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builtin functions for division and remainder division

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* add `@divTrunc` and `@divFloor` functions
 * add `@rem` and `@mod` functions
 * add compile error for `/` and `%` with signed integers
 * add `.bit_count` for float primitive types

closes #217
This commit is contained in:
Andrew Kelley
2017-05-06 23:13:12 -04:00
parent 866c841dd8
commit 157af4332a
21 changed files with 976 additions and 315 deletions
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250
src/codegen.cpp
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@@ -538,6 +538,35 @@ static LLVMValueRef get_int_overflow_fn(CodeGen *g, TypeTableEntry *type_entry,
return fn_val;
}
static LLVMValueRef get_floor_ceil_fn(CodeGen *g, TypeTableEntry *type_entry, ZigLLVMFnId fn_id) {
assert(type_entry->id == TypeTableEntryIdFloat);
ZigLLVMFnKey key = {};
key.id = fn_id;
key.data.floor_ceil.bit_count = (uint32_t)type_entry->data.floating.bit_count;
auto existing_entry = g->llvm_fn_table.maybe_get(key);
if (existing_entry)
return existing_entry->value;
const char *name;
if (fn_id == ZigLLVMFnIdFloor) {
name = "floor";
} else if (fn_id == ZigLLVMFnIdCeil) {
name = "ceil";
} else {
zig_unreachable();
}
char fn_name[64];
sprintf(fn_name, "llvm.%s.f%zu", name, type_entry->data.floating.bit_count);
LLVMTypeRef fn_type = LLVMFunctionType(type_entry->type_ref, &type_entry->type_ref, 1, false);
LLVMValueRef fn_val = LLVMAddFunction(g->module, fn_name, fn_type);
g->llvm_fn_table.put(key, fn_val);
return fn_val;
}
static LLVMValueRef get_handle_value(CodeGen *g, LLVMValueRef ptr, TypeTableEntry *type, bool is_volatile) {
if (type_has_bits(type)) {
if (handle_is_ptr(type)) {
@@ -618,7 +647,7 @@ static Buf *panic_msg_buf(PanicMsgId msg_id) {
case PanicMsgIdDivisionByZero:
return buf_create_from_str("division by zero");
case PanicMsgIdRemainderDivisionByZero:
return buf_create_from_str("remainder division by zero");
return buf_create_from_str("remainder division by zero or negative value");
case PanicMsgIdExactDivisionRemainder:
return buf_create_from_str("exact division produced remainder");
case PanicMsgIdSliceWidenRemainder:
@@ -1099,12 +1128,34 @@ static LLVMValueRef gen_overflow_shl_op(CodeGen *g, TypeTableEntry *type_entry,
return result;
}
static LLVMValueRef gen_div(CodeGen *g, bool want_debug_safety, LLVMValueRef val1, LLVMValueRef val2,
TypeTableEntry *type_entry, bool exact)
{
static LLVMValueRef gen_floor(CodeGen *g, LLVMValueRef val, TypeTableEntry *type_entry) {
if (type_entry->id == TypeTableEntryIdInt)
return val;
LLVMValueRef floor_fn = get_floor_ceil_fn(g, type_entry, ZigLLVMFnIdFloor);
return LLVMBuildCall(g->builder, floor_fn, &val, 1, "");
}
static LLVMValueRef gen_ceil(CodeGen *g, LLVMValueRef val, TypeTableEntry *type_entry) {
if (type_entry->id == TypeTableEntryIdInt)
return val;
