-expression ) offsetof-member-designator: identifier @@ -7990,6 +7991,29 @@ c_parser_postfix_expression (c_parser *parser) set_c_expr_source_range (&expr, loc, close_paren_loc); break; } + case RID_HAS_SIDE_EFFECTS_P: + c_parser_consume_token (parser); + if (!c_parser_require (parser, CPP_OPEN_PAREN, "expected %<(%>")) + { + expr.set_error (); + break; + } + { + c_expr ce = c_parser_expression (parser); + location_t close_paren_loc = c_parser_peek_token (parser)->location; + c_parser_skip_until_found (parser, CPP_CLOSE_PAREN, + "expected %<)%>"); + if (ce.value == error_mark_node) + { + expr.set_error (); + break; + } + + expr.value + = TREE_SIDE_EFFECTS(ce.value) ? integer_one_node : integer_zero_node; + set_c_expr_source_range (&expr, loc, close_paren_loc); + } + break; case RID_AT_SELECTOR: gcc_assert (c_dialect_objc ()); c_parser_consume_token (parser); diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c index df8e743..be7c946 100644 --- a/gcc/cp/parser.c +++ b/gcc/cp/parser.c @@ -4675,6 +4675,7 @@ cp_parser_fold_expression (cp_parser *parser, tree expr1) ( compound-statement ) __builtin_va_arg ( assignment-expression , type-id ) __builtin_offsetof ( type-id , offsetof-expression ) + __builtin_has_side_effects_p ( assignment-expression ) C++ Extensions: __has_nothrow_assign ( type-id ) @@ -5063,6 +5064,28 @@ cp_parser_primary_expression (cp_parser *parser, return build_x_va_arg (combined_loc, expression, type); } + case RID_HAS_SIDE_EFFECTS_P: + { + location_t start_loc + = cp_lexer_peek_token (parser->lexer)->location; + cp_lexer_consume_token (parser->lexer); + cp_parser_require (parser, CPP_OPEN_PAREN, RT_OPEN_PAREN); + + location_t expr_loc + = cp_lexer_peek_token (parser->lexer)->location; + tree expr = cp_parser_assignment_expression (parser); + + location_t finish_loc + = cp_lexer_peek_token (parser->lexer)->location; + cp_parser_require (parser, CPP_CLOSE_PAREN, RT_CLOSE_PAREN); + location_t combined_loc + = make_location (expr_loc, start_loc, finish_loc); + + tree res + = TREE_SIDE_EFFECTS(expr) ? integer_one_node : integer_zero_node; + return cp_expr (res, combined_loc); + } + case RID_OFFSETOF: return cp_parser_builtin_offsetof (parser); diff --git a/gcc/ginclude/assert.h b/gcc/ginclude/assert.h new file mode 100755 index 0000000..1c39aa9 --- /dev/null +++ b/gcc/ginclude/assert.h @@ -0,0 +1,12 @@ +#ifdef _GCC_ASSERT_H +# undef _GCC_ASSERT_H +# undef assert +#endif + +#define _GCC_ASSERT_H 1 + +#if !defined NDEBUG && defined __OPTIMIZE__ && defined __ASSUME_ASSERTS__ +# define assert(cond) ((__builtin_has_side_effects_p((cond)) || (cond)) ? (void)0 : __builtin_unreachable()) +#else +# include_next +#endif -- 2.7.4