Commit c919e9a280

Veikka Tuominen <git@vexu.eu>
2023-10-13 15:57:50
std.simd: return comptime_int from `suggestVectorSize`
1 parent f09313d
Changed files (4)
lib/std/http/protocol.zig
@@ -82,7 +82,7 @@ pub const HeadersParser = struct {
     /// If the amount returned is less than `bytes.len`, you may assume that the parser is in a content state and the
     /// first byte of content is located at `bytes[result]`.
     pub fn findHeadersEnd(r: *HeadersParser, bytes: []const u8) u32 {
-        const vector_len: comptime_int = comptime @max(std.simd.suggestVectorSize(u8) orelse 1, 8);
+        const vector_len: comptime_int = @max(std.simd.suggestVectorSize(u8) orelse 1, 8);
         const len = @as(u32, @intCast(bytes.len));
         var index: u32 = 0;
 
lib/std/mem.zig
@@ -974,7 +974,7 @@ pub fn indexOfSentinel(comptime T: type, comptime sentinel: T, p: [*:sentinel]co
             // The below branch assumes that reading past the end of the buffer is valid, as long
             // as we don't read into a new page. This should be the case for most architectures
             // which use paged memory, however should be confirmed before adding a new arch below.
-            .aarch64, .x86, .x86_64 => if (comptime std.simd.suggestVectorSize(T)) |block_len| {
+            .aarch64, .x86, .x86_64 => if (std.simd.suggestVectorSize(T)) |block_len| {
                 comptime std.debug.assert(std.mem.page_size % block_len == 0);
                 const Block = @Vector(block_len, T);
                 const mask: Block = @splat(sentinel);
@@ -1027,7 +1027,7 @@ test "indexOfSentinel vector paths" {
     const allocator = std.testing.allocator;
 
     inline for (Types) |T| {
-        const block_len = comptime std.simd.suggestVectorSize(T) orelse continue;
+        const block_len = std.simd.suggestVectorSize(T) orelse continue;
 
         // Allocate three pages so we guarantee a page-crossing address with a full page after
         const memory = try allocator.alloc(T, 3 * std.mem.page_size / @sizeOf(T));
@@ -1118,11 +1118,11 @@ pub fn indexOfScalarPos(comptime T: type, slice: []const T, start_index: usize,
         !@inComptime() and
         (@typeInfo(T) == .Int or @typeInfo(T) == .Float) and std.math.isPowerOfTwo(@bitSizeOf(T)))
     {
-        if (comptime std.simd.suggestVectorSize(T)) |block_len| {
+        if (std.simd.suggestVectorSize(T)) |block_len| {
             // For Intel Nehalem (2009) and AMD Bulldozer (2012) or later, unaligned loads on aligned data result
             // in the same execution as aligned loads. We ignore older arch's here and don't bother pre-aligning.
             //
-            // Use `comptime std.simd.suggestVectorSize(T)` to get the same alignment as used in this function
+            // Use `std.simd.suggestVectorSize(T)` to get the same alignment as used in this function
             // however this usually isn't necessary unless your arch has a performance penalty due to this.
             //
             // This may differ for other arch's. Arm for example costs a cycle when loading across a cache
lib/std/simd.zig
@@ -6,7 +6,7 @@
 const std = @import("std");
 const builtin = @import("builtin");
 
-pub fn suggestVectorSizeForCpu(comptime T: type, comptime cpu: std.Target.Cpu) ?usize {
+pub fn suggestVectorSizeForCpu(comptime T: type, comptime cpu: std.Target.Cpu) ?comptime_int {
     // This is guesswork, if you have better suggestions can add it or edit the current here
     // This can run in comptime only, but stage 1 fails at it, stage 2 can understand it
     const element_bit_size = @max(8, std.math.ceilPowerOfTwo(u16, @bitSizeOf(T)) catch unreachable);
@@ -55,7 +55,7 @@ pub fn suggestVectorSizeForCpu(comptime T: type, comptime cpu: std.Target.Cpu) ?
 
 /// Suggests a target-dependant vector size for a given type, or null if scalars are recommended.
 /// Not yet implemented for every CPU architecture.
-pub fn suggestVectorSize(comptime T: type) ?usize {
+pub fn suggestVectorSize(comptime T: type) ?comptime_int {
     return suggestVectorSizeForCpu(T, builtin.cpu);
 }
 
lib/std/unicode.zig
@@ -200,7 +200,7 @@ pub fn utf8CountCodepoints(s: []const u8) !usize {
 pub fn utf8ValidateSlice(input: []const u8) bool {
     var remaining = input;
 
-    const V_len = comptime std.simd.suggestVectorSize(usize) orelse 1;
+    const V_len = std.simd.suggestVectorSize(usize) orelse 1;
     const V = @Vector(V_len, usize);
     const u8s_in_vector = @sizeOf(usize) * V_len;