Commit 6a98bf3dba

Andrew Kelley <superjoe30@gmail.com>
2017-08-17 01:07:35
compiler_rt implementations for __fixuns* functions
* add u128 and i128 integer types * add f128 floating point type * implement big integer multiplication (See #405)
1 parent cf46cd5
src/all_types.hpp
@@ -1386,7 +1386,7 @@ struct CodeGen {
 
     struct {
         TypeTableEntry *entry_bool;
-        TypeTableEntry *entry_int[2][4]; // [signed,unsigned][8,16,32,64]
+        TypeTableEntry *entry_int[2][5]; // [signed,unsigned][8,16,32,64,128]
         TypeTableEntry *entry_c_int[CIntTypeCount];
         TypeTableEntry *entry_c_longdouble;
         TypeTableEntry *entry_c_void;
@@ -1394,14 +1394,17 @@ struct CodeGen {
         TypeTableEntry *entry_u16;
         TypeTableEntry *entry_u32;
         TypeTableEntry *entry_u64;
+        TypeTableEntry *entry_u128;
         TypeTableEntry *entry_i8;
         TypeTableEntry *entry_i16;
         TypeTableEntry *entry_i32;
         TypeTableEntry *entry_i64;
+        TypeTableEntry *entry_i128;
         TypeTableEntry *entry_isize;
         TypeTableEntry *entry_usize;
         TypeTableEntry *entry_f32;
         TypeTableEntry *entry_f64;
+        TypeTableEntry *entry_f128;
         TypeTableEntry *entry_void;
         TypeTableEntry *entry_unreachable;
         TypeTableEntry *entry_type;
src/analyze.cpp
@@ -3085,6 +3085,8 @@ TypeTableEntry **get_int_type_ptr(CodeGen *g, bool is_signed, uint32_t size_in_b
         index = 2;
     } else if (size_in_bits == 64) {
         index = 3;
+    } else if (size_in_bits == 128) {
+        index = 4;
     } else {
         return nullptr;
     }
src/bigint.cpp
@@ -373,7 +373,6 @@ void bigint_add(BigInt *dest, const BigInt *op1, const BigInt *op2) {
             bigint_normalize(dest);
             return;
         }
-        // TODO this code path is untested
         size_t i = 1;
         uint64_t first_digit = dest->data.digit;
         dest->data.digits = allocate_nonzero<uint64_t>(max(op1->digit_count, op2->digit_count) + 1);
@@ -397,17 +396,14 @@ void bigint_add(BigInt *dest, const BigInt *op1, const BigInt *op2) {
             }
 
             dest->data.digits[i] = x;
-            x += 1;
+            i += 1;
 
             if (!found_digit) {
-                break;
+                dest->digit_count = i;
+                bigint_normalize(dest);
+                return;
             }
         }
-        if (overflow > 0) {
-            dest->data.digits[i] = overflow;
-        }
-        bigint_normalize(dest);
-        return;
     }
     const BigInt *op_pos;
     const BigInt *op_neg;
@@ -500,12 +496,49 @@ static void mul_overflow(uint64_t x, uint64_t y, uint64_t *result, uint64_t *car
         *carry = 0;
         return;
     }
-    zig_panic("TODO bigint_mul with big numbers");
 
-    //unsigned __int128 big_x = x;
-    //unsigned __int128 big_y = y;
-    //unsigned __int128 big_result = big_x * big_y;
-    //*carry = big_result >> 64;
+    unsigned __int128 big_x = x;
+    unsigned __int128 big_y = y;
+    unsigned __int128 big_result = big_x * big_y;
+    *carry = big_result >> 64;
+}
+
+static void mul_scalar(BigInt *dest, const BigInt *op, uint64_t scalar) {
+    bigint_init_unsigned(dest, 0);
+
+    BigInt bi_64;
+    bigint_init_unsigned(&bi_64, 64);
+
+    const uint64_t *op_digits = bigint_ptr(op);
+    size_t i = op->digit_count - 1;
+
+    for (;;) {
+        BigInt shifted;
+        bigint_shl(&shifted, dest, &bi_64);
+
+        uint64_t result_scalar;
+        uint64_t carry_scalar;
+        mul_overflow(scalar, op_digits[i], &result_scalar, &carry_scalar);
+
+        BigInt result;
+        bigint_init_unsigned(&result, result_scalar);
+
+        BigInt carry;
+        bigint_init_unsigned(&carry, carry_scalar);
+
+        BigInt carry_shifted;
+        bigint_shl(&carry_shifted, &carry, &bi_64);
+
+        BigInt tmp;
+        bigint_add(&tmp, &shifted, &carry_shifted);
+
+        bigint_add(dest, &tmp, &result);
+
+        if (i == 0) {
+            break;
+        }
+        i -= 1;
+    }
 }
 
 void bigint_mul(BigInt *dest, const BigInt *op1, const BigInt *op2) {
@@ -523,7 +556,30 @@ void bigint_mul(BigInt *dest, const BigInt *op1, const BigInt *op2) {
