jit: Require at least LLVM 10.

Remove support for older LLVM versions.  The default on common software
distributions will be at least LLVM 10 when PostgreSQL 17 ships.

Reviewed-by: Peter Eisentraut <[email protected]>
Discussion: https://postgr.es/m/CA%2BhUKGLhNs5geZaVNj2EJ79Dx9W8fyWUU3HxcpZy55sMGcY%3DiA%40mail.gmail.com

11 files changed, 17 insertions, 243 deletions

diff --git a/config/llvm.m4 b/config/llvm.m4
index 21d8cd4f90f..44769d819a0 100644
--- a/config/llvm.m4
+++ b/config/llvm.m4
@@ -13,7 +13,7 @@ AC_DEFUN([PGAC_LLVM_SUPPORT],
   AC_REQUIRE([AC_PROG_AWK])
 
   AC_ARG_VAR(LLVM_CONFIG, [path to llvm-config command])
-  PGAC_PATH_PROGS(LLVM_CONFIG, llvm-config llvm-config-7 llvm-config-6.0 llvm-config-5.0 llvm-config-4.0 llvm-config-3.9)
+  PGAC_PATH_PROGS(LLVM_CONFIG, llvm-config llvm-config-17 llvm-config-16 llvm-config-15 llvm-config-14 llvm-config-13 llvm-config-12 llvm-config-11 llvm-config-10)
 
   # no point continuing if llvm wasn't found
   if test -z "$LLVM_CONFIG"; then
@@ -25,14 +25,14 @@ AC_DEFUN([PGAC_LLVM_SUPPORT],
     AC_MSG_ERROR([$LLVM_CONFIG does not work])
   fi
   # and whether the version is supported
-  if echo $pgac_llvm_version | $AWK -F '.' '{ if ([$]1 >= 4 || ([$]1 == 3 && [$]2 >= 9)) exit 1; else exit 0;}';then
-    AC_MSG_ERROR([$LLVM_CONFIG version is $pgac_llvm_version but at least 3.9 is required])
+  if echo $pgac_llvm_version | $AWK -F '.' '{ if ([$]1 >= 10) exit 1; else exit 0;}';then
+    AC_MSG_ERROR([$LLVM_CONFIG version is $pgac_llvm_version but at least 10 is required])
   fi
   AC_MSG_NOTICE([using llvm $pgac_llvm_version])
 
   # need clang to create some bitcode files
   AC_ARG_VAR(CLANG, [path to clang compiler to generate bitcode])
-  PGAC_PATH_PROGS(CLANG, clang clang-7 clang-6.0 clang-5.0 clang-4.0 clang-3.9)
+  PGAC_PATH_PROGS(CLANG, clang clang-17 clang-16 clang-15 clang-14 clang-13 clang-12 clang-11 clang-10)
   if test -z "$CLANG"; then
     AC_MSG_ERROR([clang not found, but required when compiling --with-llvm, specify with CLANG=])
   fi
@@ -115,8 +115,6 @@ AC_DEFUN([PGAC_CHECK_LLVM_FUNCTIONS],
   # Check which functionality is present
   SAVE_CPPFLAGS="$CPPFLAGS"
   CPPFLAGS="$CPPFLAGS $LLVM_CPPFLAGS"
-  AC_CHECK_DECLS([LLVMOrcGetSymbolAddressIn], [], [], [[#include <llvm-c/OrcBindings.h>]])
-  AC_CHECK_DECLS([LLVMGetHostCPUName, LLVMGetHostCPUFeatures], [], [], [[#include <llvm-c/TargetMachine.h>]])
   AC_CHECK_DECLS([LLVMCreateGDBRegistrationListener, LLVMCreatePerfJITEventListener], [], [], [[#include <llvm-c/ExecutionEngine.h>]])
   CPPFLAGS="$SAVE_CPPFLAGS"
 ])# PGAC_CHECK_LLVM_FUNCTIONS
diff --git a/configure b/configure
index 70a1968003c..2a1ee251f2d 100755
--- a/configure
+++ b/configure
@@ -5090,7 +5090,7 @@ if test "$with_llvm" = yes; then :
 
