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[clang] VectorExprEvaluator::VisitCallExpr - use APSInt callback instead of repeated switch statement #157137

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Merged
merged 2 commits into from
Sep 6, 2025
Merged

[clang] VectorExprEvaluator::VisitCallExpr - use APSInt callback instead of repeated switch statement #157137

merged 2 commits into from
Sep 6, 2025

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@RKSimon RKSimon commented Sep 5, 2025

Create a EvaluateBinOpExpr helper that each related group of elementwise binop builtins can use with their own custom callback, to help reduce the amount of duplication and avoid too much code bloat as more builtins are added.

This also handles builtins which have a elementwise LHS operand and a scalar RHS operand.

Similar to #155891 which did the same thing for the new ByteCode eval.

@RKSimon
[clang] VectorExprEvaluator::VisitCallExpr - use APSInt callback inst…
32f6bdf 
…ead of repeated switch statement

Create a EvaluateBinOpExpr helper that each related group of elementwise binop builtins can use with their own custom callback, to help reduce the amount of duplication and avoid too much code bloat as more builtins are added.

This also handles builtins which have a elementwise LHS operand and a scalar RHS operand.

Similar to llvm#155891 which did the same thing for the new ByteCode eval.
@RKSimon RKSimon requested a review from tbaederr September 5, 2025 16:32
@llvmbot llvmbot added clang Clang issues not falling into any other category clang:frontend Language frontend issues, e.g. anything involving "Sema" labels Sep 5, 2025
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llvmbot commented Sep 5, 2025

@llvm/pr-subscribers-clang

Author: Simon Pilgrim (RKSimon)

Changes

Create a EvaluateBinOpExpr helper that each related group of elementwise binop builtins can use with their own custom callback, to help reduce the amount of duplication and avoid too much code bloat as more builtins are added.

This also handles builtins which have a elementwise LHS operand and a scalar RHS operand.

Similar to #155891 which did the same thing for the new ByteCode eval.

Full diff: https://github.com/llvm/llvm-project/pull/157137.diff

1 Files Affected:

  • (modified) clang/lib/AST/ExprConstant.cpp (+86-195)
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 100e944f9b48c..0060e80e8e309 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -11623,6 +11623,38 @@ bool VectorExprEvaluator::VisitCallExpr(const CallExpr *E) {
   if (!IsConstantEvaluatedBuiltinCall(E))
     return ExprEvaluatorBaseTy::VisitCallExpr(E);
 
+  auto EvaluateBinOpExpr =
+      [&](llvm::function_ref<APInt(const APSInt &, const APSInt &)> Fn) {
+        APValue SourceLHS, SourceRHS;
+        if (!EvaluateAsRValue(Info, E->getArg(0), SourceLHS) ||
+            !EvaluateAsRValue(Info, E->getArg(1), SourceRHS))
+          return false;
+
+        auto *DestTy = E->getType()->castAs<VectorType>();
+        QualType DestEltTy = DestTy->getElementType();
+        bool DestUnsigned = DestEltTy->isUnsignedIntegerOrEnumerationType();
+        unsigned SourceLen = SourceLHS.getVectorLength();
+        SmallVector<APValue, 4> ResultElements;
+        ResultElements.reserve(SourceLen);
+
+        if (SourceRHS.isInt()) {
+          const APSInt &RHS = SourceRHS.getInt();
+          for (unsigned EltNum = 0; EltNum < SourceLen; ++EltNum) {
+            const APSInt &LHS = SourceLHS.getVectorElt(EltNum).getInt();
+            ResultElements.push_back(
+                APValue(APSInt(Fn(LHS, RHS), DestUnsigned)));
+          }
+        } else {
+          for (unsigned EltNum = 0; EltNum < SourceLen; ++EltNum) {
+            const APSInt &LHS = SourceLHS.getVectorElt(EltNum).getInt();
+            const APSInt &RHS = SourceRHS.getVectorElt(EltNum).getInt();
+            ResultElements.push_back(
+                APValue(APSInt(Fn(LHS, RHS), DestUnsigned)));
+          }
+        }
+        return Success(APValue(ResultElements.data(), SourceLen), E);
+      };
+
   switch (E->getBuiltinCallee()) {
   default:
     return false;
@@ -11679,27 +11711,30 @@ bool VectorExprEvaluator::VisitCallExpr(const CallExpr *E) {
   }
 
   case Builtin::BI__builtin_elementwise_add_sat:
+    return EvaluateBinOpExpr([](const APSInt &LHS, const APSInt &RHS) {
+      return LHS.isSigned() ? LHS.sadd_sat(RHS) : LHS.uadd_sat(RHS);
+    });
+
   case Builtin::BI__builtin_elementwise_sub_sat:
+    return EvaluateBinOpExpr([](const APSInt &LHS, const APSInt &RHS) {
+      return LHS.isSigned() ? LHS.ssub_sat(RHS) : LHS.usub_sat(RHS);
+    });
+
   case clang::X86::BI__builtin_ia32_pmulhuw128:
   case clang::X86::BI__builtin_ia32_pmulhuw256:
   case clang::X86::BI__builtin_ia32_pmulhuw512:
+    return EvaluateBinOpExpr(llvm::APIntOps::mulhu);
+
   case clang::X86::BI__builtin_ia32_pmulhw128:
   case clang::X86::BI__builtin_ia32_pmulhw256:
   case clang::X86::BI__builtin_ia32_pmulhw512:
+    return EvaluateBinOpExpr(llvm::APIntOps::mulhs);
+
   case clang::X86::BI__builtin_ia32_psllv2di:
   case clang::X86::BI__builtin_ia32_psllv4di:
   case clang::X86::BI__builtin_ia32_psllv4si:
   case clang::X86::BI__builtin_ia32_psllv8si:
   case clang::X86::BI__builtin_ia32_psllv16si:
-  case clang::X86::BI__builtin_ia32_psrav4si:
-  case clang::X86::BI__builtin_ia32_psrav8si:
-  case clang::X86::BI__builtin_ia32_psrav16si:
-  case clang::X86::BI__builtin_ia32_psrlv2di:
-  case clang::X86::BI__builtin_ia32_psrlv4di:
-  case clang::X86::BI__builtin_ia32_psrlv4si:
-  case clang::X86::BI__builtin_ia32_psrlv8si:
-  case clang::X86::BI__builtin_ia32_psrlv16si:
-
   case clang::X86::BI__builtin_ia32_psllwi128:
   case clang::X86::BI__builtin_ia32_pslldi128:
   case clang::X86::BI__builtin_ia32_psllqi128:
@@ -11709,17 +11744,16 @@ bool VectorExprEvaluator::VisitCallExpr(const CallExpr *E) {
   case clang::X86::BI__builtin_ia32_psllwi512:
   case clang::X86::BI__builtin_ia32_pslldi512:
   case clang::X86::BI__builtin_ia32_psllqi512:
+    return EvaluateBinOpExpr([](const APSInt &LHS, const APSInt &RHS) {
+      if (RHS.uge(LHS.getBitWidth())) {
+        return APInt::getZero(LHS.getBitWidth());
+      }
+      return LHS.shl(RHS.getZExtValue());
+    });
 
