[llvm] [llvm] Add `BasicTTIImpl::areInlineCompatible` for target feature subset checks (PR #117493)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-webassembly

Author: hev (heiher)

<details>
<summary>Changes</summary>

This patch moves the `areInlineCompatible` implementation from multiple subclasses (`AArch64TTIImpl`, `RISCVTTIImpl`, `WebAssemblyTTIImpl`) to the base class `BasicTTIImpl`. The new implementation checks whether the callee's target features are a subset of the caller's, enabling consistent behavior across targets. Subclasses now simply delegate to the base implementation, reducing code duplication and improving maintainability.

---
Full diff: https://github.com/llvm/llvm-project/pull/117493.diff


6 Files Affected:

- (modified) llvm/include/llvm/CodeGen/BasicTTIImpl.h (+14) 
- (modified) llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp (+1-10) 
- (modified) llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp (-14) 
- (modified) llvm/lib/Target/RISCV/RISCVTargetTransformInfo.h (-3) 
- (modified) llvm/lib/Target/WebAssembly/WebAssemblyTargetTransformInfo.cpp (-18) 
- (modified) llvm/lib/Target/WebAssembly/WebAssemblyTargetTransformInfo.h (-3) 


``````````diff
diff --git a/llvm/include/llvm/CodeGen/BasicTTIImpl.h b/llvm/include/llvm/CodeGen/BasicTTIImpl.h
index d3d68ff1c6ed2b..d2fc40d8ae037e 100644
--- a/llvm/include/llvm/CodeGen/BasicTTIImpl.h
+++ b/llvm/include/llvm/CodeGen/BasicTTIImpl.h
@@ -277,6 +277,20 @@ class BasicTTIImplBase : public TargetTransformInfoImplCRTPBase<T> {
         E, AddressSpace, Alignment, MachineMemOperand::MONone, Fast);
   }
 
+  bool areInlineCompatible(const Function *Caller,
+                           const Function *Callee) const {
+    const TargetMachine &TM = getTLI()->getTargetMachine();
+
+    const FeatureBitset &CallerBits =
+        TM.getSubtargetImpl(*Caller)->getFeatureBits();
+    const FeatureBitset &CalleeBits =
+        TM.getSubtargetImpl(*Callee)->getFeatureBits();
+
+    // Inline a callee if its target-features are a subset of the callers
+    // target-features.
+    return (CallerBits & CalleeBits) == CalleeBits;
+  }
+
   bool hasBranchDivergence(const Function *F = nullptr) { return false; }
 
   bool isSourceOfDivergence(const Value *V) { return false; }
diff --git a/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp b/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
index ec7bb71fd111ff..7a1e401bca18cb 100644
--- a/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
+++ b/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
@@ -266,16 +266,7 @@ bool AArch64TTIImpl::areInlineCompatible(const Function *Caller,
       return false;
   }
 
-  const TargetMachine &TM = getTLI()->getTargetMachine();
-
-  const FeatureBitset &CallerBits =
-      TM.getSubtargetImpl(*Caller)->getFeatureBits();
-  const FeatureBitset &CalleeBits =
-      TM.getSubtargetImpl(*Callee)->getFeatureBits();
-
-  // Inline a callee if its target-features are a subset of the callers
-  // target-features.
-  return (CallerBits & CalleeBits) == CalleeBits;
+  return BaseT::areInlineCompatible(Caller, Callee);
 }
 
 bool AArch64TTIImpl::areTypesABICompatible(
diff --git a/llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp b/llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp
index 45576d515112dd..b867448106aad6 100644
--- a/llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp
+++ b/llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp
@@ -2330,20 +2330,6 @@ bool RISCVTTIImpl::isLegalMaskedCompressStore(Type *DataTy, Align Alignment) {
   return true;
 }
 
-bool RISCVTTIImpl::areInlineCompatible(const Function *Caller,
-                                       const Function *Callee) const {
