[clang] [llvm] [SPIRV] Add support for the `SPV_EXT_long_vector` extension (PR #210279)

[Arseniy Obolenskiy via cfe-commits]

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@@ -1629,6 +1629,22 @@ void addInstrRequirements(const MachineInstr &MI,
     }
     break;
   }
+  case SPIRV::OpTypeVectorIdEXT: {
+    if (!ST.canUseExtension(SPIRV::Extension::SPV_EXT_long_vector))
+      reportFatalUsageError("OpTypeVectorIdEXT requires the following SPIR-V "
+                            "extension: SPV_EXT_long_vector extension");
+    Reqs.addExtension(SPIRV::Extension::SPV_EXT_long_vector);
+    Reqs.addCapability(SPIRV::Capability::LongVectorEXT);
+    assert(MI.getOperand(1).isReg());
+    const MachineRegisterInfo &MRI = MI.getMF()->getRegInfo();
+    SPIRVTypeInst ElemTypeDef = MRI.getVRegDef(MI.getOperand(1).getReg());
+    if (ElemTypeDef->getOpcode() == SPIRV::OpTypePointer &&
+        ST.canUseExtension(SPIRV::Extension::SPV_INTEL_masked_gather_scatter)) {
+      Reqs.addExtension(SPIRV::Extension::SPV_INTEL_masked_gather_scatter);
+      Reqs.addCapability(SPIRV::Capability::MaskedGatherScatterINTEL);
+    }
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aobolensk wrote:

This part is copy pasted from `SPIRV::OpTypeVector`. What do you think, is there a way to unite this branches to reuse these parts?

https://github.com/llvm/llvm-project/pull/210279