[CIR] Clean up ptr_diff operation assembly format and description (#1932)

Author: xlauko

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

@@ -377,27 +377,29 @@ def CIR_ObjSizeOp : CIR_Op<"objsize", [Pure]> {
 //===----------------------------------------------------------------------===//
 
 def CIR_PtrDiffOp : CIR_Op<"ptr_diff", [Pure, SameTypeOperands]> {
-
   let summary = "Pointer subtraction arithmetic";
   let description = [{
-    `cir.ptr_diff` performs a subtraction between two pointer types with the
-    same element type and produces a `cir::IntType` result.
+    The cir.ptr_diff operation computes the difference between two pointers that
+    have the same element type
+
+    The result reflects the ABI-defined size of the pointed-to type. For example,
+    subtracting two !cir.ptr<!u64i> values may yield 1, representing an 8-byte
+    difference. In contrast, for pointers to void or function types, a result of
+    8 corresponds to an 8-byte difference.
 
-    Note that the result considers the pointer size according to the ABI for
-    the pointee sizes, e.g. the subtraction between two `!cir.ptr<!u64i>` might
-    yield 1, meaning 8 bytes, whereas for `void` or function type pointees,
-    yielding 8 means 8 bytes.
+    Example:
 
     ```mlir
-    %7 = "cir.ptr_diff"(%0, %1) : !cir.ptr<!u64i> -> !u64i
+    %7 = cir.ptr_diff %0, %1 : !cir.ptr<!u64i> -> !u64i
     ```
   }];
 
-  let results = (outs CIR_AnyFundamentalIntType:$result);
   let arguments = (ins CIR_PointerType:$lhs, CIR_PointerType:$rhs);
+  let results = (outs CIR_AnyFundamentalIntType:$result);
 
   let assemblyFormat = [{
-    `(` $lhs `,` $rhs  `)` `:` qualified(type($lhs)) `->` qualified(type($result)) attr-dict
+    $lhs `,` $rhs  `:` qualified(type($lhs)) `->` qualified(type($result)) 
+    attr-dict
   }];
 }
 

clang/test/CIR/CodeGen/ptrdiff.cpp

@@ -9,15 +9,15 @@ size_type size(unsigned long *_start, unsigned long *_finish) {
 // CHECK: cir.func dso_local @_Z4sizePmS_(%arg0: !cir.ptr<!u64i>
 // CHECK:   %3 = cir.load{{.*}} %1 : !cir.ptr<!cir.ptr<!u64i>>, !cir.ptr<!u64i>
 // CHECK:   %4 = cir.load{{.*}} %0 : !cir.ptr<!cir.ptr<!u64i>>, !cir.ptr<!u64i>
-// CHECK:   %5 = cir.ptr_diff(%3, %4) : !cir.ptr<!u64i> -> !s64i
+// CHECK:   %5 = cir.ptr_diff %3, %4 : !cir.ptr<!u64i> -> !s64i
 // CHECK:   %6 = cir.cast integral %5 : !s64i -> !u64i
 
 long add(char *a, char *b) {
   return a - b + 1;
 }
 
 // CHECK: cir.func dso_local @_Z3addPcS_(%arg0: !cir.ptr<!s8i>
-//          %5 = cir.ptr_diff(%3, %4) : !cir.ptr<!s8i> -> !s64i
+//          %5 = cir.ptr_diff %3, %4 : !cir.ptr<!s8i> -> !s64i
 //          %6 = cir.const #cir.int<1> : !s32i
 //          %7 = cir.cast integral %6 : !s32i -> !s64i
 //          %8 = cir.binop(add, %5, %7) : !s64i

clang/test/CIR/Lowering/ptrdiff.cir

@@ -5,7 +5,7 @@
 
 module {
   cir.func @foo(%arg0: !cir.ptr<!s32i>, %arg1: !cir.ptr<!s32i>) -> !s32i {
-    %1 = cir.ptr_diff(%arg0, %arg1) : !cir.ptr<!s32i> -> !u64i
+    %1 = cir.ptr_diff %arg0, %arg1 : !cir.ptr<!s32i> -> !u64i
     %2 = cir.cast integral %1 : !u64i -> !s32i
     cir.return %2 : !s32i
   }

clang/test/CIR/Transforms/lib-opt-find.cpp

@@ -52,7 +52,7 @@ unsigned char* test2(unsigned char* first, unsigned char* last, unsigned char v)
     // CHECK: %[[pattern:.*]] = cir.cast integral %[[load_pattern:.*]] : !u8i -> !s32i
 
     // CHECK-NOT: {{.*}} cir.call @_ZSt4findIPhhET_S1_S1_RKT0_(
-    // CHECK: %[[array_size:.*]] = cir.ptr_diff(%[[last]], %[[first]]) : !cir.ptr<!u8i> -> !u64i
+    // CHECK: %[[array_size:.*]] = cir.ptr_diff %[[last]], %[[first]] : !cir.ptr<!u8i> -> !u64i
 
     // CHECK: %[[result_cast:.*]] = cir.libc.memchr(%[[cast_to_void]], %[[pattern]], %[[array_size]])
     // CHECK: %[[memchr_res:.*]] = cir.cast bitcast %[[result_cast]] : !cir.ptr<!void> -> !cir.ptr<!u8i>