7 Commits

Author	SHA1	Message	Date
Evan Cheng	1a99a5f501	It has finally happened. Spiller is now using live interval info. ... This fixes a very subtle bug. vr defined by an implicit_def is allowed overlap with any register since it doesn't actually modify anything. However, if it's used as a two-address use, its live range can be extended and it can be spilled. The spiller must take care not to emit a reload for the vn number that's defined by the implicit_def. This is both a correctness and performance issue. llvm-svn: 69743	2009-04-21 22:46:52 +00:00
Evan Cheng	b96a1082a9	Teach spiller to unfold instructions which modref spill slot when a scratch ... register is available and when it's profitable. e.g. xorq %r12<kill>, %r13 addq %rax, -184(%rbp) addq %r13, -184(%rbp) ==> xorq %r12<kill>, %r13 movq -184(%rbp), %r12 addq %rax, %r12 addq %r13, %r12 movq %r12, -184(%rbp) Two more instructions, but fewer memory accesses. It can also open up opportunities for more optimizations. llvm-svn: 69341	2009-04-17 01:29:40 +00:00
Bill Wendling	b8017e02ca	Oy! When reverting r68073, I added in experimental code. Sorry... ... llvm-svn: 68099	2009-03-31 08:41:31 +00:00
Bill Wendling	c4b08e5eb0	Revert r68073. It's causing a failure in the Apple-style builds. ... llvm-svn: 68092	2009-03-31 08:26:26 +00:00
Evan Cheng	76f1b47ec9	Spiller may unfold load / mod / store instructions as an optimization when the would be loaded value is available in a register. It needs to check if it's legal to clobber the register. Also, the register can contain values of multiple spill slots, make sure to check all instead of just the one being unfolded. ... llvm-svn: 67068	2009-03-17 01:23:09 +00:00
Owen Anderson	36a9937883	Reorganize some #include's. ... llvm-svn: 66780	2009-03-12 06:58:19 +00:00
Owen Anderson	aabe06d92a	Reorganization: Move the Spiller out of VirtRegMap.cpp into its own files. No (intended) functionality change. ... llvm-svn: 66720	2009-03-11 22:31:21 +00:00