-  case clang::X86::BI__builtin_ia32_psrlwi128:
-  case clang::X86::BI__builtin_ia32_psrldi128:
-  case clang::X86::BI__builtin_ia32_psrlqi128:
-  case clang::X86::BI__builtin_ia32_psrlwi256:
-  case clang::X86::BI__builtin_ia32_psrldi256:
-  case clang::X86::BI__builtin_ia32_psrlqi256:
-  case clang::X86::BI__builtin_ia32_psrlwi512:
-  case clang::X86::BI__builtin_ia32_psrldi512:
-  case clang::X86::BI__builtin_ia32_psrlqi512:
-
+  case clang::X86::BI__builtin_ia32_psrav4si:
+  case clang::X86::BI__builtin_ia32_psrav8si:
+  case clang::X86::BI__builtin_ia32_psrav16si:
   case clang::X86::BI__builtin_ia32_psrawi128:
   case clang::X86::BI__builtin_ia32_psradi128:
   case clang::X86::BI__builtin_ia32_psraqi128:
@@ -11728,145 +11762,35 @@ bool VectorExprEvaluator::VisitCallExpr(const CallExpr *E) {
   case clang::X86::BI__builtin_ia32_psraqi256:
   case clang::X86::BI__builtin_ia32_psrawi512:
   case clang::X86::BI__builtin_ia32_psradi512:
-  case clang::X86::BI__builtin_ia32_psraqi512: {
-
-    APValue SourceLHS, SourceRHS;
-    if (!EvaluateAsRValue(Info, E->getArg(0), SourceLHS) ||
-        !EvaluateAsRValue(Info, E->getArg(1), SourceRHS))
-      return false;
-
-    QualType DestEltTy = E->getType()->castAs<VectorType>()->getElementType();
-    bool DestUnsigned = DestEltTy->isUnsignedIntegerOrEnumerationType();
-    unsigned SourceLen = SourceLHS.getVectorLength();
-    SmallVector<APValue, 4> ResultElements;
-    ResultElements.reserve(SourceLen);
-
-    for (unsigned EltNum = 0; EltNum < SourceLen; ++EltNum) {
-      APSInt LHS = SourceLHS.getVectorElt(EltNum).getInt();
-
-      if (SourceRHS.isInt()) {
-        const unsigned LaneBitWidth = LHS.getBitWidth();
-        const unsigned ShiftAmount = SourceRHS.getInt().getZExtValue();
-
-        switch (E->getBuiltinCallee()) {
-        case clang::X86::BI__builtin_ia32_psllwi128:
-        case clang::X86::BI__builtin_ia32_psllwi256:
-        case clang::X86::BI__builtin_ia32_psllwi512:
-        case clang::X86::BI__builtin_ia32_pslldi128:
-        case clang::X86::BI__builtin_ia32_pslldi256:
-        case clang::X86::BI__builtin_ia32_pslldi512:
-        case clang::X86::BI__builtin_ia32_psllqi128:
-        case clang::X86::BI__builtin_ia32_psllqi256:
-        case clang::X86::BI__builtin_ia32_psllqi512:
-          if (ShiftAmount >= LaneBitWidth) {
-            ResultElements.push_back(
-                APValue(APSInt(APInt::getZero(LaneBitWidth), DestUnsigned)));
-          } else {
-            ResultElements.push_back(
-                APValue(APSInt(LHS.shl(ShiftAmount), DestUnsigned)));
-          }
-          break;
-        case clang::X86::BI__builtin_ia32_psrlwi128:
-        case clang::X86::BI__builtin_ia32_psrlwi256:
-        case clang::X86::BI__builtin_ia32_psrlwi512:
-        case clang::X86::BI__builtin_ia32_psrldi128:
-        case clang::X86::BI__builtin_ia32_psrldi256:
-        case clang::X86::BI__builtin_ia32_psrldi512:
-        case clang::X86::BI__builtin_ia32_psrlqi128:
-        case clang::X86::BI__builtin_ia32_psrlqi256:
-        case clang::X86::BI__builtin_ia32_psrlqi512:
-          if (ShiftAmount >= LaneBitWidth) {
-            ResultElements.push_back(
-                APValue(APSInt(APInt::getZero(LaneBitWidth), DestUnsigned)));
-          } else {
-            ResultElements.push_back(
-                APValue(APSInt(LHS.lshr(ShiftAmount), DestUnsigned)));
-          }
-          break;
-        case clang::X86::BI__builtin_ia32_psrawi128:
-        case clang::X86::BI__builtin_ia32_psrawi256:
-        case clang::X86::BI__builtin_ia32_psrawi512:
-        case clang::X86::BI__builtin_ia32_psradi128:
-        case clang::X86::BI__builtin_ia32_psradi256:
-        case clang::X86::BI__builtin_ia32_psradi512:
-        case clang::X86::BI__builtin_ia32_psraqi128:
-        case clang::X86::BI__builtin_ia32_psraqi256:
-        case clang::X86::BI__builtin_ia32_psraqi512:
-          ResultElements.push_back(
-              APValue(APSInt(LHS.ashr(std::min(ShiftAmount, LaneBitWidth - 1)),
-                             DestUnsigned)));
-          break;
