X-Git-Url: https://git.libre-soc.org/?a=blobdiff_plain;f=src%2Fgallium%2Fauxiliary%2Fgallivm%2Flp_bld_init.c;h=ef2580e8263568a472128a7f6563a0ec0f2e2165;hb=fd3e73f54e323d5de182bf6cdb6094c2fd7362b3;hp=174e20e11d9c6d2eb813b39d1afe3641281a2c63;hpb=8413b92a6f761c55f9a9e51f09d57aa7922b15a8;p=mesa.git

diff --git a/src/gallium/auxiliary/gallivm/lp_bld_init.c b/src/gallium/auxiliary/gallivm/lp_bld_init.c
index 174e20e11d9..ef2580e8263 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_init.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_init.c
@@ -26,12 +26,36 @@
  **************************************************************************/
 
 
+#include "pipe/p_config.h"
 #include "pipe/p_compiler.h"
 #include "util/u_cpu_detect.h"
 #include "util/u_debug.h"
+#include "util/u_memory.h"
+#include "util/simple_list.h"
+#include "os/os_time.h"
+#include "lp_bld.h"
 #include "lp_bld_debug.h"
+#include "lp_bld_misc.h"
 #include "lp_bld_init.h"
 
+#include <llvm-c/Analysis.h>
+#include <llvm-c/Transforms/Scalar.h>
+#include <llvm-c/BitWriter.h>
+
+
+/* Only MCJIT is available as of LLVM SVN r216982 */
+#if HAVE_LLVM >= 0x0306
+#  define USE_MCJIT 1
+#elif defined(PIPE_ARCH_PPC_64) || defined(PIPE_ARCH_S390) || defined(PIPE_ARCH_ARM) || defined(PIPE_ARCH_AARCH64)
+#  define USE_MCJIT 1
+#endif
+
+#if defined(USE_MCJIT)
+static const bool use_mcjit = USE_MCJIT;
+#else
+static bool use_mcjit = FALSE;
+#endif
+
 
 #ifdef DEBUG
 unsigned gallivm_debug = 0;
@@ -41,15 +65,22 @@ static const struct debug_named_value lp_bld_debug_flags[] = {
    { "ir",     GALLIVM_DEBUG_IR, NULL },
    { "asm",    GALLIVM_DEBUG_ASM, NULL },
    { "nopt",   GALLIVM_DEBUG_NO_OPT, NULL },
+   { "perf",   GALLIVM_DEBUG_PERF, NULL },
+   { "no_brilinear", GALLIVM_DEBUG_NO_BRILINEAR, NULL },
+   { "no_rho_approx", GALLIVM_DEBUG_NO_RHO_APPROX, NULL },
+   { "no_quad_lod", GALLIVM_DEBUG_NO_QUAD_LOD, NULL },
+   { "gc",     GALLIVM_DEBUG_GC, NULL },
+   { "dumpbc", GALLIVM_DEBUG_DUMP_BC, NULL },
    DEBUG_NAMED_VALUE_END
 };
+
+DEBUG_GET_ONCE_FLAGS_OPTION(gallivm_debug, "GALLIVM_DEBUG", lp_bld_debug_flags, 0)
 #endif
 
 
-LLVMModuleRef lp_build_module = NULL;
-LLVMExecutionEngineRef lp_build_engine = NULL;
-LLVMModuleProviderRef lp_build_provider = NULL;
-LLVMTargetDataRef lp_build_target = NULL;
+static boolean gallivm_initialized = FALSE;
+
+unsigned lp_native_vector_width;
 
