Recognize inline asm 'rev /bin/bash, ' as a bswap intrinsic call.
llvm-svn: 123048
diff --git a/llvm/lib/CodeGen/IntrinsicLowering.cpp b/llvm/lib/CodeGen/IntrinsicLowering.cpp
index 4762511..3861dda 100644
--- a/llvm/lib/CodeGen/IntrinsicLowering.cpp
+++ b/llvm/lib/CodeGen/IntrinsicLowering.cpp
@@ -538,3 +538,27 @@
"Lowering should have eliminated any uses of the intrinsic call!");
CI->eraseFromParent();
}
+
+bool IntrinsicLowering::LowerToByteSwap(CallInst *CI) {
+ // Verify this is a simple bswap.
+ if (CI->getNumArgOperands() != 1 ||
+ CI->getType() != CI->getArgOperand(0)->getType() ||
+ !CI->getType()->isIntegerTy())
+ return false;
+
+ const IntegerType *Ty = dyn_cast<IntegerType>(CI->getType());
+ if (!Ty)
+ return false;
+
+ // Okay, we can do this xform, do so now.
+ const Type *Tys[] = { Ty };
+ Module *M = CI->getParent()->getParent()->getParent();
+ Constant *Int = Intrinsic::getDeclaration(M, Intrinsic::bswap, Tys, 1);
+
+ Value *Op = CI->getArgOperand(0);
+ Op = CallInst::Create(Int, Op, CI->getName(), CI);
+
+ CI->replaceAllUsesWith(Op);
+ CI->eraseFromParent();
+ return true;
+}