[llvm] [SPIR-V] Fix 64-bit integer literal printing (PR #66686)

[Nathan Gauër via llvm-commits]

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@@ -169,7 +169,9 @@ void SPIRVInstPrinter::printInst(const MCInst *MI, uint64_t Address,
         }
         case SPIRV::OpConstantI:
         case SPIRV::OpConstantF:
-          printOpConstantVarOps(MI, NumFixedOps, OS);
+          // The last fixed operand along with any variadic operands that follow
+          // are part of the variable value.
+          printOpConstantVarOps(MI, NumFixedOps - 1, OS);
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Keenuts wrote:

Took a quick look at the MCInst builder.
Seems like the 64-bit integer is decomposed into 2 operands for the MCInstBuilder. But is that required?
Seems like the immediate could be a 64-bit int, so we wouldn't have to handle this split/merge.
Have you looked at this? (not sure how usable it would be as it stores a signed 64-bit, not unsigned).

https://github.com/llvm/llvm-project/pull/66686