[Clang][RISCV] Handle RVV tuple types correctly as OutputOperand for inline asm

The RVV tuple type maps to an aggregate type with homogeneous scalable
vectors. EmitAsmStmt does not handle this correctly and this commit
attempts to fix it.

Get pass validation check for homogeneous scalable vector types in
InlineAsm::verify.

Handle RVV tuple types correctly under CGStmt.cpp:EmitAsmStores, since
we can allow direct store for the tuple types.

A follow-up commit will deal with details when associated with
InputOperands.

Co-authored-by: Brandon Wu <[email protected]>

Author: eopXD

clang/lib/CodeGen/CGStmt.cpp

@@ -29,6 +29,7 @@
 #include "llvm/ADT/SmallSet.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/IR/Assumptions.h"
+#include "llvm/IR/Constants.h"
 #include "llvm/IR/DataLayout.h"
 #include "llvm/IR/InlineAsm.h"
 #include "llvm/IR/Intrinsics.h"
@@ -2487,22 +2488,28 @@ EmitAsmStores(CodeGenFunction &CGF, const AsmStmt &S,
     // ResultTypeRequiresCast elements correspond to the first
     // ResultTypeRequiresCast.size() elements of RegResults.
     if ((i < ResultTypeRequiresCast.size()) && ResultTypeRequiresCast[i]) {
-      unsigned Size = CGF.getContext().getTypeSize(ResultRegQualTys[i]);
-      Address A = Dest.getAddress(CGF).withElementType(ResultRegTypes[i]);
-      if (CGF.getTargetHooks().isScalarizableAsmOperand(CGF, TruncTy)) {
-        Builder.CreateStore(Tmp, A);
-        continue;
-      }
+      if (ResultRegQualTys[i]->isRVVSizelessBuiltinType() &&
+          Tmp->getType()->isStructTy()) {
+        Address A = Dest.getAddress(CGF).withElementType(ResultRegTypes[i]);
+        Dest = CGF.MakeAddrLValue(A, ResultRegQualTys[i]);
+      } else {
+        unsigned Size = CGF.getContext().getTypeSize(ResultRegQualTys[i]);
+        Address A = Dest.getAddress(CGF).withElementType(ResultRegTypes[i]);
+        if (CGF.getTargetHooks().isScalarizableAsmOperand(CGF, TruncTy)) {
+          Builder.CreateStore(Tmp, A);
+          continue;
+        }
 
-      QualType Ty =
-          CGF.getContext().getIntTypeForBitwidth(Size, /*Signed=*/false);
-      if (Ty.isNull()) {
-        const Expr *OutExpr = S.getOutputExpr(i);
-        CGM.getDiags().Report(OutExpr->getExprLoc(),
-                              diag::err_store_value_to_reg);
-        return;
+        QualType Ty =
+            CGF.getContext().getIntTypeForBitwidth(Size, /*Signed=*/false);
+        if (Ty.isNull()) {
+          const Expr *OutExpr = S.getOutputExpr(i);
+          CGM.getDiags().Report(OutExpr->getExprLoc(),
+                                diag::err_store_value_to_reg);
+          return;
+        }
+        Dest = CGF.MakeAddrLValue(A, Ty);
       }
-      Dest = CGF.MakeAddrLValue(A, Ty);
     }
     CGF.EmitStoreThroughLValue(RValue::get(Tmp), Dest);
   }
@@ -2648,7 +2655,10 @@ void CodeGenFunction::EmitAsmStmt(const AsmStmt &S) {
       ResultTruncRegTypes.push_back(Ty);
       ResultTypeRequiresCast.push_back(RequiresCast);
 
-      if (RequiresCast) {
+      // Allow RVV tuple type (aggregate of homogeneous scalable vector) to be
+      // pushed into return type of inline asm call.
+      if (RequiresCast &&
+          !(QTy->isRVVSizelessBuiltinType() && Ty->isStructTy())) {
         unsigned Size = getContext().getTypeSize(QTy);
         Ty = llvm::IntegerType::get(getLLVMContext(), Size);
       }

clang/test/CodeGen/RISCV/rvv-intrinsics-handcrafted/rvv-inline-asm.c

@@ -0,0 +1,29 @@
+// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py UTC_ARGS: --version 3
+#include <riscv_vector.h>
+
+// RUN: %clang_cc1 -triple riscv64 -target-feature +zve32x -disable-O0-optnone \
+// RUN:   -emit-llvm %s -o - | opt -S -passes=mem2reg | FileCheck %s
+
+// CHECK-LABEL: define dso_local void @foo(
+// CHECK-SAME: ) #[[ATTR0:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[TMP0:%.*]] = call { <vscale x 2 x i32>, <vscale x 2 x i32> } asm "#NOP", "=^vr"() #[[ATTR1:[0-9]+]], !srcloc [[META6:![0-9]+]]
+// CHECK-NEXT:    ret void
+//
+void foo() {
+  vint32m1x2_t v0;
+  asm ("#NOP" : "=vr" (v0));
+}
+
+// CHECK-LABEL: define dso_local void @bar(
+// CHECK-SAME: ) #[[ATTR0]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[TMP0:%.*]] = call { { <vscale x 2 x i32>, <vscale x 2 x i32> }, { <vscale x 2 x i32>, <vscale x 2 x i32> } } asm "#NOP", "=^vr,=^vr"() #[[ATTR1]], !srcloc [[META7:![0-9]+]]
+// CHECK-NEXT:    [[ASMRESULT:%.*]] = extractvalue { { <vscale x 2 x i32>, <vscale x 2 x i32> }, { <vscale x 2 x i32>, <vscale x 2 x i32> } } [[TMP0]], 0
+// CHECK-NEXT:    [[ASMRESULT1:%.*]] = extractvalue { { <vscale x 2 x i32>, <vscale x 2 x i32> }, { <vscale x 2 x i32>, <vscale x 2 x i32> } } [[TMP0]], 1
+// CHECK-NEXT:    ret void
+//
+void bar() {
+  vint32m1x2_t v0, v2;
+  asm ("#NOP" : "=vr" (v0), "=vr" (v2));
+}

llvm/lib/IR/InlineAsm.cpp

@@ -321,8 +321,15 @@ Error InlineAsm::verify(FunctionType *Ty, StringRef ConstStr) {
       return makeStringError("inline asm without outputs must return void");
     break;
   case 1:
-    if (Ty->getReturnType()->isStructTy())
-      return makeStringError("inline asm with one output cannot return struct");
+    if (Ty->getReturnType()->isStructTy()) {
+      // The return type may be a structure if the output operand is from RVV
+      // tuple types. If so the structure must be a structure with homogeneous
+      // scalable vector types.
+      if (!cast<StructType>(Ty->getReturnType())
+               ->containsHomogeneousScalableVectorTypes())
+        return makeStringError(
+            "inline asm with one output cannot return struct");
+    }
     break;
   default:
     StructType *STy = dyn_cast<StructType>(Ty->getReturnType());