Update search for bitcode files for rocm 3.9 (apache#6865)

rocm 3.9 moved the bitcodes, we adapt to that.
As this gives opaque error messages that are hard to debug
(loading the module fails with could not initialize shared object
but does not tell you about the missing symbols), we tighten
the checks at this stage:
- we become more strict with missing bitcodes,
- we let the linker fail loudly for unresolved symbols.

Author: t-vi

python/tvm/contrib/rocm.py

@@ -73,7 +73,20 @@ def rocm_link(in_file, out_file, lld=None):
         The lld linker, if not specified,
         we will try to guess the matched clang version.
     """
-    args = [lld if lld is not None else find_lld()[0], "-shared", in_file, "-o", out_file]
+
+    # if our result has undefined symbols, it will fail to load
+    # (hipModuleLoad/hipModuleLoadData), but with a somewhat opaque message
+    # so we have ld.lld check this here.
+    # If you get a complaint about missing symbols you might want to check the
+    # list of bitcode files below.
+    args = [
+        lld if lld is not None else find_lld()[0],
+        "--no-undefined",
+        "-shared",
+        in_file,
+        "-o",
+        out_file,
+    ]
     proc = subprocess.Popen(args, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
     (out, _) = proc.communicate()
 
@@ -108,7 +121,7 @@ def callback_rocm_link(obj_bin):
 
 
 @tvm._ffi.register_func("tvm_callback_rocm_bitcode_path")
-def callback_rocm_bitcode_path(rocdl_dir="/opt/rocm/lib/"):
+def callback_rocm_bitcode_path(rocdl_dir=None):
     """Utility function to find ROCm device library bitcodes
 
     Parameters
@@ -118,23 +131,40 @@ def callback_rocm_bitcode_path(rocdl_dir="/opt/rocm/lib/"):
         The default value is the standard location
     """
     # seems link order matters.
-    bitcode_files = [
-        "oclc_daz_opt_on.amdgcn.bc",
-        "ocml.amdgcn.bc",
-        "hc.amdgcn.bc",
-        "irif.amdgcn.bc",
-        "ockl.amdgcn.bc",
-        "oclc_correctly_rounded_sqrt_off.amdgcn.bc",
-        "oclc_correctly_rounded_sqrt_on.amdgcn.bc",
-        "oclc_daz_opt_off.amdgcn.bc",
-        "oclc_finite_only_off.amdgcn.bc",
-        "oclc_finite_only_on.amdgcn.bc",
-        "oclc_isa_version_803.amdgcn.bc",
-        "oclc_isa_version_900.amdgcn.bc",
-        "oclc_isa_version_906.amdgcn.bc",
-        "oclc_unsafe_math_off.amdgcn.bc",
-        "oclc_unsafe_math_on.amdgcn.bc",
-        "oclc_wavefrontsize64_on.amdgcn.bc",
+
+    if rocdl_dir is None:
+        if exists("/opt/rocm/amdgcn/bitcode/"):
+            rocdl_dir = "/opt/rocm/amdgcn/bitcode/"  # starting with rocm 3.9
+        else:
+            rocdl_dir = "/opt/rocm/lib/"  # until rocm 3.8
+
+    bitcode_names = [
+        "oclc_daz_opt_on",
+        "ocml",
+        "hc",
+        "irif",  # this does not exist in rocm 3.9, drop eventually
+        "ockl",
+        "oclc_correctly_rounded_sqrt_off",
+        "oclc_correctly_rounded_sqrt_on",
+        "oclc_daz_opt_off",
+        "oclc_finite_only_off",
+        "oclc_finite_only_on",
+        "oclc_isa_version_803",  # todo (t-vi): an alternative might be to scan for the
+        "oclc_isa_version_900",  #              isa version files (if the linker throws out
+        "oclc_isa_version_906",  #              the unneeded ones or we filter for the arch we need)
+        "oclc_unsafe_math_off",
+        "oclc_unsafe_math_on",
+        "oclc_wavefrontsize64_on",
     ]
-    paths = [join(rocdl_dir, bitcode) for bitcode in bitcode_files]
-    return tvm.runtime.convert([path for path in paths if exists(path)])
+
+    bitcode_files = []
+    for n in bitcode_names:
+        p = join(rocdl_dir, n + ".bc")  # rocm >= 3.9
+        if not exists(p):  # rocm <= 3.8
+            p = join(rocdl_dir, n + ".amdgcn.bc")
+        if exists(p):
+            bitcode_files.append(p)
+        elif "isa_version" not in n and n not in {"irif"}:
+            raise RuntimeError("could not find bitcode " + n)
+
+    return tvm.runtime.convert(bitcode_files)