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Merge branch 'fixcomptimesat'

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Closes #10393
This commit is contained in:
Veikka Tuominen 2022-01-30 11:40:03 +02:00
commit 924eb08b61
6 changed files with 216 additions and 49 deletions
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36
src/Sema.zig
View File

@ -7474,7 +7474,10 @@ fn zirShl(
}
const val = switch (air_tag) {
.shl_exact => return sema.fail(block, lhs_src, "TODO implement Sema for comptime shl_exact", .{}),
.shl_sat => try lhs_val.shlSat(rhs_val, lhs_ty, sema.arena, sema.mod.getTarget()),
.shl_sat => if (lhs_ty.zigTypeTag() == .ComptimeInt)
try lhs_val.shl(rhs_val, sema.arena)
else
try lhs_val.shlSat(rhs_val, lhs_ty, sema.arena, sema.mod.getTarget()),
.shl => try lhs_val.shl(rhs_val, sema.arena),
else => unreachable,
};
@ -8189,10 +8192,12 @@ fn analyzeArithmetic(
return casted_lhs;
}
if (maybe_lhs_val) |lhs_val| {
return sema.addConstant(
scalar_type,
try lhs_val.intAddSat(rhs_val, scalar_type, sema.arena, target),
);
const val = if (scalar_tag == .ComptimeInt)
try lhs_val.intAdd(rhs_val, sema.arena)
else
try lhs_val.intAddSat(rhs_val, scalar_type, sema.arena, target);
return sema.addConstant(scalar_type, val);
} else break :rs .{ .src = lhs_src, .air_tag = .add_sat };
} else break :rs .{ .src = rhs_src, .air_tag = .add_sat };
},
@ -8280,10 +8285,12 @@ fn analyzeArithmetic(
return sema.addConstUndef(scalar_type);
}
if (maybe_rhs_val) |rhs_val| {
return sema.addConstant(
scalar_type,
try lhs_val.intSubSat(rhs_val, scalar_type, sema.arena, target),
);
const val = if (scalar_tag == .ComptimeInt)
try lhs_val.intSub(rhs_val, sema.arena)
else
try lhs_val.intSubSat(rhs_val, scalar_type, sema.arena, target);
return sema.addConstant(scalar_type, val);
} else break :rs .{ .src = rhs_src, .air_tag = .sub_sat };
} else break :rs .{ .src = lhs_src, .air_tag = .sub_sat };
},
@ -8663,10 +8670,13 @@ fn analyzeArithmetic(
if (lhs_val.isUndef()) {
return sema.addConstUndef(scalar_type);
}
return sema.addConstant(
scalar_type,
try lhs_val.intMulSat(rhs_val, scalar_type, sema.arena, target),
);
const val = if (scalar_tag == .ComptimeInt)
try lhs_val.intMul(rhs_val, sema.arena)
else
try lhs_val.intMulSat(rhs_val, scalar_type, sema.arena, target);
return sema.addConstant(scalar_type, val);
} else break :rs .{ .src = lhs_src, .air_tag = .mul_sat };
} else break :rs .{ .src = rhs_src, .air_tag = .mul_sat };
},

