[llvm] [AMDGPU] AsmPrinter: Unify arg handling (PR #151672)

[Diana Picus via llvm-commits]

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@@ -993,89 +993,24 @@ void AMDGPUAsmPrinter::getSIProgramInfo(SIProgramInfo &ProgInfo,
   const Function &F = MF.getFunction();
 
   // Ensure there are enough SGPRs and VGPRs for wave dispatch, where wave
-  // dispatch registers are function args.
-  unsigned WaveDispatchNumSGPR = 0, WaveDispatchNumVGPR = 0;
-
-  if (isShader(F.getCallingConv())) {
-    bool IsPixelShader =
-        F.getCallingConv() == CallingConv::AMDGPU_PS && !STM.isAmdHsaOS();
-
-    // Calculate the number of VGPR registers based on the SPI input registers
-    uint32_t InputEna = 0;
-    uint32_t InputAddr = 0;
-    unsigned LastEna = 0;
-
-    if (IsPixelShader) {
-      // Note for IsPixelShader:
-      // By this stage, all enabled inputs are tagged in InputAddr as well.
-      // We will use InputAddr to determine whether the input counts against the
-      // vgpr total and only use the InputEnable to determine the last input
-      // that is relevant - if extra arguments are used, then we have to honour
-      // the InputAddr for any intermediate non-enabled inputs.
-      InputEna = MFI->getPSInputEnable();
-      InputAddr = MFI->getPSInputAddr();
-
-      // We only need to consider input args up to the last used arg.
-      assert((InputEna || InputAddr) &&
-             "PSInputAddr and PSInputEnable should "
-             "never both be 0 for AMDGPU_PS shaders");
-      // There are some rare circumstances where InputAddr is non-zero and
-      // InputEna can be set to 0. In this case we default to setting LastEna
-      // to 1.
-      LastEna = InputEna ? llvm::Log2_32(InputEna) + 1 : 1;
-    }
+  // dispatch registers as function args.
+  unsigned WaveDispatchNumSGPR = MFI->getNumWaveDispatchSGPRs(),
+           WaveDispatchNumVGPR = MFI->getNumWaveDispatchVGPRs();
 
-    // FIXME: We should be using the number of registers determined during
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rovka wrote:

Yep. I added a test with a couple of types where the calculation involving the DataLayout gave different results (usually because we split those up during arg lowering). Let me know if you have any others in mind.

https://github.com/llvm/llvm-project/pull/151672