Add binary VN funcs to TryGetRangeFromAssertions#123233
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EgorBo merged 5 commits intodotnet:mainfrom Jan 23, 2026
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@jakobbotsch PTAL again, I still have a few ideas for a refactoring, but those should be zero diffs and will be in a separate PR. Now I am slowly moving towards repeating what SSA-based GetRange does, but only with VNs Some 50-100k improvements are expected - diffs - although, there are regressions from previously semi-legal transformations based on half-defined ranges (e.g. [10..unknown]) PS: I think I also spot a few potential bugs when we could perform a multiplication on top of keBinOpArray or add two keBinOpArrays PS2: I recommend disabling the whitespaces on the review view. |
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ping @jakobbotsch |
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…124128) ## Description `RangeOps::Multiply` used `ApplyRangeOp` which independently multiplied `lo*lo` and `hi*hi`. This is wrong when ranges span negative values — e.g. `[-100..100] * [0..10]` produced `[0..1000]` instead of `[-1000..1000]`, causing incorrect codegen for expressions involving multiplication with casts. The fix computes `min`/`max` across all four endpoint products (`r1lo*r2lo`, `r1lo*r2hi`, `r1hi*r2lo`, `r1hi*r2hi`), which is the standard interval arithmetic approach for multiplication. ```cpp int lo = min(min(r1lo * r2lo, r1lo * r2hi), min(r1hi * r2lo, r1hi * r2hi)); int hi = max(max(r1lo * r2lo, r1lo * r2hi), max(r1hi * r2lo, r1hi * r2hi)); ``` - `src/coreclr/jit/rangecheck.h`: Replace `Multiply` — require constant ranges, check all four products for overflow, compute correct min/max bounds - `src/tests/JIT/Regression/JitBlue/Runtime_124082/`: Add Fuzzlyn regression test from the issue <!-- START COPILOT ORIGINAL PROMPT --> <details> <summary>Original prompt</summary> > > ---- > > *This section details on the original issue you should resolve* > > <issue_title>JIT: Bad result with multiplication and casts</issue_title> > <issue_description>```csharp > // Generated by Fuzzlyn v3.3 on 2026-02-05 22:00:13 > // Run on X64 Windows > // Seed: 3325744140221827777-vectort,vector128,vector256,x86aes,x86avx,x86avx2,x86avx512bw,x86avx512bwvl,x86avx512cd,x86avx512cdvl,x86avx512dq,x86avx512dqvl,x86avx512f,x86avx512fvl,x86avx512fx64,x86bmi1,x86bmi1x64,x86bmi2,x86bmi2x64,x86fma,x86lzcnt,x86lzcntx64,x86pclmulqdq,x86popcnt,x86popcntx64,x86sse,x86ssex64,x86sse2,x86sse2x64,x86sse3,x86sse41,x86sse41x64,x86sse42,x86sse42x64,x86ssse3,x86x86base > // Reduced from 64.4 KiB to 0.3 KiB in 00:01:42 > // Debug: Outputs -1 > // Release: Outputs 4294967295 > public class Program > { > public static sbyte s_4 = 1; > public static byte[][] s_12 = new byte[][] > { > new byte[] > { > 1 > } > }; > public static void Main() > { > byte[] vr9 = s_12[0]; > long vr10 = (ushort)s_4 * (sbyte)(-s_4); > System.Console.WriteLine(vr10); > } > } > ``` > > Bisected to #123233, cc @EgorBo </issue_description> > > <agent_instructions>Fix the #124082 bug. Replace Multiply impl with the following code: > > ```cpp > static Range Multiply(const Range& r1, const Range& r2) > { > if (!r1.IsConstantRange() || !r2.IsConstantRange()) > { > return Limit(Limit::keUnknown); > } > > int r1lo = r1.LowerLimit().GetConstant(); > int r1hi = r1.UpperLimit().GetConstant(); > int r2lo = r2.LowerLimit().GetConstant(); > int r2hi = r2.UpperLimit().GetConstant(); > > if (CheckedOps::MulOverflows(r1lo, r2lo, CheckedOps::Signed) || > CheckedOps::MulOverflows(r1lo, r2hi, CheckedOps::Signed) || > CheckedOps::MulOverflows(r1hi, r2lo, CheckedOps::Signed) || > CheckedOps::MulOverflows(r1hi, r2hi, CheckedOps::Signed)) > { > return Limit(Limit::keUnknown); > } > > int lo = min(min(r1lo * r2lo, r1lo * r2hi), min(r1hi * r2lo, r1hi * r2hi)); > int hi = max(max(r1lo * r2lo, r1lo * r2hi), max(r1hi * r2lo, r1hi * r2hi)); > assert(hi >= lo); > return Range(Limit(Limit::keConstant, lo), Limit(Limit::keConstant, hi)); > } > ``` > the problem that the original code for e.g. [-100..100] * [0..10] would return [0..1000] instead of [-1000..1000]. You can ignore "IsDependent" check here - it's not useful anyway. > > Add the JIT regression test for this case from issue (maintain the Fuzzlyn comment header in the test)</agent_instructions> > > ## Comments on the Issue (you are @copilot in this section) > > <comments> > </comments> > </details> <!-- START COPILOT CODING AGENT SUFFIX --> - Fixes #124082 <!-- START COPILOT CODING AGENT TIPS --> --- 💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more [Copilot coding agent tips](https://gh.io/copilot-coding-agent-tips) in the docs. --------- Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com> Co-authored-by: EgorBo <523221+EgorBo@users.noreply.github.com> Co-authored-by: Egor Bogatov <egorbo@gmail.com>
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diffs
Fixes #122288
Also, enables more branch foldings based on assertions - basically, mimics what SSA-based GetRange does, but based only on VNs.
I recommend reviewing with whitespaces disabled.