Commit 81e2034d4a

Jan Philipp Hafer <jan.hafer@rwth-aachen.de>
2021-08-24 23:26:37
compiler_rt: add __clzdi2 and __clzti2
- structure derived from shift.zig - rename clzsi2.zig to count0bits.zig - test cases derived from clzsi2_test.zig See #1290
master
1 parent 04b8016
Changed files (6)
lib
std
special
compiler_rt
clzdi2_test.zig
clzsi2_test.zig
clzti2_test.zig
count0bits.zig
compiler_rt.zig
CMakeLists.txt
lib/std/special/compiler_rt/clzdi2_test.zig
@@ -0,0 +1,329 @@
+const clz = @import("count0bits.zig");
+const testing = @import("std").testing;
+
+fn test__clzdi2(a: u64, expected: i64) !void {
+    // XXX At high optimization levels this test may be horribly miscompiled if
+    // one of the naked implementations is selected.
+    var nakedClzdi2 = clz.__clzdi2;
+    var actualClzdi2 = @ptrCast(fn (a: i64) callconv(.C) i32, nakedClzdi2);
+    var x = @bitCast(i64, a);
+    var result = actualClzdi2(x);
+    try testing.expectEqual(expected, result);
+}
+
+test "clzdi2" {
+    try test__clzdi2(0x00800000_00000000, 8);
+    try test__clzdi2(0x01000000_00000000, 7);
+    try test__clzdi2(0x02000000_00000000, 6);
+    try test__clzdi2(0x03000000_00000000, 6);
+    try test__clzdi2(0x04000000_00000000, 5);
+    try test__clzdi2(0x05000000_00000000, 5);
+    try test__clzdi2(0x06000000_00000000, 5);
+    try test__clzdi2(0x07000000_00000000, 5);
+    try test__clzdi2(0x08000000_00000000, 4);
+    try test__clzdi2(0x09000000_00000000, 4);
+    try test__clzdi2(0x0A000000_00000000, 4);
+    try test__clzdi2(0x0B000000_00000000, 4);
+    try test__clzdi2(0x0C000000_00000000, 4);
+    try test__clzdi2(0x0D000000_00000000, 4);
+    try test__clzdi2(0x0E000000_00000000, 4);
+    try test__clzdi2(0x0F000000_00000000, 4);
+    try test__clzdi2(0x10000000_00000000, 3);
+    try test__clzdi2(0x11000000_00000000, 3);
+    try test__clzdi2(0x12000000_00000000, 3);
+    try test__clzdi2(0x13000000_00000000, 3);
+    try test__clzdi2(0x14000000_00000000, 3);
+    try test__clzdi2(0x15000000_00000000, 3);
+    try test__clzdi2(0x16000000_00000000, 3);
+    try test__clzdi2(0x17000000_00000000, 3);
+    try test__clzdi2(0x18000000_00000000, 3);
+    try test__clzdi2(0x19000000_00000000, 3);
+    try test__clzdi2(0x1A000000_00000000, 3);
+    try test__clzdi2(0x1B000000_00000000, 3);
+    try test__clzdi2(0x1C000000_00000000, 3);
+    try test__clzdi2(0x1D000000_00000000, 3);
+    try test__clzdi2(0x1E000000_00000000, 3);
+    try test__clzdi2(0x1F000000_00000000, 3);
+    try test__clzdi2(0x20000000_00000000, 2);
+    try test__clzdi2(0x21000000_00000000, 2);
+    try test__clzdi2(0x22000000_00000000, 2);
+    try test__clzdi2(0x23000000_00000000, 2);
+    try test__clzdi2(0x24000000_00000000, 2);
+    try test__clzdi2(0x25000000_00000000, 2);
+    try test__clzdi2(0x26000000_00000000, 2);
+    try test__clzdi2(0x27000000_00000000, 2);
+    try test__clzdi2(0x28000000_00000000, 2);
+    try test__clzdi2(0x29000000_00000000, 2);
+    try test__clzdi2(0x2A000000_00000000, 2);
+    try test__clzdi2(0x2B000000_00000000, 2);
+    try test__clzdi2(0x2C000000_00000000, 2);
+    try test__clzdi2(0x2D000000_00000000, 2);
+    try test__clzdi2(0x2E000000_00000000, 2);
+    try test__clzdi2(0x2F000000_00000000, 2);
+    try test__clzdi2(0x30000000_00000000, 2);
+    try test__clzdi2(0x31000000_00000000, 2);
+    try test__clzdi2(0x32000000_00000000, 2);
+    try test__clzdi2(0x33000000_00000000, 2);
+    try test__clzdi2(0x34000000_00000000, 2);
+    try test__clzdi2(0x35000000_00000000, 2);
+    try test__clzdi2(0x36000000_00000000, 2);
+    try test__clzdi2(0x37000000_00000000, 2);
+    try test__clzdi2(0x38000000_00000000, 2);
+    try test__clzdi2(0x39000000_00000000, 2);
+    try test__clzdi2(0x3A000000_00000000, 2);
+    try test__clzdi2(0x3B000000_00000000, 2);
+    try test__clzdi2(0x3C000000_00000000, 2);
+    try test__clzdi2(0x3D000000_00000000, 2);
+    try test__clzdi2(0x3E000000_00000000, 2);
+    try test__clzdi2(0x3F000000_00000000, 2);
+    try test__clzdi2(0x40000000_00000000, 1);
+    try test__clzdi2(0x41000000_00000000, 1);
+    try test__clzdi2(0x42000000_00000000, 1);
+    try test__clzdi2(0x43000000_00000000, 1);
+    try test__clzdi2(0x44000000_00000000, 1);
+    try test__clzdi2(0x45000000_00000000, 1);
+    try test__clzdi2(0x46000000_00000000, 1);
+    try test__clzdi2(0x47000000_00000000, 1);
+    try test__clzdi2(0x48000000_00000000, 1);
+    try test__clzdi2(0x49000000_00000000, 1);
+    try test__clzdi2(0x4A000000_00000000, 1);
+    try test__clzdi2(0x4B000000_00000000, 1);
+    try test__clzdi2(0x4C000000_00000000, 1);
+    try test__clzdi2(0x4D000000_00000000, 1);
+    try test__clzdi2(0x4E000000_00000000, 1);
+    try test__clzdi2(0x4F000000_00000000, 1);
+    try test__clzdi2(0x50000000_00000000, 1);
+    try test__clzdi2(0x51000000_00000000, 1);
+    try test__clzdi2(0x52000000_00000000, 1);
+    try test__clzdi2(0x53000000_00000000, 1);
+    try test__clzdi2(0x54000000_00000000, 1);
+    try test__clzdi2(0x55000000_00000000, 1);
+    try test__clzdi2(0x56000000_00000000, 1);
+    try test__clzdi2(0x57000000_00000000, 1);
+    try test__clzdi2(0x58000000_00000000, 1);
+    try test__clzdi2(0x59000000_00000000, 1);
+    try test__clzdi2(0x5A000000_00000000, 1);
+    try test__clzdi2(0x5B000000_00000000, 1);
+    try test__clzdi2(0x5C000000_00000000, 1);
+    try test__clzdi2(0x5D000000_00000000, 1);
+    try test__clzdi2(0x5E000000_00000000, 1);
+    try test__clzdi2(0x5F000000_00000000, 1);
+    try test__clzdi2(0x60000000_00000000, 1);
+    try test__clzdi2(0x61000000_00000000, 1);
+    try test__clzdi2(0x62000000_00000000, 1);
+    try test__clzdi2(0x63000000_00000000, 1);
+    try test__clzdi2(0x64000000_00000000, 1);
+    try test__clzdi2(0x65000000_00000000, 1);
+    try test__clzdi2(0x66000000_00000000, 1);
+    try test__clzdi2(0x67000000_00000000, 1);
+    try test__clzdi2(0x68000000_00000000, 1);
+    try test__clzdi2(0x69000000_00000000, 1);
+    try test__clzdi2(0x6A000000_00000000, 1);
+    try test__clzdi2(0x6B000000_00000000, 1);
+    try test__clzdi2(0x6C000000_00000000, 1);
+    try test__clzdi2(0x6D000000_00000000, 1);
+    try test__clzdi2(0x6E000000_00000000, 1);
+    try test__clzdi2(0x6F000000_00000000, 1);
+    try test__clzdi2(0x70000000_00000000, 1);
+    try test__clzdi2(0x71000000_00000000, 1);
+    try test__clzdi2(0x72000000_00000000, 1);
+    try test__clzdi2(0x73000000_00000000, 1);
+    try test__clzdi2(0x74000000_00000000, 1);
+    try test__clzdi2(0x75000000_00000000, 1);
+    try test__clzdi2(0x76000000_00000000, 1);
+    try test__clzdi2(0x77000000_00000000, 1);
+    try test__clzdi2(0x78000000_00000000, 1);
+    try test__clzdi2(0x79000000_00000000, 1);
+    try test__clzdi2(0x7A000000_00000000, 1);
+    try test__clzdi2(0x7B000000_00000000, 1);
+    try test__clzdi2(0x7C000000_00000000, 1);
+    try test__clzdi2(0x7D000000_00000000, 1);
+    try test__clzdi2(0x7E000000_00000000, 1);
+    try test__clzdi2(0x7F000000_00000000, 1);
+    try test__clzdi2(0x80000000_00000000, 0);
+    try test__clzdi2(0x81000000_00000000, 0);
+    try test__clzdi2(0x82000000_00000000, 0);
+    try test__clzdi2(0x83000000_00000000, 0);
+    try test__clzdi2(0x84000000_00000000, 0);
+    try test__clzdi2(0x85000000_00000000, 0);
+    try test__clzdi2(0x86000000_00000000, 0);
+    try test__clzdi2(0x87000000_00000000, 0);
+    try test__clzdi2(0x88000000_00000000, 0);
+    try test__clzdi2(0x89000000_00000000, 0);
+    try test__clzdi2(0x8A000000_00000000, 0);
+    try test__clzdi2(0x8B000000_00000000, 0);
+    try test__clzdi2(0x8C000000_00000000, 0);
+    try test__clzdi2(0x8D000000_00000000, 0);
+    try test__clzdi2(0x8E000000_00000000, 0);
+    try test__clzdi2(0x8F000000_00000000, 0);
+    try test__clzdi2(0x90000000_00000000, 0);
+    try test__clzdi2(0x91000000_00000000, 0);
+    try test__clzdi2(0x92000000_00000000, 0);
+    try test__clzdi2(0x93000000_00000000, 0);
+    try test__clzdi2(0x94000000_00000000, 0);
+    try test__clzdi2(0x95000000_00000000, 0);
+    try test__clzdi2(0x96000000_00000000, 0);
+    try test__clzdi2(0x97000000_00000000, 0);
+    try test__clzdi2(0x98000000_00000000, 0);
+    try test__clzdi2(0x99000000_00000000, 0);
+    try test__clzdi2(0x9A000000_00000000, 0);
+    try test__clzdi2(0x9B000000_00000000, 0);
+    try test__clzdi2(0x9C000000_00000000, 0);
+    try test__clzdi2(0x9D000000_00000000, 0);
+    try test__clzdi2(0x9E000000_00000000, 0);
+    try test__clzdi2(0x9F000000_00000000, 0);