 
   if test -z "$LLVM_CONFIG"; then
-  for ac_prog in llvm-config llvm-config-7 llvm-config-6.0 llvm-config-5.0 llvm-config-4.0 llvm-config-3.9
+  for ac_prog in llvm-config llvm-config-17 llvm-config-16 llvm-config-15 llvm-config-14 llvm-config-13 llvm-config-12 llvm-config-11 llvm-config-10
 do
   # Extract the first word of "$ac_prog", so it can be a program name with args.
 set dummy $ac_prog; ac_word=$2
@@ -5154,8 +5154,8 @@ fi
     as_fn_error $? "$LLVM_CONFIG does not work" "$LINENO" 5
   fi
   # and whether the version is supported
-  if echo $pgac_llvm_version | $AWK -F '.' '{ if ($1 >= 4 || ($1 == 3 && $2 >= 9)) exit 1; else exit 0;}';then
-    as_fn_error $? "$LLVM_CONFIG version is $pgac_llvm_version but at least 3.9 is required" "$LINENO" 5
+  if echo $pgac_llvm_version | $AWK -F '.' '{ if ($1 >= 10) exit 1; else exit 0;}';then
+    as_fn_error $? "$LLVM_CONFIG version is $pgac_llvm_version but at least 10 is required" "$LINENO" 5
   fi
   { $as_echo "$as_me:${as_lineno-$LINENO}: using llvm $pgac_llvm_version" >&5
 $as_echo "$as_me: using llvm $pgac_llvm_version" >&6;}
@@ -5163,7 +5163,7 @@ $as_echo "$as_me: using llvm $pgac_llvm_version" >&6;}
   # need clang to create some bitcode files
 
   if test -z "$CLANG"; then
-  for ac_prog in clang clang-7 clang-6.0 clang-5.0 clang-4.0 clang-3.9
+  for ac_prog in clang clang-17 clang-16 clang-15 clang-14 clang-13 clang-12 clang-11 clang-10
 do
   # Extract the first word of "$ac_prog", so it can be a program name with args.
 set dummy $ac_prog; ac_word=$2
@@ -16546,41 +16546,6 @@ if test "$with_llvm" = yes; then
   # Check which functionality is present
   SAVE_CPPFLAGS="$CPPFLAGS"
   CPPFLAGS="$CPPFLAGS $LLVM_CPPFLAGS"
-  ac_fn_c_check_decl "$LINENO" "LLVMOrcGetSymbolAddressIn" "ac_cv_have_decl_LLVMOrcGetSymbolAddressIn" "#include <llvm-c/OrcBindings.h>
-"
-if test "x$ac_cv_have_decl_LLVMOrcGetSymbolAddressIn" = xyes; then :
-  ac_have_decl=1
-else
-  ac_have_decl=0
-fi
-
-cat >>confdefs.h <<_ACEOF
-#define HAVE_DECL_LLVMORCGETSYMBOLADDRESSIN $ac_have_decl
-_ACEOF
-
-  ac_fn_c_check_decl "$LINENO" "LLVMGetHostCPUName" "ac_cv_have_decl_LLVMGetHostCPUName" "#include <llvm-c/TargetMachine.h>
-"
-if test "x$ac_cv_have_decl_LLVMGetHostCPUName" = xyes; then :
-  ac_have_decl=1
-else
-  ac_have_decl=0
-fi
-
-cat >>confdefs.h <<_ACEOF
-#define HAVE_DECL_LLVMGETHOSTCPUNAME $ac_have_decl
-_ACEOF
-ac_fn_c_check_decl "$LINENO" "LLVMGetHostCPUFeatures" "ac_cv_have_decl_LLVMGetHostCPUFeatures" "#include <llvm-c/TargetMachine.h>
-"
-if test "x$ac_cv_have_decl_LLVMGetHostCPUFeatures" = xyes; then :
-  ac_have_decl=1
-else
-  ac_have_decl=0
-fi
-
-cat >>confdefs.h <<_ACEOF
-#define HAVE_DECL_LLVMGETHOSTCPUFEATURES $ac_have_decl
-_ACEOF
-
   ac_fn_c_check_decl "$LINENO" "LLVMCreateGDBRegistrationListener" "ac_cv_have_decl_LLVMCreateGDBRegistrationListener" "#include <llvm-c/ExecutionEngine.h>
 "
 if test "x$ac_cv_have_decl_LLVMCreateGDBRegistrationListener" = xyes; then :
diff --git a/doc/src/sgml/installation.sgml b/doc/src/sgml/installation.sgml
index e73902b3f8f..ed5b285a5ee 100644
--- a/doc/src/sgml/installation.sgml
+++ b/doc/src/sgml/installation.sgml
@@ -936,7 +936,7 @@ build-postgresql:
          <acronym>JIT</acronym> compilation (see <xref linkend="jit"/>).  This
          requires the <productname>LLVM</productname> library to be installed.
          The minimum required version of <productname>LLVM</productname> is
-         currently 3.9.
+         currently 10.
         </para>
         <para>
          <command>llvm-config</command><indexterm><primary>llvm-config</primary></indexterm>
@@ -2424,7 +2424,7 @@ ninja install
         <acronym>JIT</acronym> compilation (see <xref linkend="jit"/>).
         This requires the <productname>LLVM</productname> library to be
         installed.  The minimum required version of
-        <productname>LLVM</productname> is currently 3.9.  Disabled by
+        <productname>LLVM</productname> is currently 10.  Disabled by
         default.
        </para>
 