-  const TargetMachine &TM = getTLI()->getTargetMachine();
-
-  const FeatureBitset &CallerBits =
-      TM.getSubtargetImpl(*Caller)->getFeatureBits();
-  const FeatureBitset &CalleeBits =
-      TM.getSubtargetImpl(*Callee)->getFeatureBits();
-
-  // Inline a callee if its target-features are a subset of the callers
-  // target-features.
-  return (CallerBits & CalleeBits) == CalleeBits;
-}
-
 /// See if \p I should be considered for address type promotion. We check if \p
 /// I is a sext with right type and used in memory accesses. If it used in a
 /// "complex" getelementptr, we allow it to be promoted without finding other
diff --git a/llvm/lib/Target/RISCV/RISCVTargetTransformInfo.h b/llvm/lib/Target/RISCV/RISCVTargetTransformInfo.h
index 498f48353dc0c7..6fd36e90a02ddd 100644
--- a/llvm/lib/Target/RISCV/RISCVTargetTransformInfo.h
+++ b/llvm/lib/Target/RISCV/RISCVTargetTransformInfo.h
@@ -60,9 +60,6 @@ class RISCVTTIImpl : public BasicTTIImplBase<RISCVTTIImpl> {
       : BaseT(TM, F.getDataLayout()), ST(TM->getSubtargetImpl(F)),
         TLI(ST->getTargetLowering()) {}
 
-  bool areInlineCompatible(const Function *Caller,
-                           const Function *Callee) const;
-
   /// Return the cost of materializing an immediate for a value operand of
   /// a store instruction.
   InstructionCost getStoreImmCost(Type *VecTy, TTI::OperandValueInfo OpInfo,
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyTargetTransformInfo.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyTargetTransformInfo.cpp
index f96e3232b93f42..3d678e53841664 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyTargetTransformInfo.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyTargetTransformInfo.cpp
@@ -104,24 +104,6 @@ TTI::ReductionShuffle WebAssemblyTTIImpl::getPreferredExpandedReductionShuffle(
   return TTI::ReductionShuffle::SplitHalf;
 }
 
-bool WebAssemblyTTIImpl::areInlineCompatible(const Function *Caller,
-                                             const Function *Callee) const {
-  // Allow inlining only when the Callee has a subset of the Caller's
-  // features. In principle, we should be able to inline regardless of any
-  // features because WebAssembly supports features at module granularity, not
-  // function granularity, but without this restriction it would be possible for
-  // a module to "forget" about features if all the functions that used them
-  // were inlined.
-  const TargetMachine &TM = getTLI()->getTargetMachine();
-
-  const FeatureBitset &CallerBits =
-      TM.getSubtargetImpl(*Caller)->getFeatureBits();
-  const FeatureBitset &CalleeBits =
-      TM.getSubtargetImpl(*Callee)->getFeatureBits();
-
-  return (CallerBits & CalleeBits) == CalleeBits;
-}
-
 void WebAssemblyTTIImpl::getUnrollingPreferences(
     Loop *L, ScalarEvolution &SE, TTI::UnrollingPreferences &UP,
     OptimizationRemarkEmitter *ORE) const {
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyTargetTransformInfo.h b/llvm/lib/Target/WebAssembly/WebAssemblyTargetTransformInfo.h
index 2ce6cbf3ba0266..9691120b2e531d 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyTargetTransformInfo.h
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyTargetTransformInfo.h
@@ -72,9 +72,6 @@ class WebAssemblyTTIImpl final : public BasicTTIImplBase<WebAssemblyTTIImpl> {
   TTI::ReductionShuffle
   getPreferredExpandedReductionShuffle(const IntrinsicInst *II) const;
 
-  bool areInlineCompatible(const Function *Caller,
-                           const Function *Callee) const;
-
   bool supportsTailCalls() const;
 
   bool isProfitableToSinkOperands(Instruction *I,

``````````

</details>


https://github.com/llvm/llvm-project/pull/117493