[llvm] 9701053 - Introduce @llvm.threadlocal.address intrinsic to access TLS variable
Chuanqi Xu via llvm-commits
llvm-commits at lists.llvm.org
Sun Jul 31 19:53:11 PDT 2022
Author: Chuanqi Xu
Date: 2022-08-01T10:51:30+08:00
New Revision: 9701053517100045ca9fb0fd81233314ab08f600
URL: https://github.com/llvm/llvm-project/commit/9701053517100045ca9fb0fd81233314ab08f600
DIFF: https://github.com/llvm/llvm-project/commit/9701053517100045ca9fb0fd81233314ab08f600.diff
LOG: Introduce @llvm.threadlocal.address intrinsic to access TLS variable
This belongs to a series of patches which try to solve the thread
identification problem in coroutines. See
https://discourse.llvm.org/t/address-thread-identification-problems-with-coroutine/62015
for a full background.
The problem consists of two concrete problems: TLS variable and readnone
functions. This patch tries to convert the TLS problem to readnone
problem by converting the access of TLS variable to an intrinsic which
is marked as readnone.
The readnone problem would be addressed in following patches.
Reviewed By: nikic, jyknight, nhaehnle, ychen
Differential Revision: https://reviews.llvm.org/D125291
Added:
llvm/test/CodeGen/X86/threadlocal_address.ll
Modified:
llvm/docs/LangRef.rst
llvm/include/llvm/Analysis/TargetTransformInfoImpl.h
llvm/include/llvm/IR/IRBuilder.h
llvm/include/llvm/IR/Intrinsics.td
llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
llvm/lib/IR/IRBuilder.cpp
Removed:
################################################################################
diff --git a/llvm/docs/LangRef.rst b/llvm/docs/LangRef.rst
index 28d4121dd054e..117380ace0ed2 100644
--- a/llvm/docs/LangRef.rst
+++ b/llvm/docs/LangRef.rst
@@ -24545,6 +24545,30 @@ information on the *based on* terminology see
mask argument does not match the pointer size of the target, the mask is
zero-extended or truncated accordingly.
+.. _int_threadlocal_address:
+
+'``llvm.threadlocal.address``' Intrinsic
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Syntax:
+"""""""
+
+::
+
+ declare ptr @llvm.threadlocal.address(ptr) nounwind readnone willreturn
+
+Arguments:
+""""""""""
+
+The first argument is a pointer, which refers to a thread local global.
+
+Semantics:
+""""""""""
+
+The address of a thread local global is not a constant, since it depends on
+the calling thread. The `llvm.threadlocal.address` intrinsic returns the
+address of the given thread local global in the calling thread.
+
.. _int_vscale:
'``llvm.vscale``' Intrinsic
diff --git a/llvm/include/llvm/Analysis/TargetTransformInfoImpl.h b/llvm/include/llvm/Analysis/TargetTransformInfoImpl.h
index eb1e688735d6d..289721dc5bc5f 100644
--- a/llvm/include/llvm/Analysis/TargetTransformInfoImpl.h
+++ b/llvm/include/llvm/Analysis/TargetTransformInfoImpl.h
@@ -650,6 +650,7 @@ class TargetTransformInfoImplBase {
case Intrinsic::coro_align:
case Intrinsic::coro_suspend:
case Intrinsic::coro_subfn_addr:
+ case Intrinsic::threadlocal_address:
// These intrinsics don't actually represent code after lowering.
return 0;
}
diff --git a/llvm/include/llvm/IR/IRBuilder.h b/llvm/include/llvm/IR/IRBuilder.h
index 6e559bb8f7f33..879084e726cde 100644
--- a/llvm/include/llvm/IR/IRBuilder.h
+++ b/llvm/include/llvm/IR/IRBuilder.h
@@ -753,6 +753,9 @@ class IRBuilderBase {
/// If the pointer isn't i8* it will be converted.
CallInst *CreateInvariantStart(Value *Ptr, ConstantInt *Size = nullptr);
+ /// Create a call to llvm.threadlocal.address intrinsic.
+ CallInst *CreateThreadLocalAddress(Value *Ptr);
+
/// Create a call to Masked Load intrinsic
CallInst *CreateMaskedLoad(Type *Ty, Value *Ptr, Align Alignment, Value *Mask,
Value *PassThru = nullptr, const Twine &Name = "");
diff --git a/llvm/include/llvm/IR/Intrinsics.td b/llvm/include/llvm/IR/Intrinsics.td
index d46fa4fbf5b50..1a43ac39d5211 100644
--- a/llvm/include/llvm/IR/Intrinsics.td
+++ b/llvm/include/llvm/IR/Intrinsics.td
@@ -1404,6 +1404,10 @@ def int_is_constant : DefaultAttrsIntrinsic<[llvm_i1_ty], [llvm_any_ty],
def int_ptrmask: DefaultAttrsIntrinsic<[llvm_anyptr_ty], [LLVMMatchType<0>, llvm_anyint_ty],
[IntrNoMem, IntrSpeculatable, IntrWillReturn]>;
+// Intrinsic to wrap a thread local variable.