diff --git a/meson.build b/meson.build
index b22828479bc..8ed51b6aae8 100644
--- a/meson.build
+++ b/meson.build
@@ -757,7 +757,7 @@ endif
 llvmopt = get_option('llvm')
 llvm = not_found_dep
 if add_languages('cpp', required: llvmopt, native: false)
-  llvm = dependency('llvm', version: '>=3.9', method: 'config-tool', required: llvmopt)
+  llvm = dependency('llvm', version: '>=10', method: 'config-tool', required: llvmopt)
 
   if llvm.found()
 
diff --git a/src/backend/jit/llvm/llvmjit.c b/src/backend/jit/llvm/llvmjit.c
index 7e1d348e6b6..ec0fdd49324 100644
--- a/src/backend/jit/llvm/llvmjit.c
+++ b/src/backend/jit/llvm/llvmjit.c
@@ -34,10 +34,8 @@
 #include <llvm-c/Transforms/IPO.h>
 #include <llvm-c/Transforms/PassManagerBuilder.h>
 #include <llvm-c/Transforms/Scalar.h>
-#if LLVM_VERSION_MAJOR > 6
 #include <llvm-c/Transforms/Utils.h>
 #endif
-#endif
 
 #include "jit/llvmjit.h"
 #include "jit/llvmjit_emit.h"
@@ -381,10 +379,7 @@ llvm_expand_funcname(struct LLVMJitContext *context, const char *basename)
 void *
 llvm_get_function(LLVMJitContext *context, const char *funcname)
 {
-#if LLVM_VERSION_MAJOR > 11 || \
-	defined(HAVE_DECL_LLVMORCGETSYMBOLADDRESSIN) && HAVE_DECL_LLVMORCGETSYMBOLADDRESSIN
 	ListCell   *lc;
-#endif
 
 	llvm_assert_in_fatal_section();
 
@@ -432,7 +427,7 @@ llvm_get_function(LLVMJitContext *context, const char *funcname)
 		if (addr)
 			return (void *) (uintptr_t) addr;
 	}
-#elif defined(HAVE_DECL_LLVMORCGETSYMBOLADDRESSIN) && HAVE_DECL_LLVMORCGETSYMBOLADDRESSIN
+#else
 	foreach(lc, context->handles)
 	{
 		LLVMOrcTargetAddress addr;
@@ -444,28 +439,6 @@ llvm_get_function(LLVMJitContext *context, const char *funcname)
 		if (addr)
 			return (void *) (uintptr_t) addr;
 	}
-#elif LLVM_VERSION_MAJOR < 5
-	{
-		LLVMOrcTargetAddress addr;
-
-		if ((addr = LLVMOrcGetSymbolAddress(llvm_opt0_orc, funcname)))
-			return (void *) (uintptr_t) addr;
-		if ((addr = LLVMOrcGetSymbolAddress(llvm_opt3_orc, funcname)))
-			return (void *) (uintptr_t) addr;
-	}
-#else
-	{
-		LLVMOrcTargetAddress addr;
-
-		if (LLVMOrcGetSymbolAddress(llvm_opt0_orc, &addr, funcname))
-			elog(ERROR, "failed to look up symbol \"%s\"", funcname);
-		if (addr)
-			return (void *) (uintptr_t) addr;
-		if (LLVMOrcGetSymbolAddress(llvm_opt3_orc, &addr, funcname))
-			elog(ERROR, "failed to look up symbol \"%s\"", funcname);
-		if (addr)
-			return (void *) (uintptr_t) addr;
-	}
 #endif
 
