use object_build_id

Author: vchuravy

src/execution.jl

@@ -78,14 +78,6 @@ end
 
 cache_path() = @get_scratch!("cache")
 clear_disk_cache!() = rm(cache_path(); recursive=true, force=true)
-function cache_path(key)
-    return joinpath(
-        cache_path(),
-        # TODO: Use object_build_id from https://github.com/JuliaLang/julia/pull/53943
-        #       Should we disk cache "runtime compilation".
-        string(Base.module_build_id(GPUCompiler)), # captures dependencies as well
-        string(cache_key), "ir.jls")
-end
 
 const cache_lock = ReentrantLock()
 
@@ -133,6 +125,30 @@ function cached_compilation(cache::AbstractDict{<:Any,V},
     return obj::V
 end
 
+@noinline function cache_file(ci::CodeInstance, cfg::CompilerConfig)
+    @static if isdefined(Base, :object_build_id)
+        id = Base.object_build_id(ci)
+        if id === nothing # CI is from a runtime compilation, not worth caching on disk
+            return nothing
+        else
+            id = id % UInt64 # The upper 64bit are a checksum, unavailable during precompilation
+        end
+    else
+        id = Base.objectid(ci)
+    end
+
+    gpucompiler_buildid = Base.module_build_id(@__MODULE__)
+    if (gpucompiler_buildid >> 64) % UInt64 == 0xffffffffffffffff
+        return nothing # Don't cache during precompilation of GPUCompiler
+    end
+
+    return joinpath(
+        cache_path(),
+        # bifurcate the cache by build id of GPUCompiler
+        string(gpucompiler_buildid),
+        string(hash(cfg, hash(id)), ".jls"))
+end
+
 @noinline function actual_compilation(cache::AbstractDict, src::MethodInstance, world::UInt,
                                       cfg::CompilerConfig, compiler::Function, linker::Function)
     job = CompilerJob(src, cfg, world)
@@ -148,18 +164,22 @@ end
     # slow path: compile and link
     if obj === nothing || compile_hook[] !== nothing
         asm = nothing
-        @static if VERSION >= v"1.11.0-" && disk_cache()
-            cache_key = Base.objectid(ci)
-            path = cache_path(cache_key)
-            if isfile(path)
-                try
-                    @debug "Loading compiled kernel for $spec from $path"
-                    asm = deserialize(path)
-                catch ex
-                    @warn "Failed to load compiled kernel at $path" exception=(ex, catch_backtrace())
+        path = nothing
+        ondisk_hit = false
+        @static if VERSION >= v"1.11.0-"
+            if disk_cache() # TODO: (Should we allow backends to opt out?)
+                path = cache_file(ci, cfg)
+                if path !== nothing && isfile(path)
+                    ondisk_hit = true
+                    try
+                        @debug "Loading compiled kernel for $spec from $path"
+                        asm = deserialize(path)
+                    catch ex
+                        @warn "Failed to load compiled kernel at $path" exception=(ex, catch_backtrace())
+                    end
                 end
             end
-        else
+        end
 
         if asm === nothing
             asm = compiler(job)
@@ -169,13 +189,15 @@ end
             return obj
         end
 
-        @static if VERSION >= v"1.11.0-" && disk_cache() && !isfile(path)
-            # TODO: Should we only write out during precompilation?
-            tmppath, io = mktemp(;cleanup=false)
-            serialize(io, asm)
-            close(io)
-            # atomic move
-            Base.rename(tmppath, path, force=true)
+        @static if VERSION >= v"1.11.0-"
+            if !ondisk_hit && path !== nothing && disk_cache()
+                # TODO: Do we want to serialize some more metadata to make sure the asm matches?
+                tmppath, io = mktemp(;cleanup=false)
+                serialize(io, asm)
+                close(io)
+                # atomic move
+                Base.rename(tmppath, path, force=true)
+            end
         end
 
         obj = linker(job, asm)