[Xtensa] Fix Call ABI for 16 byte alignment.

Author: andreisfr

clang/lib/CodeGen/TargetInfo.cpp

@@ -11618,9 +11618,8 @@ ABIArgInfo XtensaABIInfo::classifyArgumentType(QualType Ty,
     if (Size < 32 && Ty->isIntegralOrEnumerationType() && !MustUseStack) {
       return extendType(Ty);
     }
-    if (Size == 64)
-      return ABIArgInfo::getDirect(llvm::IntegerType::get(getVMContext(), 64));
-    return ABIArgInfo::getDirect(llvm::IntegerType::get(getVMContext(), 32));
+    // Assume that type has 32, 64 or 128 bits
+    return ABIArgInfo::getDirect(llvm::IntegerType::get(getVMContext(), Size));
   }
 
   // Aggregates which are <= 6*32 will be passed in registers if possible,
@@ -11631,6 +11630,8 @@ ABIArgInfo XtensaABIInfo::classifyArgumentType(QualType Ty,
     } else if (NeededAlign == (2 * 32)) {
       return ABIArgInfo::getDirect(llvm::ArrayType::get(
           llvm::IntegerType::get(getVMContext(), 64), NeededArgGPRs / 2));
+    } else if (NeededAlign == (4 * 32)) {
+      return ABIArgInfo::getDirect(llvm::IntegerType::get(getVMContext(), 128));
     } else {
       return ABIArgInfo::getDirect(llvm::ArrayType::get(
           llvm::IntegerType::get(getVMContext(), 32), NeededArgGPRs));

clang/test/CodeGen/xtensa-abi.c

@@ -12,3 +12,17 @@ char *bufalloc ()
 }
 
 // CHECK: define dso_local noalias i8* @bufalloc() #0 {
+
+struct S16 { int a[4]; } __attribute__ ((aligned (16)));
+
+void callee_struct_a16b_1(struct S16 a) {}
+
+// CHECK: define dso_local void @callee_struct_a16b_1(i128 %a.coerce)
+
+void callee_struct_a16b_2(struct S16 a, int b) {}
+
+// CHECK: define dso_local void @callee_struct_a16b_2(i128 %a.coerce, i32 noundef %b)
+
+void callee_struct_a16b_3(int a, struct S16 b) {}
+
+// CHECK: define dso_local void @callee_struct_a16b_3(i32 noundef %a, %struct.S16* noundef byval(%struct.S16) align 16 %b)