 	elog(ERROR, "failed to JIT: %s", funcname);
@@ -553,12 +526,8 @@ llvm_copy_attributes_at_index(LLVMValueRef v_from, LLVMValueRef v_to, uint32 ind
 	int			num_attributes;
 	LLVMAttributeRef *attrs;
 
-	num_attributes = LLVMGetAttributeCountAtIndexPG(v_from, index);
+	num_attributes = LLVMGetAttributeCountAtIndex(v_from, index);
 
-	/*
-	 * Not just for efficiency: LLVM <= 3.9 crashes when
-	 * LLVMGetAttributesAtIndex() is called for an index with 0 attributes.
-	 */
 	if (num_attributes == 0)
 		return;
 
@@ -852,7 +821,7 @@ llvm_compile_module(LLVMJitContext *context)
 
 		/* LLVMOrcLLJITAddLLVMIRModuleWithRT takes ownership of the module */
 	}
-#elif LLVM_VERSION_MAJOR > 6
+#else
 	{
 		handle->stack = compile_orc;
 		if (LLVMOrcAddEagerlyCompiledIR(compile_orc, &handle->orc_handle, context->module,
@@ -861,26 +830,6 @@ llvm_compile_module(LLVMJitContext *context)
 
 		/* LLVMOrcAddEagerlyCompiledIR takes ownership of the module */
 	}
-#elif LLVM_VERSION_MAJOR > 4
-	{
-		LLVMSharedModuleRef smod;
-
-		smod = LLVMOrcMakeSharedModule(context->module);
-		handle->stack = compile_orc;
-		if (LLVMOrcAddEagerlyCompiledIR(compile_orc, &handle->orc_handle, smod,
-										llvm_resolve_symbol, NULL))
-			elog(ERROR, "failed to JIT module");
-
-		LLVMOrcDisposeSharedModuleRef(smod);
-	}
-#else							/* LLVM 4.0 and 3.9 */
-	{
-		handle->stack = compile_orc;
-		handle->orc_handle = LLVMOrcAddEagerlyCompiledIR(compile_orc, context->module,
-														 llvm_resolve_symbol, NULL);
-
-		LLVMDisposeModule(context->module);
-	}
 #endif
 
 	INSTR_TIME_SET_CURRENT(endtime);
diff --git a/src/backend/jit/llvm/llvmjit_error.cpp b/src/backend/jit/llvm/llvmjit_error.cpp
index 69a23f6eff9..ebe2f1baa10 100644
--- a/src/backend/jit/llvm/llvmjit_error.cpp
+++ b/src/backend/jit/llvm/llvmjit_error.cpp
@@ -29,12 +29,10 @@ static int fatal_new_handler_depth = 0;
 static std::new_handler old_new_handler = NULL;
 
 static void fatal_system_new_handler(void);
-#if LLVM_VERSION_MAJOR > 4
 static void fatal_llvm_new_handler(void *user_data, const char *reason, bool gen_crash_diag);
 #if LLVM_VERSION_MAJOR < 14
 static void fatal_llvm_new_handler(void *user_data, const std::string& reason, bool gen_crash_diag);
 #endif
-#endif
 static void fatal_llvm_error_handler(void *user_data, const char *reason, bool gen_crash_diag);
 #if LLVM_VERSION_MAJOR < 14
 static void fatal_llvm_error_handler(void *user_data, const std::string& reason, bool gen_crash_diag);
@@ -65,9 +63,7 @@ llvm_enter_fatal_on_oom(void)
 	if (fatal_new_handler_depth == 0)
 	{
 		old_new_handler = std::set_new_handler(fatal_system_new_handler);
-#if LLVM_VERSION_MAJOR > 4
 		llvm::install_bad_alloc_error_handler(fatal_llvm_new_handler);
-#endif
 		llvm::install_fatal_error_handler(fatal_llvm_error_handler);
 	}
 	fatal_new_handler_depth++;
@@ -83,9 +79,7 @@ llvm_leave_fatal_on_oom(void)
 	if (fatal_new_handler_depth == 0)
 	{
 		std::set_new_handler(old_new_handler);
-#if LLVM_VERSION_MAJOR > 4
 		llvm::remove_bad_alloc_error_handler();
-#endif
 		llvm::remove_fatal_error_handler();
 	}
 }
@@ -110,9 +104,7 @@ llvm_reset_after_error(void)
 	if (fatal_new_handler_depth != 0)
 	{
 		std::set_new_handler(old_new_handler);
-#if LLVM_VERSION_MAJOR > 4
 		llvm::remove_bad_alloc_error_handler();
-#endif
 		llvm::remove_fatal_error_handler();
 	}
 	fatal_new_handler_depth = 0;
@@ -133,7 +125,6 @@ fatal_system_new_handler(void)
 			 errdetail("while in LLVM")));
 }
 
