From f2dc8d29c26e70e9830e5df7550b17158379badd Mon Sep 17 00:00:00 2001
From: Adam Perlin <adamp@nanosoft.com>
Date: Wed, 8 Jul 2026 16:06:36 -0700
Subject: [PATCH 1/2] More precise range assertions for GT_CNS_INT

---
 src/coreclr/jit/assertionprop.cpp | 43 ++++++++++++++++++++++++++++---
 1 file changed, 39 insertions(+), 4 deletions(-)

diff --git a/src/coreclr/jit/assertionprop.cpp b/src/coreclr/jit/assertionprop.cpp
index 1a4eb8af5af569..8770f93811e2d2 100644
--- a/src/coreclr/jit/assertionprop.cpp
+++ b/src/coreclr/jit/assertionprop.cpp
@@ -290,13 +290,48 @@ static Range GetRange(Compiler* comp, GenTree* tree, BasicBlock* block, ASSERT_V
 
             int64_t constValue = node->AsIntConCommon()->IntegralValue();
 
-            if (FitsIn<int32_t>(constValue))
+            if (constValue <= UINT16_MAX)
             {
-                rangeType = TYP_INT;
+                if (constValue <= UINT8_MAX)
+                {
+                    if (constValue <= INT8_MAX)
+                    {
+                        rangeType = TYP_BYTE;
+                    }
+                    else
+                    {
+                        rangeType = TYP_UBYTE;
+                    }
+                }
+                else
+                {
+                    if (constValue <= INT16_MAX)
+                    {
+                        rangeType = TYP_SHORT;
+                    }
+                    else
+                    {
+                        rangeType = TYP_USHORT;
+                    }
+                }
             }
-            else if (FitsIn<uint32_t>(constValue))
+            else
             {
-                rangeType = TYP_UINT;
+                if (constValue <= UINT32_MAX)
+                {
+                    if (constValue <= INT32_MAX)
+                    {
+                        rangeType = TYP_INT;
+                    }
+                    else
+                    {
+                        rangeType = TYP_UINT;
+                    }
+                }
+                else
+                {
+                    rangeType = TYP_LONG;
+                }
             }
 
             if (constValue >= 0)

From 35231854dfc455e24d56d43e3386d9e8841c0894 Mon Sep 17 00:00:00 2001
From: Adam Perlin <adamp@nanosoft.com>
Date: Thu, 9 Jul 2026 09:21:58 -0700
Subject: [PATCH 2/2] Fix mis-ordering of non-negative check for constant

---
 src/coreclr/jit/assertionprop.cpp | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/src/coreclr/jit/assertionprop.cpp b/src/coreclr/jit/assertionprop.cpp
index 8770f93811e2d2..ca5de4f0f1945d 100644
--- a/src/coreclr/jit/assertionprop.cpp
+++ b/src/coreclr/jit/assertionprop.cpp
@@ -289,7 +289,13 @@ static Range GetRange(Compiler* comp, GenTree* tree, BasicBlock* block, ASSERT_V
             }
 
             int64_t constValue = node->AsIntConCommon()->IntegralValue();
+            if (constValue < 0)
+            {
+                // We don't try and reason about lower bounds here to simplify the logic.
+                break;
+            }
 
+            // For a non-negative constant, try and find a tighter upper bound
             if (constValue <= UINT16_MAX)
             {
                 if (constValue <= UINT8_MAX)
@@ -334,11 +340,7 @@ static Range GetRange(Compiler* comp, GenTree* tree, BasicBlock* block, ASSERT_V
                 }
             }
 
-            if (constValue >= 0)
-            {
-                return {SymbolicIntegerValue::Zero, UpperBoundForType(rangeType)};
-            }
-            break;
+            return {SymbolicIntegerValue::Zero, UpperBoundForType(rangeType)};
         }
 
         case GT_QMARK: