[llvm-branch-commits] [llvm] IR: Reorder ConstantData enum values (PR #138638)

[Matt Arsenault via llvm-branch-commits]

https://github.com/arsenm updated https://github.com/llvm/llvm-project/pull/138638

>From 936319ac8a9dad94aaba2f91f6464b801a0f061e Mon Sep 17 00:00:00 2001
From: Matt Arsenault <Matthew.Arsenault at amd.com>
Date: Tue, 6 May 2025 08:22:15 +0200
Subject: [PATCH] IR: Reorder ConstantData enum values

This sorts ConstantData to the low values, so we can perform
a hasUseList check in a single compare instead of requiring 2
compares plus an and for the range check.
---
 llvm/include/llvm/IR/Value.def | 38 ++++++++++++++++++----------------
 1 file changed, 20 insertions(+), 18 deletions(-)

diff --git a/llvm/include/llvm/IR/Value.def b/llvm/include/llvm/IR/Value.def
index 160e0f8513e2a..34b8d4967b28a 100644
--- a/llvm/include/llvm/IR/Value.def
+++ b/llvm/include/llvm/IR/Value.def
@@ -69,24 +69,11 @@
 #define HANDLE_CONSTANT_EXCLUDE_LLVM_C_API(ValueName)
 #endif
 
-// Having constant first makes the range check for isa<Constant> faster
-// and smaller by one operation.
+// Having constant first makes the range check for isa<Constant> faster and
+// smaller by one operation. Further, keep ConstantData as the first subset so
+// it's also as fast.
 
 // Constant
-HANDLE_GLOBAL_VALUE(Function)
-HANDLE_GLOBAL_VALUE(GlobalAlias)
-HANDLE_GLOBAL_VALUE(GlobalIFunc)
-HANDLE_GLOBAL_VALUE(GlobalVariable)
-HANDLE_CONSTANT(BlockAddress)
-HANDLE_CONSTANT(ConstantExpr)
-HANDLE_CONSTANT_EXCLUDE_LLVM_C_API(DSOLocalEquivalent)
-HANDLE_CONSTANT_EXCLUDE_LLVM_C_API(NoCFIValue)
-HANDLE_CONSTANT(ConstantPtrAuth)
-
-// ConstantAggregate.
-HANDLE_CONSTANT(ConstantArray)
-HANDLE_CONSTANT(ConstantStruct)
-HANDLE_CONSTANT(ConstantVector)
 
 // ConstantData.
 HANDLE_CONSTANT(UndefValue)
@@ -100,8 +87,23 @@ HANDLE_CONSTANT(ConstantTargetNone)
 HANDLE_CONSTANT(ConstantPointerNull)
 HANDLE_CONSTANT(ConstantTokenNone)
 
-HANDLE_CONSTANT_MARKER(ConstantFirstVal, Function)
-HANDLE_CONSTANT_MARKER(ConstantLastVal, ConstantTokenNone)
+// ConstantAggregate.
+HANDLE_CONSTANT(ConstantArray)
+HANDLE_CONSTANT(ConstantStruct)
+HANDLE_CONSTANT(ConstantVector)
+
+HANDLE_GLOBAL_VALUE(Function)
+HANDLE_GLOBAL_VALUE(GlobalAlias)
+HANDLE_GLOBAL_VALUE(GlobalIFunc)
+HANDLE_GLOBAL_VALUE(GlobalVariable)
+HANDLE_CONSTANT(BlockAddress)
+HANDLE_CONSTANT(ConstantExpr)
+HANDLE_CONSTANT_EXCLUDE_LLVM_C_API(DSOLocalEquivalent)
+HANDLE_CONSTANT_EXCLUDE_LLVM_C_API(NoCFIValue)
+HANDLE_CONSTANT(ConstantPtrAuth)
+
+HANDLE_CONSTANT_MARKER(ConstantFirstVal, UndefValue)
+HANDLE_CONSTANT_MARKER(ConstantLastVal, ConstantPtrAuth)
 HANDLE_CONSTANT_MARKER(ConstantDataFirstVal, UndefValue)
 HANDLE_CONSTANT_MARKER(ConstantDataLastVal, ConstantTokenNone)
 HANDLE_CONSTANT_MARKER(ConstantAggregateFirstVal, ConstantArray)