SPV_KHR_untyped_pointers - fix images translation (#2817)

This patch ensures that we are loading image type, not untyped pointer
type when the extension is used. This way we also preserve correct
mangling during the reverse translation.

Author: vmaksimo

lib/SPIRV/SPIRVWriter.cpp

@@ -2218,13 +2218,19 @@ LLVMToSPIRVBase::transValueWithoutDecoration(Value *V, SPIRVBasicBlock *BB,
                              MemoryAccessNoAliasINTELMaskMask);
     if (MemoryAccess.front() == 0)
       MemoryAccess.clear();
-    return mapValue(
-        V,
-        BM->addLoadInst(
-            transValue(LD->getPointerOperand(), BB), MemoryAccess, BB,
-            BM->isAllowedToUseExtension(ExtensionID::SPV_KHR_untyped_pointers)
-                ? transType(LD->getType())
-                : nullptr));
+    if (BM->isAllowedToUseExtension(ExtensionID::SPV_KHR_untyped_pointers)) {
+      SPIRVValue *Source = transValue(LD->getPointerOperand(), BB);
+      SPIRVType *LoadTy = transType(LD->getType());
+      // For images do not use explicit load type, but rather use the source
+      // type (calculated in SPIRVLoad constructor)
+      if (LoadTy->isTypeUntypedPointerKHR() &&
+          (Source->getType()->getPointerElementType()->isTypeImage())) {
+        LoadTy = nullptr;
+      }
+      return mapValue(V, BM->addLoadInst(Source, MemoryAccess, BB, LoadTy));
+    }
+    return mapValue(V, BM->addLoadInst(transValue(LD->getPointerOperand(), BB),
+                                       MemoryAccess, BB));
   }
 
   if (BinaryOperator *B = dyn_cast<BinaryOperator>(V)) {

test/transcoding/get_image_num_mip_levels.ll

@@ -8,6 +8,15 @@
 ; RUN: llvm-dis < %t.rev.bc | FileCheck %s --check-prefix=CHECK-SPV-IR
 ; RUN: llvm-spirv -spirv-text %t.rev.bc -o - | FileCheck %s --check-prefix=CHECK-SPIRV
 
+; RUN: llvm-spirv --spirv-ext=+SPV_KHR_untyped_pointers -spirv-text %t.bc -o - | FileCheck %s --check-prefix=CHECK-SPIRV
+; RUN: llvm-spirv --spirv-ext=+SPV_KHR_untyped_pointers %t.bc -o %t.spv
+; RUN: spirv-val %t.spv
+; RUN: llvm-spirv -r %t.spv -o %t.rev.bc
+; RUN: llvm-dis < %t.rev.bc | FileCheck %s --check-prefix=CHECK-LLVM
+; RUN: llvm-spirv -r %t.spv -o %t.rev.bc --spirv-target-env=SPV-IR
+; RUN: llvm-dis < %t.rev.bc | FileCheck %s --check-prefix=CHECK-SPV-IR
+; RUN: llvm-spirv -spirv-text %t.rev.bc -o - | FileCheck %s --check-prefix=CHECK-SPIRV
+
 ; Generated from the following OpenCL C code:
 ; #pragma OPENCL EXTENSION cl_khr_mipmap_image : enable
 ; void test(image1d_t img1, 

test/transcoding/image_with_access_qualifiers.ll

@@ -5,6 +5,12 @@
 ; RUN: llvm-spirv -r %t.spv -o %t.rev.bc
 ; RUN: llvm-dis < %t.rev.bc | FileCheck %s --check-prefix=CHECK-LLVM
 
+; RUN: llvm-spirv --spirv-ext=+SPV_KHR_untyped_pointers %t.bc -spirv-text -o %t.txt
+; RUN: FileCheck < %t.txt %s --check-prefix=CHECK-SPIRV
+; RUN: llvm-spirv --spirv-ext=+SPV_KHR_untyped_pointers %t.bc -o %t.spv
+; RUN: llvm-spirv -r %t.spv -o %t.rev.bc
+; RUN: llvm-dis < %t.rev.bc | FileCheck %s --check-prefix=CHECK-LLVM
+
 ; NOTE: access qualifier infomation is not preserved after round-trip conversion to LLVM
 ; CHECK-LLVM: call spir_func <4 x float> @_Z11read_imagef14ocl_image1d_rw11ocl_sampleri(ptr