TLA  Line data    Source code

       1                 : /*-------------------------------------------------------------------------
       2                 :  *
       3                 :  * llvmjit_wrap.cpp
       4                 :  *    Parts of the LLVM interface not (yet) exposed to C.
       5                 :  *
       6                 :  * Copyright (c) 2016-2023, PostgreSQL Global Development Group
       7                 :  *
       8                 :  * IDENTIFICATION
       9                 :  *    src/backend/lib/llvm/llvmjit_wrap.cpp
      10                 :  *
      11                 :  *-------------------------------------------------------------------------
      12                 :  */
      13                 : 
      14                 : extern "C"
      15                 : {
      16                 : #include "postgres.h"
      17                 : }
      18                 : 
      19                 : #include <llvm-c/Core.h>
      20                 : 
      21                 : /* Avoid macro clash with LLVM's C++ headers */
      22                 : #undef Min
      23                 : 
      24                 : #include <llvm/IR/Attributes.h>
      25                 : #include <llvm/IR/Function.h>
      26                 : #include <llvm/MC/SubtargetFeature.h>
      27                 : #include <llvm/Support/Host.h>
      28                 : 
      29                 : #include "jit/llvmjit.h"
      30                 : 
      31                 : 
      32                 : /*
      33                 :  * C-API extensions.
      34                 :  */
      35                 : #if defined(HAVE_DECL_LLVMGETHOSTCPUNAME) && !HAVE_DECL_LLVMGETHOSTCPUNAME
      36                 : char *LLVMGetHostCPUName(void) {
      37                 :     return strdup(llvm::sys::getHostCPUName().data());
      38                 : }
      39                 : #endif
      40                 : 
      41                 : 
      42                 : #if defined(HAVE_DECL_LLVMGETHOSTCPUFEATURES) && !HAVE_DECL_LLVMGETHOSTCPUFEATURES
      43                 : char *LLVMGetHostCPUFeatures(void) {
      44                 :     llvm::SubtargetFeatures Features;
      45                 :     llvm::StringMap<bool> HostFeatures;
      46                 : 
      47                 :     if (llvm::sys::getHostCPUFeatures(HostFeatures))
      48                 :         for (auto &F : HostFeatures)
      49                 :             Features.AddFeature(F.first(), F.second);
      50                 : 
      51                 :     return strdup(Features.getString().c_str());
      52                 : }
      53                 : #endif
      54                 : 
      55                 : /*
      56                 :  * Like LLVM's LLVMGetAttributeCountAtIndex(), works around a bug in LLVM 3.9.
      57                 :  *
      58                 :  * In LLVM <= 3.9, LLVMGetAttributeCountAtIndex() segfaults if there are no
      59                 :  * attributes at an index (fixed in LLVM commit ce9bb1097dc2).
      60                 :  */
      61                 : unsigned
      62 CBC       33330 : LLVMGetAttributeCountAtIndexPG(LLVMValueRef F, uint32 Idx)
      63                 : {
      64                 :     /*
      65                 :      * This is more expensive, so only do when using a problematic LLVM
      66                 :      * version.
      67                 :      */
      68                 : #if LLVM_VERSION_MAJOR < 4
      69                 :     if (!llvm::unwrap<llvm::Function>(F)->getAttributes().hasAttributes(Idx))
      70                 :         return 0;
      71                 : #endif
      72                 : 
      73                 :     /*
      74                 :      * There is no nice public API to determine the count nicely, so just
      75                 :      * always fall back to LLVM's C API.
      76                 :      */
      77           33330 :     return LLVMGetAttributeCountAtIndex(F, Idx);
      78                 : }