[llvm] Add Instruction selection support for x87 ld/st (PR #97016)

[Malay Sanghi via llvm-commits]

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@@ -472,6 +482,10 @@ unsigned X86InstructionSelector::getLoadStoreOp(const LLT &Ty,
                     : (HasAVX512 ? X86::VMOVSDZmr :
                        HasAVX    ? X86::VMOVSDmr :
                                    X86::MOVSDmr);
+    if (X86::PSRRegBankID == RB.getID())
+      return Isload ? X86::LD_Fp64m : X86::ST_Fp64m;
+  } else if (Ty == LLT::scalar(80) || Ty == LLT::pointer(0, 80)) {
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MalaySanghi wrote:

I don't really know. This check is a result of copy paste - I should have verified if we have such pointers. I'll get back on this

https://github.com/llvm/llvm-project/pull/97016