diff --git a/CHANGELOG.md b/CHANGELOG.md
index dc27742..b04274a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,19 +7,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
-### Added
-
-#### DICOM Independence & Final Integration (Milestone 20)
-- Non-DICOM usage examples in USAGE_EXAMPLES.md (general-purpose compression, web assets, archival storage)
-- DICOM-aware/DICOM-independent architecture documented in README.md
-
-### Fixed
-
-#### DICOM Independence & Final Integration (Milestone 20)
-- Fixed incorrect threshold values in `JPEGLSPresetParametersTests` for 8-bit and 12-bit images; test expectations now match the ITU-T.87 Table C.2 formula (8-bit: T1=3, T2=7, T3=21; 12-bit: T1=18, T2=67, T3=276)
-- Fixed incorrect expected values in `JPEGLSNearLosslessTests` for reconstructed-value boundary tests; test inputs now avoid the ITU-T.87 modular-wrap threshold, correctly exercising the clamp-to-MAXVAL and clamp-to-zero paths
-
-## [0.8.0] - In Progress
+## [0.8.0] - 2026-05-30
 
 ### Added
 
@@ -53,16 +41,35 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Man page documentation (man/jpegls.1) in groff format
 - Man page installation instructions in README
 
+#### DICOM Test Harness & Tooling
+- `jpegls bench-dicom` command: JPEG-LS round-trip benchmark over a DICOM corpus, reporting per-modality encode/decode throughput and lossless verification
+- First-mismatch diagnostics on `bench-dicom` lossless failures (reports row/col and decoded vs original sample value, written to stderr)
+
+#### DICOM Independence & Final Integration (Milestone 20)
+- Non-DICOM usage examples in USAGE_EXAMPLES.md (general-purpose compression, web assets, archival storage)
+- DICOM-aware/DICOM-independent architecture documented in README.md
+
 ### Changed
 - Overall project test coverage measured at 95.80% on Linux x86_64 (exceeds 95% threshold)
 - Coverage varies by platform due to conditional compilation of platform-specific optimisations
 - README.md updated with accurate coverage measurements and platform notes
 - README.md updated with links to new documentation guides
 - MILESTONES.md updated to reflect progress on Milestone 8 and 9
+- Reorganised repository layout: documentation moved into `docs/`, man page into `man/`
+- Renamed executable target `jpegls` → `jpeglscli` to avoid a case-insensitive-filesystem collision with the `JPEGLS` library target (the built product is still named `jpegls`)
 
 ### Fixed
 - Parser now handles CharLS-encoded files with extension markers
 - All 12 CharLS reference files can be parsed without errors
+- Build & test compilation on case-insensitive (Apple) filesystems
+- `SIMDMask.any()` build error on ARM64 (replaced with an equality check)
+- Metal GPU path now works under `swift build`/`swift test`: when no precompiled `default.metallib` is present (SwiftPM copies the `.metal` source rather than compiling it), `MetalAccelerator` compiles the bundled shader source at runtime instead of failing with "no default library was found"
+- `ARM64Accelerator.computeGolombRiceParameter` now clamps the result to the documented `[0, 31]` range for pathological `a/n` ratios (previously could return an unclamped value; now matches `X86_64Accelerator`)
+- `MetalAccelerator.computeGradientsBatch` CPU fallback now uses wrapping subtraction to match the GPU shader's two's-complement semantics, keeping the two paths bit-identical and preventing a trap on extreme `Int32` inputs (e.g. `0 - Int32.min`)
+
+#### DICOM Independence & Final Integration (Milestone 20)
+- Fixed incorrect threshold values in `JPEGLSPresetParametersTests` for 8-bit and 12-bit images; test expectations now match the ITU-T.87 Table C.2 formula (8-bit: T1=3, T2=7, T3=21; 12-bit: T1=18, T2=67, T3=276)
+- Fixed incorrect expected values in `JPEGLSNearLosslessTests` for reconstructed-value boundary tests; test inputs now avoid the ITU-T.87 modular-wrap threshold, correctly exercising the clamp-to-MAXVAL and clamp-to-zero paths
 
 ## [0.7.0] - Completed
 
@@ -314,5 +321,5 @@ See [RELEASE_NOTES_TEMPLATE.md](docs/RELEASE_NOTES_TEMPLATE.md) for the release
 - **0.8.0** - Validation & conformance (CharLS, benchmarks, edge cases)
 - **1.0.0** - Planned stable release
 
-<!-- Note: Comparison links will be added after the first release is tagged -->
-[Unreleased]: https://github.com/Raster-Lab/JLSwift/commits/main
+[Unreleased]: https://github.com/Raster-Lab/JLSwift/compare/v0.8.0...HEAD
+[0.8.0]: https://github.com/Raster-Lab/JLSwift/releases/tag/v0.8.0
diff --git a/README.md b/README.md
index 4fc20eb..e438b94 100644
--- a/README.md
+++ b/README.md
@@ -33,7 +33,7 @@ Add JLSwift as a dependency in your `Package.swift`:
 
 ```swift
 dependencies: [
-    .package(url: "https://github.com/Raster-Lab/JLSwift.git", from: "0.1.0")
+    .package(url: "https://github.com/Raster-Lab/JLSwift.git", from: "0.8.0")
 ]
 ```
 
diff --git a/Sources/JPEGLS/Platform/ARM64/ARM64Accelerator.swift b/Sources/JPEGLS/Platform/ARM64/ARM64Accelerator.swift
index 53f3d34..4196464 100644
--- a/Sources/JPEGLS/Platform/ARM64/ARM64Accelerator.swift
+++ b/Sources/JPEGLS/Platform/ARM64/ARM64Accelerator.swift
@@ -193,8 +193,11 @@ public struct ARM64Accelerator: PlatformAccelerator {
         while k < 31 && (n << k) < a {
             k += 1
         }
-        
-        return k
+
+        // Clamp to the documented [0, 31] range. When the CLZ-based estimate
+        // already starts above 31 (pathological a/n), the loop above is skipped,
+        // so the clamp here is what enforces the upper bound (matches X86_64Accelerator).
+        return min(k, 31)
     }
     
     // MARK: - NEON-Optimized MED Predictor
diff --git a/Sources/JPEGLS/Platform/Metal/MetalAccelerator.swift b/Sources/JPEGLS/Platform/Metal/MetalAccelerator.swift
index a376dc7..096dd0e 100644
--- a/Sources/JPEGLS/Platform/Metal/MetalAccelerator.swift
+++ b/Sources/JPEGLS/Platform/Metal/MetalAccelerator.swift
@@ -96,8 +96,8 @@ public final class MetalAccelerator: @unchecked Sendable {
         
         // Create compute pipeline states for all shaders
         do {
-            let library = try device.makeDefaultLibrary(bundle: .module)
-            
+            let library = try Self.loadShaderLibrary(device: device)
+
             self.gradientPipelineState = try Self.makePipelineState(
                 library: library, device: device, functionName: "compute_gradients")
             self.predictionPipelineState = try Self.makePipelineState(
@@ -129,7 +129,46 @@ public final class MetalAccelerator: @unchecked Sendable {
     }
     
     // MARK: - Private Helpers
-    
+
+    /// Load the Metal shader library for `JPEGLSShaders.metal`.
+    ///
+    /// Tries the precompiled `default.metallib` first — this is produced when the
+    /// package is built by Xcode's build system. Under Swift Package Manager on the
+    /// command line (`swift build`/`swift test`), `.process` only *copies* the
+    /// `.metal` file into the resource bundle without compiling it, so no
+    /// `default.metallib` exists and `makeDefaultLibrary(bundle:)` fails. In that
+    /// case we locate the bundled `.metal` source and compile it at runtime, so the
+    /// GPU path works in both environments.
+    private static func loadShaderLibrary(device: MTLDevice) throws -> MTLLibrary {
+        // Fast path: precompiled default library (Xcode-built bundles).
+        if let library = try? device.makeDefaultLibrary(bundle: .module) {
+            return library
+        }
+
+        // Fallback: compile the bundled shader source at runtime (SPM CLI builds).
+        guard let sourceURL = Bundle.module.url(
+            forResource: "JPEGLSShaders", withExtension: "metal"
+        ) else {
+            throw MetalAcceleratorError.libraryCreationFailed(
+                "JPEGLSShaders.metal not found in module bundle and no default.metallib present")
+        }
+
+        let source: String
+        do {
+            source = try String(contentsOf: sourceURL, encoding: .utf8)
+        } catch {
+            throw MetalAcceleratorError.libraryCreationFailed(
+                "Failed to read JPEGLSShaders.metal: \(error)")
+        }
+
+        do {
+            return try device.makeLibrary(source: source, options: nil)
+        } catch {
+            throw MetalAcceleratorError.libraryCreationFailed(
+                "Runtime compilation of JPEGLSShaders.metal failed: \(error)")
+        }
+    }
+
     /// Create a compute pipeline state for the named shader function.
     private static func makePipelineState(
         library: MTLLibrary,
@@ -506,9 +545,13 @@ public final class MetalAccelerator: @unchecked Sendable {
         var d3 = [Int32](repeating: 0, count: count)
         
         for i in 0..<count {
-            d1[i] = b[i] - c[i]  // horizontal gradient
-            d2[i] = a[i] - c[i]  // vertical gradient
-            d3[i] = c[i] - a[i]  // diagonal gradient
+            // Use wrapping subtraction to match the GPU shader, which computes
+            // these differences in 32-bit `int` with two's-complement wraparound.
+            // This keeps the CPU and GPU paths bit-identical and prevents the
+            // public API from trapping on extreme Int32 inputs (e.g. 0 - Int32.min).
+            d1[i] = b[i] &- c[i]  // horizontal gradient
+            d2[i] = a[i] &- c[i]  // vertical gradient
+            d3[i] = c[i] &- a[i]  // diagonal gradient
         }
         
         return (d1, d2, d3)
@@ -798,7 +841,10 @@ public enum MetalAcceleratorError: Error, CustomStringConvertible {
     
