[IR] Disallow ZeroInit for spirv.Image

[wenju-he]

According to spirv spec, OpConstantNull's result type can't be image
type. So we can't generate zeroinitializer for spirv.Image.

[llvmbot]

@llvm/pr-subscribers-llvm-ir

@llvm/pr-subscribers-llvm-transforms

Author: Wenju He (wenju-he)

Changes

According to spirv spec, OpConstantNull's result type can't be image
type. So we can't generate zeroinitializer for spirv.Image.

---

Full diff: https://github.com/llvm/llvm-project/pull/73887.diff

2 Files Affected:

• (modified) llvm/lib/IR/Type.cpp (+2)
• (modified) llvm/unittests/Transforms/Utils/ValueMapperTest.cpp (+1-1)

diff --git a/llvm/lib/IR/Type.cpp b/llvm/lib/IR/Type.cpp
index 3d2e203a20dac77..e3a09018ad8b98f 100644
--- a/llvm/lib/IR/Type.cpp
+++ b/llvm/lib/IR/Type.cpp
@@ -841,6 +841,8 @@ struct TargetTypeInfo {
 static TargetTypeInfo getTargetTypeInfo(const TargetExtType *Ty) {
   LLVMContext &C = Ty->getContext();
   StringRef Name = Ty->getName();
+  if (Name.equals("spirv.Image"))
+    return TargetTypeInfo(PointerType::get(C, 0), TargetExtType::CanBeGlobal);
   if (Name.startswith("spirv."))
     return TargetTypeInfo(PointerType::get(C, 0), TargetExtType::HasZeroInit,
                           TargetExtType::CanBeGlobal);
diff --git a/llvm/unittests/Transforms/Utils/ValueMapperTest.cpp b/llvm/unittests/Transforms/Utils/ValueMapperTest.cpp
index 17083b3846430dd..c0c9d383ac18166 100644
--- a/llvm/unittests/Transforms/Utils/ValueMapperTest.cpp
+++ b/llvm/unittests/Transforms/Utils/ValueMapperTest.cpp
@@ -423,7 +423,7 @@ TEST(ValueMapperTest, mapValuePoisonWithTypeRemap) {
 
 TEST(ValueMapperTest, mapValueConstantTargetNoneToLayoutTypeNullValue) {
   LLVMContext C;
-  auto *OldTy = TargetExtType::get(C, "spirv.Image");
+  auto *OldTy = TargetExtType::get(C, "spirv.Event");
   Type *NewTy = OldTy->getLayoutType();
 
   TestTypeRemapper TM(NewTy);

[wenju-he]

@jcranmer-intel could you please take a look?
Before this PR, there could be following ir generated:

store target("spirv.Image", void, 1, 0, 0, 0, 0, 0, 0) zeroinitializer, ptr addrspace(4) %MImageObj, align 8

llvm-spirv translator isn't able to handle it due to spec requirement.

[wenju-he]

kindly ping @jcranmer-intel

[bogner]

This change causes a number of the spir-v backend tests to crash:

Failed Tests (5):
LLVM :: CodeGen/SPIRV/image-unoptimized.ll
LLVM :: CodeGen/SPIRV/read_image.ll
LLVM :: CodeGen/SPIRV/transcoding/get_image_num_mip_levels.ll
LLVM :: CodeGen/SPIRV/transcoding/image_with_access_qualifiers.ll
LLVM :: CodeGen/SPIRV/transcoding/spirv-types.ll

[wenju-he]

image-unoptimized.ll

backtrace:

 #0 0x0000000001d2f0e1 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (llvm-project/build/bin/llc+0x1d2f0e1)
 #1 0x0000000001d2c644 SignalHandler(int) Signals.cpp:0:0
 #2 0x00007fd516a7ddb0 __restore_rt (/lib64/libc.so.6+0x59db0)
 #3 0x00007fd516aca42c __pthread_kill_implementation (/lib64/libc.so.6+0xa642c)
 #4 0x00007fd516a7dd06 gsignal (/lib64/libc.so.6+0x59d06)
 #5 0x00007fd516a507d3 abort (/lib64/libc.so.6+0x2c7d3)
 #6 0x00007fd516a506fb _nl_load_domain.cold (/lib64/libc.so.6+0x2c6fb)
 #7 0x00007fd516a76c86 (/lib64/libc.so.6+0x52c86)
 #8 0x00000000014b3bf1 llvm::ConstantTargetNone::get(llvm::TargetExtType*) (llvm-project/build/bin/llc+0x14b3bf1)
 #9 0x0000000000abac68 (anonymous namespace)::SPIRVEmitIntrinsics::runOnFunction(llvm::Function&) (.part.0) SPIRVEmitIntrinsics.cpp:0:0

SPIRVEmitIntrinsics pass probably needs fix to not generate ConstantTargetNone for spirv.Image. @bogner WDYT?