LLVMValueRef ceil_fn = get_floor_ceil_fn(g, type_entry, ZigLLVMFnIdCeil);
return LLVMBuildCall(g->builder, ceil_fn, &val, 1, "");
}
enum DivKind {
DivKindFloat,
DivKindTrunc,
DivKindFloor,
DivKindExact,
};
static LLVMValueRef gen_div(CodeGen *g, bool want_debug_safety, LLVMValueRef val1, LLVMValueRef val2,
TypeTableEntry *type_entry, DivKind div_kind)
{
LLVMValueRef zero = LLVMConstNull(type_entry->type_ref);
if (want_debug_safety) {
LLVMValueRef zero = LLVMConstNull(type_entry->type_ref);
LLVMValueRef is_zero_bit;
if (type_entry->id == TypeTableEntryIdInt) {
is_zero_bit = LLVMBuildICmp(g->builder, LLVMIntEQ, val2, zero, "");
@@ -1140,55 +1191,111 @@ static LLVMValueRef gen_div(CodeGen *g, bool want_debug_safety, LLVMValueRef val
}
if (type_entry->id == TypeTableEntryIdFloat) {
assert(!exact);
return LLVMBuildFDiv(g->builder, val1, val2, "");
LLVMValueRef result = LLVMBuildFDiv(g->builder, val1, val2, "");
switch (div_kind) {
case DivKindFloat:
return result;
case DivKindExact:
if (want_debug_safety) {
LLVMValueRef floored = gen_floor(g, result, type_entry);
LLVMBasicBlockRef ok_block = LLVMAppendBasicBlock(g->cur_fn_val, "DivExactOk");
LLVMBasicBlockRef fail_block = LLVMAppendBasicBlock(g->cur_fn_val, "DivExactFail");
LLVMValueRef ok_bit = LLVMBuildFCmp(g->builder, LLVMRealOEQ, floored, result, "");
LLVMBuildCondBr(g->builder, ok_bit, ok_block, fail_block);
LLVMPositionBuilderAtEnd(g->builder, fail_block);
gen_debug_safety_crash(g, PanicMsgIdExactDivisionRemainder);
LLVMPositionBuilderAtEnd(g->builder, ok_block);
}
return result;
case DivKindTrunc:
{
LLVMValueRef floored = gen_floor(g, result, type_entry);
LLVMValueRef ceiled = gen_ceil(g, result, type_entry);
LLVMValueRef ltz = LLVMBuildFCmp(g->builder, LLVMRealOLT, val1, zero, "");
return LLVMBuildSelect(g->builder, ltz, ceiled, floored, "");
}
case DivKindFloor:
return gen_floor(g, result, type_entry);
}
zig_unreachable();
}
assert(type_entry->id == TypeTableEntryIdInt);
if (exact) {
if (want_debug_safety) {
LLVMValueRef remainder_val;
switch (div_kind) {
case DivKindFloat:
zig_unreachable();
case DivKindTrunc:
if (type_entry->data.integral.is_signed) {
remainder_val = LLVMBuildSRem(g->builder, val1, val2, "");
return LLVMBuildSDiv(g->builder, val1, val2, "");
} else {
remainder_val = LLVMBuildURem(g->builder, val1, val2, "");
return LLVMBuildUDiv(g->builder, val1, val2, "");
}
LLVMValueRef zero = LLVMConstNull(type_entry->type_ref);
LLVMValueRef ok_bit = LLVMBuildICmp(g->builder, LLVMIntEQ, remainder_val, zero, "");
case DivKindExact:
if (want_debug_safety) {
LLVMValueRef remainder_val;
if (type_entry->data.integral.is_signed) {
remainder_val = LLVMBuildSRem(g->builder, val1, val2, "");
} else {
remainder_val = LLVMBuildURem(g->builder, val1, val2, "");
}
LLVMValueRef ok_bit = LLVMBuildICmp(g->builder, LLVMIntEQ, remainder_val, zero, "");
LLVMBasicBlockRef ok_block = LLVMAppendBasicBlock(g->cur_fn_val, "DivExactOk");
