diff options
| author | Linus Torvalds <torvalds@penguin.transmeta.com> | 2003-04-04 14:58:16 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-07 21:00:11 -0700 |
| commit | 1832118a1b60208d511f4cee1697112affb67b0d (patch) | |
| tree | 2d2623438baa21571178db0872d8a3836a7279bc | |
| parent | 44682172e79f96503bf99b7f33cba8cae8a860da (diff) | |
| download | sparse-dev-1832118a1b60208d511f4cee1697112affb67b0d.tar.gz | |
Simplify more integer constant expressions. Get sign
issues right.
| -rw-r--r-- | evaluate.c | 64 |
1 files changed, 55 insertions, 9 deletions
@@ -202,20 +202,40 @@ static struct symbol * compatible_integer_binop(struct expression *expr, struct * CAREFUL! We need to get the size and sign of the * result right! */ -static void simplify_int_binop(struct expression *expr) +static void simplify_int_binop(struct expression *expr, struct symbol *ctype) { struct expression *left = expr->left, *right = expr->right; unsigned long long v, l, r, mask; + signed long long s, sl, sr; + int is_signed; if (left->type != EXPR_VALUE || right->type != EXPR_VALUE) return; l = left->value; r = right->value; + is_signed = !(ctype->ctype.modifiers & MOD_UNSIGNED); + mask = 1ULL << (ctype->bit_size-1); + sl = l; sr = r; + if (is_signed && (sl & mask)) + sl |= ~(mask-1); + if (is_signed && (sr & mask)) + sr |= ~(mask-1); + switch (expr->op) { - case '+': v = l+r; break; - case '-': v = l-r; break; + case '+': v = l+r; s = v; break; + case '-': v = l-r; s = v; break; + case '*': v = l*r; s = sl * sr; break; + case '/': if (!r) return; v = l / r; s = sl / sr; break; + case '%': if (!r) return; v = l % r; s = sl % sr; break; + case SPECIAL_LEFTSHIFT: return; + case SPECIAL_RIGHTSHIFT: return; + case '<': v = l < r; s = sl < sr; break; + case '>': v = l > r; s = sl > sr; break; + case SPECIAL_LTE: v = l <= r; s = sl <= sr; break; + case SPECIAL_GTE: v = l >= r; s = sl >= sr; break; default: return; } - mask = 1ULL << (expr->ctype->bit_size-1); + if (is_signed) + v = s; mask = mask | (mask-1); expr->value = v & mask; expr->type = EXPR_VALUE; @@ -226,7 +246,7 @@ static struct symbol *evaluate_int_binop(struct expression *expr) struct symbol *ctype = compatible_integer_binop(expr, &expr->left, &expr->right); if (ctype) { expr->ctype = ctype; - simplify_int_binop(expr); + simplify_int_binop(expr, ctype); return ctype; } return bad_expr_type(expr); @@ -277,12 +297,12 @@ static struct symbol *evaluate_ptr_add(struct expression *expr, struct expressio mul->ctype = size_t_ctype; mul->left = i; mul->right = val; - simplify_int_binop(mul); + simplify_int_binop(mul, size_t_ctype); /* Leave 'add->op' as 'expr->op' - either '+' or '-' */ add->left = ptr; add->right = mul; - simplify_int_binop(add); + simplify_int_binop(add, add->ctype); } return expr->ctype; @@ -486,6 +506,7 @@ static struct symbol *evaluate_compare(struct expression *expr) { struct expression *left = expr->left, *right = expr->right; struct symbol *ltype = left->ctype, *rtype = right->ctype; + struct symbol *ctype; /* Pointer types? */ if (is_ptr_type(ltype) || is_ptr_type(rtype)) { @@ -494,7 +515,9 @@ static struct symbol *evaluate_compare(struct expression *expr) return &bool_ctype; } - if (compatible_integer_binop(expr, &expr->left, &expr->right)) { + ctype = compatible_integer_binop(expr, &expr->left, &expr->right); + if (ctype) { + simplify_int_binop(expr, ctype); expr->ctype = &bool_ctype; return &bool_ctype; } @@ -730,6 +753,27 @@ static struct symbol *evaluate_dereference(struct expression *expr) return ctype; } +static void simplify_preop(struct expression *expr) +{ + struct expression *op = expr->unop; + unsigned long long v, mask; + + if (op->type != EXPR_VALUE) + return; + v = op->value; + switch (expr->op) { + case '+': break; + case '-': v = -v; break; + case '!': v = !v; break; + case '~': v = ~v; break; + default: return; + } + mask = 1ULL << (expr->ctype->bit_size-1); + mask = mask | (mask-1); + expr->value = v & mask; + expr->type = EXPR_VALUE; +} + static struct symbol *evaluate_preop(struct expression *expr) { struct symbol *ctype = expr->unop->ctype; @@ -747,10 +791,12 @@ static struct symbol *evaluate_preop(struct expression *expr) case '!': expr->ctype = &bool_ctype; + simplify_preop(expr); return &bool_ctype; default: expr->ctype = ctype; + simplify_preop(expr); return ctype; } } @@ -863,7 +909,7 @@ static struct symbol *evaluate_member_dereference(struct expression *expr) add->right = alloc_expression(expr->pos, EXPR_VALUE); add->right->ctype = &int_ctype; add->right->value = offset; - simplify_int_binop(add); + simplify_int_binop(add, &ptr_ctype); } ctype = member->ctype.base_type; |