[PATCH] D72271: [Clang] Handle target-specific builtins returning aggregates.

[Simon Tatham via Phabricator via cfe-commits]

simon_tatham updated this revision to Diff 236564.
simon_tatham added a comment.

Thanks for the helpful advice!

Here's a revised version that checks `getEvaluationKind`. I've also added a test for the `vld2q(...).val[0]` construction you mentioned: you're right, of course, that that also crashed existing clang, and it still crashed with my previous patch applied. This version seems to work in both cases.

> and then we can just require EmitTargetBuiltinExpr to return null or something else that makes it clear that they've done the right thing with the slot that was passed in

The current return value of `EmitTargetBuiltinExpr` will be the `llvm::Value *` corresponding to the last of a sequence of store instructions that writes the constructed aggregate into the return value slot. There's no need to actually use that `Value` for anything in this case, but we can still test that it's non-null, to find out whether `EmitTargetBuiltinExpr` has successfully recognized a builtin and generated some code, or whether we have to fall through to the `ErrorUnsupported`.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D72271/new/

https://reviews.llvm.org/D72271

Files:
  clang/lib/CodeGen/CGBuiltin.cpp
  clang/test/CodeGen/arm-mve-intrinsics/vld24.c


Index: clang/test/CodeGen/arm-mve-intrinsics/vld24.c
===================================================================
--- clang/test/CodeGen/arm-mve-intrinsics/vld24.c
+++ clang/test/CodeGen/arm-mve-intrinsics/vld24.c
@@ -98,3 +98,45 @@
     vst2q_f16(addr, value);
 #endif /* POLYMORPHIC */
 }
+
+// CHECK-LABEL: @load_into_variable(
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[TMP0:%.*]] = call { <8 x i16>, <8 x i16> } @llvm.arm.mve.vld2q.v8i16.p0i16(i16* [[ADDR:%.*]])
+// CHECK-NEXT:    [[TMP1:%.*]] = extractvalue { <8 x i16>, <8 x i16> } [[TMP0]], 0
+// CHECK-NEXT:    [[TMP2:%.*]] = insertvalue [[STRUCT_UINT16X8X2_T:%.*]] undef, <8 x i16> [[TMP1]], 0, 0
+// CHECK-NEXT:    [[TMP3:%.*]] = extractvalue { <8 x i16>, <8 x i16> } [[TMP0]], 1
+// CHECK-NEXT:    [[TMP4:%.*]] = insertvalue [[STRUCT_UINT16X8X2_T]] [[TMP2]], <8 x i16> [[TMP3]], 0, 1
+// CHECK-NEXT:    store <8 x i16> [[TMP1]], <8 x i16>* [[VALUES:%.*]], align 8
+// CHECK-NEXT:    [[ARRAYIDX4:%.*]] = getelementptr inbounds <8 x i16>, <8 x i16>* [[VALUES]], i32 1
+// CHECK-NEXT:    store <8 x i16> [[TMP3]], <8 x i16>* [[ARRAYIDX4]], align 8
+// CHECK-NEXT:    ret void
+//
+void load_into_variable(const uint16_t *addr, uint16x8_t *values)
+{
+    uint16x8x2_t v;
+#ifdef POLYMORPHIC
+    v = vld2q(addr);
+#else /* POLYMORPHIC */
+    v = vld2q_u16(addr);
+#endif /* POLYMORPHIC */
+    values[0] = v.val[0];
+    values[1] = v.val[1];
+}
+
+// CHECK-LABEL: @extract_one_vector(
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[TMP0:%.*]] = call { <4 x i32>, <4 x i32> } @llvm.arm.mve.vld2q.v4i32.p0i32(i32* [[ADDR:%.*]])
+// CHECK-NEXT:    [[TMP1:%.*]] = extractvalue { <4 x i32>, <4 x i32> } [[TMP0]], 0
+// CHECK-NEXT:    [[TMP2:%.*]] = insertvalue [[STRUCT_INT32X4X2_T:%.*]] undef, <4 x i32> [[TMP1]], 0, 0
+// CHECK-NEXT:    [[TMP3:%.*]] = extractvalue { <4 x i32>, <4 x i32> } [[TMP0]], 1
+// CHECK-NEXT:    [[TMP4:%.*]] = insertvalue [[STRUCT_INT32X4X2_T]] [[TMP2]], <4 x i32> [[TMP3]], 0, 1
+// CHECK-NEXT:    ret <4 x i32> [[TMP1]]
+//
+int32x4_t extract_one_vector(const int32_t *addr)
+{
+#ifdef POLYMORPHIC
+    return vld2q(addr).val[0];
+#else /* POLYMORPHIC */
+    return vld2q_s32(addr).val[0];
+#endif /* POLYMORPHIC */
+}
Index: clang/lib/CodeGen/CGBuiltin.cpp
===================================================================
--- clang/lib/CodeGen/CGBuiltin.cpp
+++ clang/lib/CodeGen/CGBuiltin.cpp
@@ -4328,8 +4328,26 @@
   }
 
   // See if we have a target specific builtin that needs to be lowered.
-  if (Value *V = EmitTargetBuiltinExpr(BuiltinID, E, ReturnValue))
-    return RValue::get(V);
+  switch (getEvaluationKind(E->getType())) {
+  case TEK_Scalar:
+    if (Value *V = EmitTargetBuiltinExpr(BuiltinID, E, ReturnValue))
+      return RValue::get(V);
+    break;
+  case TEK_Aggregate: {
+    if (ReturnValue.isNull()) {
+      Address DestPtr = CreateMemTemp(E->getType(), "agg.tmp");
+      ReturnValue = ReturnValueSlot(DestPtr, false);
+    }
+    if (EmitTargetBuiltinExpr(BuiltinID, E, ReturnValue))
+        return RValue::getAggregate(ReturnValue.getValue(),
+                                    ReturnValue.isVolatile());
+    break;
+  }
+  case TEK_Complex:
+    llvm_unreachable("No currently supported builtin returns complex");
+  default:
+    llvm_unreachable("Bad evaluation kind in EmitBuiltinExpr");
+  }
 
   ErrorUnsupported(E, "builtin function");
 


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