Verifier: Check bswap is supported size

Make sure it is a multiple of 2 bytes as specified in the LangRef.

llvm/lib/IR/Verifier.cpp

@@ -4783,6 +4783,12 @@ void Verifier::visitIntrinsicCall(Intrinsic::ID ID, CallBase &Call) {
            "Intrinsic does not support vectors", &Call);
     break;
   }
+  case Intrinsic::bswap: {
+    Type *Ty = Call.getType();
+    unsigned Size = Ty->getScalarSizeInBits();
+    Assert(Size % 16 == 0, "bswap must be an even number of bytes", &Call);
+    break;
+  }
   };
 }
 

llvm/test/Verifier/bswap.ll

@@ -0,0 +1,53 @@
+; RUN: not llvm-as %s -o /dev/null 2>&1 | FileCheck %s
+; Check handling of bswap with unsupported sizes.
+
+declare i8 @llvm.bswap.i8(i8)
+declare <2 x i8> @llvm.bswap.v2i8(<2 x i8>)
+
+declare i12 @llvm.bswap.i12(i12)
+declare <2 x i12> @llvm.bswap.v2i12(<2 x i12>)
+
+declare i18 @llvm.bswap.i18(i18)
+declare <2 x i18> @llvm.bswap.v2i18(<2 x i18>)
+
+define i8 @bswap_i8(i8 %arg) {
+; CHECK: bswap must be an even number of bytes
+; CHECK-NEXT: %res = call i8 @llvm.bswap.i8(i8 %arg)
+  %res = call i8 @llvm.bswap.i8(i8 %arg)
+  ret i8 %res
+}
+
+define <2 x i8> @bswap_v2i8(<2 x i8> %arg) {
+; CHECK: bswap must be an even number of bytes
+; CHECK-NEXT: %res = call <2 x i8> @llvm.bswap.v2i8(<2 x i8> %arg)
+  %res = call <2 x i8> @llvm.bswap.v2i8(<2 x i8> %arg)
+  ret <2 x i8> %res
+}
+
+define i12 @bswap_i12(i12 %arg) {
+; CHECK: bswap must be an even number of bytes
+; CHECK-NEXT: %res = call i12 @llvm.bswap.i12(i12 %arg)
+  %res = call i12 @llvm.bswap.i12(i12 %arg)
+  ret i12 %res
+}
+
+define <2 x i12> @bswap_v2i12(<2 x i12> %arg) {
+; CHECK: bswap must be an even number of bytes
+; CHECK-NEXT: %res = call <2 x i12> @llvm.bswap.v2i12(<2 x i12> %arg)
+  %res = call <2 x i12> @llvm.bswap.v2i12(<2 x i12> %arg)
+  ret <2 x i12> %res
+}
+
+define i18 @bswap_i18(i18 %arg) {
+; CHECK: bswap must be an even number of bytes
+; CHECK-NEXT: %res = call i18 @llvm.bswap.i18(i18 %arg)
+  %res = call i18 @llvm.bswap.i18(i18 %arg)
+  ret i18 %res
+}
+
+define <2 x i18> @bswap_v2i18(<2 x i18> %arg) {
+; CHECK: bswap must be an even number of bytes
+; CHECK-NEXT: %res = call <2 x i18> @llvm.bswap.v2i18(<2 x i18> %arg)
+  %res = call <2 x i18> @llvm.bswap.v2i18(<2 x i18> %arg)
+  ret <2 x i18> %res
+}