+def int_threadlocal_address : DefaultAttrsIntrinsic<[llvm_anyptr_ty], [LLVMMatchType<0>],
+ [IntrNoMem, IntrSpeculatable, IntrWillReturn]>;
+
def int_experimental_stepvector : DefaultAttrsIntrinsic<[llvm_anyvector_ty],
[], [IntrNoMem]>;
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 35650b9bd00e4..2239148bf4476 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -7178,6 +7178,10 @@ void SelectionDAGBuilder::visitIntrinsicCall(const CallInst &I,
DAG.getZExtOrTrunc(Const, sdl, PtrVT)));
return;
}
+ case Intrinsic::threadlocal_address: {
+ setValue(&I, getValue(I.getOperand(0)));
+ return;
+ }
case Intrinsic::get_active_lane_mask: {
EVT CCVT = TLI.getValueType(DAG.getDataLayout(), I.getType());
SDValue Index = getValue(I.getOperand(0));
diff --git a/llvm/lib/IR/IRBuilder.cpp b/llvm/lib/IR/IRBuilder.cpp
index 137d6eaa57427..0b11fb6c4f4c6 100644
--- a/llvm/lib/IR/IRBuilder.cpp
+++ b/llvm/lib/IR/IRBuilder.cpp
@@ -526,6 +526,13 @@ CallInst *IRBuilderBase::CreateInvariantStart(Value *Ptr, ConstantInt *Size) {
return CreateCall(TheFn, Ops);
}
+CallInst *IRBuilderBase::CreateThreadLocalAddress(Value *Ptr) {
+ assert(isa<GlobalValue>(Ptr) && cast<GlobalValue>(Ptr)->isThreadLocal() &&
+ "threadlocal_address only applies to thread local variables.");
+ return CreateIntrinsic(llvm::Intrinsic::threadlocal_address, {Ptr->getType()},
+ {Ptr});
+}
+
CallInst *
IRBuilderBase::CreateAssumption(Value *Cond,
ArrayRef<OperandBundleDef> OpBundles) {
diff --git a/llvm/test/CodeGen/X86/threadlocal_address.ll b/llvm/test/CodeGen/X86/threadlocal_address.ll
new file mode 100644
index 0000000000000..7a641c7773b6f
--- /dev/null
+++ b/llvm/test/CodeGen/X86/threadlocal_address.ll
@@ -0,0 +1,41 @@
+; RUN: llc -mtriple=x86_64-unknown-linux-gnu -stop-after=finalize-isel %s -o - | FileCheck %s
+
+ at i = thread_local global i32 0, align 4
+
+define noundef i32 @foo() {
+; CHECK: %0:gr64 = MOV64rm $rip, 1, $noreg, target-flags(x86-gottpoff) @i, $noreg :: (load (s64) from got)
+; CHECK: %1:gr32 = MOV32rm %0, 1, $noreg, 0, $fs :: (load (s32) from %ir.0)
+; CHECK: %2:gr32 = nsw INC32r %1, implicit-def dead $eflags
+; CHECK: MOV32mr %0, 1, $noreg, 0, $fs, %2 :: (store (s32) into %ir.0)
+; CHECK: $eax = COPY %2
+; CHECK: RET 0, $eax
+entry:
+ %0 = call ptr @llvm.threadlocal.address(ptr @i)
+ %1 = load i32, ptr %0, align 4
+ %inc = add nsw i32 %1, 1
+ store i32 %inc, ptr %0, align 4
+ %2 = call ptr @llvm.threadlocal.address(ptr @i)
+ %3 = load i32, ptr %2, align 4
+ ret i32 %3
+}
+
+ at j = thread_local addrspace(1) global i32 addrspace(0)* @i, align 4
+define noundef i32 @bar() {
+; CHECK: %0:gr64 = MOV64rm $rip, 1, $noreg, target-flags(x86-gottpoff) @j, $noreg :: (load (s64) from got)
+; CHECK: %1:gr32 = MOV32rm %0, 1, $noreg, 0, $fs :: (load (s32) from %ir.0, addrspace 1)
+; CHECK: %2:gr32 = nsw INC32r %1, implicit-def dead $eflags
+; CHECK: MOV32mr %0, 1, $noreg, 0, $fs, %2 :: (store (s32) into %ir.0, addrspace 1)
+; CHECK: $eax = COPY %2
+; CHECK: RET 0, $eax
+entry:
+ %0 = call ptr addrspace(1) @llvm.threadlocal.address.p1(ptr addrspace(1) @j)
+ %1 = load i32, ptr addrspace(1) %0, align 4
+ %inc = add nsw i32 %1, 1
+ store i32 %inc, ptr addrspace(1) %0, align 4
+ %2 = call ptr addrspace(1) @llvm.threadlocal.address.p1(ptr addrspace(1) @j)
+ %3 = load i32, ptr addrspace(1) %2, align 4
+ ret i32 %3
+}
+
+declare ptr @llvm.threadlocal.address(ptr) nounwind readnone willreturn
+declare ptr addrspace(1) @llvm.threadlocal.address.p1(ptr addrspace(1)) nounwind readnone willreturn
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