diff lib/Target/NVPTX/NVVMReflect.cpp @ 95:afa8332a0e37 LLVM3.8

LLVM 3.8
author Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
date Tue, 13 Oct 2015 17:48:58 +0900
parents 54457678186b
children 1172e4bd9c6f
line wrap: on
line diff
--- a/lib/Target/NVPTX/NVVMReflect.cpp	Wed Feb 18 14:56:07 2015 +0900
+++ b/lib/Target/NVPTX/NVVMReflect.cpp	Tue Oct 13 17:48:58 2015 +0900
@@ -29,6 +29,7 @@
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_os_ostream.h"
+#include "llvm/Support/raw_ostream.h"
 #include "llvm/Transforms/Scalar.h"
 #include <map>
 #include <sstream>
@@ -108,10 +109,10 @@
   for (unsigned i = 0, e = ReflectList.size(); i != e; ++i) {
     DEBUG(dbgs() << "Option : "  << ReflectList[i] << "\n");
     SmallVector<StringRef, 4> NameValList;
-    StringRef(ReflectList[i]).split(NameValList, ",");
+    StringRef(ReflectList[i]).split(NameValList, ',');
     for (unsigned j = 0, ej = NameValList.size(); j != ej; ++j) {
       SmallVector<StringRef, 2> NameValPair;
-      NameValList[j].split(NameValPair, "=");
+      NameValList[j].split(NameValPair, '=');
       assert(NameValPair.size() == 2 && "name=val expected");
       std::stringstream ValStream(NameValPair[1]);
       int Val;
@@ -137,6 +138,26 @@
   // ConstantArray can be found successfully, see if it can be
   // found in VarMap. If so, replace the uses of CallInst with the
   // value found in VarMap. If not, replace the use  with value 0.
+
+  // IR for __nvvm_reflect calls differs between CUDA versions:
+  // CUDA 6.5 and earlier uses this sequence:
+  //    %ptr = tail call i8* @llvm.nvvm.ptr.constant.to.gen.p0i8.p4i8
+  //        (i8 addrspace(4)* getelementptr inbounds
+  //           ([8 x i8], [8 x i8] addrspace(4)* @str, i32 0, i32 0))
+  //    %reflect = tail call i32 @__nvvm_reflect(i8* %ptr)
+  //
+  // Value returned by Sym->getOperand(0) is a Constant with a
+  // ConstantDataSequential operand which can be converted to string and used
+  // for lookup.
+  //
+  // CUDA 7.0 does it slightly differently:
+  //   %reflect = call i32 @__nvvm_reflect(i8* addrspacecast
+  //        (i8 addrspace(1)* getelementptr inbounds
+  //           ([8 x i8], [8 x i8] addrspace(1)* @str, i32 0, i32 0) to i8*))
+  //
+  // In this case, we get a Constant with a GlobalVariable operand and we need
+  // to dig deeper to find its initializer with the string we'll use for lookup.
+
   for (User *U : ReflectFunction->users()) {
     assert(isa<CallInst>(U) && "Only a call instruction can use _reflect");
     CallInst *Reflect = cast<CallInst>(U);
@@ -158,16 +179,23 @@
     const Value *Sym = GEP->getOperand(0);
     assert(isa<Constant>(Sym) && "Format of _reflect function not recognized");
 
-    const Constant *SymStr = cast<Constant>(Sym);
+    const Value *Operand = cast<Constant>(Sym)->getOperand(0);
+    if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(Operand)) {
+      // For CUDA-7.0 style __nvvm_reflect calls we need to find operand's
+      // initializer.
+      assert(GV->hasInitializer() &&
+             "Format of _reflect function not recognized");
+      const Constant *Initializer = GV->getInitializer();
+      Operand = Initializer;
+    }
 
-    assert(isa<ConstantDataSequential>(SymStr->getOperand(0)) &&
+    assert(isa<ConstantDataSequential>(Operand) &&
            "Format of _reflect function not recognized");
-
-    assert(cast<ConstantDataSequential>(SymStr->getOperand(0))->isCString() &&
+    assert(cast<ConstantDataSequential>(Operand)->isCString() &&
            "Format of _reflect function not recognized");
 
     std::string ReflectArg =
-        cast<ConstantDataSequential>(SymStr->getOperand(0))->getAsString();
+        cast<ConstantDataSequential>(Operand)->getAsString();
 
     ReflectArg = ReflectArg.substr(0, ReflectArg.size() - 1);
     DEBUG(dbgs() << "Arg of _reflect : " << ReflectArg << "\n");