Add inlining support to LLVM JIT provider.

This provides infrastructure to allow JITed code to inline code
implemented in C. This e.g. can be postgres internal functions or
extension code.

This already speeds up long running queries, by allowing the LLVM
optimizer to optimize across function boundaries. The optimization
potential currently doesn't reach its full potential because LLVM
cannot optimize the FunctionCallInfoData argument fully away, because
it's allocated on the heap rather than the stack. Fixing that is
beyond what's realistic for v11.

To be able to do that, use CLANG to convert C code to LLVM bitcode,
and have LLVM build a summary for it. That bitcode can then be used to
to inline functions at runtime. For that the bitcode needs to be
installed. Postgres bitcode goes into $pkglibdir/bitcode/postgres,
extensions go into equivalent directories.  PGXS has been modified so
that happens automatically if postgres has been compiled with LLVM
support.

Currently this isn't the fastest inline implementation, modules are
reloaded from disk during inlining. That's to work around an apparent
LLVM bug, triggering an apparently spurious error in LLVM assertion
enabled builds.  Once that is resolved we can remove the superfluous
read from disk.

Docs will follow in a later commit containing docs for the whole JIT
feature.

Author: Andres Freund
Discussion: https://postgr.es/m/20170901064131.tazjxwus3k2w3ybh@alap3.anarazel.de

1 files changed, 22 insertions, 4 deletions

diff --git a/src/makefiles/pgxs.mk b/src/makefiles/pgxs.mk
index c27004ecfb..5beb1e6b3c 100644
--- a/src/makefiles/pgxs.mk
+++ b/src/makefiles/pgxs.mk
@@ -101,6 +101,10 @@ endif
 
 all: $(PROGRAM) $(DATA_built) $(SCRIPTS_built) $(addsuffix $(DLSUFFIX), $(MODULES)) $(addsuffix .control, $(EXTENSION))
 
+ifeq ($(with_llvm), yes)
+all: $(addsuffix .bc, $(MODULES)) $(patsubst %.o,%.bc, $(OBJS))
+endif
+
 ifdef MODULE_big
 # shared library parameters
 NAME = $(MODULE_big)
@@ -123,6 +127,9 @@ ifneq (,$(DATA_TSEARCH))
 endif # DATA_TSEARCH
 ifdef MODULES
 	$(INSTALL_SHLIB) $(addsuffix $(DLSUFFIX), $(MODULES)) '$(DESTDIR)$(pkglibdir)/'
+ifeq ($(with_llvm), yes)
+	$(foreach mod, $(MODULES), $(call install_llvm_module,$(mod),$(mod).bc))
+endif # with_llvm
 endif # MODULES
 ifdef DOCS
 ifdef docdir
@@ -138,8 +145,11 @@ endif # SCRIPTS
 ifdef SCRIPTS_built
 	$(INSTALL_SCRIPT) $(SCRIPTS_built) '$(DESTDIR)$(bindir)/'
 endif # SCRIPTS_built
-
 ifdef MODULE_big
+ifeq ($(with_llvm), yes)
+	$(call install_llvm_module,$(MODULE_big),$(OBJS))
+endif # with_llvm
+
 install: install-lib
 endif # MODULE_big
 
@@ -183,7 +193,10 @@ ifneq (,$(DATA_TSEARCH))
 endif
 ifdef MODULES
 	rm -f $(addprefix '$(DESTDIR)$(pkglibdir)'/, $(addsuffix $(DLSUFFIX), $(MODULES)))
-endif
+ifeq ($(with_llvm), yes)
+	$(foreach mod, $(MODULES), $(call uninstall_llvm_module,$(mod)))
+endif # with_llvm
+endif # MODULES
 ifdef DOCS
 	rm -f $(addprefix '$(DESTDIR)$(docdir)/$(docmoduledir)'/, $(DOCS))
 endif
@@ -198,13 +211,18 @@ ifdef SCRIPTS_built
 endif
 
 ifdef MODULE_big
+ifeq ($(with_llvm), yes)
+	$(call uninstall_llvm_module,$(MODULE_big))
+endif # with_llvm
+
 uninstall: uninstall-lib
 endif # MODULE_big
 
 
 clean:
 ifdef MODULES
-	rm -f $(addsuffix $(DLSUFFIX), $(MODULES)) $(addsuffix .o, $(MODULES)) $(if $(PGFILEDESC),$(WIN32RES))
+	rm -f $(addsuffix $(DLSUFFIX), $(MODULES)) $(addsuffix .o, $(MODULES)) $(if $(PGFILEDESC),$(WIN32RES)) \
+	    $(addsuffix .bc, $(MODULES))
 endif
 ifdef DATA_built
 	rm -f $(DATA_built)
@@ -216,7 +234,7 @@ ifdef PROGRAM
 	rm -f $(PROGRAM)$(X)
 endif
 ifdef OBJS
-	rm -f $(OBJS)
+	rm -f $(OBJS) $(patsubst %.o,%.bc, $(OBJS))
 endif
 ifdef EXTRA_CLEAN
 	rm -rf $(EXTRA_CLEAN)