[clang] Upstream support for setjmp & longjmp builtins (PR #178989)

[Chibuoyim Ogbonna via cfe-commits]

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@@ -1352,8 +1335,44 @@ RValue CIRGenFunction::emitBuiltinExpr(const GlobalDecl &gd, unsigned builtinID,
   case Builtin::BI__builtin_eh_return:
   case Builtin::BI__builtin_unwind_init:
   case Builtin::BI__builtin_extend_pointer:
-  case Builtin::BI__builtin_setjmp:
-  case Builtin::BI__builtin_longjmp:
+    return errorBuiltinNYI(*this, e, builtinID);
+  case Builtin::BI__builtin_setjmp: {
+    Address buf = emitPointerWithAlignment(e->getArg(0));
+    mlir::Location loc = getLoc(e->getExprLoc());
+
+    cir::PointerType ppTy = builder.getPointerTo(builder.getVoidPtrTy());
+    mlir::Value castBuf = builder.createBitcast(buf.getPointer(), ppTy);
+
+    assert(!cir::MissingFeatures::emitCheckedInBoundsGEP());
+    if (getTarget().getTriple().isSystemZ()) {
+      llvm_unreachable("SYSTEMZ NYI");
+    }
+
+    mlir::Value frameaddress =
+        cir::FrameAddrOp::create(builder, loc, builder.getVoidPtrTy(),
+                                 mlir::ValueRange{builder.getUInt32(0, loc)})
+            .getResult();
+
+    builder.createStore(loc, frameaddress, castBuf);
+
+    mlir::Value stacksave =
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bruteforceboy wrote:

camel case here?

https://github.com/llvm/llvm-project/pull/178989