[CGExprScalar] In EmitCompare trunc the result if it has different type as E->getType()

Usually compare expression should return i1 type, so EmitScalarConversion is called before return

return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType(), E->getExprLoc());

But when ppc intrinsic is called to compare vectors, the ppc intrinsic can return i32 even E->getType() is BoolTy, in this case EmitScalarConversion does nothing, an i32 type result is returned and causes crash later.

This patch detects this case and truncates the result before return.

Differential Revision: https://reviews.llvm.org/D38656

llvm-svn: 315358

1 files changed, 10 insertions, 0 deletions

diff --git a/clang/lib/CodeGen/CGExprScalar.cpp b/clang/lib/CodeGen/CGExprScalar.cpp
index fba9574b021..68a2f13e70b 100644
--- a/clang/lib/CodeGen/CGExprScalar.cpp
+++ b/clang/lib/CodeGen/CGExprScalar.cpp
@@ -3214,6 +3214,16 @@ Value *ScalarExprEmitter::EmitCompare(const BinaryOperator *E,
       Value *CR6Param = Builder.getInt32(CR6);
       llvm::Function *F = CGF.CGM.getIntrinsic(ID);
       Result = Builder.CreateCall(F, {CR6Param, FirstVecArg, SecondVecArg});
+
+      // The result type of intrinsic may not be same as E->getType().
+      // If E->getType() is not BoolTy, EmitScalarConversion will do the
+      // conversion work. If E->getType() is BoolTy, EmitScalarConversion will
+      // do nothing, if ResultTy is not i1 at the same time, it will cause
+      // crash later.
+      llvm::IntegerType *ResultTy = cast<llvm::IntegerType>(Result->getType());
+      if (ResultTy->getBitWidth() > 1 &&
+          E->getType() == CGF.getContext().BoolTy)
+        Result = Builder.CreateTrunc(Result, Builder.getInt1Ty());
       return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType(),
                                   E->getExprLoc());
     }