fix: add -O3 optimization to CGO flags

CGO_CFLAGS and CGO_CXXFLAGS were being set without optimization flags,
which overrides Go's default -O2 and results in unoptimized C++ code.

This caused significant performance degradation in release builds
compared to local `go build` which uses the default optimization.

- build_darwin.sh: add -O3 to CGO_CFLAGS and CGO_CXXFLAGS exports
- Dockerfile: preserve CGO_CFLAGS/CGO_CXXFLAGS from build args instead
  of overwriting them
- app/README.md: update documentation to include -O3

Dockerfile

@@ -169,8 +169,10 @@ COPY . .
 RUN git clone --depth 1 --branch "$(cat MLX_VERSION)" https://github.com/ml-explore/mlx-c.git build/_deps/mlx-c-src
 ARG GOFLAGS="'-ldflags=-w -s'"
 ENV CGO_ENABLED=1
-ENV CGO_CFLAGS="-I/go/src/github.com/ollama/ollama/build/_deps/mlx-c-src"
+ARG CGO_CFLAGS
 ARG CGO_CXXFLAGS
+ENV CGO_CFLAGS="${CGO_CFLAGS} -I/go/src/github.com/ollama/ollama/build/_deps/mlx-c-src"
+ENV CGO_CXXFLAGS="${CGO_CXXFLAGS}"
 RUN --mount=type=cache,target=/root/.cache/go-build \
     go build -tags mlx -trimpath -buildmode=pie -o /bin/ollama .
 

app/README.md

@@ -75,9 +75,9 @@ The `-dev` flag enables:
 CI builds with Xcode 14.1 for OS compatibility prior to v13.  If you want to manually build v11+ support, you can download the older Xcode [here](https://developer.apple.com/services-account/download?path=/Developer_Tools/Xcode_14.1/Xcode_14.1.xip), extract, then `mv ./Xcode.app /Applications/Xcode_14.1.0.app` then activate with:
 
 ```
-export CGO_CFLAGS=-mmacosx-version-min=12.0
-export CGO_CXXFLAGS=-mmacosx-version-min=12.0
-export CGO_LDFLAGS=-mmacosx-version-min=12.0
+export CGO_CFLAGS="-O3 -mmacosx-version-min=12.0"
+export CGO_CXXFLAGS="-O3 -mmacosx-version-min=12.0"
+export CGO_LDFLAGS="-mmacosx-version-min=12.0"
 export SDKROOT=/Applications/Xcode_14.1.0.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk
 export DEVELOPER_DIR=/Applications/Xcode_14.1.0.app/Contents/Developer
 ```

scripts/build_darwin.sh

@@ -14,8 +14,8 @@
 VOL_NAME=${VOL_NAME:-"Ollama"}
 export VERSION=${VERSION:-$(git describe --tags --first-parent --abbrev=7 --long --dirty --always | sed -e "s/^v//g")}
 export GOFLAGS="'-ldflags=-w -s \"-X=github.com/ollama/ollama/version.Version=${VERSION#v}\" \"-X=github.com/ollama/ollama/server.mode=release\"'"
-export CGO_CFLAGS="-mmacosx-version-min=14.0"
-export CGO_CXXFLAGS="-mmacosx-version-min=14.0"
+export CGO_CFLAGS="-O3 -mmacosx-version-min=14.0"
+export CGO_CXXFLAGS="-O3 -mmacosx-version-min=14.0"
 export CGO_LDFLAGS="-mmacosx-version-min=14.0"
 
 set -e