authorgravatar for git@adrianjdelgado.comAdrian Delgado <git@adrianjdelgado.com> 2023-03-22 13:22:25-05:00
committergravatar for git@adrianjdelgado.comAdrian Delgado <git@adrianjdelgado.com> 2023-03-22 13:22:25-05:00
logd6ad69d40a3ba32e9f10a12618dbeece2e62a051
tree5e3c5e308dfd8adb752f0507dcd5c43a967533cc
parentf34aa2d14fbacc7e4d2471c8b4897da257cffc03

workaround bootstrapping limitations

1 files changed, 36 insertions(+), 4 deletions(-)

lib/std/math/log10.zig+36-4
......@@ -1,4 +1,5 @@
11const std = @import("../std.zig");
2const builtin = @import("builtin");
23const math = std.math;
34const testing = std.testing;
45const maxInt = std.math.maxInt;
......@@ -74,11 +75,26 @@ pub fn log10_int(x: anytype) Log2Int(@TypeOf(x)) {
7475}
7576
7677fn pow10(comptime y: comptime_int) comptime_int {
77 var result = 1;
78 for (0..y) |_| {
79 result *= 10;
78 if (y == 0) return 1;
79
80 var squaring = 0;
81 var s = 1;
82
83 while (s <= y) : (s <<= 1) {
84 squaring += 1;
85 }
86
87 squaring -= 1;
88
89 var result = 10;
90
91 for (0..squaring) |_| {
92 result *= result;
8093 }
81 return result;
94
95 const rest_exp = y - (1 << squaring);
96
97 return result * pow10(rest_exp);
8298}
8399
84100inline fn log10_int_u8(x: u8) u32 {
......@@ -129,6 +145,14 @@ test "oldlog10 doesn't work" {
129145}
130146
131147test "log10_int vs old implementation" {
148 if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
149 if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
150 if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
151 if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
152 if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
153 if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
154 if (builtin.zig_backend == .stage2_llvm and comptime builtin.target.isWasm()) return error.SkipZigTest; // TODO
155
132156 const int_types = .{ u8, u16, u32, u64, u128 };
133157
134158 inline for (int_types) |T| {
......@@ -144,6 +168,14 @@ test "log10_int vs old implementation" {
144168}
145169
146170test "log10_int close to powers of 10" {
171 if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
172 if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
173 if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
174 if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
175 if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
176 if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
177 if (builtin.zig_backend == .stage2_llvm and comptime builtin.target.isWasm()) return error.SkipZigTest; // TODO
178
147179 const int_types = .{ u8, u16, u32, u64, u128, u256, u512 };
148180 const max_log_values: [7]usize = .{ 2, 4, 9, 19, 38, 77, 154 };
149181