At the moment, an anti range ~[A,B] is stored as [B+1,A-1]. This makes it harder to store the range in the natural precision of A and B, since B+1 and A-1 might not be representable in that precision.
This patch instead stores the original minimum and maximum values and uses a spare tree bit to represent the range type. The version below is for trunk; I've also tested a wide-int version. Tested on x86_64-linux-gnu. OK to install? Thanks, Richard gcc/ * tree-core.h (tree_base): Document use of static_flag for SSA_NAME. * tree.h (SSA_NAME_ANTI_RANGE_P, SSA_NAME_RANGE_TYPE): New macros. * tree-ssanames.h (set_range_info): Add range_type argument. (duplicate_ssa_name_range_info): Likewise. * tree-ssanames.c (set_range_info): Take the range type as argument and store it in SSA_NAME_ANTI_RANGE_P. (duplicate_ssa_name_range_info): Likewise. (get_range_info): Use SSA_NAME_ANTI_RANGE_P. (set_nonzero_bits): Update call to set_range_info. (duplicate_ssa_name_fn): Update call to duplicate_ssa_name_range_info. * tree-ssa-copy.c (fini_copy_prop): Likewise. * tree-vrp.c (remove_range_assertions): Update call to set_range_info. (vrp_finalize): Likewise, passing anti-ranges directly. Index: gcc/tree-core.h =================================================================== --- gcc/tree-core.h 2013-11-15 18:23:21.113488640 +0000 +++ gcc/tree-core.h 2013-11-28 11:12:32.956977322 +0000 @@ -822,6 +822,9 @@ struct GTY(()) tree_base { TRANSACTION_EXPR_OUTER in TRANSACTION_EXPR + SSA_NAME_ANTI_RANGE_P in + SSA_NAME + public_flag: TREE_OVERFLOW in Index: gcc/tree.h =================================================================== --- gcc/tree.h 2013-11-20 10:58:57.275831561 +0000 +++ gcc/tree.h 2013-11-28 11:12:32.969977280 +0000 @@ -1434,6 +1434,14 @@ #define SSA_NAME_IS_DEFAULT_DEF(NODE) \ #define SSA_NAME_PTR_INFO(N) \ SSA_NAME_CHECK (N)->ssa_name.info.ptr_info +/* True if SSA_NAME_RANGE_INFO describes an anti-range. */ +#define SSA_NAME_ANTI_RANGE_P(N) \ + SSA_NAME_CHECK (N)->base.static_flag + +/* The type of range described by SSA_NAME_RANGE_INFO. */ +#define SSA_NAME_RANGE_TYPE(N) \ + (SSA_NAME_ANTI_RANGE_P (N) ? VR_ANTI_RANGE : VR_RANGE) + /* Value range info attributes for SSA_NAMEs of non pointer-type variables. */ #define SSA_NAME_RANGE_INFO(N) \ SSA_NAME_CHECK (N)->ssa_name.info.range_info Index: gcc/tree-ssanames.h =================================================================== --- gcc/tree-ssanames.h 2013-11-15 18:23:22.050485010 +0000 +++ gcc/tree-ssanames.h 2013-11-28 11:12:32.964977296 +0000 @@ -70,7 +70,8 @@ #define ssa_name(i) ((*cfun->gimple_df-> enum value_range_type { VR_UNDEFINED, VR_RANGE, VR_ANTI_RANGE, VR_VARYING }; /* Sets the value range to SSA. */ -extern void set_range_info (tree, double_int, double_int); +extern void set_range_info (tree, enum value_range_type, double_int, + double_int); /* Gets the value range from SSA. */ extern enum value_range_type get_range_info (const_tree, double_int *, double_int *); @@ -93,7 +94,8 @@ extern struct ptr_info_def *get_ptr_info extern tree copy_ssa_name_fn (struct function *, tree, gimple); extern void duplicate_ssa_name_ptr_info (tree, struct ptr_info_def *); extern tree duplicate_ssa_name_fn (struct function *, tree, gimple); -extern void duplicate_ssa_name_range_info (tree, struct range_info_def *); +extern void duplicate_ssa_name_range_info (tree, enum value_range_type, + struct range_info_def *); extern void release_defs (gimple); extern void replace_ssa_name_symbol (tree, tree); Index: gcc/tree-ssanames.c =================================================================== --- gcc/tree-ssanames.c 2013-11-20 10:59:18.330782865 +0000 +++ gcc/tree-ssanames.c 2013-11-28 11:12:32.963977300 +0000 @@ -178,12 +178,14 @@ make_ssa_name_fn (struct function *fn, t return t; } -/* Store range information MIN, and MAX to tree ssa_name NAME. */ +/* Store range information RANGE_TYPE, MIN, and MAX to tree ssa_name NAME. */ void -set_range_info (tree name, double_int min, double_int max) +set_range_info (tree name, enum value_range_type range_type, double_int min, + double_int max) { gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name))); + gcc_assert (range_type == VR_RANGE || range_type == VR_ANTI_RANGE); range_info_def *ri = SSA_NAME_RANGE_INFO (name); /* Allocate if not available. */ @@ -194,12 +196,16 @@ set_range_info (tree name, double_int mi ri->nonzero_bits = double_int::mask (TYPE_PRECISION (TREE_TYPE (name))); } + /* Record the range type. */ + if (SSA_NAME_RANGE_TYPE (name) != range_type) + SSA_NAME_ANTI_RANGE_P (name) = (range_type == VR_ANTI_RANGE); + /* Set the values. */ ri->min = min; ri->max = max; /* If it is a range, try to improve nonzero_bits from the min/max. */ - if (min.cmp (max, TYPE_UNSIGNED (TREE_TYPE (name))) != 1) + if (range_type == VR_RANGE) { int prec = TYPE_PRECISION (TREE_TYPE (name)); double_int xorv; @@ -225,7 +231,6 @@ set_range_info (tree name, double_int mi enum value_range_type get_range_info (const_tree name, double_int *min, double_int *max) { - enum value_range_type range_type; gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name))); gcc_assert (min && max); range_info_def *ri = SSA_NAME_RANGE_INFO (name); @@ -236,22 +241,9 @@ get_range_info (const_tree name, double_ > 2 * HOST_BITS_PER_WIDE_INT)) return VR_VARYING; - /* If min > max, it is VR_ANTI_RANGE. */ - if (ri->min.cmp (ri->max, TYPE_UNSIGNED (TREE_TYPE (name))) == 1) - { - /* VR_ANTI_RANGE ~[min, max] is encoded as [max + 1, min - 1]. */ - range_type = VR_ANTI_RANGE; - *min = ri->max + double_int_one; - *max = ri->min - double_int_one; - } - else - { - /* Otherwise (when min <= max), it is VR_RANGE. */ - range_type = VR_RANGE; - *min = ri->min; - *max = ri->max; - } - return range_type; + *min = ri->min; + *max = ri->max; + return SSA_NAME_RANGE_TYPE (name); } /* Change non-zero bits bitmask of NAME. */ @@ -261,7 +253,7 @@ set_nonzero_bits (tree name, double_int { gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name))); if (SSA_NAME_RANGE_INFO (name) == NULL) - set_range_info (name, + set_range_info (name, VR_RANGE, tree_to_double_int (TYPE_MIN_VALUE (TREE_TYPE (name))), tree_to_double_int (TYPE_MAX_VALUE (TREE_TYPE (name)))); range_info_def *ri = SSA_NAME_RANGE_INFO (name); @@ -490,15 +482,17 @@ duplicate_ssa_name_ptr_info (tree name, SSA_NAME_PTR_INFO (name) = new_ptr_info; } -/* Creates a duplicate of the range_info_def at RANGE_INFO for use by - the SSA name NAME. */ +/* Creates a duplicate of the range_info_def at RANGE_INFO of type + RANGE_TYPE for use by the SSA name NAME. */ void -duplicate_ssa_name_range_info (tree name, struct range_info_def *range_info) +duplicate_ssa_name_range_info (tree name, enum value_range_type range_type, + struct range_info_def *range_info) { struct range_info_def *new_range_info; gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name))); gcc_assert (!SSA_NAME_RANGE_INFO (name)); + gcc_assert (!SSA_NAME_ANTI_RANGE_P (name)); if (!range_info) return; @@ -506,6 +500,8 @@ duplicate_ssa_name_range_info (tree name new_range_info = ggc_alloc_range_info_def (); *new_range_info = *range_info; + gcc_assert (range_type == VR_RANGE || range_type == VR_ANTI_RANGE); + SSA_NAME_ANTI_RANGE_P (name) = (range_type == VR_ANTI_RANGE); SSA_NAME_RANGE_INFO (name) = new_range_info; } @@ -530,7 +526,8 @@ duplicate_ssa_name_fn (struct function * struct range_info_def *old_range_info = SSA_NAME_RANGE_INFO (name); if (old_range_info) - duplicate_ssa_name_range_info (new_name, old_range_info); + duplicate_ssa_name_range_info (new_name, SSA_NAME_RANGE_TYPE (name), + old_range_info); } return new_name; Index: gcc/tree-ssa-copy.c =================================================================== --- gcc/tree-ssa-copy.c 2013-11-20 10:59:13.528790271 +0000 +++ gcc/tree-ssa-copy.c 2013-11-28 11:12:32.961977306 +0000 @@ -572,6 +572,7 @@ fini_copy_prop (void) && SSA_NAME_RANGE_INFO (var) && !SSA_NAME_RANGE_INFO (copy_of[i].value)) duplicate_ssa_name_range_info (copy_of[i].value, + SSA_NAME_RANGE_TYPE (var), SSA_NAME_RANGE_INFO (var)); } } Index: gcc/tree-vrp.c =================================================================== --- gcc/tree-vrp.c 2013-11-20 10:58:52.760847630 +0000 +++ gcc/tree-vrp.c 2013-11-28 11:12:32.967977287 +0000 @@ -6583,7 +6583,8 @@ remove_range_assertions (void) && all_imm_uses_in_stmt_or_feed_cond (var, stmt, single_pred (bb))) { - set_range_info (var, SSA_NAME_RANGE_INFO (lhs)->min, + set_range_info (var, SSA_NAME_RANGE_TYPE (lhs), + SSA_NAME_RANGE_INFO (lhs)->min, SSA_NAME_RANGE_INFO (lhs)->max); maybe_set_nonzero_bits (bb, var); } @@ -9589,36 +9590,12 @@ vrp_finalize (void) continue; if ((TREE_CODE (vr_value[i]->min) == INTEGER_CST) - && (TREE_CODE (vr_value[i]->max) == INTEGER_CST)) - { - if (vr_value[i]->type == VR_RANGE) - set_range_info (name, - tree_to_double_int (vr_value[i]->min), - tree_to_double_int (vr_value[i]->max)); - else if (vr_value[i]->type == VR_ANTI_RANGE) - { - /* VR_ANTI_RANGE ~[min, max] is encoded compactly as - [max + 1, min - 1] without additional attributes. - When min value > max value, we know that it is - VR_ANTI_RANGE; it is VR_RANGE otherwise. */ - - /* ~[0,0] anti-range is represented as - range. */ - if (TYPE_UNSIGNED (TREE_TYPE (name)) - && integer_zerop (vr_value[i]->min) - && integer_zerop (vr_value[i]->max)) - set_range_info (name, - double_int_one, - double_int::max_value - (TYPE_PRECISION (TREE_TYPE (name)), true)); - else - set_range_info (name, - tree_to_double_int (vr_value[i]->max) - + double_int_one, - tree_to_double_int (vr_value[i]->min) - - double_int_one); - } - } + && (TREE_CODE (vr_value[i]->max) == INTEGER_CST) + && (vr_value[i]->type == VR_RANGE + || vr_value[i]->type == VR_ANTI_RANGE)) + set_range_info (name, vr_value[i]->type, + tree_to_double_int (vr_value[i]->min), + tree_to_double_int (vr_value[i]->max)); } /* Free allocated memory. */