 
 /*
@@ -62,39 +93,152 @@ LLVMTargetDataRef lp_build_target = NULL;
  * See also CodeGenOpt::Level in llvm/Target/TargetMachine.h
  */
 enum LLVM_CodeGenOpt_Level {
-#if HAVE_LLVM >= 0x207
    None,        // -O0
    Less,        // -O1
    Default,     // -O2, -Os
    Aggressive   // -O3
+};
+
+
+/**
+ * Create the LLVM (optimization) pass manager and install
+ * relevant optimization passes.
+ * \return  TRUE for success, FALSE for failure
+ */
+static boolean
+create_pass_manager(struct gallivm_state *gallivm)
+{
+   assert(!gallivm->passmgr);
+   assert(gallivm->target);
+
+   gallivm->passmgr = LLVMCreateFunctionPassManagerForModule(gallivm->module);
+   if (!gallivm->passmgr)
+      return FALSE;
+   /*
+    * TODO: some per module pass manager with IPO passes might be helpful -
+    * the generated texture functions may benefit from inlining if they are
+    * simple, or constant propagation into them, etc.
+    */
+
+#if HAVE_LLVM < 0x0309
+   // Old versions of LLVM get the DataLayout from the pass manager.
+   LLVMAddTargetData(gallivm->target, gallivm->passmgr);
+#endif
+
+   /* Setting the module's DataLayout to an empty string will cause the
+    * ExecutionEngine to copy to the DataLayout string from its target
+    * machine to the module.  As of LLVM 3.8 the module and the execution
+    * engine are required to have the same DataLayout.
+    *
+    * TODO: This is just a temporary work-around.  The correct solution is
+    * for gallivm_init_state() to create a TargetMachine and pull the
+    * DataLayout from there.  Currently, the TargetMachine used by llvmpipe
+    * is being implicitly created by the EngineBuilder in
+    * lp_build_create_jit_compiler_for_module()
+    */
+
+#if HAVE_LLVM < 0x0308
+   {
+      char *td_str;
+      // New ones from the Module.
+      td_str = LLVMCopyStringRepOfTargetData(gallivm->target);
+      LLVMSetDataLayout(gallivm->module, td_str);
+      free(td_str);
+   }
 #else
-   Default,
-   None,
-   Aggressive
+   LLVMSetDataLayout(gallivm->module, "");
 #endif
-};
+
+   if ((gallivm_debug & GALLIVM_DEBUG_NO_OPT) == 0) {
+      /* These are the passes currently listed in llvm-c/Transforms/Scalar.h,
+       * but there are more on SVN.
+       * TODO: Add more passes.
+       */
+      LLVMAddScalarReplAggregatesPass(gallivm->passmgr);
+      LLVMAddLICMPass(gallivm->passmgr);
+      LLVMAddCFGSimplificationPass(gallivm->passmgr);
+      LLVMAddReassociatePass(gallivm->passmgr);
+      LLVMAddPromoteMemoryToRegisterPass(gallivm->passmgr);
+      LLVMAddConstantPropagationPass(gallivm->passmgr);
+      LLVMAddInstructionCombiningPass(gallivm->passmgr);
+      LLVMAddGVNPass(gallivm->passmgr);
+   }
+   else {
+      /* We need at least this pass to prevent the backends to fail in
+       * unexpected ways.
+       */
+      LLVMAddPromoteMemoryToRegisterPass(gallivm->passmgr);
+   }
+
+   return TRUE;
+}
 
 
+/**
+ * Free gallivm object's LLVM allocations, but not any generated code
+ * nor the gallivm object itself.
+ */
 void
-lp_build_init(void)
+gallivm_free_ir(struct gallivm_state *gallivm)
 {
-#ifdef DEBUG
-   gallivm_debug = debug_get_flags_option("GALLIVM_DEBUG", lp_bld_debug_flags, 0 );
-#endif
+   if (gallivm->passmgr) {
+      LLVMDisposePassManager(gallivm->passmgr);
+   }
 
-   LLVMInitializeNativeTarget();
+   if (gallivm->engine) {
+      /* This will already destroy any associated module */
+      LLVMDisposeExecutionEngine(gallivm->engine);
+   } else if (gallivm->module) {
+      LLVMDisposeModule(gallivm->module);
+   }
 
-   LLVMLinkInJIT();
+   FREE(gallivm->module_name);
 
-   if (!lp_build_module)
-      lp_build_module = LLVMModuleCreateWithName("gallivm");
+   if (!use_mcjit) {
+      /* Don't free the TargetData, it's owned by the exec engine */
+   } else {
+      if (gallivm->target) {
+         LLVMDisposeTargetData(gallivm->target);
+      }
+   }
+
+   if (gallivm->builder)
+      LLVMDisposeBuilder(gallivm->builder);
+
+   /* The LLVMContext should be owned by the parent of gallivm. */
+
+   gallivm->engine = NULL;
+   gallivm->target = NULL;
+   gallivm->module = NULL;
+   gallivm->module_name = NULL;
+   gallivm->passmgr = NULL;
+   gallivm->context = NULL;
+   gallivm->builder = NULL;
+}
+
+
+/**
+ * Free LLVM-generated code.  Should be done AFTER gallivm_free_ir().
+ */
+static void
+gallivm_free_code(struct gallivm_state *gallivm)
+{
+   assert(!gallivm->module);
+   assert(!gallivm->engine);
+   lp_free_generated_code(gallivm->code);
+   gallivm->code = NULL;
+   lp_free_memory_manager(gallivm->memorymgr);
+   gallivm->memorymgr = NULL;
+}
 
