motiejus/zig
1
Fork 0
Code Releases Activity

add div_exact builtin fn

Browse Source 
closes #149
This commit is contained in:
Andrew Kelley
2016-05-07 20:53:16 -07:00
parent eb83111f02
commit 404defd99b
8 changed files with 153 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

42
src/eval.cpp
View File

@@ -709,6 +709,46 @@ static bool eval_min_max(EvalFn *ef, AstNode *node, ConstExprValue *out_val, boo
return false;
}
static bool eval_div_exact(EvalFn *ef, AstNode *node, ConstExprValue *out_val) {
assert(node->type == NodeTypeFnCallExpr);
AstNode *op1_node = node->data.fn_call_expr.params.at(0);
AstNode *op2_node = node->data.fn_call_expr.params.at(1);
TypeTableEntry *type_entry = get_resolved_expr(op1_node)->type_entry;
assert(type_entry->id == TypeTableEntryIdInt);
ConstExprValue op1_val = {0};
if (eval_expr(ef, op1_node, &op1_val)) return true;
ConstExprValue op2_val = {0};
if (eval_expr(ef, op2_node, &op2_val)) return true;
if (op2_val.data.x_bignum.data.x_uint == 0) {
ErrorMsg *msg = add_node_error(ef->root->codegen, ef->root->fn->fn_def_node,
buf_sprintf("function evaluation caused division by zero"));
add_error_note(ef->root->codegen, msg, ef->root->call_node, buf_sprintf("called from here"));
add_error_note(ef->root->codegen, msg, node, buf_sprintf("division by zero here"));
return true;
}
bignum_div(&out_val->data.x_bignum, &op1_val.data.x_bignum, &op2_val.data.x_bignum);
BigNum orig_bn;
bignum_mul(&orig_bn, &out_val->data.x_bignum, &op2_val.data.x_bignum);
if (bignum_cmp_neq(&orig_bn, &op1_val.data.x_bignum)) {
ErrorMsg *msg = add_node_error(ef->root->codegen, ef->root->fn->fn_def_node,
buf_sprintf("function evaluation violated exact division"));
add_error_note(ef->root->codegen, msg, ef->root->call_node, buf_sprintf("called from here"));
add_error_note(ef->root->codegen, msg, node, buf_sprintf("exact division violation here"));
return true;
}
out_val->ok = true;
out_val->depends_on_compile_var = op1_val.depends_on_compile_var || op2_val.depends_on_compile_var;
return false;
}
static bool eval_fn_with_overflow(EvalFn *ef, AstNode *node, ConstExprValue *out_val,
bool (*bignum_fn)(BigNum *dest, BigNum *op1, BigNum *op2))
{
@@ -767,6 +807,8 @@ static bool eval_fn_call_builtin(EvalFn *ef, AstNode *node, ConstExprValue *out_
return eval_fn_with_overflow(ef, node, out_val, bignum_shl);
case BuiltinFnIdFence:
return false;
case BuiltinFnIdDivExact:
return eval_div_exact(ef, node, out_val);
case BuiltinFnIdMemcpy:
case BuiltinFnIdMemset:
case BuiltinFnIdSizeof: