[Mlir-commits] [mlir] a048d73 - [MLIR][LLVM] Only disallow inlining for selected function attributes.
Tobias Gysi
llvmlistbot at llvm.org
Fri Feb 17 00:19:22 PST 2023
Author: Johannes de Fine Licht
Date: 2023-02-17T09:18:17+01:00
New Revision: a048d7394be54008d0f69506cefa359cfc6117a2
URL: https://github.com/llvm/llvm-project/commit/a048d7394be54008d0f69506cefa359cfc6117a2
DIFF: https://github.com/llvm/llvm-project/commit/a048d7394be54008d0f69506cefa359cfc6117a2.diff
LOG: [MLIR][LLVM] Only disallow inlining for selected function attributes.
This loosens the requirement of no passthrough function attribute being
present to checking for specific attributes that prevent inlining. Since
these attributes are no longer strictly passthrough, they should
eventually be upgraded to some form of addressable attributes.
Drops the expensive StringSwitches over call and function attributes in
favor of selectively disallowing attributes that prevent inlining
(similiar to the LLVM inliner), thereby moving to a less conservative
approach.
Reviewed By: gysit
Differential Revision: https://reviews.llvm.org/D144104
Added:
Modified:
mlir/lib/Dialect/LLVMIR/IR/LLVMDialect.cpp
mlir/test/Dialect/LLVMIR/inlining.mlir
Removed:
################################################################################
diff --git a/mlir/lib/Dialect/LLVMIR/IR/LLVMDialect.cpp b/mlir/lib/Dialect/LLVMIR/IR/LLVMDialect.cpp
index ec3d202790d5d..8d854a3301231 100644
--- a/mlir/lib/Dialect/LLVMIR/IR/LLVMDialect.cpp
+++ b/mlir/lib/Dialect/LLVMIR/IR/LLVMDialect.cpp
@@ -2865,15 +2865,37 @@ struct LLVMInlinerInterface : public DialectInlinerInterface {
auto funcOp = dyn_cast<LLVM::LLVMFuncOp>(callable);
if (!callOp || !funcOp)
return false;
- return isLegalToInlineCallAttributes(callOp) &&
- isLegalToInlineFuncAttributes(funcOp);
+ // TODO: Handle argument and result attributes;
+ if (funcOp.getArgAttrs() || funcOp.getResAttrs())
+ return false;
+ // TODO: Handle exceptions.
+ if (funcOp.getPersonality())
+ return false;
+ if (funcOp.getPassthrough()) {
+ // TODO: Used attributes should not be passthrough.
+ DenseSet<StringAttr> disallowed(
+ {StringAttr::get(funcOp->getContext(), "noduplicate"),
+ StringAttr::get(funcOp->getContext(), "noinline"),
+ StringAttr::get(funcOp->getContext(), "optnone"),
+ StringAttr::get(funcOp->getContext(), "presplitcoroutine"),
+ StringAttr::get(funcOp->getContext(), "returns_twice"),
+ StringAttr::get(funcOp->getContext(), "strictfp")});
+ if (llvm::any_of(*funcOp.getPassthrough(), [&](Attribute attr) {
+ auto stringAttr = dyn_cast<StringAttr>(attr);
+ if (!stringAttr)
+ return false;
+ return disallowed.contains(stringAttr);
+ }))
+ return false;
+ }
+ return true;
}
bool isLegalToInline(Region *, Region *, bool, IRMapping &) const final {
return true;
}
- /// Conservative allowlist-based inlining of operations supported so far.
+ /// Conservative allowlist of operations supported so far.
bool isLegalToInline(Operation *op, Region *, bool, IRMapping &) const final {
if (isPure(op))
return true;
@@ -2934,53 +2956,6 @@ struct LLVMInlinerInterface : public DialectInlinerInterface {
// which newly inlined block was previously the entry block of the callee.
moveConstantAllocasToEntryBlock(inlinedBlocks);
}
-
-private:
- /// Returns true if all attributes of `callOp` are handled during inlining.
- [[nodiscard]] static bool isLegalToInlineCallAttributes(LLVM::CallOp callOp) {
- return all_of(callOp.getAttributeNames(), [&](StringRef attrName) {
- return llvm::StringSwitch<bool>(attrName)
- // TODO: Propagate and update branch weights.
- .Case("branch_weights", !callOp.getBranchWeights())
- .Case("callee", true)
- .Case("fastmathFlags", true)
- .Default(false);
- });
- }
-
- /// Returns true if all attributes of `funcOp` are handled during inlining.
- [[nodiscard]] static bool
- isLegalToInlineFuncAttributes(LLVM::LLVMFuncOp funcOp) {
- return all_of(funcOp.getAttributeNames(), [&](StringRef attrName) {
- return llvm::StringSwitch<bool>(attrName)
- .Case("CConv", true)
- .Case("arg_attrs", ([&]() {
- if (!funcOp.getArgAttrs())
- return true;
- return llvm::all_of(funcOp.getArgAttrs().value(),
- [&](Attribute) {
- // TODO: Handle argument attributes.