     /// Failed to find shader function.
     case shaderFunctionNotFound(String)
-    
+
+    /// Failed to load or compile the Metal shader library.
+    case libraryCreationFailed(String)
+
     /// Failed to create compute pipeline state.
     case pipelineCreationFailed(Error)
     
@@ -819,6 +865,8 @@ public enum MetalAcceleratorError: Error, CustomStringConvertible {
             return "Failed to create Metal command queue"
         case .shaderFunctionNotFound(let name):
             return "Shader function '\(name)' not found in Metal library"
+        case .libraryCreationFailed(let reason):
+            return "Failed to load Metal shader library: \(reason)"
         case .pipelineCreationFailed(let error):
             return "Failed to create compute pipeline state: \(error)"
         case .bufferCreationFailed:
diff --git a/Sources/jpeglscli/BenchDICOMCommand.swift b/Sources/jpeglscli/BenchDICOMCommand.swift
index 841ce4f..f60010c 100644
--- a/Sources/jpeglscli/BenchDICOMCommand.swift
+++ b/Sources/jpeglscli/BenchDICOMCommand.swift
@@ -161,7 +161,12 @@ extension JPEGLSCLITool {
                         s.encodeSeconds += encS
                         s.decodeSeconds += decS
                         s.pixels += pixelCount
-                        if near == 0 && !lossless { s.failures += 1 }
+                        if near == 0 && !lossless {
+                            s.failures += 1
+                            let where_ = firstMismatch(decoded.components.first?.pixels, pixels)
+                            FileHandle.standardError.write(Data(
+                                "FAIL lossless: \(url.path)  \(img.columns)x\(img.rows) \(bps)-bit\(where_)\n".utf8))
+                        }
 
                         frames.append(FrameResult(
                             modality: mod, width: img.columns, height: img.rows,
@@ -171,6 +176,8 @@ extension JPEGLSCLITool {
                         ))
                     } catch {
                         s.failures += 1
+                        FileHandle.standardError.write(Data(
+                            "FAIL error: \(url.path)  \(error)\n".utf8))
                     }
                 }
                 stats[mod] = s
@@ -191,6 +198,21 @@ extension JPEGLSCLITool {
             return true
         }
 
+        /// Describe the first differing sample between decoded and original
+        /// pixels, for actionable failure reports. Empty string if identical.
+        private func firstMismatch(_ a: [[Int]]?, _ b: [[Int]]) -> String {
+            guard let a = a else { return "  (decoded image had no component)" }
+            if a.count != b.count { return "  (decoded \(a.count) rows != original \(b.count))" }
+            for r in 0..<a.count where a[r] != b[r] {
+                let cols = min(a[r].count, b[r].count)
+                for c in 0..<cols where a[r][c] != b[r][c] {
+                    return "  first mismatch at (row \(r), col \(c)): decoded \(a[r][c]) != original \(b[r][c])"
+                }
+                return "  row \(r) length differs (decoded \(a[r].count) vs original \(b[r].count))"
+            }
+            return ""
+        }
+
         private func printTable(stats: [String: ModalityStats]) {
             print("")
             print("JPEG-LS DICOM round-trip  (near=\(near))")
diff --git a/Tests/JPEGLSTests/MetalAcceleratorTests.swift b/Tests/JPEGLSTests/MetalAcceleratorTests.swift
index 7c58340..95fc117 100644
--- a/Tests/JPEGLSTests/MetalAcceleratorTests.swift
+++ b/Tests/JPEGLSTests/MetalAcceleratorTests.swift
@@ -135,15 +135,18 @@ struct MetalAcceleratorTests {
         let c: [Int32] = [32768, 32768, 0, 0]
         
         let (d1, d2, d3) = try accelerator.computeGradientsBatch(a: a, b: b, c: c)
-        
-        // Verify gradients computed correctly
+
+        // Verify gradients computed correctly. Use wrapping subtraction to match
+        // the accelerator's two's-complement wraparound semantics — with Int32.min
+        // boundary inputs, plain subtraction (e.g. 0 - Int32.min) would itself
+        // overflow and trap.
         for i in 0..<a.count {
-            #expect(d1[i] == b[i] - c[i])
-            #expect(d2[i] == a[i] - c[i])
-            #expect(d3[i] == c[i] - a[i])
+            #expect(d1[i] == b[i] &- c[i])
+            #expect(d2[i] == a[i] &- c[i])
+            #expect(d3[i] == c[i] &- a[i])
         }
     }
-    
+
     @Test("Compute gradients with empty arrays")
     func testGradientsWithEmptyArrays() throws {
         guard MetalAccelerator.isSupported else { return }