chore: update CPU feature detection to use archsimd package (#60)

Author: nnnkkk7

go.mod

@@ -4,5 +4,3 @@ module github.com/nnnkkk7/go-simdcsv
 // For local development on Apple Silicon, use Docker: make docker-test
 // Using go 1.25 for IDE compatibility (SIMD code won't compile locally)
 go 1.25
-
-require golang.org/x/sys v0.40.0

go.sum

@@ -1,2 +0,0 @@
-golang.org/x/sys v0.40.0 h1:DBZZqJ2Rkml6QMQsZywtnjnnGvHza6BTfYFWY9kjEWQ=
-golang.org/x/sys v0.40.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=

simd_scanner.go

@@ -7,45 +7,9 @@ import (
 	"simd/archsimd"
 	"sync"
 	"unsafe"
-
-	"golang.org/x/sys/cpu"
 )
 
-// =============================================================================
-// AVX-512 CPU Detection and Fallback
-// =============================================================================
-//
-// NOTE: The simd/archsimd package in Go 1.26 is an experimental feature enabled via
-// GOEXPERIMENT=simd. This package is AMD64-specific, and a higher-level portable
-// SIMD package is planned for future development.
-// See: https://github.com/golang/go/issues/73787 (archsimd proposal)
-// See: https://go.dev/doc/go1.26 (Go 1.26 Release Notes)
-//
-// NOTE: The archsimd.Int8x64.Equal().ToBits() method internally uses the VPMOVB2M
-// instruction (AVX-512BW). This instruction causes SIGILL (illegal instruction) on
-// CPUs that do not support AVX-512, including GitHub Actions ubuntu-latest runners,
-// most CI environments, and older CPUs.
-//
-// TODO: Revisit this fallback implementation when the simd/archsimd package provides:
-//   - Mandatory runtime CPU feature checks within the archsimd package
-//     (Issue #73787: "It is an open question whether we want to enforce that a CPU
-//      feature check must be performed before using a vector intrinsic.")
-//   - AVX2-only alternative to ToBits() (using VPMOVMSKB instruction)
-//   - A high-level portable SIMD package
-//
-// TODO: Replace golang.org/x/sys/cpu usage with official archsimd API (e.g.,
-// archsimd.HasAVX512()) when such API becomes available. Currently, the archsimd
-// package does not provide CPU feature detection functions (as of Go 1.26).
-//
-// =============================================================================
-
 // useAVX512 indicates whether AVX-512 instructions are available at runtime.
-// This is set once at init time and used to dispatch to the appropriate implementation.
-//
-// NOTE: All three feature flags are required:
-//   - AVX512F: Foundation 512-bit vector operations
-//   - AVX512BW: Byte/word granularity operations (ToBits() uses VPMOVB2M)
-//   - AVX512VL: 128/256-bit vector support with AVX-512 instructions
 var useAVX512 bool
 
 // SIMD processing constants.
@@ -58,9 +22,7 @@ const (
 )
 
 func init() {
-	// NOTE: Using golang.org/x/sys/cpu for runtime CPU feature detection.
-	// The archsimd package itself does not provide CPU detection functions (as of Go 1.26).
-	useAVX512 = cpu.X86.HasAVX512F && cpu.X86.HasAVX512BW && cpu.X86.HasAVX512VL
+	useAVX512 = archsimd.X86.AVX512()
 }
 
 // =============================================================================