[llvm] [SPIRV] Add support for the SPIR-V extension SPV_KHR_bfloat16 (PR #155645)

[Marcos Maronas via llvm-commits]

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@@ -1261,12 +1267,30 @@ void addInstrRequirements(const MachineInstr &MI,
       Reqs.addCapability(SPIRV::Capability::Int8);
     break;
   }
+  case SPIRV::OpDot: {
+    const MachineRegisterInfo &MRI = MI.getMF()->getRegInfo();
+    SPIRVType *TypeDef = MRI.getVRegDef(MI.getOperand(1).getReg());
+    if (isBFloat16Type(TypeDef))
+      Reqs.addCapability(SPIRV::Capability::BFloat16DotProductKHR);
+    break;
+  }
   case SPIRV::OpTypeFloat: {
     unsigned BitWidth = MI.getOperand(1).getImm();
     if (BitWidth == 64)
       Reqs.addCapability(SPIRV::Capability::Float64);
-    else if (BitWidth == 16)
-      Reqs.addCapability(SPIRV::Capability::Float16);
+    else if (BitWidth == 16) {
+      if ((MI.getNumOperands() == 3) &&
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maarquitos14 wrote:

Can we use `isBFloat16Type(MI)` instead?

https://github.com/llvm/llvm-project/pull/155645