[llvm] [RISCV] Make amocas.q require Ziccamoc (PR #201536)

[Craig Topper via llvm-commits]

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@@ -65,6 +65,7 @@ defm AMOCAS_D_RV32 : AMO_cas_aq_rl<0b00101, 0b011, "amocas.d", GPRPairRV32>;
 
 let Predicates = [HasStdExtZacas, IsRV64] in {
 defm AMOCAS_D_RV64 : AMO_cas_aq_rl<0b00101, 0b011, "amocas.d", GPR>;
+let append Predicates = [HasStdExtZiccamoc] in
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topperc wrote:

I'm not sure we should block assembler support for this instruction. The Ziccamoc extension refers to main memory. Couldn't a different memory region support amocas.q?

https://github.com/llvm/llvm-project/pull/201536