         bigint_normalize(dest);
         return;
     }
-    zig_panic("TODO bigint_mul with big numbers");
+
+    bigint_init_unsigned(dest, 0);
+
+    BigInt bi_64;
+    bigint_init_unsigned(&bi_64, 64);
+
+    size_t i = op2->digit_count - 1;
+    for (;;) {
+        BigInt shifted;
+        bigint_shl(&shifted, dest, &bi_64);
+
+        BigInt scalar_result;
+        mul_scalar(&scalar_result, op1, op2_digits[i]);
+
+        bigint_add(dest, &scalar_result, &shifted);
+
+        if (i == 0) {
+            break;
+        }
+        i -= 1;
+    }
+
+    dest->is_negative = (op1->is_negative != op2->is_negative);
+    bigint_normalize(dest);
 }
 
 void bigint_mul_wrap(BigInt *dest, const BigInt *op1, const BigInt *op2, size_t bit_count, bool is_signed) {
src/codegen.cpp
@@ -4208,6 +4208,7 @@ static const uint8_t int_sizes_in_bits[] = {
     16,
     32,
     64,
+    128,
 };
 
 struct CIntTypeInfo {
@@ -4390,6 +4391,19 @@ static void define_builtin_types(CodeGen *g) {
         g->builtin_types.entry_f64 = entry;
         g->primitive_type_table.put(&entry->name, entry);
     }
+    {
+        TypeTableEntry *entry = new_type_table_entry(TypeTableEntryIdFloat);
+        entry->type_ref = LLVMFP128Type();
+        buf_init_from_str(&entry->name, "f128");
+        entry->data.floating.bit_count = 128;
+
+        uint64_t debug_size_in_bits = 8*LLVMStoreSizeOfType(g->target_data_ref, entry->type_ref);
+        entry->di_type = ZigLLVMCreateDebugBasicType(g->dbuilder, buf_ptr(&entry->name),
+                debug_size_in_bits,
+                ZigLLVMEncoding_DW_ATE_float());
+        g->builtin_types.entry_f128 = entry;
+        g->primitive_type_table.put(&entry->name, entry);
+    }
     {
         TypeTableEntry *entry = new_type_table_entry(TypeTableEntryIdFloat);
         entry->type_ref = LLVMX86FP80Type();
@@ -4435,10 +4449,12 @@ static void define_builtin_types(CodeGen *g) {
     g->builtin_types.entry_u16 = get_int_type(g, false, 16);
     g->builtin_types.entry_u32 = get_int_type(g, false, 32);
     g->builtin_types.entry_u64 = get_int_type(g, false, 64);
+    g->builtin_types.entry_u128 = get_int_type(g, false, 128);
     g->builtin_types.entry_i8 = get_int_type(g, true, 8);
     g->builtin_types.entry_i16 = get_int_type(g, true, 16);
     g->builtin_types.entry_i32 = get_int_type(g, true, 32);
     g->builtin_types.entry_i64 = get_int_type(g, true, 64);
+    g->builtin_types.entry_i128 = get_int_type(g, true, 128);
 
     {
         g->builtin_types.entry_c_void = get_opaque_type(g, nullptr, nullptr, "c_void");
std/special/compiler_rt/fixuint.zig
@@ -0,0 +1,50 @@
+pub fn fixuint(comptime fp_t: type, comptime fixuint_t: type, a: fp_t) -> fixuint_t {
+    @setDebugSafety(this, true); // TODO
+
+    const rep_t = switch (fp_t) {
+        f32 => u32,
+        f64 => u64,
+        f128 => u128,
+        else => unreachable,
+    };
+    const srep_t = @IntType(true, rep_t.bit_count);
+    const significandBits = switch (fp_t) {
+        f32 => 23,
+        f64 => 52,
+        f128 => 112,
+        else => unreachable,
+    };
+    const typeWidth = rep_t.bit_count;
+    const exponentBits = (typeWidth - significandBits - 1);
+    const signBit = (rep_t(1) << (significandBits + exponentBits));
+    const maxExponent = ((1 << exponentBits) - 1);
+    const exponentBias = (maxExponent >> 1);
+
+    const implicitBit = (rep_t(1) << significandBits);
+    const significandMask = (implicitBit - 1);
+
+    // Break a into sign, exponent, significand
+    const aRep: rep_t = @bitCast(rep_t, a);
+    const absMask = signBit - 1;
+    const aAbs: rep_t = aRep & absMask;
+
+    const sign = if ((aRep & signBit) != 0) i32(-1) else i32(1);
+    const exponent = i32(aAbs >> significandBits) - exponentBias;
+    const significand: rep_t = (aAbs & significandMask) | implicitBit;
+
+    // If either the value or the exponent is negative, the result is zero.
+    if (sign == -1 or exponent < 0)
+        return 0;
+
+    // If the value is too large for the integer type, saturate.
+    if (c_uint(exponent) >= fixuint_t.bit_count)
+        return ~fixuint_t(0);
+
+    // If 0 <= exponent < significandBits, right shift to get the result.
+    // Otherwise, shift left.
+    if (exponent < significandBits) {
+        return fixuint_t(significand >> rep_t(significandBits - exponent));
+    } else {
+        return fixuint_t(significand) << fixuint_t(exponent - significandBits);
+    }
+}
std/special/compiler_rt/fixunsdfdi.zig
@@ -0,0 +1,10 @@
+const fixuint = @import("fixuint.zig").fixuint;
+
+export fn __fixunsdfdi(a: f64) -> u64 {
+    return fixuint(f64, u64, a);
+}
+
+test "import fixunsdfdi" {
+    _ = @import("fixunsdfdi_test.zig");
+}
+
std/special/compiler_rt/fixunsdfdi_test.zig
@@ -0,0 +1,39 @@
+const __fixunsdfdi = @import("fixunsdfdi.zig").__fixunsdfdi;
+const assert = @import("../../debug.zig").assert;
+
+fn test__fixunsdfdi(a: f64, expected: u64) {
+    const x = __fixunsdfdi(a);
+    assert(x == expected);
+}
+
+test "fixunsdfdi" {
+    test__fixunsdfdi(0.0, 0);
+    test__fixunsdfdi(0.5, 0);
+    test__fixunsdfdi(0.99, 0);
+    test__fixunsdfdi(1.0, 1);
+    test__fixunsdfdi(1.5, 1);
+    test__fixunsdfdi(1.99, 1);
+    test__fixunsdfdi(2.0, 2);
+    test__fixunsdfdi(2.01, 2);
+    test__fixunsdfdi(-0.5, 0);
+    test__fixunsdfdi(-0.99, 0);
+    test__fixunsdfdi(-1.0, 0);
+    test__fixunsdfdi(-1.5, 0);
+    test__fixunsdfdi(-1.99, 0);
+    test__fixunsdfdi(-2.0, 0);
+    test__fixunsdfdi(-2.01, 0);
+
+    test__fixunsdfdi(0x1.FFFFFEp+62, 0x7FFFFF8000000000);
+    test__fixunsdfdi(0x1.FFFFFCp+62, 0x7FFFFF0000000000);
+
+    test__fixunsdfdi(-0x1.FFFFFEp+62, 0);
+    test__fixunsdfdi(-0x1.FFFFFCp+62, 0);
+
+    test__fixunsdfdi(0x1.FFFFFFFFFFFFFp+63, 0xFFFFFFFFFFFFF800);
+    test__fixunsdfdi(0x1.0000000000000p+63, 0x8000000000000000);
+    test__fixunsdfdi(0x1.FFFFFFFFFFFFFp+62, 0x7FFFFFFFFFFFFC00);
+    test__fixunsdfdi(0x1.FFFFFFFFFFFFEp+62, 0x7FFFFFFFFFFFF800);
+
+    test__fixunsdfdi(-0x1.FFFFFFFFFFFFFp+62, 0);
+    test__fixunsdfdi(-0x1.FFFFFFFFFFFFEp+62, 0);
+}
std/special/compiler_rt/fixunsdfsi.zig
@@ -0,0 +1,10 @@
+const fixuint = @import("fixuint.zig").fixuint;
+
+export fn __fixunsdfsi(a: f64) -> u32 {
+    return fixuint(f64, u32, a);
+}
+
+test "import fixunsdfsi" {
+    _ = @import("fixunsdfsi_test.zig");
+}
+
std/special/compiler_rt/fixunsdfsi_test.zig
@@ -0,0 +1,39 @@
+const __fixunsdfsi = @import("fixunsdfsi.zig").__fixunsdfsi;
+const assert = @import("../../debug.zig").assert;
+
+fn test__fixunsdfsi(a: f64, expected: u32) {
+    const x = __fixunsdfsi(a);
+    assert(x == expected);
+}
+
+test "fixunsdfsi" {
+    test__fixunsdfsi(0.0, 0);
+
+    test__fixunsdfsi(0.5, 0);
+    test__fixunsdfsi(0.99, 0);
+    test__fixunsdfsi(1.0, 1);
+    test__fixunsdfsi(1.5, 1);
+    test__fixunsdfsi(1.99, 1);
+    test__fixunsdfsi(2.0, 2);
+    test__fixunsdfsi(2.01, 2);
+    test__fixunsdfsi(-0.5, 0);
+    test__fixunsdfsi(-0.99, 0);
+    test__fixunsdfsi(-1.0, 0);
+    test__fixunsdfsi(-1.5, 0);
+    test__fixunsdfsi(-1.99, 0);
+    test__fixunsdfsi(-2.0, 0);
+    test__fixunsdfsi(-2.01, 0);
+
+    test__fixunsdfsi(0x1.000000p+31, 0x80000000);
+    test__fixunsdfsi(0x1.000000p+32, 0xFFFFFFFF);
+    test__fixunsdfsi(0x1.FFFFFEp+31, 0xFFFFFF00);
+    test__fixunsdfsi(0x1.FFFFFEp+30, 0x7FFFFF80);
+    test__fixunsdfsi(0x1.FFFFFCp+30, 0x7FFFFF00);
+
+    test__fixunsdfsi(-0x1.FFFFFEp+30, 0);
+    test__fixunsdfsi(-0x1.FFFFFCp+30, 0);
+
+    test__fixunsdfsi(0x1.FFFFFFFEp+31, 0xFFFFFFFF);
+    test__fixunsdfsi(0x1.FFFFFFFC00000p+30, 0x7FFFFFFF);
+    test__fixunsdfsi(0x1.FFFFFFF800000p+30, 0x7FFFFFFE);
+}
std/special/compiler_rt/fixunsdfti.zig
@@ -0,0 +1,9 @@
+const fixuint = @import("fixuint.zig").fixuint;
+
+export fn __fixunsdfti(a: f64) -> u128 {
+    return fixuint(f64, u128, a);
+}
+
+test "import fixunsdfti" {
+    _ = @import("fixunsdfti_test.zig");
+}
std/special/compiler_rt/fixunsdfti_test.zig
@@ -0,0 +1,47 @@
+const __fixunsdfti = @import("fixunsdfti.zig").__fixunsdfti;
+const assert = @import("../../debug.zig").assert;
+
+fn test__fixunsdfti(a: f64, expected: u128) {
+    const x = __fixunsdfti(a);
+    assert(x == expected);
+}
+
+test "fixunsdfti" {
+    test__fixunsdfti(0.0, 0);
+
+    test__fixunsdfti(0.5, 0);
+    test__fixunsdfti(0.99, 0);
+    test__fixunsdfti(1.0, 1);
+    test__fixunsdfti(1.5, 1);
+    test__fixunsdfti(1.99, 1);
+    test__fixunsdfti(2.0, 2);
+    test__fixunsdfti(2.01, 2);
+    test__fixunsdfti(-0.5, 0);
+    test__fixunsdfti(-0.99, 0);
+    test__fixunsdfti(-1.0, 0);
+    test__fixunsdfti(-1.5, 0);
+    test__fixunsdfti(-1.99, 0);
+    test__fixunsdfti(-2.0, 0);
+    test__fixunsdfti(-2.01, 0);
+
+    test__fixunsdfti(0x1.FFFFFEp+62, 0x7FFFFF8000000000);
+    test__fixunsdfti(0x1.FFFFFCp+62, 0x7FFFFF0000000000);
+
+    test__fixunsdfti(-0x1.FFFFFEp+62, 0);
+    test__fixunsdfti(-0x1.FFFFFCp+62, 0);
+
+    test__fixunsdfti(0x1.FFFFFFFFFFFFFp+63, 0xFFFFFFFFFFFFF800);
+    test__fixunsdfti(0x1.0000000000000p+63, 0x8000000000000000);
+    test__fixunsdfti(0x1.FFFFFFFFFFFFFp+62, 0x7FFFFFFFFFFFFC00);
+    test__fixunsdfti(0x1.FFFFFFFFFFFFEp+62, 0x7FFFFFFFFFFFF800);
+
+    test__fixunsdfti(0x1.FFFFFFFFFFFFFp+127, 0xFFFFFFFFFFFFF8000000000000000000);
+    test__fixunsdfti(0x1.0000000000000p+127, 0x80000000000000000000000000000000);
+    test__fixunsdfti(0x1.FFFFFFFFFFFFFp+126, 0x7FFFFFFFFFFFFC000000000000000000);
+    test__fixunsdfti(0x1.FFFFFFFFFFFFEp+126, 0x7FFFFFFFFFFFF8000000000000000000);
+    test__fixunsdfti(0x1.0000000000000p+128, 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF);
+
+    test__fixunsdfti(-0x1.FFFFFFFFFFFFFp+62, 0);
+    test__fixunsdfti(-0x1.FFFFFFFFFFFFEp+62, 0);
+}
+
std/special/compiler_rt/fixunssfdi.zig
@@ -0,0 +1,9 @@
+const fixuint = @import("fixuint.zig").fixuint;
+
+export fn __fixunssfdi(a: f32) -> u64 {
+    return fixuint(f32, u64, a);
+}
+
+test "import fixunssfdi" {
+    _ = @import("fixunssfdi_test.zig");
+}
std/special/compiler_rt/fixunssfdi_test.zig
@@ -0,0 +1,35 @@
+const __fixunssfdi = @import("fixunssfdi.zig").__fixunssfdi;
+const assert = @import("../../debug.zig").assert;
+
+fn test__fixunssfdi(a: f32, expected: u64) {
+    const x = __fixunssfdi(a);
+    assert(x == expected);
+}
+
+test "fixunssfdi" {
+    test__fixunssfdi(0.0, 0);
+
+    test__fixunssfdi(0.5, 0);
+    test__fixunssfdi(0.99, 0);
+    test__fixunssfdi(1.0, 1);
+    test__fixunssfdi(1.5, 1);
+    test__fixunssfdi(1.99, 1);
+    test__fixunssfdi(2.0, 2);
+    test__fixunssfdi(2.01, 2);
+    test__fixunssfdi(-0.5, 0);
+    test__fixunssfdi(-0.99, 0);
+
+    test__fixunssfdi(-1.0, 0);
