jit: Use the new pass manager only.

XXX This doesn't work on LLVM < 16, because you need
PTO.InlinerThreshold:

llvm/llvm-project@4fa3280

src/backend/jit/llvm/llvmjit.c

@@ -18,20 +18,12 @@
 #include <llvm-c/BitWriter.h>
 #include <llvm-c/Core.h>
 #include <llvm-c/ExecutionEngine.h>
-#if LLVM_VERSION_MAJOR > 16
 #include <llvm-c/Transforms/PassBuilder.h>
-#endif
 #include <llvm-c/Orc.h>
 #include <llvm-c/OrcEE.h>
 #include <llvm-c/LLJIT.h>
 #include <llvm-c/Support.h>
 #include <llvm-c/Target.h>
-#if LLVM_VERSION_MAJOR < 17
-#include <llvm-c/Transforms/IPO.h>
-#include <llvm-c/Transforms/PassManagerBuilder.h>
-#include <llvm-c/Transforms/Scalar.h>
-#include <llvm-c/Transforms/Utils.h>
-#endif
 
 #include "jit/llvmjit.h"
 #include "jit/llvmjit_emit.h"
@@ -598,71 +590,6 @@ llvm_function_reference(LLVMJitContext *context,
 static void
 llvm_optimize_module(LLVMJitContext *context, LLVMModuleRef module)
 {
-#if LLVM_VERSION_MAJOR < 17
-	LLVMPassManagerBuilderRef llvm_pmb;
-	LLVMPassManagerRef llvm_mpm;
-	LLVMPassManagerRef llvm_fpm;
-	LLVMValueRef func;
-	int			compile_optlevel;
-
-	if (context->base.flags & PGJIT_OPT3)
-		compile_optlevel = 3;
-	else
-		compile_optlevel = 0;
-
-	/*
-	 * Have to create a new pass manager builder every pass through, as the
-	 * inliner has some per-builder state. Otherwise one ends up only inlining
-	 * a function the first time though.
-	 */
-	llvm_pmb = LLVMPassManagerBuilderCreate();
-	LLVMPassManagerBuilderSetOptLevel(llvm_pmb, compile_optlevel);
-	llvm_fpm = LLVMCreateFunctionPassManagerForModule(module);
-
-	if (context->base.flags & PGJIT_OPT3)
-	{
-		/* TODO: Unscientifically determined threshold */
-		LLVMPassManagerBuilderUseInlinerWithThreshold(llvm_pmb, 512);
-	}
-	else
-	{
-		/* we rely on mem2reg heavily, so emit even in the O0 case */
-		LLVMAddPromoteMemoryToRegisterPass(llvm_fpm);
-	}
-
-	LLVMPassManagerBuilderPopulateFunctionPassManager(llvm_pmb, llvm_fpm);
-
-	/*
-	 * Do function level optimization. This could be moved to the point where
-	 * functions are emitted, to reduce memory usage a bit.
-	 */
-	LLVMInitializeFunctionPassManager(llvm_fpm);
-	for (func = LLVMGetFirstFunction(context->module);
-		 func != NULL;
-		 func = LLVMGetNextFunction(func))
-		LLVMRunFunctionPassManager(llvm_fpm, func);
-	LLVMFinalizeFunctionPassManager(llvm_fpm);
-	LLVMDisposePassManager(llvm_fpm);
-
-	/*
-	 * Perform module level optimization. We do so even in the non-optimized
-	 * case, so always-inline functions etc get inlined. It's cheap enough.
-	 */
-	llvm_mpm = LLVMCreatePassManager();
-	LLVMPassManagerBuilderPopulateModulePassManager(llvm_pmb,
-													llvm_mpm);
-	/* always use always-inliner pass */
-	if (!(context->base.flags & PGJIT_OPT3))
-		LLVMAddAlwaysInlinerPass(llvm_mpm);
-	/* if doing inlining, but no expensive optimization, add inlining pass */
-	if (context->base.flags & PGJIT_INLINE
-		&& !(context->base.flags & PGJIT_OPT3))
-		LLVMAddFunctionInliningPass(llvm_mpm);
-	LLVMRunPassManager(llvm_mpm, context->module);
-	LLVMDisposePassManager(llvm_mpm);
-
-	LLVMPassManagerBuilderDispose(llvm_pmb);
-#else
 	LLVMPassBuilderOptionsRef options;
 	LLVMErrorRef err;
 	const char *passes;
@@ -686,7 +613,6 @@ llvm_optimize_module(LLVMJitContext *context, LLVMModuleRef module)
 		elog(ERROR, "failed to JIT module: %s", llvm_error_message(err));
 
 	LLVMDisposePassBuilderOptions(options);
-#endif
 }
 
 /*

src/backend/jit/llvm/llvmjit_wrap.cpp

@@ -19,6 +19,11 @@ extern "C"
 #include <llvm-c/Core.h>
 #include <llvm/IR/Function.h>
 
+#if LLVM_VERSION_MAJOR < 17
+#undef PIC		/* an unfortunately chosen identifier */
+#include <llvm/Passes/PassBuilder.h>
+#endif
+
 #include "jit/llvmjit.h"
 
 
@@ -37,3 +42,30 @@ LLVMGetFunctionType(LLVMValueRef r)
 {
 	return llvm::wrap(llvm::unwrap<llvm::Function>(r)->getFunctionType());
 }
+
+#if LLVM_VERSION_MAJOR < 17
+void
+LLVMPassBuilderOptionsSetInlinerThreshold(LLVMPassBuilderOptionsRef Options,
+										  int Threshold)
+{
+	/*
+	 * A struct that is layout compatible with:
+	 *
+	 * https://github.com/llvm/llvm-project/blob/release/14.x/llvm/lib/Passes/PassBuilderBindings.cpp#L26
+	 * https://github.com/llvm/llvm-project/blob/release/15.x/llvm/lib/Passes/PassBuilderBindings.cpp#L26
+	 * https://github.com/llvm/llvm-project/blob/release/16.x/llvm/lib/Passes/PassBuilderBindings.cpp#L26
+	 *
+	 * This function that we needed was upstreamed in LLVM 17, but
+	 * unfortunately we can't see the class definition from here.
+	 *
+	 * https://github.com/llvm/llvm-project/commit/c20a9bb001855da5d14721ce2894e3be77a999fe
+	 */
+	struct FakePassBuilderOptions {
+		bool DebugLogging;
+		bool VerifyEach;
+		llvm::PipelineTuningOptions PTO;
+	};
+
+	reinterpret_cast<FakePassBuilderOptions *>(Options)->PTO.InlinerThreshold = Threshold;
+}
+#endif

src/include/jit/llvmjit.h

@@ -18,6 +18,7 @@
 #ifdef USE_LLVM
 
 #include <llvm-c/Types.h>
+#include <llvm-c/Transforms/PassBuilder.h>
 
 
 /*
@@ -133,6 +134,11 @@ extern LLVMValueRef slot_compile_deform(struct LLVMJitContext *context, TupleDes
 extern LLVMTypeRef LLVMGetFunctionReturnType(LLVMValueRef r);
 extern LLVMTypeRef LLVMGetFunctionType(LLVMValueRef r);
 
+#if LLVM_VERSION_MAJOR < 17
+extern void LLVMPassBuilderOptionsSetInlinerThreshold(LLVMPassBuilderOptionsRef Options,
+													  int Threshold);
+#endif
+
 #ifdef __cplusplus
 } /* extern "C" */
 #endif