43
src/stage1/bigint.cpp
View File

@ -60,6 +60,9 @@ static void to_twos_complement(BigInt *dest, const BigInt *op, size_t bit_count)
bigint_init_unsigned(dest, 0);
return;
}
BigInt pos_op = {0};
if (op->is_negative) {
BigInt negated = {0};
bigint_negate(&negated, op);
@ -70,13 +73,14 @@ static void to_twos_complement(BigInt *dest, const BigInt *op, size_t bit_count)
BigInt one = {0};
bigint_init_unsigned(&one, 1);
bigint_add(dest, &inverted, &one);
return;
bigint_add(&pos_op, &inverted, &one);
} else {
bigint_init_bigint(&pos_op, op);
}
dest->is_negative = false;
const uint64_t *op_digits = bigint_ptr(op);
if (op->digit_count == 1) {
const uint64_t *op_digits = bigint_ptr(&pos_op);
if (pos_op.digit_count == 1) {
dest->data.digit = op_digits[0];
if (bit_count < 64) {
dest->data.digit &= (1ULL << bit_count) - 1;
@ -98,11 +102,11 @@ static void to_twos_complement(BigInt *dest, const BigInt *op, size_t bit_count)
}
dest->data.digits = heap::c_allocator.allocate_nonzero<uint64_t>(dest->digit_count);
for (size_t i = 0; i < digits_to_copy; i += 1) {
uint64_t digit = (i < op->digit_count) ? op_digits[i] : 0;
uint64_t digit = (i < pos_op.digit_count) ? op_digits[i] : 0;
dest->data.digits[i] = digit;
}
if (leftover_bits != 0) {
uint64_t digit = (digits_to_copy < op->digit_count) ? op_digits[digits_to_copy] : 0;
uint64_t digit = (digits_to_copy < pos_op.digit_count) ? op_digits[digits_to_copy] : 0;
dest->data.digits[digits_to_copy] = digit & ((1ULL << leftover_bits) - 1);
}
bigint_normalize(dest);
@ -469,18 +473,18 @@ void bigint_min(BigInt* dest, const BigInt *op1, const BigInt *op2) {
}
/// clamps op within bit_count/signedness boundaries
/// signed bounds are [-2^(bit_count-1)..2^(bit_count-1)-1]
/// unsigned bounds are [0..2^bit_count-1]
/// signed bounds are [-2^(bit_count-1)..2^(bit_count-1)-1]
/// unsigned bounds are [0..2^bit_count-1]
void bigint_clamp_by_bitcount(BigInt* dest, uint32_t bit_count, bool is_signed) {
// compute the number of bits required to store the value, and use that
// compute the number of bits required to store the value, and use that
// to decide whether to clamp the result
bool is_negative = dest->is_negative;
// to workaround the fact this bits_needed calculation would yield 65 or more for
// all negative numbers, set is_negative to false. this is a cheap way to find
// bits_needed(abs(dest)).
// to workaround the fact this bits_needed calculation would yield 65 or more for
// all negative numbers, set is_negative to false. this is a cheap way to find
// bits_needed(abs(dest)).
dest->is_negative = false;
// because we've set is_negative to false, we have to account for the extra bit here
// by adding 1 additional bit_needed when (is_negative && !is_signed).
// by adding 1 additional bit_needed when (is_negative && !is_signed).
size_t full_bits = dest->digit_count * 64;
size_t leading_zero_count = bigint_clz(dest, full_bits);
size_t bits_needed = full_bits - leading_zero_count + (is_negative && !is_signed);
@ -491,7 +495,7 @@ void bigint_clamp_by_bitcount(BigInt* dest, uint32_t bit_count, bool is_signed)
bigint_init_unsigned(&one, 1);
BigInt bit_count_big;
bigint_init_unsigned(&bit_count_big, bit_count);
if(is_signed) {
if(is_negative) {
BigInt bound;
@ -639,25 +643,22 @@ void bigint_add(BigInt *dest, const BigInt *op1, const BigInt *op2) {
size_t i = 1;
for (;;) {
bool found_digit = false;
uint64_t x = bigger_op_digits[i];
uint64_t prev_overflow = overflow;
overflow = 0;
if (i < smaller_op->digit_count) {
found_digit = true;
uint64_t digit = smaller_op_digits[i];
overflow += sub_u64_overflow(x, digit, &x);
}
if (sub_u64_overflow(x, prev_overflow, &x)) {
found_digit = true;
overflow += 1;
}
overflow += sub_u64_overflow(x, prev_overflow, &x);
dest->data.digits[i] = x;
i += 1;
if (!found_digit || i >= bigger_op->digit_count)
if (i >= bigger_op->digit_count) {
break;
}
}
assert(overflow == 0);
dest->digit_count = i;