+    try test__clzdi2(0xA0000000_00000000, 0);
+    try test__clzdi2(0xA1000000_00000000, 0);
+    try test__clzdi2(0xA2000000_00000000, 0);
+    try test__clzdi2(0xA3000000_00000000, 0);
+    try test__clzdi2(0xA4000000_00000000, 0);
+    try test__clzdi2(0xA5000000_00000000, 0);
+    try test__clzdi2(0xA6000000_00000000, 0);
+    try test__clzdi2(0xA7000000_00000000, 0);
+    try test__clzdi2(0xA8000000_00000000, 0);
+    try test__clzdi2(0xA9000000_00000000, 0);
+    try test__clzdi2(0xAA000000_00000000, 0);
+    try test__clzdi2(0xAB000000_00000000, 0);
+    try test__clzdi2(0xAC000000_00000000, 0);
+    try test__clzdi2(0xAD000000_00000000, 0);
+    try test__clzdi2(0xAE000000_00000000, 0);
+    try test__clzdi2(0xAF000000_00000000, 0);
+    try test__clzdi2(0xB0000000_00000000, 0);
+    try test__clzdi2(0xB1000000_00000000, 0);
+    try test__clzdi2(0xB2000000_00000000, 0);
+    try test__clzdi2(0xB3000000_00000000, 0);
+    try test__clzdi2(0xB4000000_00000000, 0);
+    try test__clzdi2(0xB5000000_00000000, 0);
+    try test__clzdi2(0xB6000000_00000000, 0);
+    try test__clzdi2(0xB7000000_00000000, 0);
+    try test__clzdi2(0xB8000000_00000000, 0);
+    try test__clzdi2(0xB9000000_00000000, 0);
+    try test__clzdi2(0xBA000000_00000000, 0);
+    try test__clzdi2(0xBB000000_00000000, 0);
+    try test__clzdi2(0xBC000000_00000000, 0);
+    try test__clzdi2(0xBD000000_00000000, 0);
+    try test__clzdi2(0xBE000000_00000000, 0);
+    try test__clzdi2(0xBF000000_00000000, 0);
+    try test__clzdi2(0xC0000000_00000000, 0);
+    try test__clzdi2(0xC1000000_00000000, 0);
+    try test__clzdi2(0xC2000000_00000000, 0);
+    try test__clzdi2(0xC3000000_00000000, 0);
+    try test__clzdi2(0xC4000000_00000000, 0);
+    try test__clzdi2(0xC5000000_00000000, 0);
+    try test__clzdi2(0xC6000000_00000000, 0);
+    try test__clzdi2(0xC7000000_00000000, 0);
+    try test__clzdi2(0xC8000000_00000000, 0);
+    try test__clzdi2(0xC9000000_00000000, 0);
+    try test__clzdi2(0xCA000000_00000000, 0);
+    try test__clzdi2(0xCB000000_00000000, 0);
+    try test__clzdi2(0xCC000000_00000000, 0);
+    try test__clzdi2(0xCD000000_00000000, 0);
+    try test__clzdi2(0xCE000000_00000000, 0);
+    try test__clzdi2(0xCF000000_00000000, 0);
+    try test__clzdi2(0xD0000000_00000000, 0);
+    try test__clzdi2(0xD1000000_00000000, 0);
+    try test__clzdi2(0xD2000000_00000000, 0);
+    try test__clzdi2(0xD3000000_00000000, 0);
+    try test__clzdi2(0xD4000000_00000000, 0);
+    try test__clzdi2(0xD5000000_00000000, 0);
+    try test__clzdi2(0xD6000000_00000000, 0);
+    try test__clzdi2(0xD7000000_00000000, 0);
+    try test__clzdi2(0xD8000000_00000000, 0);
+    try test__clzdi2(0xD9000000_00000000, 0);
+    try test__clzdi2(0xDA000000_00000000, 0);
+    try test__clzdi2(0xDB000000_00000000, 0);
+    try test__clzdi2(0xDC000000_00000000, 0);
+    try test__clzdi2(0xDD000000_00000000, 0);
+    try test__clzdi2(0xDE000000_00000000, 0);
+    try test__clzdi2(0xDF000000_00000000, 0);
+    try test__clzdi2(0xE0000000_00000000, 0);
+    try test__clzdi2(0xE1000000_00000000, 0);
+    try test__clzdi2(0xE2000000_00000000, 0);
+    try test__clzdi2(0xE3000000_00000000, 0);
+    try test__clzdi2(0xE4000000_00000000, 0);
+    try test__clzdi2(0xE5000000_00000000, 0);
+    try test__clzdi2(0xE6000000_00000000, 0);
+    try test__clzdi2(0xE7000000_00000000, 0);
+    try test__clzdi2(0xE8000000_00000000, 0);
+    try test__clzdi2(0xE9000000_00000000, 0);
+    try test__clzdi2(0xEA000000_00000000, 0);
+    try test__clzdi2(0xEB000000_00000000, 0);
+    try test__clzdi2(0xEC000000_00000000, 0);
+    try test__clzdi2(0xED000000_00000000, 0);
+    try test__clzdi2(0xEE000000_00000000, 0);
+    try test__clzdi2(0xEF000000_00000000, 0);
+    try test__clzdi2(0xF0000000_00000000, 0);
+    try test__clzdi2(0xF1000000_00000000, 0);
+    try test__clzdi2(0xF2000000_00000000, 0);
+    try test__clzdi2(0xF3000000_00000000, 0);
+    try test__clzdi2(0xF4000000_00000000, 0);
+    try test__clzdi2(0xF5000000_00000000, 0);
+    try test__clzdi2(0xF6000000_00000000, 0);
+    try test__clzdi2(0xF7000000_00000000, 0);
+    try test__clzdi2(0xF8000000_00000000, 0);
+    try test__clzdi2(0xF9000000_00000000, 0);
+    try test__clzdi2(0xFA000000_00000000, 0);
+    try test__clzdi2(0xFB000000_00000000, 0);
+    try test__clzdi2(0xFC000000_00000000, 0);
+    try test__clzdi2(0xFD000000_00000000, 0);
+    try test__clzdi2(0xFE000000_00000000, 0);
+    try test__clzdi2(0xFF000000_00000000, 0);
+
+    try test__clzdi2(0x00000000_00000000, 64);
+    try test__clzdi2(0x00000000_00000001, 63);
+    try test__clzdi2(0x00000000_00000002, 62);
+    try test__clzdi2(0x00000000_00000004, 61);
+    try test__clzdi2(0x00000000_00000008, 60);
+    try test__clzdi2(0x00000000_00000010, 59);
+    try test__clzdi2(0x00000000_00000020, 58);
+    try test__clzdi2(0x00000000_00000040, 57);
+    try test__clzdi2(0x00000000_00000080, 56);
+    try test__clzdi2(0x00000000_00000100, 55);
+    try test__clzdi2(0x00000000_00000200, 54);
+    try test__clzdi2(0x00000000_00000400, 53);
+    try test__clzdi2(0x00000000_00000800, 52);
+    try test__clzdi2(0x00000000_00001000, 51);
+    try test__clzdi2(0x00000000_00002000, 50);
+    try test__clzdi2(0x00000000_00004000, 49);
+    try test__clzdi2(0x00000000_00008000, 48);
+    try test__clzdi2(0x00000000_00010000, 47);
+    try test__clzdi2(0x00000000_00020000, 46);
+    try test__clzdi2(0x00000000_00040000, 45);
+    try test__clzdi2(0x00000000_00080000, 44);
+    try test__clzdi2(0x00000000_00100000, 43);
+    try test__clzdi2(0x00000000_00200000, 42);
+    try test__clzdi2(0x00000000_00400000, 41);
+    try test__clzdi2(0x00000000_00800000, 40);
+    try test__clzdi2(0x00000000_01000000, 39);
+    try test__clzdi2(0x00000000_02000000, 38);
+    try test__clzdi2(0x00000000_04000000, 37);
+    try test__clzdi2(0x00000000_08000000, 36);
+    try test__clzdi2(0x00000000_10000000, 35);
+    try test__clzdi2(0x00000000_20000000, 34);
+    try test__clzdi2(0x00000000_40000000, 33);
+    try test__clzdi2(0x00000000_80000000, 32);
+
+    try test__clzdi2(0x00000001_00000000, 31);
+    try test__clzdi2(0x00000002_00000000, 30);
+    try test__clzdi2(0x00000004_00000000, 29);
+    try test__clzdi2(0x00000008_00000000, 28);
+    try test__clzdi2(0x00000010_00000000, 27);
+    try test__clzdi2(0x00000020_00000000, 26);
+    try test__clzdi2(0x00000040_00000000, 25);
+    try test__clzdi2(0x00000080_00000000, 24);
+    try test__clzdi2(0x00000100_00000000, 23);
+    try test__clzdi2(0x00000200_00000000, 22);
+    try test__clzdi2(0x00000400_00000000, 21);
+    try test__clzdi2(0x00000800_00000000, 20);
+    try test__clzdi2(0x00001000_00000000, 19);
+    try test__clzdi2(0x00002000_00000000, 18);
+    try test__clzdi2(0x00004000_00000000, 17);
+    try test__clzdi2(0x00008000_00000000, 16);
+    try test__clzdi2(0x00010000_00000000, 15);
+    try test__clzdi2(0x00020000_00000000, 14);
+    try test__clzdi2(0x00040000_00000000, 13);
+    try test__clzdi2(0x00080000_00000000, 12);
+    try test__clzdi2(0x00100000_00000000, 11);
+    try test__clzdi2(0x00200000_00000000, 10);
+    try test__clzdi2(0x00400000_00000000, 9);
+}
lib/std/special/compiler_rt/clzsi2_test.zig
@@ -1,10 +1,10 @@
-const clzsi2 = @import("clzsi2.zig");
+const clz = @import("count0bits.zig");
 const testing = @import("std").testing;
 
 fn test__clzsi2(a: u32, expected: i32) !void {
     // XXX At high optimization levels this test may be horribly miscompiled if
     // one of the naked implementations is selected.
-    var nakedClzsi2 = clzsi2.__clzsi2;
+    var nakedClzsi2 = clz.__clzsi2;
     var actualClzsi2 = @ptrCast(fn (a: i32) callconv(.C) i32, nakedClzsi2);
     var x = @bitCast(i32, a);
     var result = actualClzsi2(x);
@@ -268,6 +268,8 @@ test "clzsi2" {
     try test__clzsi2(0xFD000000, 0);
     try test__clzsi2(0xFE000000, 0);
     try test__clzsi2(0xFF000000, 0);
+    // arm and thumb1 assume input a != 0
+    //try test__clzsi2(0x00000000, 32);
     try test__clzsi2(0x00000001, 31);
     try test__clzsi2(0x00000002, 30);
     try test__clzsi2(0x00000004, 29);
lib/std/special/compiler_rt/clzti2_test.zig
@@ -0,0 +1,395 @@
+const clz = @import("count0bits.zig");
+const testing = @import("std").testing;
+
+fn test__clzti2(a: u128, expected: i64) !void {
+    // XXX At high optimization levels this test may be horribly miscompiled if
+    // one of the naked implementations is selected.
+    var nakedClzti2 = clz.__clzti2;
+    var actualClzti2 = @ptrCast(fn (a: i128) callconv(.C) i32, nakedClzti2);
+    var x = @bitCast(i128, a);
+    var result = actualClzti2(x);
+    try testing.expectEqual(expected, result);
+}
+
+test "clzti2" {
+    try test__clzti2(0x00800000_00000000_00000000_00000000, 8);
+    try test__clzti2(0x01000000_00000000_00000000_00000000, 7);
+    try test__clzti2(0x02000000_00000000_00000000_00000000, 6);
+    try test__clzti2(0x03000000_00000000_00000000_00000000, 6);
+    try test__clzti2(0x04000000_00000000_00000000_00000000, 5);
+    try test__clzti2(0x05000000_00000000_00000000_00000000, 5);
+    try test__clzti2(0x06000000_00000000_00000000_00000000, 5);
+    try test__clzti2(0x07000000_00000000_00000000_00000000, 5);
+    try test__clzti2(0x08000000_00000000_00000000_00000000, 4);
+    try test__clzti2(0x09000000_00000000_00000000_00000000, 4);
+    try test__clzti2(0x0A000000_00000000_00000000_00000000, 4);
+    try test__clzti2(0x0B000000_00000000_00000000_00000000, 4);
+    try test__clzti2(0x0C000000_00000000_00000000_00000000, 4);
+    try test__clzti2(0x0D000000_00000000_00000000_00000000, 4);
+    try test__clzti2(0x0E000000_00000000_00000000_00000000, 4);
+    try test__clzti2(0x0F000000_00000000_00000000_00000000, 4);
+    try test__clzti2(0x10000000_00000000_00000000_00000000, 3);
+    try test__clzti2(0x11000000_00000000_00000000_00000000, 3);
+    try test__clzti2(0x12000000_00000000_00000000_00000000, 3);
+    try test__clzti2(0x13000000_00000000_00000000_00000000, 3);
+    try test__clzti2(0x14000000_00000000_00000000_00000000, 3);
+    try test__clzti2(0x15000000_00000000_00000000_00000000, 3);
+    try test__clzti2(0x16000000_00000000_00000000_00000000, 3);
+    try test__clzti2(0x17000000_00000000_00000000_00000000, 3);
+    try test__clzti2(0x18000000_00000000_00000000_00000000, 3);
+    try test__clzti2(0x19000000_00000000_00000000_00000000, 3);
+    try test__clzti2(0x1A000000_00000000_00000000_00000000, 3);
+    try test__clzti2(0x1B000000_00000000_00000000_00000000, 3);
+    try test__clzti2(0x1C000000_00000000_00000000_00000000, 3);
+    try test__clzti2(0x1D000000_00000000_00000000_00000000, 3);
+    try test__clzti2(0x1E000000_00000000_00000000_00000000, 3);
+    try test__clzti2(0x1F000000_00000000_00000000_00000000, 3);
+    try test__clzti2(0x20000000_00000000_00000000_00000000, 2);
+    try test__clzti2(0x21000000_00000000_00000000_00000000, 2);
+    try test__clzti2(0x22000000_00000000_00000000_00000000, 2);
+    try test__clzti2(0x23000000_00000000_00000000_00000000, 2);
+    try test__clzti2(0x24000000_00000000_00000000_00000000, 2);
+    try test__clzti2(0x25000000_00000000_00000000_00000000, 2);
+    try test__clzti2(0x26000000_00000000_00000000_00000000, 2);
+    try test__clzti2(0x27000000_00000000_00000000_00000000, 2);
+    try test__clzti2(0x28000000_00000000_00000000_00000000, 2);
+    try test__clzti2(0x29000000_00000000_00000000_00000000, 2);
+    try test__clzti2(0x2A000000_00000000_00000000_00000000, 2);
+    try test__clzti2(0x2B000000_00000000_00000000_00000000, 2);
+    try test__clzti2(0x2C000000_00000000_00000000_00000000, 2);
+    try test__clzti2(0x2D000000_00000000_00000000_00000000, 2);
+    try test__clzti2(0x2E000000_00000000_00000000_00000000, 2);
+    try test__clzti2(0x2F000000_00000000_00000000_00000000, 2);
+    try test__clzti2(0x30000000_00000000_00000000_00000000, 2);
+    try test__clzti2(0x31000000_00000000_00000000_00000000, 2);
+    try test__clzti2(0x32000000_00000000_00000000_00000000, 2);
+    try test__clzti2(0x33000000_00000000_00000000_00000000, 2);
+    try test__clzti2(0x34000000_00000000_00000000_00000000, 2);
+    try test__clzti2(0x35000000_00000000_00000000_00000000, 2);
+    try test__clzti2(0x36000000_00000000_00000000_00000000, 2);
+    try test__clzti2(0x37000000_00000000_00000000_00000000, 2);
+    try test__clzti2(0x38000000_00000000_00000000_00000000, 2);
+    try test__clzti2(0x39000000_00000000_00000000_00000000, 2);
+    try test__clzti2(0x3A000000_00000000_00000000_00000000, 2);
+    try test__clzti2(0x3B000000_00000000_00000000_00000000, 2);
+    try test__clzti2(0x3C000000_00000000_00000000_00000000, 2);
+    try test__clzti2(0x3D000000_00000000_00000000_00000000, 2);
+    try test__clzti2(0x3E000000_00000000_00000000_00000000, 2);
+    try test__clzti2(0x3F000000_00000000_00000000_00000000, 2);
+    try test__clzti2(0x40000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x41000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x42000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x43000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x44000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x45000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x46000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x47000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x48000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x49000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x4A000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x4B000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x4C000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x4D000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x4E000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x4F000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x50000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x51000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x52000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x53000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x54000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x55000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x56000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x57000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x58000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x59000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x5A000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x5B000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x5C000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x5D000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x5E000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x5F000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x60000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x61000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x62000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x63000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x64000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x65000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x66000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x67000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x68000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x69000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x6A000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x6B000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x6C000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x6D000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x6E000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x6F000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x70000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x71000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x72000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x73000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x74000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x75000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x76000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x77000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x78000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x79000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x7A000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x7B000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x7C000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x7D000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x7E000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x7F000000_00000000_00000000_00000000, 1);
+    try test__clzti2(0x80000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0x81000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0x82000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0x83000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0x84000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0x85000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0x86000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0x87000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0x88000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0x89000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0x8A000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0x8B000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0x8C000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0x8D000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0x8E000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0x8F000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0x90000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0x91000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0x92000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0x93000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0x94000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0x95000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0x96000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0x97000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0x98000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0x99000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0x9A000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0x9B000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0x9C000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0x9D000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0x9E000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0x9F000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xA0000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xA1000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xA2000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xA3000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xA4000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xA5000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xA6000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xA7000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xA8000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xA9000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xAA000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xAB000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xAC000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xAD000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xAE000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xAF000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xB0000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xB1000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xB2000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xB3000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xB4000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xB5000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xB6000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xB7000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xB8000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xB9000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xBA000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xBB000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xBC000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xBD000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xBE000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xBF000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xC0000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xC1000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xC2000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xC3000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xC4000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xC5000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xC6000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xC7000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xC8000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xC9000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xCA000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xCB000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xCC000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xCD000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xCE000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xCF000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xD0000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xD1000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xD2000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xD3000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xD4000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xD5000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xD6000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xD7000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xD8000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xD9000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xDA000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xDB000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xDC000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xDD000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xDE000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xDF000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xE0000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xE1000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xE2000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xE3000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xE4000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xE5000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xE6000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xE7000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xE8000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xE9000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xEA000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xEB000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xEC000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xED000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xEE000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xEF000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xF0000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xF1000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xF2000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xF3000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xF4000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xF5000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xF6000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xF7000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xF8000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xF9000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xFA000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xFB000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xFC000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xFD000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xFE000000_00000000_00000000_00000000, 0);
+    try test__clzti2(0xFF000000_00000000_00000000_00000000, 0);
+
+    try test__clzti2(0x00000000_00000000_00000000_00000000, 128);
+    try test__clzti2(0x00000000_00000000_00000000_00000001, 127);
+    try test__clzti2(0x00000000_00000000_00000000_00000002, 126);
+    try test__clzti2(0x00000000_00000000_00000000_00000004, 125);
+    try test__clzti2(0x00000000_00000000_00000000_00000008, 124);
+    try test__clzti2(0x00000000_00000000_00000000_00000010, 123);
+    try test__clzti2(0x00000000_00000000_00000000_00000020, 122);
+    try test__clzti2(0x00000000_00000000_00000000_00000040, 121);
+    try test__clzti2(0x00000000_00000000_00000000_00000080, 120);
+    try test__clzti2(0x00000000_00000000_00000000_00000100, 119);
+    try test__clzti2(0x00000000_00000000_00000000_00000200, 118);
+    try test__clzti2(0x00000000_00000000_00000000_00000400, 117);
+    try test__clzti2(0x00000000_00000000_00000000_00000800, 116);
+    try test__clzti2(0x00000000_00000000_00000000_00001000, 115);
+    try test__clzti2(0x00000000_00000000_00000000_00002000, 114);
+    try test__clzti2(0x00000000_00000000_00000000_00004000, 113);
+    try test__clzti2(0x00000000_00000000_00000000_00008000, 112);
+    try test__clzti2(0x00000000_00000000_00000000_00010000, 111);
+    try test__clzti2(0x00000000_00000000_00000000_00020000, 110);
+    try test__clzti2(0x00000000_00000000_00000000_00040000, 109);
+    try test__clzti2(0x00000000_00000000_00000000_00080000, 108);
+    try test__clzti2(0x00000000_00000000_00000000_00100000, 107);
+    try test__clzti2(0x00000000_00000000_00000000_00200000, 106);
+    try test__clzti2(0x00000000_00000000_00000000_00400000, 105);
+    try test__clzti2(0x00000000_00000000_00000000_00800000, 104);
+    try test__clzti2(0x00000000_00000000_00000000_01000000, 103);
+    try test__clzti2(0x00000000_00000000_00000000_02000000, 102);
+    try test__clzti2(0x00000000_00000000_00000000_04000000, 101);
+    try test__clzti2(0x00000000_00000000_00000000_08000000, 100);
+    try test__clzti2(0x00000000_00000000_00000000_10000000, 99);
+    try test__clzti2(0x00000000_00000000_00000000_20000000, 98);
+    try test__clzti2(0x00000000_00000000_00000000_40000000, 97);
+    try test__clzti2(0x00000000_00000000_00000000_80000000, 96);
+
+    try test__clzti2(0x00000000_00000000_00000001_00000000, 95);
+    try test__clzti2(0x00000000_00000000_00000002_00000000, 94);
+    try test__clzti2(0x00000000_00000000_00000004_00000000, 93);
+    try test__clzti2(0x00000000_00000000_00000008_00000000, 92);
+    try test__clzti2(0x00000000_00000000_00000010_00000000, 91);
+    try test__clzti2(0x00000000_00000000_00000020_00000000, 90);
+    try test__clzti2(0x00000000_00000000_00000040_00000000, 89);
+    try test__clzti2(0x00000000_00000000_00000080_00000000, 88);
+    try test__clzti2(0x00000000_00000000_00000100_00000000, 87);
+    try test__clzti2(0x00000000_00000000_00000200_00000000, 86);
+    try test__clzti2(0x00000000_00000000_00000400_00000000, 85);
+    try test__clzti2(0x00000000_00000000_00000800_00000000, 84);
+    try test__clzti2(0x00000000_00000000_00001000_00000000, 83);
+    try test__clzti2(0x00000000_00000000_00002000_00000000, 82);
+    try test__clzti2(0x00000000_00000000_00004000_00000000, 81);
+    try test__clzti2(0x00000000_00000000_00008000_00000000, 80);
+    try test__clzti2(0x00000000_00000000_00010000_00000000, 79);
+    try test__clzti2(0x00000000_00000000_00020000_00000000, 78);
+    try test__clzti2(0x00000000_00000000_00040000_00000000, 77);
+    try test__clzti2(0x00000000_00000000_00080000_00000000, 76);
+    try test__clzti2(0x00000000_00000000_00100000_00000000, 75);
+    try test__clzti2(0x00000000_00000000_00200000_00000000, 74);
+    try test__clzti2(0x00000000_00000000_00400000_00000000, 73);
+    try test__clzti2(0x00000000_00000000_00800000_00000000, 72);
+    try test__clzti2(0x00000000_00000000_01000000_00000000, 71);
+    try test__clzti2(0x00000000_00000000_02000000_00000000, 70);
+    try test__clzti2(0x00000000_00000000_04000000_00000000, 69);
+    try test__clzti2(0x00000000_00000000_08000000_00000000, 68);
+    try test__clzti2(0x00000000_00000000_10000000_00000000, 67);
+    try test__clzti2(0x00000000_00000000_20000000_00000000, 66);
+    try test__clzti2(0x00000000_00000000_40000000_00000000, 65);
+    try test__clzti2(0x00000000_00000000_80000000_00000000, 64);
+
+    try test__clzti2(0x00000000_00000001_00000000_00000000, 63);
+    try test__clzti2(0x00000000_00000002_00000000_00000000, 62);
+    try test__clzti2(0x00000000_00000004_00000000_00000000, 61);
+    try test__clzti2(0x00000000_00000008_00000000_00000000, 60);
+    try test__clzti2(0x00000000_00000010_00000000_00000000, 59);
+    try test__clzti2(0x00000000_00000020_00000000_00000000, 58);
+    try test__clzti2(0x00000000_00000040_00000000_00000000, 57);
+    try test__clzti2(0x00000000_00000080_00000000_00000000, 56);
+    try test__clzti2(0x00000000_00000100_00000000_00000000, 55);
+    try test__clzti2(0x00000000_00000200_00000000_00000000, 54);
+    try test__clzti2(0x00000000_00000400_00000000_00000000, 53);
+    try test__clzti2(0x00000000_00000800_00000000_00000000, 52);
+    try test__clzti2(0x00000000_00001000_00000000_00000000, 51);
+    try test__clzti2(0x00000000_00002000_00000000_00000000, 50);
+    try test__clzti2(0x00000000_00004000_00000000_00000000, 49);
+    try test__clzti2(0x00000000_00008000_00000000_00000000, 48);
+    try test__clzti2(0x00000000_00010000_00000000_00000000, 47);
+    try test__clzti2(0x00000000_00020000_00000000_00000000, 46);
