On Mon, 12 Jan 2009, Joel Sherrill wrote: > The unfortunate thing is that I think these > tests are really ensuring that MASK_DLMZB is > used as expected. If this is right, then > shouldn't there be a cpp predefine similar > to __NO_LWSYNC__ for dlmzb? And the tests use > that rather than testing for a specific CPU model?
Exactly one of the tests (for each processor) is testing for dlmzb; the others are testing for half-word multiply instructions. The tests are that the compiler, generating code for those processors, with the options people are expected to use for those processors, generates the instructions. The tests are likely very sensitive to cost tuning. > And then should there be tests for the other > CPU models which have this feature to ensure > the -mcpu=[405fp|440fp|464|464fp] also do the > right thing? I don't see why 2 of the 6 CPU > models have this test. It happens that all those processors use ppc405_cost or ppc440_cost, so the most obvious variation is already covered. -- Joseph S. Myers jos...@codesourcery.com
