Evan Cheng b55c8bed9d Add a pseudo instruction REG_SEQUENCE that takes a list of registers and ... sub-register indices and outputs a single super register which is formed from a consecutive sequence of registers. This is used as register allocation / coalescing aid and it is useful to represent instructions that output register pairs / quads. For example, v1024, v1025 = vload <address> where v1024 and v1025 forms a register pair. This really should be modelled as v1024<3>, v1025<4> = vload <address> but it would violate SSA property before register allocation is done. Currently we use insert_subreg to form the super register: v1026 = implicit_def v1027 - insert_subreg v1026, v1024, 3 v1028 = insert_subreg v1027, v1025, 4 ... = use v1024 = use v1028 But this adds pseudo live interval overlap between v1024 and v1025. We can now modeled it as v1024, v1025 = vload <address> v1026 = REG_SEQUENCE v1024, 3, v1025, 4 ... = use v1024 = use v1026 After coalescing, it will be v1026<3>, v1025<4> = vload <address> ... = use v1026<3> = use v1026 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@102815 91177308-0d34-0410-b5e6-96231b3b80d8		2010-05-01 00:28:44 +00:00
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llvm	Add a pseudo instruction REG_SEQUENCE that takes a list of registers and	2010-05-01 00:28:44 +00:00
llvm-c	add some more (void)'s to prototypes for PR6961	2010-04-29 23:27:32 +00:00