-   if (!lp_build_provider)
-      lp_build_provider = LLVMCreateModuleProviderForExistingModule(lp_build_module);
 
-   if (!lp_build_engine) {
+static boolean
+init_gallivm_engine(struct gallivm_state *gallivm)
+{
+   if (1) {
       enum LLVM_CodeGenOpt_Level optlevel;
       char *error = NULL;
+      int ret;
 
       if (gallivm_debug & GALLIVM_DEBUG_NO_OPT) {
          optlevel = None;
@@ -103,36 +247,454 @@ lp_build_init(void)
          optlevel = Default;
       }
 
-      if (LLVMCreateJITCompiler(&lp_build_engine, lp_build_provider,
-                                (unsigned)optlevel, &error)) {
+      ret = lp_build_create_jit_compiler_for_module(&gallivm->engine,
+                                                    &gallivm->code,
+                                                    gallivm->module,
+                                                    gallivm->memorymgr,
+                                                    (unsigned) optlevel,
+                                                    use_mcjit,
+                                                    &error);
+      if (ret) {
          _debug_printf("%s\n", error);
          LLVMDisposeMessage(error);
-         assert(0);
+         goto fail;
+      }
+   }
+
+   if (!use_mcjit) {
+      gallivm->target = LLVMGetExecutionEngineTargetData(gallivm->engine);
+      if (!gallivm->target)
+         goto fail;
+   } else {
+      if (0) {
+          /*
+           * Dump the data layout strings.
+           */
+
+          LLVMTargetDataRef target = LLVMGetExecutionEngineTargetData(gallivm->engine);
+          char *data_layout;
+          char *engine_data_layout;
+
+          data_layout = LLVMCopyStringRepOfTargetData(gallivm->target);
+          engine_data_layout = LLVMCopyStringRepOfTargetData(target);
+
+          if (1) {
+             debug_printf("module target data = %s\n", data_layout);
+             debug_printf("engine target data = %s\n", engine_data_layout);
+          }
+
+          free(data_layout);
+          free(engine_data_layout);
+      }
+   }
+
+   return TRUE;
+
+fail:
+   return FALSE;
+}
+
+
+/**
+ * Allocate gallivm LLVM objects.
+ * \return  TRUE for success, FALSE for failure
+ */
+static boolean
+init_gallivm_state(struct gallivm_state *gallivm, const char *name,
+                   LLVMContextRef context)
+{
+   assert(!gallivm->context);
+   assert(!gallivm->module);
+
+   if (!lp_build_init())
+      return FALSE;
+
+   gallivm->context = context;
+
+   if (!gallivm->context)
+      goto fail;
+
+   gallivm->module_name = NULL;
+   if (name) {
+      size_t size = strlen(name) + 1;
+      gallivm->module_name = MALLOC(size);
+      if (gallivm->module_name) {
+         memcpy(gallivm->module_name, name, size);
       }
    }
 
