[CIR] Clean up cir.objsize to follow new format and add documentation (#1931)

Author: xlauko

clang/include/clang/CIR/Dialect/IR/CIROps.td

@@ -331,29 +331,39 @@ def CIR_DynamicCastOp : CIR_Op<"dyn_cast"> {
 // ObjSizeOp
 //===----------------------------------------------------------------------===//
 
-def CIR_SizeInfoType : CIR_I32EnumAttr< "SizeInfoType", "size info type", [
-  I32EnumAttrCase<"Min", 0, "min">,
-  I32EnumAttrCase<"Max", 1, "max">
-]>;
-
 def CIR_ObjSizeOp : CIR_Op<"objsize", [Pure]> {
-  let summary = "Conversion between values of different types";
+  let summary = "Implements llvm.objsize builtin.";
+  let description = [{
+    The `cir.objsize` operation models the behavior of the `llvm.objectsize`
+    builtins in Clang. It returns the number of accessible bytes past ptr.
+
+    The `kind` argument  determines whether `cir.objsize` returns 0 (if
+    true) or -1 (if false) when the object size is unknown. Corresponds to 
+    `llvm.objectsize`'s `min` argument.
+    
+    The `dynamic` attribute determines if the value should be evaluated at
+    runtime. Corresponds to `llvm.objectsize`'s `dynamic` argument.
+
+    Example:
+
+    ```mlir
+    %size = cir.objsize min %ptr : !cir.ptr<i32> -> i64
+    %dsize = cir.objsize max dynamic %ptr : !cir.ptr<i32> -> i64
+    ```
+  }];
 
   let arguments = (ins
     CIR_PointerType:$ptr,
-    CIR_SizeInfoType:$kind,
+    UnitAttr:$min,
     UnitAttr:$dynamic
   );
 
   let results = (outs CIR_AnyFundamentalIntType:$result);
 
   let assemblyFormat = [{
-    `(`
-        $ptr `:` type($ptr) `,`
-        $kind
-        (`,` `dynamic` $dynamic^)?
-    `)`
-    `->` type($result) attr-dict
+      (`min` $min^) : (`max`)?
+      (`dynamic` $dynamic^)?
+      $ptr `:` qualified(type($ptr)) `->` qualified(type($result)) attr-dict
   }];
 }
 

clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp

@@ -3010,12 +3010,11 @@ mlir::Value CIRGenFunction::emitBuiltinObjectSize(const Expr *E, unsigned Type,
 
   // LLVM intrinsics (which CIR lowers to at some point, only supports 0
   // and 2, account for that right now.
-  cir::SizeInfoType sizeInfoTy =
-      ((Type & 2) != 0) ? cir::SizeInfoType::Min : cir::SizeInfoType::Max;
+  bool sizeInfoTy = ((Type & 2) != 0);
   // TODO(cir): Heads up for LLVM lowering, For GCC compatibility,
   // __builtin_object_size treat NULL as unknown size.
-  return builder.create<cir::ObjSizeOp>(getLoc(E->getSourceRange()), ResType,
-                                        Ptr, sizeInfoTy, IsDynamic);
+  return cir::ObjSizeOp::create(builder, getLoc(E->getSourceRange()), ResType,
+                                Ptr, sizeInfoTy, IsDynamic);
 }
 
 mlir::Value CIRGenFunction::evaluateOrEmitBuiltinObjectSize(

clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp

@@ -3375,18 +3375,20 @@ mlir::LogicalResult CIRToLLVMObjSizeOpLowering::matchAndRewrite(
   auto llvmResTy = getTypeConverter()->convertType(op.getType());
   auto loc = op->getLoc();
 
-  cir::SizeInfoType kindInfo = op.getKind();
-  auto falseValue =
-      rewriter.create<mlir::LLVM::ConstantOp>(loc, rewriter.getI1Type(), false);
-  auto trueValue =
-      rewriter.create<mlir::LLVM::ConstantOp>(loc, rewriter.getI1Type(), true);
-
-  replaceOpWithCallLLVMIntrinsicOp(
-      rewriter, op, "llvm.objectsize", llvmResTy,
-      mlir::ValueRange{adaptor.getPtr(),
-                       kindInfo == cir::SizeInfoType::Max ? falseValue
-                                                          : trueValue,
-                       trueValue, op.getDynamic() ? trueValue : falseValue});
+  auto i1Ty = rewriter.getI1Type();
+
+  auto i1Val = [&rewriter, &loc, &i1Ty](bool val) {
+    return mlir::LLVM::ConstantOp::create(rewriter, loc, i1Ty, val);
+  };
+
+  // clang-format off
+  replaceOpWithCallLLVMIntrinsicOp(rewriter, op, "llvm.objectsize", llvmResTy, {
+    /*ptr=*/adaptor.getPtr(),
+    /*min=*/i1Val(op.getMin()),
+    /*nullunknown=*/i1Val(true),
+    /*dynamic=*/i1Val(op.getDynamic())
+  });
+  // clang-format on
 
   return mlir::LogicalResult::success();
 }

clang/test/CIR/CodeGen/libcall.cpp

@@ -43,7 +43,7 @@ void t(const char* fmt, ...) {
 // CHECK:   %0 = cir.alloca !cir.ptr<!s8i>, !cir.ptr<!cir.ptr<!s8i>>, ["m", init] {alignment = 8 : i64}
 
 // CHECK:   %3 = cir.load{{.*}} %0 : !cir.ptr<!cir.ptr<!s8i>>, !cir.ptr<!s8i>
-// CHECK:   %4 = cir.objsize(%3 : <!s8i>, max) -> !u64i
+// CHECK:   %4 = cir.objsize max %3 : !cir.ptr<!s8i> -> !u64i
 // CHECK:   %5 = cir.call @_ZL6strlenPKcU17pass_object_size0(%3, %4) : (!cir.ptr<!s8i>, !u64i) -> !u64i
 
 // CHECK: cir.func private @__vsnprintf_chk

clang/test/CIR/CodeGen/pass-object-size.c

@@ -15,10 +15,10 @@ void c() {
 // CIR: cir.func no_proto dso_local @c()
 // CIR: [[TMP0:%.*]] = cir.alloca !s32i, !cir.ptr<!s32i>, %{{[0-9]+}} : !u64i, ["vla"] {alignment = 16 : i64}
 // CIR: [[TMP1:%.*]] = cir.cast bitcast [[TMP0]] : !cir.ptr<!s32i> -> !cir.ptr<!void>
-// CIR-NEXT: [[TMP2:%.*]] = cir.objsize([[TMP1]] : <!void>, max) -> !u64i
+// CIR-NEXT: [[TMP2:%.*]] = cir.objsize max [[TMP1]] : !cir.ptr<!void> -> !u64i
 // CIR-NEXT: cir.call @b([[TMP1]], [[TMP2]]) : (!cir.ptr<!void>, !u64i) -> ()
 // CIR: [[TMP3:%.*]] = cir.cast bitcast [[TMP0]] : !cir.ptr<!s32i> -> !cir.ptr<!void>
-// CIR: [[TMP4:%.*]] = cir.objsize([[TMP3]] : <!void>, min) -> !u64i
+// CIR: [[TMP4:%.*]] = cir.objsize min [[TMP3]] : !cir.ptr<!void> -> !u64i
 // CIR-NEXT: cir.call @e([[TMP3]], [[TMP4]]) : (!cir.ptr<!void>, !u64i) -> ()
 
 // LLVM: define dso_local void @c()

clang/test/CIR/IR/cir-ops.cir

@@ -53,8 +53,8 @@ module  {
   cir.func @os() {
     %0 = cir.alloca !cir.ptr<!s8i>, !cir.ptr<!cir.ptr<!s8i>>, ["m", init] {alignment = 8 : i64}
     %3 = cir.load %0 : !cir.ptr<!cir.ptr<!s8i>>, !cir.ptr<!s8i>
-    %4 = cir.objsize(%3 : <!s8i>, max) -> !u64i
-    %5 = cir.objsize(%3 : <!s8i>, min) -> !u64i
+    %4 = cir.objsize max %3 : !cir.ptr<!s8i> -> !u64i
+    %5 = cir.objsize min %3 : !cir.ptr<!s8i> -> !u64i
     cir.return
   }
 
@@ -105,8 +105,8 @@ module  {
 // CHECK: cir.func @os() {
 // CHECK-NEXT:   %0 = cir.alloca !cir.ptr<!s8i>, !cir.ptr<!cir.ptr<!s8i>>, ["m", init] {alignment = 8 : i64}
 // CHECK-NEXT:   %1 = cir.load %0 : !cir.ptr<!cir.ptr<!s8i>>, !cir.ptr<!s8i>
-// CHECK-NEXT:   %2 = cir.objsize(%1 : <!s8i>, max) -> !u64i
-// CHECK-NEXT:   %3 = cir.objsize(%1 : <!s8i>, min) -> !u64i
+// CHECK-NEXT:   %2 = cir.objsize max %1 : !cir.ptr<!s8i> -> !u64i
+// CHECK-NEXT:   %3 = cir.objsize min %1 : !cir.ptr<!s8i> -> !u64i
 // CHECK-NEXT:   cir.return
 // CHECK-NEXT: }