More precise ranges for casts in GetRangeFromAssertions

[EgorBo]

diffs

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[Copilot]

Pull request overview

This PR improves range analysis in the JIT's range check optimization pass by enabling more precise range propagation through cast operations and adding support for TYP_INT in GetRangeFromType.

Changes:

• Add early range tightening based on VN type for small types in GetRangeFromAssertions (though this appears to be dead code due to VN normalization)
• Change cast source type check from exact TYP_INT match to using genActualType, making the code more defensive
• Add TYP_INT case to GetRangeFromType to return the full int32 range instead of Unknown

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 2 comments.

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated no new comments.

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated no new comments.

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated no new comments.

[EgorBo]

@EgorBot -arm -amd

using BenchmarkDotNet.Attributes;

public class Benchmarks
{
    private byte b = 42;

    [Benchmark]
    public string ByteToString() => b.ToString();
}

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated no new comments.

[EgorBo]

I think this is ready, PTAL @jakobbotsch @dotnet/jit-contrib
Some nice diffs

An example of what it folds:

runtime/src/libraries/System.Private.CoreLib/src/System/Number.Formatting.cs

Lines 1934 to 1941 in 7900769

	internal static string UInt32ToDecStr(uint value)
	{
	// For small numbers, consult a lazily-populated cache.
	if (value < SmallNumberCacheLength)
	{
	return UInt32ToDecStrForKnownSmallNumber(value);
	}

When Byte.cs pass itself on its ToString() we can fold the value < 300 check

[EgorBo]

/ba-g timeouts