-   if (!lp_build_target)
-      lp_build_target = LLVMGetExecutionEngineTargetData(lp_build_engine);
+   gallivm->module = LLVMModuleCreateWithNameInContext(name,
+                                                       gallivm->context);
+   if (!gallivm->module)
+      goto fail;
+
+   gallivm->builder = LLVMCreateBuilderInContext(gallivm->context);
+   if (!gallivm->builder)
+      goto fail;
+
+   gallivm->memorymgr = lp_get_default_memory_manager();
+   if (!gallivm->memorymgr)
+      goto fail;
+
+   /* FIXME: MC-JIT only allows compiling one module at a time, and it must be
+    * complete when MC-JIT is created. So defer the MC-JIT engine creation for
+    * now.
+    */
+   if (!use_mcjit) {
+      if (!init_gallivm_engine(gallivm)) {
+         goto fail;
+      }
+   } else {
+      /*
+       * MC-JIT engine compiles the module immediately on creation, so we can't
+       * obtain the target data from it.  Instead we create a target data layout
+       * from a string.
+       *
+       * The produced layout strings are not precisely the same, but should make
+       * no difference for the kind of optimization passes we run.
+       *
+       * For reference this is the layout string on x64:
+       *
+       *   e-p:64:64:64-S128-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f16:16:16-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-f128:128:128-n8:16:32:64
+       *
+       * See also:
+       * - http://llvm.org/docs/LangRef.html#datalayout
+       */
+
+      {
+         const unsigned pointer_size = 8 * sizeof(void *);
+         char layout[512];
+         util_snprintf(layout, sizeof layout, "%c-p:%u:%u:%u-i64:64:64-a0:0:%u-s0:%u:%u",
+#ifdef PIPE_ARCH_LITTLE_ENDIAN
+                       'e', // little endian
+#else
+                       'E', // big endian
+#endif
+                       pointer_size, pointer_size, pointer_size, // pointer size, abi alignment, preferred alignment
+                       pointer_size, // aggregate preferred alignment
+                       pointer_size, pointer_size); // stack objects abi alignment, preferred alignment
+
+         gallivm->target = LLVMCreateTargetData(layout);
+         if (!gallivm->target) {
+            return FALSE;
+         }
+      }
+   }
+
+   if (!create_pass_manager(gallivm))
+      goto fail;
+
+   return TRUE;
+
+fail:
+   gallivm_free_ir(gallivm);
+   gallivm_free_code(gallivm);
+   return FALSE;
+}
+
+
+boolean
+lp_build_init(void)
+{
+   if (gallivm_initialized)
+      return TRUE;
+
+
+   /* LLVMLinkIn* are no-ops at runtime.  They just ensure the respective
+    * component is linked at buildtime, which is sufficient for its static
+    * constructors to be called at load time.
+    */
+#if defined(USE_MCJIT)
+#  if USE_MCJIT
+      LLVMLinkInMCJIT();
+#  else
+      LLVMLinkInJIT();
+#  endif
+#else
+   use_mcjit = debug_get_bool_option("GALLIVM_MCJIT", FALSE);
+   LLVMLinkInJIT();
+   LLVMLinkInMCJIT();
+#endif
+
+#ifdef DEBUG
+   gallivm_debug = debug_get_option_gallivm_debug();
+#endif
+
+   lp_set_target_options();
 
    util_cpu_detect();
 
-#if 0
    /* For simulating less capable machines */
-   util_cpu_caps.has_sse3 = 0;
-   util_cpu_caps.has_ssse3 = 0;
-   util_cpu_caps.has_sse4_1 = 0;
+#ifdef DEBUG
+   if (debug_get_bool_option("LP_FORCE_SSE2", FALSE)) {
+      assert(util_cpu_caps.has_sse2);
+      util_cpu_caps.has_sse3 = 0;
+      util_cpu_caps.has_ssse3 = 0;
+      util_cpu_caps.has_sse4_1 = 0;
+      util_cpu_caps.has_sse4_2 = 0;
+      util_cpu_caps.has_avx = 0;
+      util_cpu_caps.has_avx2 = 0;
+      util_cpu_caps.has_f16c = 0;
+      util_cpu_caps.has_fma = 0;
+   }
+#endif
+
+   /* AMD Bulldozer AVX's throughput is the same as SSE2; and because using
+    * 8-wide vector needs more floating ops than 4-wide (due to padding), it is
+    * actually more efficient to use 4-wide vectors on this processor.
+    *
+    * See also:
+    * - http://www.anandtech.com/show/4955/the-bulldozer-review-amd-fx8150-tested/2
+    */
+   if (util_cpu_caps.has_avx &&
+       util_cpu_caps.has_intel) {
+      lp_native_vector_width = 256;
+   } else {
+      /* Leave it at 128, even when no SIMD extensions are available.
+       * Really needs to be a multiple of 128 so can fit 4 floats.
+       */
+      lp_native_vector_width = 128;
+   }
+ 
+   lp_native_vector_width = debug_get_num_option("LP_NATIVE_VECTOR_WIDTH",
+                                                 lp_native_vector_width);
+
+   if (lp_native_vector_width <= 128) {
+      /* Hide AVX support, as often LLVM AVX intrinsics are only guarded by
+       * "util_cpu_caps.has_avx" predicate, and lack the
+       * "lp_native_vector_width > 128" predicate. And also to ensure a more
+       * consistent behavior, allowing one to test SSE2 on AVX machines.
+       * XXX: should not play games with util_cpu_caps directly as it might
+       * get used for other things outside llvm too.
+       */
+      util_cpu_caps.has_avx = 0;
+      util_cpu_caps.has_avx2 = 0;
+      util_cpu_caps.has_f16c = 0;
+      util_cpu_caps.has_fma = 0;
+   }
+   if (HAVE_LLVM < 0x0304 || !use_mcjit) {
+      /* AVX2 support has only been tested with LLVM 3.4, and it requires
+       * MCJIT. */
+      util_cpu_caps.has_avx2 = 0;
+   }
+
+#ifdef PIPE_ARCH_PPC_64
+   /* Set the NJ bit in VSCR to 0 so denormalized values are handled as
+    * specified by IEEE standard (PowerISA 2.06 - Section 6.3). This guarantees
+    * that some rounding and half-float to float handling does not round
+    * incorrectly to 0.
+    * XXX: should eventually follow same logic on all platforms.
+    * Right now denorms get explicitly disabled (but elsewhere) for x86,
+    * whereas ppc64 explicitly enables them...
+    */
+   if (util_cpu_caps.has_altivec) {
+      unsigned short mask[] = { 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
+                                0xFFFF, 0xFFFF, 0xFFFE, 0xFFFF };
+      __asm (
+        "mfvscr %%v1\n"
+        "vand   %0,%%v1,%0\n"
+        "mtvscr %0"
+        :
+        : "r" (*mask)
+      );
+   }
 #endif
+
+   gallivm_initialized = TRUE;
+
+   return TRUE;
 }
 
