Commit 9110140514

Marc Tiehuis <marctiehuis@gmail.com>
2018-06-13 12:25:04
Add i128 compiler-rt div/mul support
master
1 parent 86adc1e
Changed files (6)
std
special
compiler_rt
divti3.zig
divti3_test.zig
index.zig
muloti4.zig
muloti4_test.zig
CMakeLists.txt
std/special/compiler_rt/divti3.zig
@@ -0,0 +1,16 @@
+const udivmod = @import("udivmod.zig").udivmod;
+const builtin = @import("builtin");
+
+pub extern fn __divti3(a: i128, b: i128) i128 {
+    @setRuntimeSafety(builtin.is_test);
+
+    const s_a = a >> (i128.bit_count - 1);
+    const s_b = b >> (i128.bit_count - 1);
+
+    const an = (a ^ s_a) -% s_a;
+    const bn = (b ^ s_b) -% s_b;
+
+    const r = udivmod(u128, @bitCast(u128, an), @bitCast(u128, bn), null);
+    const s = s_a ^ s_b;
+    return (i128(r) ^ s) -% s;
+}
std/special/compiler_rt/divti3_test.zig
@@ -0,0 +1,21 @@
+const __divti3 = @import("divti3.zig").__divti3;
+const assert = @import("std").debug.assert;
+
+fn test__divti3(a: i128, b: i128, expected: i128) void {
+    const x = __divti3(a, b);
+    assert(x == expected);
+}
+
+test "divti3" {
+    test__divti3(0, 1, 0);
+    test__divti3(0, -1, 0);
+    test__divti3(2, 1, 2);
+    test__divti3(2, -1, -2);
+    test__divti3(-2, 1, -2);
+    test__divti3(-2, -1, 2);
+
+    test__divti3(@bitCast(i128, u128(0x8 << 124)), 1, @bitCast(i128, u128(0x8 << 124)));
+    test__divti3(@bitCast(i128, u128(0x8 << 124)), -1, @bitCast(i128, u128(0x8 << 124)));
+    test__divti3(@bitCast(i128, u128(0x8 << 124)), -2, @bitCast(i128, u128(0x4 << 124)));
+    test__divti3(@bitCast(i128, u128(0x8 << 124)), 2, @bitCast(i128, u128(0xc << 124)));
+}
std/special/compiler_rt/index.zig
@@ -38,6 +38,9 @@ comptime {
     @export("__umoddi3", __umoddi3, linkage);
     @export("__udivmodsi4", __udivmodsi4, linkage);
 
+    @export("__divti3", @import("divti3.zig").__divti3, linkage);
+    @export("__muloti4", @import("muloti4.zig").__muloti4, linkage);
+
     if (isArmArch()) {
         @export("__aeabi_uldivmod", __aeabi_uldivmod, linkage);
         @export("__aeabi_uidivmod", __aeabi_uidivmod, linkage);
std/special/compiler_rt/muloti4.zig
@@ -0,0 +1,45 @@
+const udivmod = @import("udivmod.zig").udivmod;
+const builtin = @import("builtin");
+
+pub extern fn __muloti4(a: i128, b: i128, overflow: *c_int) i128 {
+    @setRuntimeSafety(builtin.is_test);
+
+    const min = @bitCast(i128, u128(1 << (i128.bit_count - 1)));
+    const max = ~min;
+    overflow.* = 0;
+
+    const r = a *% b;
+    if (a == min) {
+        if (b != 0 and b != 1) {
+            overflow.* = 1;
+        }
+        return r;
+    }
+    if (b == min) {
+        if (a != 0 and a != 1) {
+            overflow.* = 1;
+        }
+        return r;
+    }
+
+    const sa = a >> (i128.bit_count - 1);
+    const abs_a = (a ^ sa) -% sa;
+    const sb = b >> (i128.bit_count - 1);
+    const abs_b = (b ^ sb) -% sb;
+
+    if (abs_a < 2 or abs_b < 2) {
+        return r;
+    }
+
+    if (sa == sb) {
+        if (abs_a > @divFloor(max, abs_b)) {
+            overflow.* = 1;
+        }
+    } else {
+        if (abs_a > @divFloor(min, -abs_b)) {
+            overflow.* = 1;
+        }
+    }
+
+    return r;
+}
std/special/compiler_rt/muloti4_test.zig
@@ -0,0 +1,76 @@
+const __muloti4 = @import("muloti4.zig").__muloti4;
+const assert = @import("std").debug.assert;
+
+fn test__muloti4(a: i128, b: i128, expected: i128, expected_overflow: c_int) void {
+    var overflow: c_int = undefined;
+    const x = __muloti4(a, b, &overflow);
+    assert(overflow == expected_overflow and (overflow != 0 or x == expected));
+}
+
+test "muloti4" {
+    test__muloti4(0, 0, 0, 0);
+    test__muloti4(0, 1, 0, 0);
+    test__muloti4(1, 0, 0, 0);
+    test__muloti4(0, 10, 0, 0);
+    test__muloti4(10, 0, 0, 0);
+
+    test__muloti4(0, 81985529216486895, 0, 0);
+    test__muloti4(81985529216486895, 0, 0, 0);
+
+    test__muloti4(0, -1, 0, 0);
+    test__muloti4(-1, 0, 0, 0);
+    test__muloti4(0, -10, 0, 0);
+    test__muloti4(-10, 0, 0, 0);
+    test__muloti4(0, -81985529216486895, 0, 0);
+    test__muloti4(-81985529216486895, 0, 0, 0);
+
+    test__muloti4(3037000499, 3037000499, 9223372030926249001, 0);
+    test__muloti4(-3037000499, 3037000499, -9223372030926249001, 0);
+    test__muloti4(3037000499, -3037000499, -9223372030926249001, 0);
+    test__muloti4(-3037000499, -3037000499, 9223372030926249001, 0);
+
+    test__muloti4(4398046511103, 2097152, 9223372036852678656, 0);
+    test__muloti4(-4398046511103, 2097152, -9223372036852678656, 0);
+    test__muloti4(4398046511103, -2097152, -9223372036852678656, 0);
+    test__muloti4(-4398046511103, -2097152, 9223372036852678656, 0);
+
+    test__muloti4(2097152, 4398046511103, 9223372036852678656, 0);
+    test__muloti4(-2097152, 4398046511103, -9223372036852678656, 0);
+    test__muloti4(2097152, -4398046511103, -9223372036852678656, 0);
+    test__muloti4(-2097152, -4398046511103, 9223372036852678656, 0);
+
+    test__muloti4(@bitCast(i128, u128(0x00000000000000B504F333F9DE5BE000)), @bitCast(i128, u128(0x000000000000000000B504F333F9DE5B)), @bitCast(i128, u128(0x7FFFFFFFFFFFF328DF915DA296E8A000)), 0);
+    test__muloti4(@bitCast(i128, u128(0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF)), -2, @bitCast(i128, u128(0x80000000000000000000000000000001)), 1);
+    test__muloti4(-2, @bitCast(i128, u128(0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF)), @bitCast(i128, u128(0x80000000000000000000000000000001)), 1);
+
+    test__muloti4(@bitCast(i128, u128(0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF)), -1, @bitCast(i128, u128(0x80000000000000000000000000000001)), 0);
+    test__muloti4(-1, @bitCast(i128, u128(0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF)), @bitCast(i128, u128(0x80000000000000000000000000000001)), 0);
+    test__muloti4(@bitCast(i128, u128(0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF)), 0, 0, 0);
+    test__muloti4(0, @bitCast(i128, u128(0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF)), 0, 0);
+    test__muloti4(@bitCast(i128, u128(0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF)), 1, @bitCast(i128, u128(0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF)), 0);
+    test__muloti4(1, @bitCast(i128, u128(0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF)), @bitCast(i128, u128(0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF)), 0);
+    test__muloti4(@bitCast(i128, u128(0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF)), 2, @bitCast(i128, u128(0x80000000000000000000000000000001)), 1);
+    test__muloti4(2, @bitCast(i128, u128(0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF)), @bitCast(i128, u128(0x80000000000000000000000000000001)), 1);
+
+    test__muloti4(@bitCast(i128, u128(0x80000000000000000000000000000000)), -2, @bitCast(i128, u128(0x80000000000000000000000000000000)), 1);
+    test__muloti4(-2, @bitCast(i128, u128(0x80000000000000000000000000000000)), @bitCast(i128, u128(0x80000000000000000000000000000000)), 1);
+    test__muloti4(@bitCast(i128, u128(0x80000000000000000000000000000000)), -1, @bitCast(i128, u128(0x80000000000000000000000000000000)), 1);
+    test__muloti4(-1, @bitCast(i128, u128(0x80000000000000000000000000000000)), @bitCast(i128, u128(0x80000000000000000000000000000000)), 1);
+    test__muloti4(@bitCast(i128, u128(0x80000000000000000000000000000000)), 0, 0, 0);
+    test__muloti4(0, @bitCast(i128, u128(0x80000000000000000000000000000000)), 0, 0);
+    test__muloti4(@bitCast(i128, u128(0x80000000000000000000000000000000)), 1, @bitCast(i128, u128(0x80000000000000000000000000000000)), 0);
+    test__muloti4(1, @bitCast(i128, u128(0x80000000000000000000000000000000)), @bitCast(i128, u128(0x80000000000000000000000000000000)), 0);
+    test__muloti4(@bitCast(i128, u128(0x80000000000000000000000000000000)), 2, @bitCast(i128, u128(0x80000000000000000000000000000000)), 1);
+    test__muloti4(2, @bitCast(i128, u128(0x80000000000000000000000000000000)), @bitCast(i128, u128(0x80000000000000000000000000000000)), 1);
+
+    test__muloti4(@bitCast(i128, u128(0x80000000000000000000000000000001)), -2, @bitCast(i128, u128(0x80000000000000000000000000000001)), 1);
+    test__muloti4(-2, @bitCast(i128, u128(0x80000000000000000000000000000001)), @bitCast(i128, u128(0x80000000000000000000000000000001)), 1);
+    test__muloti4(@bitCast(i128, u128(0x80000000000000000000000000000001)), -1, @bitCast(i128, u128(0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF)), 0);
+    test__muloti4(-1, @bitCast(i128, u128(0x80000000000000000000000000000001)), @bitCast(i128, u128(0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF)), 0);
+    test__muloti4(@bitCast(i128, u128(0x80000000000000000000000000000001)), 0, 0, 0);
+    test__muloti4(0, @bitCast(i128, u128(0x80000000000000000000000000000001)), 0, 0);
+    test__muloti4(@bitCast(i128, u128(0x80000000000000000000000000000001)), 1, @bitCast(i128, u128(0x80000000000000000000000000000001)), 0);
+    test__muloti4(1, @bitCast(i128, u128(0x80000000000000000000000000000001)), @bitCast(i128, u128(0x80000000000000000000000000000001)), 0);
+    test__muloti4(@bitCast(i128, u128(0x80000000000000000000000000000001)), 2, @bitCast(i128, u128(0x80000000000000000000000000000000)), 1);
+    test__muloti4(2, @bitCast(i128, u128(0x80000000000000000000000000000001)), @bitCast(i128, u128(0x80000000000000000000000000000000)), 1);
+}
CMakeLists.txt
@@ -556,6 +556,7 @@ set(ZIG_STD_FILES
     "special/compiler_rt/aulldiv.zig"
     "special/compiler_rt/aullrem.zig"
     "special/compiler_rt/comparetf2.zig"
+    "special/compiler_rt/divti3.zig"
     "special/compiler_rt/fixuint.zig"
     "special/compiler_rt/fixunsdfdi.zig"
     "special/compiler_rt/fixunsdfsi.zig"
@@ -566,6 +567,7 @@ set(ZIG_STD_FILES
     "special/compiler_rt/fixunstfdi.zig"
     "special/compiler_rt/fixunstfsi.zig"
     "special/compiler_rt/fixunstfti.zig"
+    "special/compiler_rt/muloti4.zig"
     "special/compiler_rt/index.zig"
     "special/compiler_rt/udivmod.zig"
     "special/compiler_rt/udivmoddi4.zig"