on the mallai shore temple - its actually a vishnu shrine sandwitched inbetween two shiva shrines. the two shiva shrines gopurams survive while that of the vishnu shrine was not there or was damaged.
We have already seen the references in alwars works of Kadalmallai Talasayana perumal. In Rajaraja's later inscriptions he mentions the names of the three shrines of at Kshatriyasimha Pallavesvaragriham, Rajasimha Pallavesvaragriham and Pallikondaruliya Devar shrine. Kshtriyasimha and rajsimha are ofcourse titles of rajasimha himself and hence we can conculde that these shiva shrines were built by him.
A recently discovered label inscription found on the lintel of this Vishnu shrine, in the Pallava grantha script of the Rajasimha age, gives the name of the temple as Narapathisimha Pallava Vishnu griham. This find confirms that the Vishnu temple was also built by Rajasimha. so does this mean that the vishnu shrine was also built by rajasimha?
some scholars works quote the court poet dandin's reference to the vishnu shrine in mallai - as he had prayed there already without a reference to the shiva - as maybe the vishnu shrine was already existing and rajasimha only added the two shiva shrines..
the actual verse from dandin's Avantisundarikatha, (9. Avantisundarikatha.)
Late M. Raghava Iyengar concludes, that the Vishnu image was under worship long before Rajasimha.
some reference i found form Dr. Nagaswamy' site would be of interest to you from the pallava court poet dandin's works ...
>>>>>>>>> That the Yavana architects were held in great esteem, even in the Eighth century CE, is made known from a Sanskrit work: Avanti Sundari Katha composed by Dandin, a court poet, under the Pallavas of Kanchi, in the beginning of the eighth century CE. Referring to a great artist Lalitalaya, who was working at Mamallapuram, the text mentions him as an accomplished sculptor surpassing in his skill even the Yavanas. Master sculptors >>>>>>>>>>
following references from Dr Gift Siromoney's
A few personal names of the artists of Tamil Nadu have come down to us from the Pallava period. In the work of Dandin called Dasakumara Charitram, there is an introductory reference to a silpi called Lalithaalaya who cleverly repairs the broken arm of the reclining Vishnu image in the Shore Temple complex. The name may be real or fictitious, but the story belongs to the period when the Vishnu shrine alone existed for Dandin describes how the waves washed the feet of the Vishnu image. The Siva shrines built on either side of the Vishnu shrine belong to the later period around 700 A.D. when king Rajasimha was the ruling Pallava monarch.