From 018262d537959701566f2dfece66a462c3bbc976 Mon Sep 17 00:00:00 2001
From: mlugg <mlugg@mlugg.co.uk>
Date: Mon, 19 Aug 2024 10:26:51 +0100
Subject: [PATCH] std: update eval branch quotas after bdbc485

Also, update `std.math.Log2Int[Ceil]` to more efficient implementations
that don't use up so much damn quota!
---
 lib/std/crypto/aes/soft.zig |  2 ++
 lib/std/crypto/blake2.zig   |  4 ++--
 lib/std/enums.zig           |  2 +-
 lib/std/hash/xxhash.zig     |  2 +-
 lib/std/math.zig            | 24 ++++++++----------------
 lib/std/math/hypot.zig      |  1 +
 lib/std/math/nextafter.zig  |  2 +-
 lib/std/unicode.zig         |  1 +
 8 files changed, 17 insertions(+), 21 deletions(-)

diff --git a/lib/std/crypto/aes/soft.zig b/lib/std/crypto/aes/soft.zig
index 9e7af0606d..fd0dfaf001 100644
--- a/lib/std/crypto/aes/soft.zig
+++ b/lib/std/crypto/aes/soft.zig
@@ -629,6 +629,8 @@ fn generateSbox(invert: bool) [256]u8 {
 
 // Generate lookup tables.
 fn generateTable(invert: bool) [4][256]u32 {
+    @setEvalBranchQuota(50000);
+
     var table: [4][256]u32 = undefined;
 
     for (generateSbox(invert), 0..) |value, index| {
diff --git a/lib/std/crypto/blake2.zig b/lib/std/crypto/blake2.zig
index 255011de87..1a285080b5 100644
--- a/lib/std/crypto/blake2.zig
+++ b/lib/std/crypto/blake2.zig
@@ -786,7 +786,7 @@ test "blake2b384 streaming" {
 
 test "comptime blake2b384" {
     comptime {
-        @setEvalBranchQuota(10000);
+        @setEvalBranchQuota(20000);
         var block = [_]u8{0} ** Blake2b384.block_length;
         var out: [Blake2b384.digest_length]u8 = undefined;
 
@@ -878,7 +878,7 @@ test "blake2b512 keyed" {
 
 test "comptime blake2b512" {
     comptime {
-        @setEvalBranchQuota(10000);
+        @setEvalBranchQuota(12000);
         var block = [_]u8{0} ** Blake2b512.block_length;
         var out: [Blake2b512.digest_length]u8 = undefined;
 
diff --git a/lib/std/enums.zig b/lib/std/enums.zig
index aea194683d..1cc7bde8d2 100644
--- a/lib/std/enums.zig
+++ b/lib/std/enums.zig
@@ -6,7 +6,7 @@ const testing = std.testing;
 const EnumField = std.builtin.Type.EnumField;
 
 /// Increment this value when adding APIs that add single backwards branches.
-const eval_branch_quota_cushion = 5;
+const eval_branch_quota_cushion = 10;
 
 /// Returns a struct with a field matching each unique named enum element.
 /// If the enum is extern and has multiple names for the same value, only
diff --git a/lib/std/hash/xxhash.zig b/lib/std/hash/xxhash.zig
index 88ec3ba372..1d7c8399fc 100644
--- a/lib/std/hash/xxhash.zig
+++ b/lib/std/hash/xxhash.zig
@@ -890,7 +890,7 @@ test "xxhash32 smhasher" {
         }
     };
     try Test.do();
-    @setEvalBranchQuota(75000);
+    @setEvalBranchQuota(85000);
     comptime try Test.do();
 }
 
diff --git a/lib/std/math.zig b/lib/std/math.zig
index 0c00818a1e..f18739095c 100644
--- a/lib/std/math.zig
+++ b/lib/std/math.zig
@@ -749,31 +749,23 @@ test rotl {
     try testing.expect(rotl(@Vector(1, u32), @Vector(1, u32){1 << 31}, @as(isize, -1))[0] == @as(u32, 1) << 30);
 }
 
-/// Returns an unsigned int type that can hold the number of bits in T
-/// - 1. Suitable for 0-based bit indices of T.
+/// Returns an unsigned int type that can hold the number of bits in T - 1.
+/// Suitable for 0-based bit indices of T.
 pub fn Log2Int(comptime T: type) type {
     // comptime ceil log2
     if (T == comptime_int) return comptime_int;
-    comptime var count = 0;
-    comptime var s = @typeInfo(T).Int.bits - 1;
-    inline while (s != 0) : (s >>= 1) {
-        count += 1;
-    }
-
-    return std.meta.Int(.unsigned, count);
+    const bits: u16 = @typeInfo(T).Int.bits;
+    const log2_bits = 16 - @clz(bits - 1);
+    return std.meta.Int(.unsigned, log2_bits);
 }
 
 /// Returns an unsigned int type that can hold the number of bits in T.
 pub fn Log2IntCeil(comptime T: type) type {
     // comptime ceil log2
     if (T == comptime_int) return comptime_int;
-    comptime var count = 0;
-    comptime var s = @typeInfo(T).Int.bits;
-    inline while (s != 0) : (s >>= 1) {
-        count += 1;
-    }
-
-    return std.meta.Int(.unsigned, count);
+    const bits: u16 = @typeInfo(T).Int.bits;
+    const log2_bits = 16 - @clz(bits);
+    return std.meta.Int(.unsigned, log2_bits);
 }
 
 /// Returns the smallest integer type that can hold both from and to.
diff --git a/lib/std/math/hypot.zig b/lib/std/math/hypot.zig
index cc0dc17ab1..ddc9408aba 100644
--- a/lib/std/math/hypot.zig
+++ b/lib/std/math/hypot.zig
@@ -114,6 +114,7 @@ test "hypot.precise" {
 }
 
 test "hypot.special" {
+    @setEvalBranchQuota(2000);
     inline for (.{ f16, f32, f64, f128 }) |T| {
         try expect(math.isNan(hypot(nan(T), 0.0)));
         try expect(math.isNan(hypot(0.0, nan(T))));
diff --git a/lib/std/math/nextafter.zig b/lib/std/math/nextafter.zig
index 717cbf4700..b88648229b 100644
--- a/lib/std/math/nextafter.zig
+++ b/lib/std/math/nextafter.zig
@@ -144,7 +144,7 @@ test "int" {
 }
 
 test "float" {
-    @setEvalBranchQuota(3000);
+    @setEvalBranchQuota(4000);
 
     // normal -> normal
     try expect(nextAfter(f16, 0x1.234p0, 2.0) == 0x1.238p0);
diff --git a/lib/std/unicode.zig b/lib/std/unicode.zig
index a8fa1454a5..4c6ec1294b 100644
--- a/lib/std/unicode.zig
+++ b/lib/std/unicode.zig
@@ -535,6 +535,7 @@ fn testUtf16CountCodepoints() !void {
 }
 
 test "utf16 count codepoints" {
+    @setEvalBranchQuota(2000);
     try testUtf16CountCodepoints();
     try comptime testUtf16CountCodepoints();
 }