[llvm] [LLVM][IR] Replace `unsigned >= ConstantDataFirstVal` with static_assert (PR #140827)

[Rahul Joshi via llvm-commits]

https://github.com/jurahul created https://github.com/llvm/llvm-project/pull/140827

`ConstantDataFirstVal` is 0, so `getValueID() >= ConstantDataFirstVal` leads to a compiler warning that the expression is always true. Replace such comparisons with a static_assert() to verify that `ConstantDataFirstVal` is 0, similar to the existing code in Value.h

>From ef6788d068d2dd16a74dba3f66b2a51776933083 Mon Sep 17 00:00:00 2001
From: Rahul Joshi <rjoshi at nvidia.com>
Date: Tue, 20 May 2025 18:07:07 -0700
Subject: [PATCH] [LLVM][IR] Replace `unsigned >= ConstantDataFirstVal` with
 static_assert

`ConstantDataFirstVal` is 0, so `getValueID() >= ConstantDataFirstVal`
leads to a compiler warning that the expression is always true. Replace
such comparisons with a static_assert() to verify that `ConstantDataFirstVal`
is 0, similar to the existing code in Value.h
---
 llvm/include/llvm/IR/Constants.h | 5 +++--
 llvm/include/llvm/IR/Value.h     | 8 +++++---
 2 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/llvm/include/llvm/IR/Constants.h b/llvm/include/llvm/IR/Constants.h
index 7137c699cc992..6a01e8209071d 100644
--- a/llvm/include/llvm/IR/Constants.h
+++ b/llvm/include/llvm/IR/Constants.h
@@ -74,8 +74,9 @@ class ConstantData : public Constant {
 
   /// Methods to support type inquiry through isa, cast, and dyn_cast.
   static bool classof(const Value *V) {
-    return V->getValueID() >= ConstantDataFirstVal &&
-           V->getValueID() <= ConstantDataLastVal;
+    static_assert(Value::ConstantDataFirstVal == 0,
+                  "V->getValueID() >= Value::ConstantDataFirstVal");
+    return V->getValueID() <= ConstantDataLastVal;
   }
 };
 
diff --git a/llvm/include/llvm/IR/Value.h b/llvm/include/llvm/IR/Value.h
index c276899e673a3..999eeb3dad874 100644
--- a/llvm/include/llvm/IR/Value.h
+++ b/llvm/include/llvm/IR/Value.h
@@ -987,15 +987,17 @@ template <class Compare> void Value::sortUseList(Compare Cmp) {
 //
 template <> struct isa_impl<Constant, Value> {
   static inline bool doit(const Value &Val) {
-    static_assert(Value::ConstantFirstVal == 0, "Val.getValueID() >= Value::ConstantFirstVal");
+    static_assert(Value::ConstantFirstVal == 0,
+                  "Val.getValueID() >= Value::ConstantFirstVal");
     return Val.getValueID() <= Value::ConstantLastVal;
   }
 };
 
 template <> struct isa_impl<ConstantData, Value> {
   static inline bool doit(const Value &Val) {
-    return Val.getValueID() >= Value::ConstantDataFirstVal &&
-           Val.getValueID() <= Value::ConstantDataLastVal;
+    static_assert(Value::ConstantDataFirstVal == 0,
+                  "Val.getValueID() >= Value::ConstantDataFirstVal");
+    return Val.getValueID() <= Value::ConstantDataLastVal;
   }
 };