[llvm] [RISCV][GlobalISel] Legalize and select G_ATOMICRMW_ADD instruction (PR #153791)

[Craig Topper via llvm-commits]

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@@ -692,6 +692,13 @@ RISCVLegalizerInfo::RISCVLegalizerInfo(const RISCVSubtarget &ST)
       .customIf(all(typeIsLegalIntOrFPVec(0, IntOrFPVecTys, ST),
                     typeIsLegalIntOrFPVec(1, IntOrFPVecTys, ST)));
 
+  bool ForceAtomics = ST.hasForcedAtomics() && !ST.hasStdExtA();
+
+  getActionDefinitionsBuilder(G_ATOMICRMW_ADD)
+      .legalFor(!ForceAtomics, {{s32, p0}, {sXLen, p0}})
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topperc wrote:

Should only be legal with `ST.hasStdExtA`?

https://github.com/llvm/llvm-project/pull/153791