-        default:
-          llvm_unreachable("Unexpected builtin callee");
-        }
-        continue;
+  case clang::X86::BI__builtin_ia32_psraqi512:
+    return EvaluateBinOpExpr([](const APSInt &LHS, const APSInt &RHS) {
+      if (RHS.uge(LHS.getBitWidth())) {
+        return LHS.ashr(LHS.getBitWidth() - 1);
       }
-      APSInt RHS = SourceRHS.getVectorElt(EltNum).getInt();
-      switch (E->getBuiltinCallee()) {
-      case Builtin::BI__builtin_elementwise_add_sat:
-        ResultElements.push_back(APValue(
-            APSInt(LHS.isSigned() ? LHS.sadd_sat(RHS) : LHS.uadd_sat(RHS),
-                   DestUnsigned)));
-        break;
-      case Builtin::BI__builtin_elementwise_sub_sat:
-        ResultElements.push_back(APValue(
-            APSInt(LHS.isSigned() ? LHS.ssub_sat(RHS) : LHS.usub_sat(RHS),
-                   DestUnsigned)));
-        break;
-      case clang::X86::BI__builtin_ia32_pmulhuw128:
-      case clang::X86::BI__builtin_ia32_pmulhuw256:
-      case clang::X86::BI__builtin_ia32_pmulhuw512:
-        ResultElements.push_back(APValue(APSInt(llvm::APIntOps::mulhu(LHS, RHS),
-                                                /*isUnsigned=*/true)));
-        break;
-      case clang::X86::BI__builtin_ia32_pmulhw128:
-      case clang::X86::BI__builtin_ia32_pmulhw256:
-      case clang::X86::BI__builtin_ia32_pmulhw512:
-        ResultElements.push_back(APValue(APSInt(llvm::APIntOps::mulhs(LHS, RHS),
-                                                /*isUnsigned=*/false)));
-        break;
-      case clang::X86::BI__builtin_ia32_psllv2di:
-      case clang::X86::BI__builtin_ia32_psllv4di:
-      case clang::X86::BI__builtin_ia32_psllv4si:
-      case clang::X86::BI__builtin_ia32_psllv8si:
-      case clang::X86::BI__builtin_ia32_psllv16si:
-        if (RHS.uge(RHS.getBitWidth())) {
-          ResultElements.push_back(
-              APValue(APSInt(APInt::getZero(RHS.getBitWidth()), DestUnsigned)));
-          break;
-        }
-        ResultElements.push_back(
-            APValue(APSInt(LHS.shl(RHS.getZExtValue()), DestUnsigned)));
-        break;
-      case clang::X86::BI__builtin_ia32_psrav4si:
-      case clang::X86::BI__builtin_ia32_psrav8si:
-      case clang::X86::BI__builtin_ia32_psrav16si:
-        if (RHS.uge(RHS.getBitWidth())) {
-          ResultElements.push_back(
-              APValue(APSInt(LHS.ashr(RHS.getBitWidth() - 1), DestUnsigned)));
-          break;
-        }
-        ResultElements.push_back(
-            APValue(APSInt(LHS.ashr(RHS.getZExtValue()), DestUnsigned)));
-        break;
-      case clang::X86::BI__builtin_ia32_psrlv2di:
-      case clang::X86::BI__builtin_ia32_psrlv4di:
-      case clang::X86::BI__builtin_ia32_psrlv4si:
-      case clang::X86::BI__builtin_ia32_psrlv8si:
-      case clang::X86::BI__builtin_ia32_psrlv16si:
-        if (RHS.uge(RHS.getBitWidth())) {
-          ResultElements.push_back(
-              APValue(APSInt(APInt::getZero(RHS.getBitWidth()), DestUnsigned)));
-          break;
-        }
-        ResultElements.push_back(
-            APValue(APSInt(LHS.lshr(RHS.getZExtValue()), DestUnsigned)));
-        break;
+      return LHS.ashr(RHS.getZExtValue());
+    });
+
+  case clang::X86::BI__builtin_ia32_psrlv2di:
+  case clang::X86::BI__builtin_ia32_psrlv4di:
+  case clang::X86::BI__builtin_ia32_psrlv4si:
+  case clang::X86::BI__builtin_ia32_psrlv8si:
+  case clang::X86::BI__builtin_ia32_psrlv16si:
+  case clang::X86::BI__builtin_ia32_psrlwi128:
+  case clang::X86::BI__builtin_ia32_psrldi128:
+  case clang::X86::BI__builtin_ia32_psrlqi128:
+  case clang::X86::BI__builtin_ia32_psrlwi256:
+  case clang::X86::BI__builtin_ia32_psrldi256:
+  case clang::X86::BI__builtin_ia32_psrlqi256:
+  case clang::X86::BI__builtin_ia32_psrlwi512:
+  case clang::X86::BI__builtin_ia32_psrldi512:
+  case clang::X86::BI__builtin_ia32_psrlqi512:
+    return EvaluateBinOpExpr([](const APSInt &LHS, const APSInt &RHS) {
+      if (RHS.uge(LHS.getBitWidth())) {
+        return APInt::getZero(LHS.getBitWidth());
       }
-    }
+      return LHS.lshr(RHS.getZExtValue());
+    });
 