-#if LLVM_VERSION_MAJOR > 4
 static void
 fatal_llvm_new_handler(void *user_data,
 					   const char *reason,
@@ -153,7 +144,6 @@ fatal_llvm_new_handler(void *user_data,
 	fatal_llvm_new_handler(user_data, reason.c_str(), gen_crash_diag);
 }
 #endif
-#endif
 
 static void
 fatal_llvm_error_handler(void *user_data,
diff --git a/src/backend/jit/llvm/llvmjit_expr.c b/src/backend/jit/llvm/llvmjit_expr.c
index 09994503b15..0c448422e20 100644
--- a/src/backend/jit/llvm/llvmjit_expr.c
+++ b/src/backend/jit/llvm/llvmjit_expr.c
@@ -2650,12 +2650,8 @@ create_LifetimeEnd(LLVMModuleRef mod)
 	LLVMTypeRef param_types[2];
 	LLVMContextRef lc;
 
-	/* LLVM 5+ has a variadic pointer argument */
-#if LLVM_VERSION_MAJOR < 5
-	const char *nm = "llvm.lifetime.end";
-#else
+	/* variadic pointer argument */
 	const char *nm = "llvm.lifetime.end.p0i8";
-#endif
 
 	fn = LLVMGetNamedFunction(mod, nm);
 	if (fn)
diff --git a/src/backend/jit/llvm/llvmjit_inline.cpp b/src/backend/jit/llvm/llvmjit_inline.cpp
index c9efc0bc994..2007eb523c9 100644
--- a/src/backend/jit/llvm/llvmjit_inline.cpp
+++ b/src/backend/jit/llvm/llvmjit_inline.cpp
@@ -49,12 +49,7 @@ extern "C"
 #include <llvm/ADT/StringSet.h>
 #include <llvm/ADT/StringMap.h>
 #include <llvm/Analysis/ModuleSummaryAnalysis.h>
-#if LLVM_VERSION_MAJOR > 3
 #include <llvm/Bitcode/BitcodeReader.h>
-#else
-#include <llvm/Bitcode/ReaderWriter.h>
-#include <llvm/Support/Error.h>
-#endif
 #include <llvm/IR/Attributes.h>
 #include <llvm/IR/DebugInfo.h>
 #include <llvm/IR/IntrinsicInst.h>
@@ -267,14 +262,12 @@ llvm_build_inline_plan(LLVMContextRef lc, llvm::Module *mod)
 
 			fs = llvm::cast<llvm::FunctionSummary>(gvs);
 
-#if LLVM_VERSION_MAJOR > 3
 			if (gvs->notEligibleToImport())
 			{
 				ilog(DEBUG1, "ineligibile to import %s due to summary",
 					 symbolName.data());
 				continue;
 			}
-#endif
 
 			if ((int) fs->instCount() > inlineState.costLimit)
 			{
@@ -458,16 +451,9 @@ llvm_execute_inline_plan(llvm::Module *mod, ImportMapTy *globalsToInline)
 
 		}
 
-#if LLVM_VERSION_MAJOR > 4
-#define IRMOVE_PARAMS , /*IsPerformingImport=*/false
-#elif LLVM_VERSION_MAJOR > 3
-#define IRMOVE_PARAMS , /*LinkModuleInlineAsm=*/false, /*IsPerformingImport=*/false
-#else
-#define IRMOVE_PARAMS
-#endif
 		if (Mover.move(std::move(importMod), GlobalsToImport.getArrayRef(),
-					   [](llvm::GlobalValue &, llvm::IRMover::ValueAdder) {}
-					   IRMOVE_PARAMS))
+					   [](llvm::GlobalValue &, llvm::IRMover::ValueAdder) {},
+					   /*IsPerformingImport=*/false))
 			elog(FATAL, "function import failed with linker error");
 	}
 }
@@ -793,7 +779,6 @@ llvm_load_summary(llvm::StringRef path)
 	{
 		llvm::MemoryBufferRef ref(*MBOrErr.get().get());
 
-#if LLVM_VERSION_MAJOR > 3
 		llvm::Expected<std::unique_ptr<llvm::ModuleSummaryIndex> > IndexOrErr =
 			llvm::getModuleSummaryIndex(ref);
 		if (IndexOrErr)
@@ -801,15 +786,6 @@ llvm_load_summary(llvm::StringRef path)
 		elog(FATAL, "failed to load summary \"%s\": %s",
 			 path.data(),
 			 toString(IndexOrErr.takeError()).c_str());
-#else
-		llvm::ErrorOr<std::unique_ptr<llvm::ModuleSummaryIndex> > IndexOrErr =
-			llvm::getModuleSummaryIndex(ref, [](const llvm::DiagnosticInfo &) {});
-		if (IndexOrErr)
-			return std::move(IndexOrErr.get());
-		elog(FATAL, "failed to load summary \"%s\": %s",
-			 path.data(),
-			 IndexOrErr.getError().message().c_str());
-#endif
 	}
 	return nullptr;
 }
@@ -856,22 +832,12 @@ summaries_for_guid(const InlineSearchPath& path, llvm::GlobalValue::GUID guid)
 
 	for (auto index : path)
 	{
-#if LLVM_VERSION_MAJOR > 4
 		llvm::ValueInfo funcVI = index->getValueInfo(guid);
 
 		/* if index doesn't know function, we don't have a body, continue */
 		if (funcVI)
 			for (auto &gv : funcVI.getSummaryList())
 				matches.push_back(gv.get());
-#else
-		const llvm::const_gvsummary_iterator &I =
-			index->findGlobalValueSummaryList(guid);
-		if (I != index->end())
-		{
-			for (auto &gv : I->second)
-				matches.push_back(gv.get());
-		}
-#endif
 	}
 
 	return matches;
diff --git a/src/backend/jit/llvm/llvmjit_wrap.cpp b/src/backend/jit/llvm/llvmjit_wrap.cpp
index 878f8edf55c..641c8841ca3 100644
--- a/src/backend/jit/llvm/llvmjit_wrap.cpp
+++ b/src/backend/jit/llvm/llvmjit_wrap.cpp
@@ -21,16 +21,7 @@ extern "C"
 /* Avoid macro clash with LLVM's C++ headers */
 #undef Min
 
-#include <llvm/IR/Attributes.h>
 #include <llvm/IR/Function.h>
-#if LLVM_VERSION_MAJOR < 17
-#include <llvm/MC/SubtargetFeature.h>
-#endif
-#if LLVM_VERSION_MAJOR > 16
-#include <llvm/TargetParser/Host.h>
-#else
-#include <llvm/Support/Host.h>
-#endif
 
 #include "jit/llvmjit.h"
 
