[clang] [llvm] [Clang][RISCV] Handle RVV tuple types correctly as OutputOperand for inline asm (PR #89883)

via cfe-commits cfe-commits at lists.llvm.org
Wed Apr 24 00:14:20 PDT 2024


llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang-codegen

Author: Brandon Wu (4vtomat)

<details>
<summary>Changes</summary>

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 <brandon.wu@<!-- -->sifive.com>


---
Full diff: https://github.com/llvm/llvm-project/pull/89883.diff


3 Files Affected:

- (modified) clang/lib/CodeGen/CGStmt.cpp (+25-15) 
- (added) clang/test/CodeGen/RISCV/rvv-intrinsics-handcrafted/rvv-inline-asm.c (+29) 
- (modified) llvm/lib/IR/InlineAsm.cpp (+9-2) 


``````````diff
diff --git a/clang/lib/CodeGen/CGStmt.cpp b/clang/lib/CodeGen/CGStmt.cpp
index 576fe2f7a2d46f..099faf419ba5cd 100644
--- a/clang/lib/CodeGen/CGStmt.cpp
+++ b/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);
       }
diff --git a/clang/test/CodeGen/RISCV/rvv-intrinsics-handcrafted/rvv-inline-asm.c b/clang/test/CodeGen/RISCV/rvv-intrinsics-handcrafted/rvv-inline-asm.c
new file mode 100644
index 00000000000000..c5beb33d0ef8cd
--- /dev/null
+++ b/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));
+}
diff --git a/llvm/lib/IR/InlineAsm.cpp b/llvm/lib/IR/InlineAsm.cpp
index aeaa6a3741b949..319678cbb8fe16 100644
--- a/llvm/lib/IR/InlineAsm.cpp
+++ b/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());

``````````

</details>


https://github.com/llvm/llvm-project/pull/89883


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