-    return Success(APValue(ResultElements.data(), ResultElements.size()), E);
-  }
   case clang::X86::BI__builtin_ia32_pmuldq128:
   case clang::X86::BI__builtin_ia32_pmuldq256:
   case clang::X86::BI__builtin_ia32_pmuldq512:
@@ -11904,6 +11828,7 @@ bool VectorExprEvaluator::VisitCallExpr(const CallExpr *E) {
 
     return Success(APValue(ResultElements.data(), ResultElements.size()), E);
   }
+
   case clang::X86::BI__builtin_ia32_vprotbi:
   case clang::X86::BI__builtin_ia32_vprotdi:
   case clang::X86::BI__builtin_ia32_vprotqi:
@@ -11913,53 +11838,19 @@ bool VectorExprEvaluator::VisitCallExpr(const CallExpr *E) {
   case clang::X86::BI__builtin_ia32_prold512:
   case clang::X86::BI__builtin_ia32_prolq128:
   case clang::X86::BI__builtin_ia32_prolq256:
-  case clang::X86::BI__builtin_ia32_prolq512: {
-    APValue SourceLHS, SourceRHS;
-    if (!EvaluateAsRValue(Info, E->getArg(0), SourceLHS) ||
-        !EvaluateAsRValue(Info, E->getArg(1), SourceRHS))
-      return false;
-
-    QualType DestEltTy = E->getType()->castAs<VectorType>()->getElementType();
-    bool DestUnsigned = DestEltTy->isUnsignedIntegerOrEnumerationType();
-    unsigned SourceLen = SourceLHS.getVectorLength();
-    SmallVector<APValue, 4> ResultElements;
-    ResultElements.reserve(SourceLen);
-
-    APSInt RHS = SourceRHS.getInt();
-
-    for (unsigned EltNum = 0; EltNum < SourceLen; ++EltNum) {
-      const APSInt &LHS = SourceLHS.getVectorElt(EltNum).getInt();
-      ResultElements.push_back(APValue(APSInt(LHS.rotl(RHS), DestUnsigned)));
-    }
+  case clang::X86::BI__builtin_ia32_prolq512:
+    return EvaluateBinOpExpr(
+        [](const APSInt &LHS, const APSInt &RHS) { return LHS.rotl(RHS); });
 
-    return Success(APValue(ResultElements.data(), ResultElements.size()), E);
-  }
   case clang::X86::BI__builtin_ia32_prord128:
   case clang::X86::BI__builtin_ia32_prord256:
   case clang::X86::BI__builtin_ia32_prord512:
   case clang::X86::BI__builtin_ia32_prorq128:
   case clang::X86::BI__builtin_ia32_prorq256:
-  case clang::X86::BI__builtin_ia32_prorq512: {
-    APValue SourceLHS, SourceRHS;
-    if (!EvaluateAsRValue(Info, E->getArg(0), SourceLHS) ||
-        !EvaluateAsRValue(Info, E->getArg(1), SourceRHS))
-      return false;
+  case clang::X86::BI__builtin_ia32_prorq512:
+    return EvaluateBinOpExpr(
+        [](const APSInt &LHS, const APSInt &RHS) { return LHS.rotr(RHS); });
 
-    QualType DestEltTy = E->getType()->castAs<VectorType>()->getElementType();
-    bool DestUnsigned = DestEltTy->isUnsignedIntegerOrEnumerationType();
-    unsigned SourceLen = SourceLHS.getVectorLength();
-    SmallVector<APValue, 4> ResultElements;
-    ResultElements.reserve(SourceLen);
-
-    APSInt RHS = SourceRHS.getInt();
-
-    for (unsigned EltNum = 0; EltNum < SourceLen; ++EltNum) {
-      const APSInt &LHS = SourceLHS.getVectorElt(EltNum).getInt();
-      ResultElements.push_back(APValue(APSInt(LHS.rotr(RHS), DestUnsigned)));
-    }
-
-    return Success(APValue(ResultElements.data(), ResultElements.size()), E);
-  }
   case Builtin::BI__builtin_elementwise_max:
   case Builtin::BI__builtin_elementwise_min: {
     APValue SourceLHS, SourceRHS;

@RKSimon RKSimon enabled auto-merge (squash) September 6, 2025 11:56
@RKSimon RKSimon merged commit 6e52283 into llvm:main Sep 6, 2025
9 checks passed
@RKSimon RKSimon deleted the constexpr-binop-callback branch September 6, 2025 12:49
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