@@ -38,50 +29,6 @@ extern "C"
 /*
  * C-API extensions.
  */
-#if defined(HAVE_DECL_LLVMGETHOSTCPUNAME) && !HAVE_DECL_LLVMGETHOSTCPUNAME
-char *LLVMGetHostCPUName(void) {
-	return strdup(llvm::sys::getHostCPUName().data());
-}
-#endif
-
-
-#if defined(HAVE_DECL_LLVMGETHOSTCPUFEATURES) && !HAVE_DECL_LLVMGETHOSTCPUFEATURES
-char *LLVMGetHostCPUFeatures(void) {
-	llvm::SubtargetFeatures Features;
-	llvm::StringMap<bool> HostFeatures;
-
-	if (llvm::sys::getHostCPUFeatures(HostFeatures))
-		for (auto &F : HostFeatures)
-			Features.AddFeature(F.first(), F.second);
-
-	return strdup(Features.getString().c_str());
-}
-#endif
-
-/*
- * Like LLVM's LLVMGetAttributeCountAtIndex(), works around a bug in LLVM 3.9.
- *
- * In LLVM <= 3.9, LLVMGetAttributeCountAtIndex() segfaults if there are no
- * attributes at an index (fixed in LLVM commit ce9bb1097dc2).
- */
-unsigned
-LLVMGetAttributeCountAtIndexPG(LLVMValueRef F, uint32 Idx)
-{
-	/*
-	 * This is more expensive, so only do when using a problematic LLVM
-	 * version.
-	 */
-#if LLVM_VERSION_MAJOR < 4
-	if (!llvm::unwrap<llvm::Function>(F)->getAttributes().hasAttributes(Idx))
-		return 0;
-#endif
-
-	/*
-	 * There is no nice public API to determine the count nicely, so just
-	 * always fall back to LLVM's C API.
-	 */
-	return LLVMGetAttributeCountAtIndex(F, Idx);
-}
 
 LLVMTypeRef
 LLVMGetFunctionReturnType(LLVMValueRef r)
@@ -94,11 +41,3 @@ LLVMGetFunctionType(LLVMValueRef r)
 {
 	return llvm::wrap(llvm::unwrap<llvm::Function>(r)->getFunctionType());
 }
-
-#if LLVM_VERSION_MAJOR < 8
-LLVMTypeRef
-LLVMGlobalGetValueType(LLVMValueRef g)
-{
-	return llvm::wrap(llvm::unwrap<llvm::GlobalValue>(g)->getValueType());
-}
-#endif
diff --git a/src/include/jit/llvmjit.h b/src/include/jit/llvmjit.h
index 8b0c059f268..9d9db806625 100644
--- a/src/include/jit/llvmjit.h
+++ b/src/include/jit/llvmjit.h
@@ -130,26 +130,9 @@ extern LLVMValueRef slot_compile_deform(struct LLVMJitContext *context, TupleDes
  * Error handling related functions.
  ****************************************************************************
  */
-#if defined(HAVE_DECL_LLVMGETHOSTCPUNAME) && !HAVE_DECL_LLVMGETHOSTCPUNAME
-/** Get the host CPU as a string. The result needs to be disposed with
-  LLVMDisposeMessage. */
-extern char *LLVMGetHostCPUName(void);
-#endif
-
-#if defined(HAVE_DECL_LLVMGETHOSTCPUFEATURES) && !HAVE_DECL_LLVMGETHOSTCPUFEATURES
-/** Get the host CPU features as a string. The result needs to be disposed
-  with LLVMDisposeMessage. */
-extern char *LLVMGetHostCPUFeatures(void);
-#endif
-
-extern unsigned LLVMGetAttributeCountAtIndexPG(LLVMValueRef F, uint32 Idx);
 extern LLVMTypeRef LLVMGetFunctionReturnType(LLVMValueRef r);
 extern LLVMTypeRef LLVMGetFunctionType(LLVMValueRef r);
 
-#if LLVM_MAJOR_VERSION < 8
-extern LLVMTypeRef LLVMGlobalGetValueType(LLVMValueRef g);
-#endif
-
 #ifdef __cplusplus
 } /* extern "C" */
 #endif
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 288bb9cb426..07e73567dc7 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -100,18 +100,6 @@
    `LLVMCreatePerfJITEventListener', and to 0 if you don't. */
 #undef HAVE_DECL_LLVMCREATEPERFJITEVENTLISTENER
 
-/* Define to 1 if you have the declaration of `LLVMGetHostCPUFeatures', and to
-   0 if you don't. */
-#undef HAVE_DECL_LLVMGETHOSTCPUFEATURES
-
-/* Define to 1 if you have the declaration of `LLVMGetHostCPUName', and to 0
-   if you don't. */
-#undef HAVE_DECL_LLVMGETHOSTCPUNAME
-
-/* Define to 1 if you have the declaration of `LLVMOrcGetSymbolAddressIn', and
-   to 0 if you don't. */
-#undef HAVE_DECL_LLVMORCGETSYMBOLADDRESSIN
-
 /* Define to 1 if you have the declaration of `posix_fadvise', and to 0 if you
    don't. */
 #undef HAVE_DECL_POSIX_FADVISE