38
src/stage1/ir.cpp
View File

@ -10230,13 +10230,7 @@ static Stage1AirInst *ir_analyze_bit_shift(IrAnalyze *ira, Stage1ZirInstBinOp *b
// comptime_int has no finite bit width
casted_op2 = op2;
if (op_id == IrBinOpShlSat) {
ir_add_error_node(ira, bin_op_instruction->base.source_node,
buf_sprintf("saturating shift on a comptime_int which has unlimited bits"));
return ira->codegen->invalid_inst_gen;
}
if (op_id == IrBinOpBitShiftLeftLossy) {
if (op_id == IrBinOpBitShiftLeftLossy || op_id == IrBinOpShlSat) {
op_id = IrBinOpBitShiftLeftExact;
}
@ -10398,6 +10392,25 @@ static bool ok_float_op(IrBinOp op) {
zig_unreachable();
}
static IrBinOp map_comptime_arithmetic_op(IrBinOp op) {
switch (op) {
case IrBinOpAddWrap:
case IrBinOpAddSat:
return IrBinOpAdd;
case IrBinOpSubWrap:
case IrBinOpSubSat:
return IrBinOpSub;
case IrBinOpMultWrap:
case IrBinOpMultSat:
return IrBinOpMult;
default:
return op;
}
}
static bool is_pointer_arithmetic_allowed(ZigType *lhs_type, IrBinOp op) {
switch (op) {
case IrBinOpAdd:
@ -10620,15 +10633,10 @@ static Stage1AirInst *ir_analyze_bin_op_math(IrAnalyze *ira, Stage1ZirInstBinOp
if (type_is_invalid(casted_op2->value->type))
return ira->codegen->invalid_inst_gen;
// Comptime integers have no fixed size
// Comptime integers have no fixed size, so wrapping or saturating operations should be mapped
// to their non wrapping or saturating equivalents
if (scalar_type->id == ZigTypeIdComptimeInt) {
if (op_id == IrBinOpAddWrap) {
op_id = IrBinOpAdd;
} else if (op_id == IrBinOpSubWrap) {
op_id = IrBinOpSub;
} else if (op_id == IrBinOpMultWrap) {
op_id = IrBinOpMult;
}
op_id = map_comptime_arithmetic_op(op_id);
}
if (instr_is_comptime(casted_op1) && instr_is_comptime(casted_op2)) {

12
src/value.zig
View File

@ -2275,6 +2275,10 @@ pub const Value = extern union {
) !Value {
if (lhs.isUndef() or rhs.isUndef()) return Value.initTag(.undef);
if (ty.zigTypeTag() == .ComptimeInt) {
return intAdd(lhs, rhs, arena);
}
if (ty.isAnyFloat()) {
return floatAdd(lhs, rhs, ty, arena);
}
@ -2361,6 +2365,10 @@ pub const Value = extern union {
) !Value {
if (lhs.isUndef() or rhs.isUndef()) return Value.initTag(.undef);
if (ty.zigTypeTag() == .ComptimeInt) {
return intSub(lhs, rhs, arena);
}
if (ty.isAnyFloat()) {
return floatSub(lhs, rhs, ty, arena);
}
@ -2440,6 +2448,10 @@ pub const Value = extern union {
) !Value {
if (lhs.isUndef() or rhs.isUndef()) return Value.initTag(.undef);
if (ty.zigTypeTag() == .ComptimeInt) {
return intMul(lhs, rhs, arena);
}
if (ty.isAnyFloat()) {
return floatMul(lhs, rhs, ty, arena);
}

