From 37999cbd101366517b9c22cd75e7b518de1465a8 Mon Sep 17 00:00:00 2001 From: soumyadeep2007 Date: Sun, 6 Oct 2019 17:47:08 -0700 Subject: [PATCH v1] Optimize generated functions earlier to lower memory usage We can optimize functions as soon as they are generated as opposed to optimizing during module optimization, in order to lower memory usage. This commit introduces `llvm_optimize_function()`, which will execute function level passes in accordance with the optimization settings inside `LLVMJitContext`. --- src/backend/jit/llvm/llvmjit.c | 66 ++++++++++++++++----------- src/backend/jit/llvm/llvmjit_deform.c | 3 ++ src/backend/jit/llvm/llvmjit_expr.c | 3 ++ src/include/jit/llvmjit.h | 2 + 4 files changed, 48 insertions(+), 26 deletions(-) diff --git a/src/backend/jit/llvm/llvmjit.c b/src/backend/jit/llvm/llvmjit.c index 82c4afb701..a57793becd 100644 --- a/src/backend/jit/llvm/llvmjit.c +++ b/src/backend/jit/llvm/llvmjit.c @@ -109,7 +109,7 @@ static void llvm_release_context(JitContext *context); static void llvm_session_initialize(void); static void llvm_shutdown(int code, Datum arg); static void llvm_compile_module(LLVMJitContext *context); -static void llvm_optimize_module(LLVMJitContext *context, LLVMModuleRef module); +static void llvm_optimize_module(LLVMJitContext *context); static void llvm_create_types(void); static uint64_t llvm_resolve_symbol(const char *name, void *ctx); @@ -414,15 +414,49 @@ llvm_function_reference(LLVMJitContext *context, } /* - * Optimize code in module using the flags set in context. + * Optimize code at the function-level for func using the flags set in context. + */ +void +llvm_optimize_function(LLVMJitContext *context, LLVMValueRef func) +{ + LLVMPassManagerBuilderRef llvm_pmb; + LLVMPassManagerRef llvm_fpm; + int compile_optlevel = context->base.flags & PGJIT_OPT3; + instr_time starttime; + instr_time endtime; + + INSTR_TIME_SET_CURRENT(starttime); + + llvm_pmb = LLVMPassManagerBuilderCreate(); + LLVMPassManagerBuilderSetOptLevel(llvm_pmb, compile_optlevel); + llvm_fpm = LLVMCreateFunctionPassManagerForModule(context->module); + if (compile_optlevel == 0) + { + /* we rely on mem2reg heavily, so emit even in the O0 case */ + LLVMAddPromoteMemoryToRegisterPass(llvm_fpm); + } + LLVMPassManagerBuilderPopulateFunctionPassManager(llvm_pmb, llvm_fpm); + + LLVMRunFunctionPassManager(llvm_fpm, func); + + LLVMFinalizeFunctionPassManager(llvm_fpm); + LLVMDisposePassManager(llvm_fpm); + LLVMPassManagerBuilderDispose(llvm_pmb); + + INSTR_TIME_SET_CURRENT(endtime); + INSTR_TIME_ACCUM_DIFF(context->base.instr.optimization_counter, + endtime, starttime); +} + +/* + * Optimize code at the module-level for the current module using the flags set + * in context. */ static void -llvm_optimize_module(LLVMJitContext *context, LLVMModuleRef module) +llvm_optimize_module(LLVMJitContext *context) { LLVMPassManagerBuilderRef llvm_pmb; LLVMPassManagerRef llvm_mpm; - LLVMPassManagerRef llvm_fpm; - LLVMValueRef func; int compile_optlevel; if (context->base.flags & PGJIT_OPT3) @@ -437,32 +471,12 @@ llvm_optimize_module(LLVMJitContext *context, LLVMModuleRef module) */ 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 @@ -525,7 +539,7 @@ llvm_compile_module(LLVMJitContext *context) /* optimize according to the chosen optimization settings */ INSTR_TIME_SET_CURRENT(starttime); - llvm_optimize_module(context, context->module); + llvm_optimize_module(context); INSTR_TIME_SET_CURRENT(endtime); INSTR_TIME_ACCUM_DIFF(context->base.instr.optimization_counter, endtime, starttime); diff --git a/src/backend/jit/llvm/llvmjit_deform.c b/src/backend/jit/llvm/llvmjit_deform.c index 835aea83e9..c5407d9566 100644 --- a/src/backend/jit/llvm/llvmjit_deform.c +++ b/src/backend/jit/llvm/llvmjit_deform.c @@ -752,5 +752,8 @@ slot_compile_deform(LLVMJitContext *context, TupleDesc desc, LLVMDisposeBuilder(b); + /* optimize according to the chosen optimization settings */ + llvm_optimize_function(context, v_deform_fn); + return v_deform_fn; } diff --git a/src/backend/jit/llvm/llvmjit_expr.c b/src/backend/jit/llvm/llvmjit_expr.c index d09324637b..4b2ad92c98 100644 --- a/src/backend/jit/llvm/llvmjit_expr.c +++ b/src/backend/jit/llvm/llvmjit_expr.c @@ -2439,6 +2439,9 @@ llvm_compile_expr(ExprState *state) LLVMDisposeBuilder(b); + /* optimize according to the chosen optimization settings */ + llvm_optimize_function(context, eval_fn); + /* * Don't immediately emit function, instead do so the first time the * expression is actually evaluated. That allows to emit a lot of diff --git a/src/include/jit/llvmjit.h b/src/include/jit/llvmjit.h index 6178864b2e..738ff3283a 100644 --- a/src/include/jit/llvmjit.h +++ b/src/include/jit/llvmjit.h @@ -107,6 +107,8 @@ extern LLVMValueRef llvm_function_reference(LLVMJitContext *context, LLVMBuilderRef builder, LLVMModuleRef mod, FunctionCallInfo fcinfo); +extern void llvm_optimize_function(LLVMJitContext *context, + LLVMValueRef func); extern void llvm_inline(LLVMModuleRef mod); -- 2.23.0