Previously, large builds could see 100%+ build time increase from enabling PGO.
In Go 1.23, overhead should be in the single digit percentages.

## Assembler {#assembler}

## Compiler {#compiler}

## Assembler {#assembler}

// license that can be found in the LICENSE file.

package cgotest

// Test that we have no more than one build ID.  In the past we used
// to generate a separate build ID for each package using cgo, and the
// linker concatenated them all.  We don't want that--we only want
// one.

import (
	"bytes"
	"debug/elf"
	"os"
	"testing"
)

func testBuildID(t *testing.T) {
	f, err := elf.Open("/proc/self/exe")

//go:build (ppc64 || ppc64le) && internal

package cgotest

import "testing"

// If gcc is used, and linking internally, __mulsc3 and __muldc3
// will be linked in from libgcc which make several R_PPC64_TOC16_DS
// relocations which may not be resolvable with the internal linker.
func test8694(t *testing.T) { t.Skip("not supported on ppc64/ppc64le with internal linking") }

// Copyright 2019 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

//go:build cgo && !windows

// Issue 29563: internal linker fails on duplicate weak symbols.
// No runtime test; just make sure it compiles.

package cgotest

This is necessary to avoid compiler and linker conflicts. Adding
a "vendor/" prefix also maintains the invariant that standard
library packages begin with a dotless path element.

The module requirements of std and cmd do not influence version
selection in other modules. They are only considered when running
module commands like 'go get' and 'go mod vendor' from a directory
in GOROOT/src.

      --enable-initfini-array \
      --enable-languages="c,c++" \
      --enable-linker-build-id \
      --enable-plugin \
      --enable-shared \
      --enable-threads=posix \
      --with-default-libstdcxx-abi=${LIBSTDCXX_ABI} \
      --with-gcc-major-version-only \
      --with-linker-hash-style="gnu" \
      && \
      make -j$(nproc) && \
      make install

		if f == nil {
			continue
		}
		fname := f.Name()
		switch fname {
		case "goCallback":
			// TODO(qmuntal): investigate why this function doesn't appear
			// when using the external linker.
			continue
		}
		// In module mode, this package has a fully-qualified import path.
		// Remove it if present.
		fname = strings.TrimPrefix(fname, "cmd/cgo/internal/")
		if !strings.HasPrefix(fname, "test.") {

      const char* attr_name, absl::Span<const AbstractOperation*> values) = 0;

 private:
  const AbstractOperationKind kind_;
};

// TODO(b/193656009): Defining these in a cc file causes linker errors with
// fastbuild.
inline Status AbstractOperation::SetAttrShape(const char* attr_name,
                                              const PartialTensorShape shape) {

build --action_env PYTHON_BIN_PATH="/usr/local/bin/python3"
build --python_path="/usr/local/bin/python3"

# Build TensorFlow v2
build --define=tf_api_version=2 --action_env=TF2_BEHAVIOR=1

# Use lld as the linker
build --linkopt="-fuse-ld=lld"
build --linkopt="-lm"
build --linkopt="-Wl,--undefined-version"

# Prevent double-compilation of some TF code, ref. b/183279666 (internal)