26
test/behavior/saturating_arithmetic.zig
View File

@ -29,8 +29,14 @@ test "saturating add" {
try expect(x == expected);
}
};
try S.doTheTest();
comptime try S.doTheTest();
comptime try S.testSatAdd(comptime_int, 0, 0, 0);
comptime try S.testSatAdd(comptime_int, 3, 2, 5);
comptime try S.testSatAdd(comptime_int, 651075816498665588400716961808225370057, 468229432685078038144554201546849378455, 1119305249183743626545271163355074748512);
comptime try S.testSatAdd(comptime_int, 7, -593423721213448152027139550640105366508, -593423721213448152027139550640105366501);
}
test "saturating subtraction" {
@ -56,8 +62,14 @@ test "saturating subtraction" {
try expect(x == expected);
}
};
try S.doTheTest();
comptime try S.doTheTest();
comptime try S.testSatSub(comptime_int, 0, 0, 0);
comptime try S.testSatSub(comptime_int, 3, 2, 1);
comptime try S.testSatSub(comptime_int, 651075816498665588400716961808225370057, 468229432685078038144554201546849378455, 182846383813587550256162760261375991602);
comptime try S.testSatSub(comptime_int, 7, -593423721213448152027139550640105366508, 593423721213448152027139550640105366515);
}
test "saturating multiplication" {
@ -90,6 +102,11 @@ test "saturating multiplication" {
try S.doTheTest();
comptime try S.doTheTest();
comptime try S.testSatMul(comptime_int, 0, 0, 0);
comptime try S.testSatMul(comptime_int, 3, 2, 6);
comptime try S.testSatMul(comptime_int, 651075816498665588400716961808225370057, 468229432685078038144554201546849378455, 304852860194144160265083087140337419215516305999637969803722975979232817921935);
comptime try S.testSatMul(comptime_int, 7, -593423721213448152027139550640105366508, -4153966048494137064189976854480737565556);
}
test "saturating shift-left" {
@ -107,6 +124,7 @@ test "saturating shift-left" {
try testSatShl(u8, 1, 2, 4);
try testSatShl(u8, 255, 1, 255);
}
fn testSatShl(comptime T: type, lhs: T, rhs: T, expected: T) !void {
try expect((lhs <<| rhs) == expected);
@ -115,8 +133,14 @@ test "saturating shift-left" {
try expect(x == expected);
}
};
try S.doTheTest();
comptime try S.doTheTest();
comptime try S.testSatShl(comptime_int, 0, 0, 0);
comptime try S.testSatShl(comptime_int, 1, 2, 4);
comptime try S.testSatShl(comptime_int, 13, 150, 18554220005177478453757717602843436772975706112);
comptime try S.testSatShl(comptime_int, -582769, 180, -893090893854873184096635538665358532628308979495815656505344);
}
test "saturating shl uses the LHS type" {
@ -139,4 +163,6 @@ test "saturating shl uses the LHS type" {
try expect((@as(u8, 1) <<| 8) == 255);
try expect((@as(u8, 1) <<| rhs_const) == 255);
try expect((@as(u8, 1) <<| rhs_var) == 255);
try expect((1 <<| @as(u8, 200)) == 1606938044258990275541962092341162602522202993782792835301376);
}