LLVMBasicBlockRef fail_block = LLVMAppendBasicBlock(g->cur_fn_val, "DivExactFail");
LLVMBuildCondBr(g->builder, ok_bit, ok_block, fail_block);
LLVMBasicBlockRef ok_block = LLVMAppendBasicBlock(g->cur_fn_val, "DivExactOk");
LLVMBasicBlockRef fail_block = LLVMAppendBasicBlock(g->cur_fn_val, "DivExactFail");
LLVMBuildCondBr(g->builder, ok_bit, ok_block, fail_block);
LLVMPositionBuilderAtEnd(g->builder, fail_block);
gen_debug_safety_crash(g, PanicMsgIdExactDivisionRemainder);
LLVMPositionBuilderAtEnd(g->builder, fail_block);
gen_debug_safety_crash(g, PanicMsgIdExactDivisionRemainder);
LLVMPositionBuilderAtEnd(g->builder, ok_block);
}
if (type_entry->data.integral.is_signed) {
return LLVMBuildExactSDiv(g->builder, val1, val2, "");
} else {
return LLVMBuildExactUDiv(g->builder, val1, val2, "");
}
} else {
if (type_entry->data.integral.is_signed) {
return LLVMBuildSDiv(g->builder, val1, val2, "");
} else {
return LLVMBuildUDiv(g->builder, val1, val2, "");
}
LLVMPositionBuilderAtEnd(g->builder, ok_block);
}
if (type_entry->data.integral.is_signed) {
return LLVMBuildExactSDiv(g->builder, val1, val2, "");
} else {
return LLVMBuildExactUDiv(g->builder, val1, val2, "");
}
case DivKindFloor:
{
if (!type_entry->data.integral.is_signed) {
return LLVMBuildUDiv(g->builder, val1, val2, "");
}
// const result = @divTrunc(a, b);
// if (result >= 0 or result * b == a)
// return result;
// else
// return result - 1;
LLVMValueRef result = LLVMBuildSDiv(g->builder, val1, val2, "");
LLVMValueRef is_pos = LLVMBuildICmp(g->builder, LLVMIntSGE, result, zero, "");
LLVMValueRef orig_num = LLVMBuildNSWMul(g->builder, result, val2, "");
LLVMValueRef orig_ok = LLVMBuildICmp(g->builder, LLVMIntEQ, orig_num, val1, "");
LLVMValueRef ok_bit = LLVMBuildOr(g->builder, orig_ok, is_pos, "");
LLVMValueRef one = LLVMConstInt(type_entry->type_ref, 1, true);
LLVMValueRef result_minus_1 = LLVMBuildNSWSub(g->builder, result, one, "");
return LLVMBuildSelect(g->builder, ok_bit, result, result_minus_1, "");
}
}
zig_unreachable();
}
static LLVMValueRef gen_rem(CodeGen *g, bool want_debug_safety, LLVMValueRef val1, LLVMValueRef val2,
TypeTableEntry *type_entry)
{
enum RemKind {
RemKindRem,
RemKindMod,
};
static LLVMValueRef gen_rem(CodeGen *g, bool want_debug_safety, LLVMValueRef val1, LLVMValueRef val2,
TypeTableEntry *type_entry, RemKind rem_kind)
{
LLVMValueRef zero = LLVMConstNull(type_entry->type_ref);
if (want_debug_safety) {
LLVMValueRef zero = LLVMConstNull(type_entry->type_ref);
LLVMValueRef is_zero_bit;
if (type_entry->id == TypeTableEntryIdInt) {
is_zero_bit = LLVMBuildICmp(g->builder, LLVMIntEQ, val2, zero, "");
LLVMIntPredicate pred = type_entry->data.integral.is_signed ? LLVMIntSLE : LLVMIntEQ;
is_zero_bit = LLVMBuildICmp(g->builder, pred, val2, zero, "");
} else if (type_entry->id == TypeTableEntryIdFloat) {
is_zero_bit = LLVMBuildFCmp(g->builder, LLVMRealOEQ, val2, zero, "");
} else {
@@ -1202,30 +1309,30 @@ static LLVMValueRef gen_rem(CodeGen *g, bool want_debug_safety, LLVMValueRef val
