prevent undefined behaviour of SPIR-V Backend non-asserts builds when dealing with token type #78437
Conversation
…s detected that would lead to undefined behavior of SPIR-V Backend code generator
|
Thank you for submitting a Pull Request (PR) to the LLVM Project! This PR will be automatically labeled and the relevant teams will be If you wish to, you can add reviewers by using the "Reviewers" section on this page. If this is not working for you, it is probably because you do not have write If you have received no comments on your PR for a week, you can request a review If you have further questions, they may be answered by the LLVM GitHub User Guide. You can also ask questions in a comment on this PR, on the LLVM Discord or on the forums. |
|
@llvm/pr-subscribers-backend-spir-v Author: Vyacheslav Levytskyy (VyacheslavLevytskyy) ChangesThe goal of this PR is to fix the issue when use of token type in LLVM intrinsic causes undefined behavior of SPIR-V Backend code generator when assertions are disabled: #78434 Among possible fix options, discussed in the #78434 issue description, the option to generate a meaningful error before execution arrives at the The PR is to generate a user-friendly error message and exit without generating a stack dump when such a usage of token type was detected that would lead to undefined behavior of SPIR-V Backend code generator. Full diff: https://github.com/llvm/llvm-project/pull/78437.diff 3 Files Affected:
diff --git a/llvm/lib/Target/SPIRV/SPIRVEmitIntrinsics.cpp b/llvm/lib/Target/SPIRV/SPIRVEmitIntrinsics.cpp
index ec62a819b00eedf..907bf87dc406d31 100644
--- a/llvm/lib/Target/SPIRV/SPIRVEmitIntrinsics.cpp
+++ b/llvm/lib/Target/SPIRV/SPIRVEmitIntrinsics.cpp
@@ -147,6 +147,13 @@ static bool requireAssignType(Instruction *I) {
return true;
}
+static inline void reportFatalOnTokenType(const Instruction *I) {
+ if (I->getType()->isTokenTy())
+ report_fatal_error("A token is encountered but SPIR-V without extensions "
+ "does not support token type",
+ false);
+}
+
void SPIRVEmitIntrinsics::replaceMemInstrUses(Instruction *Old,
Instruction *New) {
while (!Old->user_empty()) {
@@ -402,6 +409,7 @@ void SPIRVEmitIntrinsics::processGlobalValue(GlobalVariable &GV) {
}
void SPIRVEmitIntrinsics::insertAssignPtrTypeIntrs(Instruction *I) {
+ reportFatalOnTokenType(I);
if (I->getType()->isVoidTy() || !requireAssignPtrType(I))
return;
@@ -424,6 +432,7 @@ void SPIRVEmitIntrinsics::insertAssignPtrTypeIntrs(Instruction *I) {
}
void SPIRVEmitIntrinsics::insertAssignTypeIntrs(Instruction *I) {
+ reportFatalOnTokenType(I);
Type *Ty = I->getType();
if (!Ty->isVoidTy() && requireAssignType(I) && !requireAssignPtrType(I)) {
setInsertPointSkippingPhis(*IRB, I->getNextNode());
@@ -483,6 +492,7 @@ void SPIRVEmitIntrinsics::processInstrAfterVisit(Instruction *I) {
}
}
if (I->hasName()) {
+ reportFatalOnTokenType(I);
setInsertPointSkippingPhis(*IRB, I->getNextNode());
std::vector<Value *> Args = {I};
addStringImm(I->getName(), *IRB, Args);
diff --git a/llvm/test/CodeGen/SPIRV/token/token_type_preallocated_setup_arg.ll b/llvm/test/CodeGen/SPIRV/token/token_type_preallocated_setup_arg.ll
new file mode 100644
index 000000000000000..42e59c726b6fdc7
--- /dev/null
+++ b/llvm/test/CodeGen/SPIRV/token/token_type_preallocated_setup_arg.ll
@@ -0,0 +1,17 @@
+; Example of token usage is from https://llvm.org/docs/LangRef.html (Preallocated Operand Bundles)
+
+; RUN: not llc -O0 -mtriple=spirv64-unknown-unknown %s -o - 2>&1 | FileCheck %s
+
+; CHECK: A token is encountered but SPIR-V without extensions does not support token type
+
+%foo = type { i64, i32 }
+
+define dso_local spir_func void @test() {
+entry:
+ %tok = call token @llvm.call.preallocated.setup(i32 1)
+ %a = call ptr @llvm.call.preallocated.arg(token %tok, i32 0) preallocated(%foo)
+ ret void
+}
+
+declare token @llvm.call.preallocated.setup(i32 %num_args)
+declare ptr @llvm.call.preallocated.arg(token %setup_token, i32 %arg_index)
diff --git a/llvm/test/CodeGen/SPIRV/token/token_type_requires_extension.ll b/llvm/test/CodeGen/SPIRV/token/token_type_requires_extension.ll
new file mode 100644
index 000000000000000..ee545a77e5d68f8
--- /dev/null
+++ b/llvm/test/CodeGen/SPIRV/token/token_type_requires_extension.ll
@@ -0,0 +1,11 @@
+; RUN: not llc -O0 -mtriple=spirv64-unknown-unknown %s -o - 2>&1 | FileCheck %s
+
+; CHECK: A token is encountered but SPIR-V without extensions does not support token type
+
+declare token @llvm.myfun()
+
+define dso_local spir_func void @func() {
+entry:
+ %tok = call token @llvm.myfun()
+ ret void
+}
|
|
@michalpaszkowski Can you please have a look at this one as well when you have time. Thank you! |
| @@ -0,0 +1,17 @@ | |||
| ; Example of token usage is from https://llvm.org/docs/LangRef.html (Preallocated Operand Bundles) | |||
There was a problem hiding this comment.
Please change the name to use dashes instead of underscores
The goal of this PR is to fix the issue when use of token type in LLVM intrinsic causes undefined behavior of SPIR-V Backend code generator when assertions are disabled: #78434
Among possible fix options, discussed in the #78434 issue description, the option to generate a meaningful error before execution arrives at the
llvm_unreachablecall looks like a better solution for now, because SPIR-V doesn't support token type anyway without additional extensions.The PR is to generate a user-friendly error message and exit without generating a stack dump when such a usage of token type was detected that would lead to undefined behavior of SPIR-V Backend code generator.