From 5dd5096dfac2fa5adceae6bfee6d27671fec2eef Mon Sep 17 00:00:00 2001
From: Alexey Sotkin <alexey.sotkin@intel.com>
Date: Thu, 13 Jul 2017 19:34:07 +0300
Subject: Insert bitcast during translation of llvm.memset (#219)

This commit supplements 94ed068c81cac48eed41e8851115520949664e2c
"Changing translation of llvm.memset intrinsic (#217)"

With arguments bitcasted to i8* OpCopyMemorySized can be correctly
translated to llvm.memcpy, i.e.
llvm.memcpy.p0i8.p0i8.i32(i8*, i8*, ...) instead of
llvm.memcpy.p0i8.p0i8.i32(i8*, [n x i8]*, ...)
---
 lib/SPIRV/SPIRVReader.cpp       | 24 ++++++++++++++----------
 lib/SPIRV/SPIRVWriter.cpp       |  9 ++++++---
 lib/SPIRV/libSPIRV/SPIRVEntry.h |  2 +-
 test/transcoding/llvm.memset.ll |  4 +++-
 4 files changed, 24 insertions(+), 15 deletions(-)

diff --git a/lib/SPIRV/SPIRVReader.cpp b/lib/SPIRV/SPIRVReader.cpp
index a8d9f08..8bd80a7 100644
--- a/lib/SPIRV/SPIRVReader.cpp
+++ b/lib/SPIRV/SPIRVReader.cpp
@@ -1668,16 +1668,20 @@ SPIRVToLLVM::transValueWithoutDecoration(SPIRVValue *BV, Function *F,
              << "i8";
     Value *Src = nullptr;
     // If we copy from zero-initialized array, we can optimize it to llvm.memset
-    if (BC->getSource()->isVariable()) {
-      auto *Init = static_cast<SPIRVVariable*>(BC->getSource())->getInitializer();
-      if (isa<OpConstantNull>(Init)) {
-        SPIRVType *Ty = static_cast<SPIRVConstantNull*>(Init)->getType();
-        if (isa<OpTypeArray>(Ty)) {
-          SPIRVTypeArray *AT = static_cast<SPIRVTypeArray*>(Ty);
-          SrcTy = transType(AT->getArrayElementType());
-          assert(SrcTy->isIntegerTy(8));
-          Src = ConstantInt::get(SrcTy, 0);
-          FuncName = "llvm.memset";
+    if (BC->getSource()->getOpCode() == OpBitcast) {
+      SPIRVValue *Source =
+        static_cast<SPIRVBitcast*>(BC->getSource())->getOperand(0);
+      if (Source->isVariable()) {
+        auto *Init = static_cast<SPIRVVariable*>(Source)->getInitializer();
+        if (isa<OpConstantNull>(Init)) {
+          SPIRVType *Ty = static_cast<SPIRVConstantNull*>(Init)->getType();
+          if (isa<OpTypeArray>(Ty)) {
+            SPIRVTypeArray *AT = static_cast<SPIRVTypeArray*>(Ty);
+            SrcTy = transType(AT->getArrayElementType());
+            assert(SrcTy->isIntegerTy(8));
+            Src = ConstantInt::get(SrcTy, 0);
+            FuncName = "llvm.memset";
+          }
         }
       }
     }
diff --git a/lib/SPIRV/SPIRVWriter.cpp b/lib/SPIRV/SPIRVWriter.cpp
index 9bc2937..604ab71 100644
--- a/lib/SPIRV/SPIRVWriter.cpp
+++ b/lib/SPIRV/SPIRVWriter.cpp
@@ -1302,9 +1302,12 @@ LLVMToSPIRV::transIntrinsicInst(IntrinsicInst *II, SPIRVBasicBlock *BB) {
     SPIRVTypeArray *CompositeTy = static_cast<SPIRVTypeArray*>(transType(AT));
     SPIRVValue *Init = BM->addNullConstant(CompositeTy);
     SPIRVType *VarTy = transType(PointerType::get(AT, SPIRV::SPIRAS_Constant));
-    SPIRVValue *Source = BM->addVariable(VarTy,/*isConstant*/true,
-                                         spv::LinkageTypeInternal, Init, "",
-                                         StorageClassUniformConstant, nullptr);
+    SPIRVValue *Var = BM->addVariable(VarTy,/*isConstant*/true,
+                                      spv::LinkageTypeInternal, Init, "",
+                                      StorageClassUniformConstant, nullptr);
+    SPIRVType *SourceTy = transType(PointerType::get(Val->getType(),
+                                                     SPIRV::SPIRAS_Constant));
+    SPIRVValue *Source = BM->addUnaryInst(OpBitcast, SourceTy, Var, BB);
     SPIRVValue *Target = transValue(MSI->getRawDest(), BB);
     return BM->addCopyMemorySizedInst(Target, Source, CompositeTy->getLength(),
                                       getMemoryAccess(MSI), BB);
diff --git a/lib/SPIRV/libSPIRV/SPIRVEntry.h b/lib/SPIRV/libSPIRV/SPIRVEntry.h
index 004e3de..8cdb3dd 100644
--- a/lib/SPIRV/libSPIRV/SPIRVEntry.h
+++ b/lib/SPIRV/libSPIRV/SPIRVEntry.h
@@ -698,7 +698,7 @@ T* bcast(SPIRVEntry *E) {
 
 template<spv::Op OC>
 bool isa(SPIRVEntry *E) {
-  return E->getOpCode() == OC;
+  return E ? E->getOpCode() == OC : false;
 }
 
 // ToDo: The following typedef's are place holders for SPIRV entity classes
diff --git a/test/transcoding/llvm.memset.ll b/test/transcoding/llvm.memset.ll
index 22eb041..b41fa96 100644
--- a/test/transcoding/llvm.memset.ll
+++ b/test/transcoding/llvm.memset.ll
@@ -20,10 +20,12 @@
 ; CHECK-SPIRV: Constant {{[0-9]+}} [[Len:[0-9]+]] 12
 ; CHECK-SPIRV: TypePointer [[Int8Ptr:[0-9]+]] 8 [[Int8]]
 ; CHECK-SPIRV: TypeArray [[Int8x12:[0-9]+]] [[Int8]] [[Len]]
+; CHECK-SPIRV: TypePointer [[Int8PtrConst:[0-9]+]] 0 [[Int8]]
 ; CHECK-SPIRV: ConstantNull [[Int8x12]] [[Init:[0-9]+]]
-; CHECK-SPIRV: Variable {{[0-9]+}} [[Source:[0-9]+]] 0 [[Init]]
+; CHECK-SPIRV: Variable {{[0-9]+}} [[Val:[0-9]+]] 0 [[Init]]
 
 ; CHECK-SPIRV: Bitcast [[Int8Ptr]] [[Target:[0-9]+]] {{[0-9]+}}
+; CHECK-SPIRV: Bitcast [[Int8PtrConst]] [[Source:[0-9]+]] [[Val]]
 ; CHECK-SPIRV: CopyMemorySized [[Target]] [[Source]] [[Len]] 2 4
 
 
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