+    try test__clzti2(0x00000000_00040000_00000000_00000000, 45);
+    try test__clzti2(0x00000000_00080000_00000000_00000000, 44);
+    try test__clzti2(0x00000000_00100000_00000000_00000000, 43);
+    try test__clzti2(0x00000000_00200000_00000000_00000000, 42);
+    try test__clzti2(0x00000000_00400000_00000000_00000000, 41);
+    try test__clzti2(0x00000000_00800000_00000000_00000000, 40);
+    try test__clzti2(0x00000000_01000000_00000000_00000000, 39);
+    try test__clzti2(0x00000000_02000000_00000000_00000000, 38);
+    try test__clzti2(0x00000000_04000000_00000000_00000000, 37);
+    try test__clzti2(0x00000000_08000000_00000000_00000000, 36);
+    try test__clzti2(0x00000000_10000000_00000000_00000000, 35);
+    try test__clzti2(0x00000000_20000000_00000000_00000000, 34);
+    try test__clzti2(0x00000000_40000000_00000000_00000000, 33);
+    try test__clzti2(0x00000000_80000000_00000000_00000000, 32);
+
+    try test__clzti2(0x00000001_00000000_00000000_00000000, 31);
+    try test__clzti2(0x00000002_00000000_00000000_00000000, 30);
+    try test__clzti2(0x00000004_00000000_00000000_00000000, 29);
+    try test__clzti2(0x00000008_00000000_00000000_00000000, 28);
+    try test__clzti2(0x00000010_00000000_00000000_00000000, 27);
+    try test__clzti2(0x00000020_00000000_00000000_00000000, 26);
+    try test__clzti2(0x00000040_00000000_00000000_00000000, 25);
+    try test__clzti2(0x00000080_00000000_00000000_00000000, 24);
+    try test__clzti2(0x00000100_00000000_00000000_00000000, 23);
+    try test__clzti2(0x00000200_00000000_00000000_00000000, 22);
+    try test__clzti2(0x00000400_00000000_00000000_00000000, 21);
+    try test__clzti2(0x00000800_00000000_00000000_00000000, 20);
+    try test__clzti2(0x00001000_00000000_00000000_00000000, 19);
+    try test__clzti2(0x00002000_00000000_00000000_00000000, 18);
+    try test__clzti2(0x00004000_00000000_00000000_00000000, 17);
+    try test__clzti2(0x00008000_00000000_00000000_00000000, 16);
+    try test__clzti2(0x00010000_00000000_00000000_00000000, 15);
+    try test__clzti2(0x00020000_00000000_00000000_00000000, 14);
+    try test__clzti2(0x00040000_00000000_00000000_00000000, 13);
+    try test__clzti2(0x00080000_00000000_00000000_00000000, 12);
+    try test__clzti2(0x00100000_00000000_00000000_00000000, 11);
+    try test__clzti2(0x00200000_00000000_00000000_00000000, 10);
+    try test__clzti2(0x00400000_00000000_00000000_00000000, 9);
+}
lib/std/special/compiler_rt/clzsi2.zig → lib/std/special/compiler_rt/count0bits.zig
@@ -1,23 +1,37 @@
 const std = @import("std");
 const builtin = std.builtin;
 
-fn __clzsi2_generic(a: i32) callconv(.C) i32 {
-    @setRuntimeSafety(builtin.is_test);
+// clz - count leading zeroes
+// - clzXi2_generic for little endian
+// - __clzsi2_thumb1: assume a != 0
+// - __clzsi2_arm32: assume a != 0
 
-    var x = @bitCast(u32, a);
-    var n: i32 = 32;
+fn clzXi2_generic(comptime T: type) fn (a: T) callconv(.C) i32 {
+    return struct {
+        fn f(a: T) callconv(.C) i32 {
+            @setRuntimeSafety(builtin.is_test);
 
-    // Count first bit set using binary search, from Hacker's Delight
-    var y: u32 = 0;
-    inline for ([_]i32{ 16, 8, 4, 2, 1 }) |shift| {
-        y = x >> shift;
-        if (y != 0) {
-            n = n - shift;
-            x = y;
+            var x = switch (@bitSizeOf(T)) {
+                32 => @bitCast(u32, a),
+                64 => @bitCast(u64, a),
+                128 => @bitCast(u128, a),
+                else => unreachable,
+            };
+            var n: T = @bitSizeOf(T);
+            // Count first bit set using binary search, from Hacker's Delight
+            var y: @TypeOf(x) = 0;
+            comptime var shift: u8 = @bitSizeOf(T);
+            inline while (shift > 0) {
+                shift = shift >> 1;
+                y = x >> shift;
+                if (y != 0) {
+                    n = n - shift;
+                    x = y;
+                }
+            }
+            return @intCast(i32, n - @bitCast(T, x));
         }
-    }
-
-    return n - @bitCast(i32, x);
+    }.f;
 }
 
 fn __clzsi2_thumb1() callconv(.Naked) void {
@@ -111,16 +125,36 @@ pub const __clzsi2 = impl: {
                 std.Target.arm.featureSetHas(std.Target.current.cpu.features, .noarm)) and
                 !std.Target.arm.featureSetHas(std.Target.current.cpu.features, .thumb2);
 
-            if (use_thumb1) break :impl __clzsi2_thumb1
+            if (use_thumb1) {
+                break :impl __clzsi2_thumb1;
+            }
             // From here on we're either targeting Thumb2 or ARM.
-            else if (!std.Target.current.cpu.arch.isThumb()) break :impl __clzsi2_arm32
+            else if (!std.Target.current.cpu.arch.isThumb()) {
+                break :impl __clzsi2_arm32;
+            }
             // Use the generic implementation otherwise.
-            else break :impl __clzsi2_generic;
+            else break :impl clzXi2_generic(i32);
         },
-        else => break :impl __clzsi2_generic,
+        else => break :impl clzXi2_generic(i32),
+    }
+};
+
+pub const __clzdi2 = impl: {
+    switch (std.Target.current.cpu.arch) {
+        // TODO architecture optimised versions
+        else => break :impl clzXi2_generic(i64),
+    }
+};
+
+pub const __clzti2 = impl: {
+    switch (std.Target.current.cpu.arch) {
+        // TODO architecture optimised versions
+        else => break :impl clzXi2_generic(i128),
     }
 };
 
-test "test clzsi2" {
+test {
     _ = @import("clzsi2_test.zig");
+    _ = @import("clzdi2_test.zig");
+    _ = @import("clzti2_test.zig");
 }
lib/std/special/compiler_rt.zig
@@ -269,8 +269,12 @@ comptime {
     const __negdf2 = @import("compiler_rt/negXf2.zig").__negdf2;
     @export(__negdf2, .{ .name = "__negdf2", .linkage = linkage });
 
-    const __clzsi2 = @import("compiler_rt/clzsi2.zig").__clzsi2;
+    const __clzsi2 = @import("compiler_rt/count0bits.zig").__clzsi2;
     @export(__clzsi2, .{ .name = "__clzsi2", .linkage = linkage });
+    const __clzdi2 = @import("compiler_rt/count0bits.zig").__clzdi2;
+    @export(__clzdi2, .{ .name = "__clzdi2", .linkage = linkage });
+    const __clzti2 = @import("compiler_rt/count0bits.zig").__clzti2;
+    @export(__clzti2, .{ .name = "__clzti2", .linkage = linkage });
 
     if (builtin.link_libc and os_tag == .openbsd) {
         const __emutls_get_address = @import("compiler_rt/emutls.zig").__emutls_get_address;
CMakeLists.txt
@@ -447,8 +447,8 @@ set(ZIG_STAGE2_SOURCES
     "${CMAKE_SOURCE_DIR}/lib/std/special/compiler_rt/addXf3.zig"
     "${CMAKE_SOURCE_DIR}/lib/std/special/compiler_rt/atomics.zig"
     "${CMAKE_SOURCE_DIR}/lib/std/special/compiler_rt/clear_cache.zig"
-    "${CMAKE_SOURCE_DIR}/lib/std/special/compiler_rt/clzsi2.zig"
     "${CMAKE_SOURCE_DIR}/lib/std/special/compiler_rt/compareXf2.zig"
+    "${CMAKE_SOURCE_DIR}/lib/std/special/compiler_rt/count0bits.zig"
     "${CMAKE_SOURCE_DIR}/lib/std/special/compiler_rt/divdf3.zig"
     "${CMAKE_SOURCE_DIR}/lib/std/special/compiler_rt/divsf3.zig"
     "${CMAKE_SOURCE_DIR}/lib/std/special/compiler_rt/divtf3.zig"