 
-/* 
- * Hack to allow the linking of release LLVM static libraries on a debug build.
- *
- * See also:
- * - http://social.msdn.microsoft.com/Forums/en-US/vclanguage/thread/7234ea2b-0042-42ed-b4e2-5d8644dfb57d
+
+/**
+ * Create a new gallivm_state object.
+ */
+struct gallivm_state *
+gallivm_create(const char *name, LLVMContextRef context)
+{
+   struct gallivm_state *gallivm;
+
+   gallivm = CALLOC_STRUCT(gallivm_state);
+   if (gallivm) {
+      if (!init_gallivm_state(gallivm, name, context)) {
+         FREE(gallivm);
+         gallivm = NULL;
+      }
+   }
+
+   return gallivm;
+}
+
+
+/**
+ * Destroy a gallivm_state object.
+ */
+void
+gallivm_destroy(struct gallivm_state *gallivm)
+{
+   gallivm_free_ir(gallivm);
+   gallivm_free_code(gallivm);
+   FREE(gallivm);
+}
+
+
+/**
+ * Validate a function.
+ * Verification is only done with debug builds.
  */
-#if defined(_MSC_VER) && defined(_DEBUG)
-#include <crtdefs.h>
-_CRTIMP void __cdecl
-_invalid_parameter_noinfo(void) {}
+void
+gallivm_verify_function(struct gallivm_state *gallivm,
+                        LLVMValueRef func)
+{
+   /* Verify the LLVM IR.  If invalid, dump and abort */
+#ifdef DEBUG
+   if (LLVMVerifyFunction(func, LLVMPrintMessageAction)) {
+      lp_debug_dump_value(func);
+      assert(0);
+      return;
+   }
 #endif
+
+   if (gallivm_debug & GALLIVM_DEBUG_IR) {
+      /* Print the LLVM IR to stderr */
+      lp_debug_dump_value(func);
+      debug_printf("\n");
+   }
+}
+
+
+/**
+ * Compile a module.
+ * This does IR optimization on all functions in the module.
+ */
+void
+gallivm_compile_module(struct gallivm_state *gallivm)
+{
+   LLVMValueRef func;
+   int64_t time_begin = 0;
+
+   assert(!gallivm->compiled);
+
+   if (gallivm->builder) {
+      LLVMDisposeBuilder(gallivm->builder);
+      gallivm->builder = NULL;
+   }
+
+   if (gallivm_debug & GALLIVM_DEBUG_PERF)
+      time_begin = os_time_get();
+
+   /* Run optimization passes */
+   LLVMInitializeFunctionPassManager(gallivm->passmgr);
+   func = LLVMGetFirstFunction(gallivm->module);
+   while (func) {
+      if (0) {
+         debug_printf("optimizing func %s...\n", LLVMGetValueName(func));
+      }
+
+   /* Disable frame pointer omission on debug/profile builds */
+   /* XXX: And workaround http://llvm.org/PR21435 */
+#if HAVE_LLVM >= 0x0307 && \
+    (defined(DEBUG) || defined(PROFILE) || \
+     defined(PIPE_ARCH_X86) || defined(PIPE_ARCH_X86_64))
+      LLVMAddTargetDependentFunctionAttr(func, "no-frame-pointer-elim", "true");
+      LLVMAddTargetDependentFunctionAttr(func, "no-frame-pointer-elim-non-leaf", "true");
+#endif
+
+      LLVMRunFunctionPassManager(gallivm->passmgr, func);
+      func = LLVMGetNextFunction(func);
+   }
+   LLVMFinalizeFunctionPassManager(gallivm->passmgr);
+
+   if (gallivm_debug & GALLIVM_DEBUG_PERF) {