+    test__fixunssfdi(-1.5, 0);
+    test__fixunssfdi(-1.99, 0);
+    test__fixunssfdi(-2.0, 0);
+    test__fixunssfdi(-2.01, 0);
+
+    test__fixunssfdi(0x1.FFFFFEp+63, 0xFFFFFF0000000000);
+    test__fixunssfdi(0x1.000000p+63, 0x8000000000000000);
+    test__fixunssfdi(0x1.FFFFFEp+62, 0x7FFFFF8000000000);
+    test__fixunssfdi(0x1.FFFFFCp+62, 0x7FFFFF0000000000);
+
+    test__fixunssfdi(-0x1.FFFFFEp+62, 0x0000000000000000);
+    test__fixunssfdi(-0x1.FFFFFCp+62, 0x0000000000000000);
+}
std/special/compiler_rt/fixunssfsi.zig
@@ -0,0 +1,9 @@
+const fixuint = @import("fixuint.zig").fixuint;
+
+export fn __fixunssfsi(a: f32) -> u32 {
+    return fixuint(f32, u32, a);
+}
+
+test "import fixunssfsi" {
+    _ = @import("fixunssfsi_test.zig");
+}
std/special/compiler_rt/fixunssfsi_test.zig
@@ -0,0 +1,36 @@
+const __fixunssfsi = @import("fixunssfsi.zig").__fixunssfsi;
+const assert = @import("../../debug.zig").assert;
+
+fn test__fixunssfsi(a: f32, expected: u32) {
+    const x = __fixunssfsi(a);
+    assert(x == expected);
+}
+
+test "fixunssfsi" {
+    test__fixunssfsi(0.0, 0);
+
+    test__fixunssfsi(0.5, 0);
+    test__fixunssfsi(0.99, 0);
+    test__fixunssfsi(1.0, 1);
+    test__fixunssfsi(1.5, 1);
+    test__fixunssfsi(1.99, 1);
+    test__fixunssfsi(2.0, 2);
+    test__fixunssfsi(2.01, 2);
+    test__fixunssfsi(-0.5, 0);
+    test__fixunssfsi(-0.99, 0);
+
+    test__fixunssfsi(-1.0, 0);
+    test__fixunssfsi(-1.5, 0);
+    test__fixunssfsi(-1.99, 0);
+    test__fixunssfsi(-2.0, 0);
+    test__fixunssfsi(-2.01, 0);
+
+    test__fixunssfsi(0x1.000000p+31, 0x80000000);
+    test__fixunssfsi(0x1.000000p+32, 0xFFFFFFFF);
+    test__fixunssfsi(0x1.FFFFFEp+31, 0xFFFFFF00);
+    test__fixunssfsi(0x1.FFFFFEp+30, 0x7FFFFF80);
+    test__fixunssfsi(0x1.FFFFFCp+30, 0x7FFFFF00);
+
+    test__fixunssfsi(-0x1.FFFFFEp+30, 0);
+    test__fixunssfsi(-0x1.FFFFFCp+30, 0);
+}
std/special/compiler_rt/fixunssfti.zig
@@ -0,0 +1,10 @@
+const fixuint = @import("fixuint.zig").fixuint;
+
+export fn __fixunssfti(a: f32) -> u128 {
+    return fixuint(f32, u128, a);
+}
+
+test "import fixunssfti" {
+    _ = @import("fixunssfti_test.zig");
+}
+
std/special/compiler_rt/fixunssfti_test.zig
@@ -0,0 +1,41 @@
+const __fixunssfti = @import("fixunssfti.zig").__fixunssfti;
+const assert = @import("../../debug.zig").assert;
+
+fn test__fixunssfti(a: f32, expected: u128) {
+    const x = __fixunssfti(a);
+    assert(x == expected);
+}
+
+test "fixunssfti" {
+    test__fixunssfti(0.0, 0);
+
+    test__fixunssfti(0.5, 0);
+    test__fixunssfti(0.99, 0);
+    test__fixunssfti(1.0, 1);
+    test__fixunssfti(1.5, 1);
+    test__fixunssfti(1.99, 1);
+    test__fixunssfti(2.0, 2);
+    test__fixunssfti(2.01, 2);
+    test__fixunssfti(-0.5, 0);
+    test__fixunssfti(-0.99, 0);
+
+    test__fixunssfti(-1.0, 0);
+    test__fixunssfti(-1.5, 0);
+    test__fixunssfti(-1.99, 0);
+    test__fixunssfti(-2.0, 0);
+    test__fixunssfti(-2.01, 0);
+
+    test__fixunssfti(0x1.FFFFFEp+63, 0xFFFFFF0000000000);
+    test__fixunssfti(0x1.000000p+63, 0x8000000000000000);
+    test__fixunssfti(0x1.FFFFFEp+62, 0x7FFFFF8000000000);
+    test__fixunssfti(0x1.FFFFFCp+62, 0x7FFFFF0000000000);