110
test/behavior/wrapping_arithmetic.zig Normal file
View File

@ -0,0 +1,110 @@
const std = @import("std");
const builtin = @import("builtin");
const minInt = std.math.minInt;
const maxInt = std.math.maxInt;
const expect = std.testing.expect;
test "wrapping add" {
const S = struct {
fn doTheTest() !void {
try testWrapAdd(i8, -3, 10, 7);
try testWrapAdd(i8, -128, -128, 0);
try testWrapAdd(i2, 1, 1, -2);
try testWrapAdd(i64, maxInt(i64), 1, minInt(i64));
try testWrapAdd(i128, maxInt(i128), -maxInt(i128), 0);
try testWrapAdd(i128, minInt(i128), maxInt(i128), -1);
try testWrapAdd(i8, 127, 127, -2);
try testWrapAdd(u8, 3, 10, 13);
try testWrapAdd(u8, 255, 255, 254);
try testWrapAdd(u2, 3, 2, 1);
try testWrapAdd(u3, 7, 1, 0);
try testWrapAdd(u128, maxInt(u128), 1, minInt(u128));
}
fn testWrapAdd(comptime T: type, lhs: T, rhs: T, expected: T) !void {
try expect((lhs +% rhs) == expected);
var x = lhs;
x +%= rhs;
try expect(x == expected);
}
};
try S.doTheTest();
comptime try S.doTheTest();
comptime try S.testWrapAdd(comptime_int, 0, 0, 0);
comptime try S.testWrapAdd(comptime_int, 3, 2, 5);
comptime try S.testWrapAdd(comptime_int, 651075816498665588400716961808225370057, 468229432685078038144554201546849378455, 1119305249183743626545271163355074748512);
comptime try S.testWrapAdd(comptime_int, 7, -593423721213448152027139550640105366508, -593423721213448152027139550640105366501);
}
test "wrapping subtraction" {
const S = struct {
fn doTheTest() !void {
try testWrapSub(i8, -3, 10, -13);
try testWrapSub(i8, -128, -128, 0);
try testWrapSub(i8, -1, 127, -128);
try testWrapSub(i64, minInt(i64), 1, maxInt(i64));
try testWrapSub(i128, maxInt(i128), -1, minInt(i128));
try testWrapSub(i128, minInt(i128), -maxInt(i128), -1);
try testWrapSub(u8, 10, 3, 7);
try testWrapSub(u8, 0, 255, 1);
try testWrapSub(u5, 0, 31, 1);
try testWrapSub(u128, 0, maxInt(u128), 1);
}
fn testWrapSub(comptime T: type, lhs: T, rhs: T, expected: T) !void {
try expect((lhs -% rhs) == expected);
var x = lhs;
x -%= rhs;
try expect(x == expected);
}
};
try S.doTheTest();
comptime try S.doTheTest();
comptime try S.testWrapSub(comptime_int, 0, 0, 0);
comptime try S.testWrapSub(comptime_int, 3, 2, 1);
comptime try S.testWrapSub(comptime_int, 651075816498665588400716961808225370057, 468229432685078038144554201546849378455, 182846383813587550256162760261375991602);
comptime try S.testWrapSub(comptime_int, 7, -593423721213448152027139550640105366508, 593423721213448152027139550640105366515);
}
test "wrapping multiplication" {
// TODO: once #9660 has been solved, remove this line
if (builtin.cpu.arch == .wasm32) return error.SkipZigTest;
const S = struct {
fn doTheTest() !void {
try testWrapMul(i8, -3, 10, -30);
try testWrapMul(i4, 2, 4, -8);
try testWrapMul(i8, 2, 127, -2);
try testWrapMul(i8, -128, -128, 0);
try testWrapMul(i8, maxInt(i8), maxInt(i8), 1);
try testWrapMul(i16, maxInt(i16), -1, minInt(i16) + 1);
try testWrapMul(i128, maxInt(i128), -1, minInt(i128) + 1);
try testWrapMul(i128, minInt(i128), -1, minInt(i128));
try testWrapMul(u8, 10, 3, 30);
try testWrapMul(u8, 2, 255, 254);
try testWrapMul(u128, maxInt(u128), maxInt(u128), 1);
}
fn testWrapMul(comptime T: type, lhs: T, rhs: T, expected: T) !void {
try expect((lhs *% rhs) == expected);
var x = lhs;
x *%= rhs;
try expect(x == expected);
}
};
try S.doTheTest();
comptime try S.doTheTest();
comptime try S.testWrapMul(comptime_int, 0, 0, 0);
comptime try S.testWrapMul(comptime_int, 3, 2, 6);
comptime try S.testWrapMul(comptime_int, 651075816498665588400716961808225370057, 468229432685078038144554201546849378455, 304852860194144160265083087140337419215516305999637969803722975979232817921935);
comptime try S.testWrapMul(comptime_int, 7, -593423721213448152027139550640105366508, -4153966048494137064189976854480737565556);
}