gen_debug_safety_crash(g, PanicMsgIdRemainderDivisionByZero);
LLVMPositionBuilderAtEnd(g->builder, rem_zero_ok_block);
if (type_entry->id == TypeTableEntryIdInt && type_entry->data.integral.is_signed) {
LLVMValueRef neg_1_value = LLVMConstInt(type_entry->type_ref, -1, true);
LLVMValueRef int_min_value = LLVMConstInt(type_entry->type_ref, min_signed_val(type_entry), true);
LLVMBasicBlockRef overflow_ok_block = LLVMAppendBasicBlock(g->cur_fn_val, "RemOverflowOk");
LLVMBasicBlockRef overflow_fail_block = LLVMAppendBasicBlock(g->cur_fn_val, "RemOverflowFail");
LLVMValueRef num_is_int_min = LLVMBuildICmp(g->builder, LLVMIntEQ, val1, int_min_value, "");
LLVMValueRef den_is_neg_1 = LLVMBuildICmp(g->builder, LLVMIntEQ, val2, neg_1_value, "");
LLVMValueRef overflow_fail_bit = LLVMBuildAnd(g->builder, num_is_int_min, den_is_neg_1, "");
LLVMBuildCondBr(g->builder, overflow_fail_bit, overflow_fail_block, overflow_ok_block);
LLVMPositionBuilderAtEnd(g->builder, overflow_fail_block);
gen_debug_safety_crash(g, PanicMsgIdIntegerOverflow);
LLVMPositionBuilderAtEnd(g->builder, overflow_ok_block);
}
}
if (type_entry->id == TypeTableEntryIdFloat) {
return LLVMBuildFRem(g->builder, val1, val2, "");
if (rem_kind == RemKindRem) {
return LLVMBuildFRem(g->builder, val1, val2, "");
} else {
LLVMValueRef a = LLVMBuildFRem(g->builder, val1, val2, "");
LLVMValueRef b = LLVMBuildFAdd(g->builder, a, val2, "");
LLVMValueRef c = LLVMBuildFRem(g->builder, b, val2, "");
LLVMValueRef ltz = LLVMBuildFCmp(g->builder, LLVMRealOLT, val1, zero, "");
return LLVMBuildSelect(g->builder, ltz, c, a, "");
}
} else {
assert(type_entry->id == TypeTableEntryIdInt);
if (type_entry->data.integral.is_signed) {
return LLVMBuildSRem(g->builder, val1, val2, "");
if (rem_kind == RemKindRem) {
return LLVMBuildSRem(g->builder, val1, val2, "");
} else {
LLVMValueRef a = LLVMBuildSRem(g->builder, val1, val2, "");
LLVMValueRef b = LLVMBuildNSWAdd(g->builder, a, val2, "");
LLVMValueRef c = LLVMBuildSRem(g->builder, b, val2, "");
LLVMValueRef ltz = LLVMBuildICmp(g->builder, LLVMIntSLT, val1, zero, "");
return LLVMBuildSelect(g->builder, ltz, c, a, "");
}
} else {
return LLVMBuildURem(g->builder, val1, val2, "");
}
@@ -1252,6 +1359,7 @@ static LLVMValueRef ir_render_bin_op(CodeGen *g, IrExecutable *executable,
case IrBinOpInvalid:
case IrBinOpArrayCat:
case IrBinOpArrayMult:
case IrBinOpRemUnspecified:
zig_unreachable();
case IrBinOpBoolOr:
return LLVMBuildOr(g->builder, op1_value, op2_value, "");
@@ -1367,10 +1475,18 @@ static LLVMValueRef ir_render_bin_op(CodeGen *g, IrExecutable *executable,
} else {
zig_unreachable();
}
case IrBinOpDiv:
return gen_div(g, want_debug_safety, op1_value, op2_value, type_entry, false);
case IrBinOpRem:
return gen_rem(g, want_debug_safety, op1_value, op2_value, type_entry);
case IrBinOpDivUnspecified:
return gen_div(g, want_debug_safety, op1_value, op2_value, type_entry, DivKindFloat);
case IrBinOpDivExact:
return gen_div(g, want_debug_safety, op1_value, op2_value, type_entry, DivKindExact);
case IrBinOpDivTrunc:
return gen_div(g, want_debug_safety, op1_value, op2_value, type_entry, DivKindTrunc);
case IrBinOpDivFloor:
return gen_div(g, want_debug_safety, op1_value, op2_value, type_entry, DivKindFloor);
case IrBinOpRemRem:
return gen_rem(g, want_debug_safety, op1_value, op2_value, type_entry, RemKindRem);
case IrBinOpRemMod:
return gen_rem(g, want_debug_safety, op1_value, op2_value, type_entry, RemKindMod);
}
zig_unreachable();
}
@@ -2353,14 +2469,6 @@ static LLVMValueRef ir_render_fence(CodeGen *g, IrExecutable *executable, IrInst
return nullptr;
}
static LLVMValueRef ir_render_div_exact(CodeGen *g, IrExecutable *executable, IrInstructionDivExact *instruction) {
LLVMValueRef op1_val = ir_llvm_value(g, instruction->op1);
LLVMValueRef op2_val = ir_llvm_value(g, instruction->op2);
bool want_debug_safety = ir_want_debug_safety(g, &instruction->base);
return gen_div(g, want_debug_safety, op1_val, op2_val, instruction->base.value.type, true);
}
static LLVMValueRef ir_render_truncate(CodeGen *g, IrExecutable *executable, IrInstructionTruncate *instruction) {
LLVMValueRef target_val = ir_llvm_value(g, instruction->target);
TypeTableEntry *dest_type = instruction->base.value.type;
@@ -2965,8 +3073,6 @@ static LLVMValueRef ir_render_instruction(CodeGen *g, IrExecutable *executable,
return ir_render_cmpxchg(g, executable, (IrInstructionCmpxchg *)instruction);
case IrInstructionIdFence:
return ir_render_fence(g, executable, (IrInstructionFence *)instruction);
case IrInstructionIdDivExact:
return ir_render_div_exact(g, executable, (IrInstructionDivExact *)instruction);
case IrInstructionIdTruncate:
return ir_render_truncate(g, executable, (IrInstructionTruncate *)instruction);
case IrInstructionIdBoolNot:
@@ -4320,7 +4426,6 @@ static void define_builtin_fns(CodeGen *g) {
create_builtin_fn(g, BuiltinFnIdEmbedFile, "embedFile", 1);
create_builtin_fn(g, BuiltinFnIdCmpExchange, "cmpxchg", 5);
create_builtin_fn(g, BuiltinFnIdFence, "fence", 1);
create_builtin_fn(g, BuiltinFnIdDivExact, "divExact", 2);
create_builtin_fn(g, BuiltinFnIdTruncate, "truncate", 2);
create_builtin_fn(g, BuiltinFnIdCompileErr, "compileError", 1);
create_builtin_fn(g, BuiltinFnIdCompileLog, "compileLog", SIZE_MAX);
@@ -4335,6 +4440,11 @@ static void define_builtin_fns(CodeGen *g) {
create_builtin_fn(g, BuiltinFnIdEnumTagName, "enumTagName", 1);
create_builtin_fn(g, BuiltinFnIdFieldParentPtr, "fieldParentPtr", 3);
create_builtin_fn(g, BuiltinFnIdOffsetOf, "offsetOf", 2);
create_builtin_fn(g, BuiltinFnIdDivExact, "divExact", 2);
create_builtin_fn(g, BuiltinFnIdDivTrunc, "divTrunc", 2);
create_builtin_fn(g, BuiltinFnIdDivFloor, "divFloor", 2);
create_builtin_fn(g, BuiltinFnIdRem, "rem", 2);
create_builtin_fn(g, BuiltinFnIdMod, "mod", 2);
}
static const char *bool_to_str(bool b) {