+    test__fixunssfti(0x1.FFFFFEp+127, 0xFFFFFF00000000000000000000000000);
+    test__fixunssfti(0x1.000000p+127, 0x80000000000000000000000000000000);
+    test__fixunssfti(0x1.FFFFFEp+126, 0x7FFFFF80000000000000000000000000);
+    test__fixunssfti(0x1.FFFFFCp+126, 0x7FFFFF00000000000000000000000000);
+
+    test__fixunssfti(-0x1.FFFFFEp+62, 0x0000000000000000);
+    test__fixunssfti(-0x1.FFFFFCp+62, 0x0000000000000000);
+    test__fixunssfti(-0x1.FFFFFEp+126, 0x0000000000000000);
+    test__fixunssfti(-0x1.FFFFFCp+126, 0x0000000000000000);
+}
std/special/compiler_rt/fixunstfdi.zig
@@ -0,0 +1,9 @@
+const fixuint = @import("fixuint.zig").fixuint;
+
+export fn __fixunstfdi(a: f128) -> u64 {
+    return fixuint(f128, u64, a);
+}
+
+test "import fixunstfdi" {
+    _ = @import("fixunstfdi_test.zig");
+}
std/special/compiler_rt/fixunstfdi_test.zig
@@ -0,0 +1,49 @@
+const __fixunstfdi = @import("fixunstfdi.zig").__fixunstfdi;
+const assert = @import("../../debug.zig").assert;
+
+fn test__fixunstfdi(a: f128, expected: u64) {
+    const x = __fixunstfdi(a);
+    assert(x == expected);
+}
+
+test "fixunstfdi" {
+    test__fixunstfdi(0.0, 0);
+
+    test__fixunstfdi(0.5, 0);
+    test__fixunstfdi(0.99, 0);
+    test__fixunstfdi(1.0, 1);
+    test__fixunstfdi(1.5, 1);
+    test__fixunstfdi(1.99, 1);
+    test__fixunstfdi(2.0, 2);
+    test__fixunstfdi(2.01, 2);
+    test__fixunstfdi(-0.5, 0);
+    test__fixunstfdi(-0.99, 0);
+    test__fixunstfdi(-1.0, 0);
+    test__fixunstfdi(-1.5, 0);
+    test__fixunstfdi(-1.99, 0);
+    test__fixunstfdi(-2.0, 0);
+    test__fixunstfdi(-2.01, 0);
+
+    test__fixunstfdi(0x1.FFFFFEp+62, 0x7FFFFF8000000000);
+    test__fixunstfdi(0x1.FFFFFCp+62, 0x7FFFFF0000000000);
+
+    test__fixunstfdi(-0x1.FFFFFEp+62, 0);
+    test__fixunstfdi(-0x1.FFFFFCp+62, 0);
+
+    test__fixunstfdi(0x1.FFFFFFFFFFFFFp+62, 0x7FFFFFFFFFFFFC00);
+    test__fixunstfdi(0x1.FFFFFFFFFFFFEp+62, 0x7FFFFFFFFFFFF800);
+
+    test__fixunstfdi(-0x1.FFFFFFFFFFFFFp+62, 0);
+    test__fixunstfdi(-0x1.FFFFFFFFFFFFEp+62, 0);
+
+    test__fixunstfdi(0x1.FFFFFFFFFFFFFFFEp+63, 0xFFFFFFFFFFFFFFFF);
+    test__fixunstfdi(0x1.0000000000000002p+63, 0x8000000000000001);
+    test__fixunstfdi(0x1.0000000000000000p+63, 0x8000000000000000);
+    test__fixunstfdi(0x1.FFFFFFFFFFFFFFFCp+62, 0x7FFFFFFFFFFFFFFF);
+    test__fixunstfdi(0x1.FFFFFFFFFFFFFFF8p+62, 0x7FFFFFFFFFFFFFFE);
+    test__fixunstfdi(0x1.p+64, 0xFFFFFFFFFFFFFFFF);
+
+    test__fixunstfdi(-0x1.0000000000000000p+63, 0);
+    test__fixunstfdi(-0x1.FFFFFFFFFFFFFFFCp+62, 0);
+    test__fixunstfdi(-0x1.FFFFFFFFFFFFFFF8p+62, 0);
+}
std/special/compiler_rt/fixunstfsi.zig
@@ -0,0 +1,9 @@
+const fixuint = @import("fixuint.zig").fixuint;
+
+export fn __fixunstfsi(a: f128) -> u32 {
+    return fixuint(f128, u32, a);
+}
+
+test "fixunstfsi" {
+    _ = @import("fixunstfsi_test.zig");
+}
std/special/compiler_rt/fixunstfti.zig
@@ -0,0 +1,10 @@
+const fixuint = @import("fixuint.zig").fixuint;
+
+export fn __fixunstfti(a: f128) -> u128 {
+    return fixuint(f128, u128, a);
+}
+
+test "fixunstfti" {
+    _ = @import("fixunstfti_test.zig");
+}
+
std/special/compiler_rt/index.zig
@@ -1,6 +1,20 @@
+// Find all the exported functions.
