[llvm] [RISCV] Improve assembler error message for Zcmp stack adjustment. (PR #129180)

[Craig Topper via llvm-commits]

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@@ -2771,12 +2766,25 @@ ParseStatus RISCVAsmParser::parseZcmpStackAdj(OperandVector &Operands,
 
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topperc wrote:

I'm considering restructuring how push/pop are represented in MCInst and moving this check to validateInstruction. It's a bit odd that we're peeking at the parsed reglist operand while still in the parsing stage.

My thought is that we should parse this as a regular immediate and do the range check in validateInstruction. Simplify the InstPrinter by printing the immediate directly. Change RISCVFrameLowering to include StackAdjBase in the immediate when it creates a push/pop.

https://github.com/llvm/llvm-project/pull/129180