+      int64_t time_end = os_time_get();
+      int time_msec = (int)(time_end - time_begin) / 1000;
+      assert(gallivm->module_name);
+      debug_printf("optimizing module %s took %d msec\n",
+                   gallivm->module_name, time_msec);
+   }
+
+   /* Dump byte code to a file */
+   if (gallivm_debug & GALLIVM_DEBUG_DUMP_BC) {
+      char filename[256];
+      assert(gallivm->module_name);
+      util_snprintf(filename, sizeof(filename), "ir_%s.bc", gallivm->module_name);
+      LLVMWriteBitcodeToFile(gallivm->module, filename);
+      debug_printf("%s written\n", filename);
+      debug_printf("Invoke as \"llc %s%s -o - %s\"\n",
+                   (HAVE_LLVM >= 0x0305) ? "[-mcpu=<-mcpu option] " : "",
+                   "[-mattr=<-mattr option(s)>]",
+                   filename);
+   }
+
+   if (use_mcjit) {
+      assert(!gallivm->engine);
+      if (!init_gallivm_engine(gallivm)) {
+         assert(0);
+      }
+   }
+   assert(gallivm->engine);
+
+   ++gallivm->compiled;
+
+   if (gallivm_debug & GALLIVM_DEBUG_ASM) {
+      LLVMValueRef llvm_func = LLVMGetFirstFunction(gallivm->module);
+
+      while (llvm_func) {
+         /*
+          * Need to filter out functions which don't have an implementation,
+          * such as the intrinsics. May not be sufficient in case of IPO?
+          * LLVMGetPointerToGlobal() will abort otherwise.
+          */
+         if (!LLVMIsDeclaration(llvm_func)) {
+            void *func_code = LLVMGetPointerToGlobal(gallivm->engine, llvm_func);
+            lp_disassemble(llvm_func, func_code);
+         }
+         llvm_func = LLVMGetNextFunction(llvm_func);
+      }
+   }
+
+#if defined(PROFILE)
+   {
+      LLVMValueRef llvm_func = LLVMGetFirstFunction(gallivm->module);
+
+      while (llvm_func) {
+         if (!LLVMIsDeclaration(llvm_func)) {
+            void *func_code = LLVMGetPointerToGlobal(gallivm->engine, llvm_func);
+            lp_profile(llvm_func, func_code);
+         }
+         llvm_func = LLVMGetNextFunction(llvm_func);
+      }
+   }
+#endif
+}
+
+
+
+func_pointer
+gallivm_jit_function(struct gallivm_state *gallivm,
+                     LLVMValueRef func)
+{
+   void *code;
+   func_pointer jit_func;
+   int64_t time_begin = 0;
+
+   assert(gallivm->compiled);
+   assert(gallivm->engine);
+
+   if (gallivm_debug & GALLIVM_DEBUG_PERF)
+      time_begin = os_time_get();
+
+   code = LLVMGetPointerToGlobal(gallivm->engine, func);
+   assert(code);
+   jit_func = pointer_to_func(code);
+
+   if (gallivm_debug & GALLIVM_DEBUG_PERF) {
+      int64_t time_end = os_time_get();
+      int time_msec = (int)(time_end - time_begin) / 1000;
+      debug_printf("   jitting func %s took %d msec\n",
+                   LLVMGetValueName(func), time_msec);
+   }
+
+   return jit_func;
+}