+comptime {
+    _ = @import("fixunsdfdi.zig");
+    _ = @import("fixunsdfsi.zig");
+    _ = @import("fixunsdfti.zig");
+    _ = @import("fixunssfdi.zig");
+    _ = @import("fixunssfsi.zig");
+    _ = @import("fixunssfti.zig");
+    _ = @import("fixunstfdi.zig");
+    _ = @import("fixunstfsi.zig");
+    _ = @import("fixunstfti.zig");
+    _ = @import("udivti3.zig");
+    _ = @import("umodti3.zig");
+}
+
 const builtin = @import("builtin");
 
-const CHAR_BIT = 8;
 const du_int = u64;
 const di_int = i64;
 const si_int = c_int;
@@ -23,8 +37,8 @@ fn du_int_to_udwords(x: du_int) -> udwords {
 export fn __udivmoddi4(a: du_int, b: du_int, maybe_rem: ?&du_int) -> du_int {
     @setDebugSafety(this, false);
 
-    const n_uword_bits = @sizeOf(su_int) * CHAR_BIT;
-    const n_udword_bits = @sizeOf(du_int) * CHAR_BIT;
+    const n_uword_bits = su_int.bit_count;
+    const n_udword_bits = du_int.bit_count;
     var n = du_int_to_udwords(a);
     var d = du_int_to_udwords(b);
     var q: udwords = undefined;
@@ -219,6 +233,7 @@ fn isArmArch() -> bool {
         builtin.Arch.armv8_2a,
         builtin.Arch.armv8_1a,
         builtin.Arch.armv8,
+        builtin.Arch.armv8r,
         builtin.Arch.armv8m_baseline,
         builtin.Arch.armv8m_mainline,
         builtin.Arch.armv7,
@@ -278,7 +293,7 @@ export fn __aeabi_uidiv(n: su_int, d: su_int) -> su_int {
 export fn __udivsi3(n: su_int, d: su_int) -> su_int {
     @setDebugSafety(this, false);
 
-    const n_uword_bits: c_uint = @sizeOf(su_int) * CHAR_BIT;
+    const n_uword_bits: c_uint = su_int.bit_count;
     // special cases
     if (d == 0)
         return 0; // ?!
std/special/compiler_rt/README.md
@@ -0,0 +1,15 @@
+This compiler-rt library is ported from [LLVM](http://compiler-rt.llvm.org/).
+
+It's needed because LLVM emits library calls to compiler-rt when hardware lacks
+functionality, for example, 64-bit integer multiplication on 32-bit x86.
+
+This library is automatically built as-needed for the compilation target and
+then statically linked and therefore is a transparent dependency for the
+programmer.
+
+Any bugs should be solved by trying to duplicate the bug upstream.
+ * If the bug exists upstream, get it fixed with the LLVM team and then port
+   the fix downstream to Zig.
+ * If the bug only exists in Zig, something went wrong porting the code,
+   and you can run the C code and Zig code side by side in a debugger
+   to figure out what's happening differently.
std/special/compiler_rt/udivti3.zig
std/special/compiler_rt/umodti3.zig
test/cases/math.zig
@@ -284,3 +284,29 @@ fn testShrExact(x: u8) {
     const shifted = @shrExact(x, 2);
     assert(shifted == 0b00101101);
 }
+
+test "big number addition" {
+    comptime {
+        assert(
+            35361831660712422535336160538497375248 +
+            101752735581729509668353361206450473702 ==
+            137114567242441932203689521744947848950);
+        assert(
+            594491908217841670578297176641415611445982232488944558774612 +
+            390603545391089362063884922208143568023166603618446395589768 ==
+            985095453608931032642182098849559179469148836107390954364380);
+    }
+}
+
+test "big number multiplication" {
+    comptime {
+        assert(
+            45960427431263824329884196484953148229 *
+            128339149605334697009938835852565949723 ==
+            5898522172026096622534201617172456926982464453350084962781392314016180490567);
+        assert(
+            594491908217841670578297176641415611445982232488944558774612 *
+            390603545391089362063884922208143568023166603618446395589768 ==
+            232210647056203049913662402532976186578842425262306016094292237500303028346593132411865381225871291702600263463125370016);
+    }
+}
CMakeLists.txt
@@ -239,10 +239,10 @@ install(FILES "${CMAKE_SOURCE_DIR}/std/dwarf.zig" DESTINATION "${ZIG_STD_DEST}")
 install(FILES "${CMAKE_SOURCE_DIR}/std/elf.zig" DESTINATION "${ZIG_STD_DEST}")
 install(FILES "${CMAKE_SOURCE_DIR}/std/empty.zig" DESTINATION "${ZIG_STD_DEST}")
 install(FILES "${CMAKE_SOURCE_DIR}/std/endian.zig" DESTINATION "${ZIG_STD_DEST}")
-install(FILES "${CMAKE_SOURCE_DIR}/std/fmt/index.zig" DESTINATION "${ZIG_STD_DEST}/fmt")
-install(FILES "${CMAKE_SOURCE_DIR}/std/fmt/errol/index.zig" DESTINATION "${ZIG_STD_DEST}/fmt/errol")
 install(FILES "${CMAKE_SOURCE_DIR}/std/fmt/errol/enum3.zig" DESTINATION "${ZIG_STD_DEST}/fmt/errol")
+install(FILES "${CMAKE_SOURCE_DIR}/std/fmt/errol/index.zig" DESTINATION "${ZIG_STD_DEST}/fmt/errol")
 install(FILES "${CMAKE_SOURCE_DIR}/std/fmt/errol/lookup.zig" DESTINATION "${ZIG_STD_DEST}/fmt/errol")
+install(FILES "${CMAKE_SOURCE_DIR}/std/fmt/index.zig" DESTINATION "${ZIG_STD_DEST}/fmt")
 install(FILES "${CMAKE_SOURCE_DIR}/std/hash_map.zig" DESTINATION "${ZIG_STD_DEST}")
 install(FILES "${CMAKE_SOURCE_DIR}/std/index.zig" DESTINATION "${ZIG_STD_DEST}")
 install(FILES "${CMAKE_SOURCE_DIR}/std/io.zig" DESTINATION "${ZIG_STD_DEST}")
@@ -303,15 +303,27 @@ install(FILES "${CMAKE_SOURCE_DIR}/std/os/linux.zig" DESTINATION "${ZIG_STD_DEST
 install(FILES "${CMAKE_SOURCE_DIR}/std/os/linux_i386.zig" DESTINATION "${ZIG_STD_DEST}/os")
 install(FILES "${CMAKE_SOURCE_DIR}/std/os/linux_x86_64.zig" DESTINATION "${ZIG_STD_DEST}/os")
 install(FILES "${CMAKE_SOURCE_DIR}/std/os/path.zig" DESTINATION "${ZIG_STD_DEST}/os")
-install(FILES "${CMAKE_SOURCE_DIR}/std/os/windows/index.zig" DESTINATION "${ZIG_STD_DEST}/os/windows")
 install(FILES "${CMAKE_SOURCE_DIR}/std/os/windows/error.zig" DESTINATION "${ZIG_STD_DEST}/os/windows")
+install(FILES "${CMAKE_SOURCE_DIR}/std/os/windows/index.zig" DESTINATION "${ZIG_STD_DEST}/os/windows")
 install(FILES "${CMAKE_SOURCE_DIR}/std/rand.zig" DESTINATION "${ZIG_STD_DEST}")
 install(FILES "${CMAKE_SOURCE_DIR}/std/sort.zig" DESTINATION "${ZIG_STD_DEST}")
 install(FILES "${CMAKE_SOURCE_DIR}/std/special/bootstrap.zig" DESTINATION "${ZIG_STD_DEST}/special")
 install(FILES "${CMAKE_SOURCE_DIR}/std/special/build_file_template.zig" DESTINATION "${ZIG_STD_DEST}/special")
 install(FILES "${CMAKE_SOURCE_DIR}/std/special/build_runner.zig" DESTINATION "${ZIG_STD_DEST}/special")
 install(FILES "${CMAKE_SOURCE_DIR}/std/special/builtin.zig" DESTINATION "${ZIG_STD_DEST}/special")
+install(FILES "${CMAKE_SOURCE_DIR}/std/special/compiler_rt/fixuint.zig" DESTINATION "${ZIG_STD_DEST}/special/compiler_rt")
+install(FILES "${CMAKE_SOURCE_DIR}/std/special/compiler_rt/fixunsdfdi.zig" DESTINATION "${ZIG_STD_DEST}/special/compiler_rt")
+install(FILES "${CMAKE_SOURCE_DIR}/std/special/compiler_rt/fixunsdfsi.zig" DESTINATION "${ZIG_STD_DEST}/special/compiler_rt")
+install(FILES "${CMAKE_SOURCE_DIR}/std/special/compiler_rt/fixunsdfti.zig" DESTINATION "${ZIG_STD_DEST}/special/compiler_rt")
+install(FILES "${CMAKE_SOURCE_DIR}/std/special/compiler_rt/fixunssfdi.zig" DESTINATION "${ZIG_STD_DEST}/special/compiler_rt")
+install(FILES "${CMAKE_SOURCE_DIR}/std/special/compiler_rt/fixunssfsi.zig" DESTINATION "${ZIG_STD_DEST}/special/compiler_rt")
+install(FILES "${CMAKE_SOURCE_DIR}/std/special/compiler_rt/fixunssfti.zig" DESTINATION "${ZIG_STD_DEST}/special/compiler_rt")
+install(FILES "${CMAKE_SOURCE_DIR}/std/special/compiler_rt/fixunstfdi.zig" DESTINATION "${ZIG_STD_DEST}/special/compiler_rt")
+install(FILES "${CMAKE_SOURCE_DIR}/std/special/compiler_rt/fixunstfsi.zig" DESTINATION "${ZIG_STD_DEST}/special/compiler_rt")
+install(FILES "${CMAKE_SOURCE_DIR}/std/special/compiler_rt/fixunstfti.zig" DESTINATION "${ZIG_STD_DEST}/special/compiler_rt")
 install(FILES "${CMAKE_SOURCE_DIR}/std/special/compiler_rt/index.zig" DESTINATION "${ZIG_STD_DEST}/special/compiler_rt")
+install(FILES "${CMAKE_SOURCE_DIR}/std/special/compiler_rt/udivti3.zig" DESTINATION "${ZIG_STD_DEST}/special/compiler_rt")
+install(FILES "${CMAKE_SOURCE_DIR}/std/special/compiler_rt/umodti3.zig" DESTINATION "${ZIG_STD_DEST}/special/compiler_rt")
 install(FILES "${CMAKE_SOURCE_DIR}/std/special/test_runner.zig" DESTINATION "${ZIG_STD_DEST}/special")
 install(FILES "${CMAKE_SOURCE_DIR}/std/special/zigrt.zig" DESTINATION "${ZIG_STD_DEST}/special")