[PIX] Fix dynamic bind-point identity and range bounds

[Damyan Pepper (damyanp)]

Part 7 of 14 in the PIX instrumentation stack. It targets users/damyanp/pix-fixes-06, which supplies the access-record test support. Both changes are in the same pass.

RSRegisterIdentifier::operator< combines its three fields with &&. This is not a strict weak ordering. Two distinct ranges can compare as neither less than the other, so the map treats them as one key and gives their slot assignments to one of them. Accesses to one range are then reported against the other.

RegisterID comes from the position of the resource in the module's resource list. PIX needs the register that the binding occupies.

The range check for a constant index is off by one, so the pass accepts an index that addresses the slot after the range.

An index outside the range is still recorded at slot zero.

The meaning of RegisterID changes. A tool that resolved the old value against the module's resource list must resolve the new value against the root signature.

Assisted-by: Copilot

This changes only the PIX instrumentation, so it needs no release note.

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[Copilot]

Pull request overview

Fixes PIX resource access tracking so dynamic bind points use root-signature identities and range boundaries are enforced correctly.

Changes:

• Implements strict bind-point ordering and correct register identities.
• Fixes the constant-index upper-bound check.
• Adds regression tests for both behaviors.

Reviewed changes

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

File	Description
lib/DxilPIXPasses/DxilShaderAccessTracking.cpp	Corrects ordering, bounds checking, and register identity.
tools/clang/unittests/HLSL/PixTest.cpp	Adds PIX access-tracking regression tests.

Suppressed comments (3)

tools/clang/unittests/HLSL/PixTest.cpp:1339

• These inferred types are all short (CComPtr<IDxcBlob>, PassOutput, and std::string), so using auto conflicts with the repository's “almost never auto” convention.

  auto compiled = Compile(m_dllSupport, hlsl, L"cs_6_0", {L"-Od"}, L"CSMain");
  auto output =
      RunShaderAccessTrackingPass(compiled, L"S0:0:2i0;U0:0:10i0;.0;0;0.");
  auto text = JoinLines(output.lines);

tools/clang/unittests/HLSL/PixTest.cpp:1384

• The inferred types here are short and unambiguous, so auto conflicts with the repository's “almost never auto” convention. Please make all three declarations explicit.

  auto compiled = Compile(m_dllSupport, hlsl, L"cs_6_0", {L"-Od"}, L"CSMain");
  auto output = RunShaderAccessTrackingPass(compiled, L"U0:0:1i0;.0;0;0.");
  auto lines = Split(Disassemble(output.blob), '\n');

tools/clang/unittests/HLSL/PixTest.cpp:1364

• These inferred types are short and already exposed by the helper APIs. Please use explicit CComPtr<IDxcBlob>, PassOutput, and std::string types to follow the repository's “almost never auto” convention.

  auto compiled = Compile(m_dllSupport, hlsl, L"cs_6_6", {L"-Od"}, L"CSMain");
  auto output = RunShaderAccessTrackingPass(compiled, L"U0:0:10i0;.0;0;0.");
  auto text = JoinLines(output.lines);

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