[SYCL] Add --host-target flag and remove --arm flag (#6620)

This patch adds a new flag to `configure.py` to allow changing the host
target to build, this makes it easier to build on different hosts such
as ARM or PowerPC.

This patch also removes the `--arm` flag as it is now redundant,
`--host-target=ARM` or `--host-target=AArch64` should be used instead.

This is slightly different than the original `--arm` flag as it only
allows to enable one of the ARM platforms. But I'm not sure what the use
case was for enabling both, as only one will be the host platform for a
given build. And compilation time was given as a reason to drop the X86
architecture originally so only enabling the correct ARM architecture
should also help with that.

Co-authored-by: Alexey Bader <[email protected]>

Author: npmiller

buildbot/configure.py

@@ -27,7 +27,7 @@ def do_configure(args):
     xpti_dir = os.path.join(abs_src_dir, "xpti")
     xptifw_dir = os.path.join(abs_src_dir, "xptifw")
     libdevice_dir = os.path.join(abs_src_dir, "libdevice")
-    llvm_targets_to_build = 'X86'
+    llvm_targets_to_build = args.host_target
     llvm_enable_projects = 'clang;' + llvm_external_projects
     libclc_targets_to_build = ''
     libclc_gen_remangled_variants = 'OFF'
@@ -48,10 +48,6 @@ def do_configure(args):
     if platform.system() == 'Windows' or (args.hip and args.hip_platform == 'AMD'):
         llvm_enable_projects += ';lld'
 
-    # replace not append, so ARM ^ X86
-    if args.arm:
-        llvm_targets_to_build = 'ARM;AArch64'
-
     if args.enable_esimd_emulator:
         sycl_enabled_plugins.append("esimd_emulator")
 
@@ -215,7 +211,8 @@ def main():
     parser.add_argument("--cuda", action='store_true', help="switch from OpenCL to CUDA")
     parser.add_argument("--hip", action='store_true', help="switch from OpenCL to HIP")
     parser.add_argument("--hip-platform", type=str, choices=['AMD', 'NVIDIA'], default='AMD', help="choose hardware platform for HIP backend")
-    parser.add_argument("--arm", action='store_true', help="build ARM support rather than x86")
+    parser.add_argument("--host-target", default='X86',
+                        help="host LLVM target architecture, defaults to X86, multiple targets may be provided as a semi-colon separated string")
     parser.add_argument("--enable-esimd-emulator", action='store_true', help="build with ESIMD emulation support")
     parser.add_argument("--enable-all-llvm-targets", action='store_true', help="build compiler with all supported targets, it doesn't change runtime build")
     parser.add_argument("--no-assertions", action='store_true', help="build without assertions")