- return false;
- });
- })())
- .Case("dso_local", true)
- .Case("function_entry_count", true)
- .Case("function_type", true)
- // TODO: Once the garbage collector attribute is supported on
- // LLVM::CallOp, make sure that the garbage collector matches.
- .Case("garbageCollector", !funcOp.getGarbageCollector())
- .Case("linkage", true)
- .Case("memory", true)
- .Case("passthrough", !funcOp.getPassthrough())
- // Exception handling is not yet supported, so bail out if the
- // personality is set.
- .Case("personality", !funcOp.getPersonality())
- // TODO: Handle result attributes.
- .Case("res_attrs", !funcOp.getResAttrs())
- .Case("sym_name", true)
- .Default(false);
- });
- }
};
} // end anonymous namespace
diff --git a/mlir/test/Dialect/LLVMIR/inlining.mlir b/mlir/test/Dialect/LLVMIR/inlining.mlir
index 65632434b1349..ab28f4236af97 100644
--- a/mlir/test/Dialect/LLVMIR/inlining.mlir
+++ b/mlir/test/Dialect/LLVMIR/inlining.mlir
@@ -83,7 +83,7 @@ llvm.func internal fastcc @callee() -> (i32) attributes { function_entry_count =
// CHECK-NEXT: llvm.return %[[CST]]
llvm.func @caller() -> (i32) {
// Include all call attributes that don't prevent inlining.
- %0 = llvm.call @callee() { fastmathFlags = #llvm.fastmath<nnan, ninf> } : () -> (i32)
+ %0 = llvm.call @callee() { fastmathFlags = #llvm.fastmath<nnan, ninf>, branch_weights = dense<42> : vector<1xi32> } : () -> (i32)
llvm.return %0 : i32
}
@@ -147,32 +147,42 @@ llvm.func @caller() -> (i32) {
// -----
-llvm.func @callee() -> (i32) attributes { passthrough = ["foo"] } {
- %0 = llvm.mlir.constant(42 : i32) : i32
- llvm.return %0 : i32
+llvm.func @callee() attributes { passthrough = ["foo", "bar"] } {
+ llvm.return
}
// CHECK-LABEL: llvm.func @caller
-// CHECK-NEXT: llvm.call @callee
-// CHECK-NEXT: return
-llvm.func @caller() -> (i32) {
- %0 = llvm.call @callee() : () -> (i32)
- llvm.return %0 : i32
+// CHECK-NEXT: llvm.return
+llvm.func @caller() {
+ llvm.call @callee() : () -> ()
+ llvm.return
}
// -----
-llvm.func @callee() -> (i32) attributes { garbageCollector = "foo" } {
- %0 = llvm.mlir.constant(42 : i32) : i32
- llvm.return %0 : i32
-}
+llvm.func @callee_noinline() attributes { passthrough = ["noinline"] }
+llvm.func @callee_optnone() attributes { passthrough = ["optnone"] }
+llvm.func @callee_noduplicate() attributes { passthrough = ["noduplicate"] }
+llvm.func @callee_presplitcoroutine() attributes { passthrough = ["presplitcoroutine"] }
+llvm.func @callee_returns_twice() attributes { passthrough = ["returns_twice"] }
+llvm.func @callee_strictfp() attributes { passthrough = ["strictfp"] }
// CHECK-LABEL: llvm.func @caller
-// CHECK-NEXT: llvm.call @callee
-// CHECK-NEXT: return
-llvm.func @caller() -> (i32) {
- %0 = llvm.call @callee() : () -> (i32)
- llvm.return %0 : i32
+// CHECK-NEXT: llvm.call @callee_noinline
+// CHECK-NEXT: llvm.call @callee_optnone
+// CHECK-NEXT: llvm.call @callee_noduplicate
+// CHECK-NEXT: llvm.call @callee_presplitcoroutine
+// CHECK-NEXT: llvm.call @callee_returns_twice
+// CHECK-NEXT: llvm.call @callee_strictfp
+// CHECK-NEXT: llvm.return
+llvm.func @caller() {
+ llvm.call @callee_noinline() : () -> ()
+ llvm.call @callee_optnone() : () -> ()
+ llvm.call @callee_noduplicate() : () -> ()
+ llvm.call @callee_presplitcoroutine() : () -> ()
+ llvm.call @callee_returns_twice() : () -> ()
+ llvm.call @callee_strictfp() : () -> ()
+ llvm.return
}
// -----
@@ -191,20 +201,6 @@ llvm.func @caller(%ptr : !llvm.ptr) -> (!llvm.ptr) {
// -----
-llvm.func @callee() {
- llvm.return
-}
-
-// CHECK-LABEL: llvm.func @caller
-// CHECK-NEXT: llvm.call @callee
-// CHECK-NEXT: llvm.return
-llvm.func @caller() {
- llvm.call @callee() { branch_weights = dense<42> : vector<1xi32> } : () -> ()
- llvm.return
-}
-
-// -----
-
llvm.func @static_alloca() -> f32 {
%0 = llvm.mlir.constant(4 : i32) : i32
%1 = llvm.alloca %0 x f32 : (i32) -> !llvm.ptr
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