[llvm] [AMDGPU][MC] GFX9 - Support NV bit in FLAT instructions in pre-GFX90A (PR #154237)

[Matt Arsenault via llvm-commits]

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@@ -5405,7 +5405,8 @@ bool AMDGPUAsmParser::validateCoherencyBits(const MCInst &Inst,
       S = SMLoc::getFromPointer(&CStr.data()[CStr.find("scale_offset")]);
       Error(S, "scale_offset is not supported on this GPU");
     }
-    if (CPol & CPol::NV) {
+    if ((CPol & CPol::NV) && (!isGFX9() || isGFX90A())) {
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arsenm wrote:

Avoid generation checks, should have a named predicate for this 

https://github.com/llvm/llvm-project/pull/154237