When a live interval is being spilled, rather than creating short, non-spillable
intervals for every def / use, split the interval at BB boundaries. That is, for
every BB where the live interval is defined or used, create a new interval that
covers all the defs and uses in the BB.

This is designed to eliminate one common problem: multiple reloads of the same
value in a single basic block. Note, it does *not* decrease the number of spills
since no copies are inserted so the split intervals are *connected* through
spill and reloads (or rematerialization). The newly created intervals can be
spilled again, in that case, since it does not span multiple basic blocks, it's
spilled in the usual manner. However, it can reuse the same stack slot as the
previously split interval.

This is currently controlled by -split-intervals-at-bb.

llvm-svn: 44198

llvm-svn: 44197

llvm-svn: 44196

orthogonal to the main problem there)

llvm-svn: 44194

llvm-svn: 44193

llvm-svn: 44189

llvm-svn: 44188

llvm-svn: 44187

llvm-svn: 44183

Codegen bits and llvm-gcc support will follow.

llvm-svn: 44182

llvm-svn: 44181

llvm-svn: 44177

llvm-svn: 44174

llvm-svn: 44167

llvm-svn: 44166

is disabled in the sense that it will refuse to create one from a UDiv
instruction, until the code is better tested.

llvm-svn: 44163

Thanks to him for his detailed analysis of the problem.

llvm-svn: 44162

Cédric Venet.

llvm-svn: 44161

llvm-svn: 44158

llvm-svn: 44157

llvm-svn: 44154

llvm-svn: 44153

deserialize objects if BatchReadOwnedPtrs was called more than once in the
same call chain then the second call would overwrite the SerializedPtrIDs
being used by the first call. Solved this problem by making the vector that
holds the pointer IDs local to a function call. Now BatchReadOwnedPtrs is
reentrant.

llvm-svn: 44152

llvm-svn: 44139

llvm-svn: 44132

llvm-svn: 44128

the deserializer.

Fixed assertion when "stream jumping" in the deserializer to properly function
when we have reached the end of the stream.

llvm-svn: 44124

llvm-svn: 44116

the fix from 4.2.

llvm-svn: 44115

llvm-svn: 44111

llvm-svn: 44110

llvm-svn: 44109

to all targets uses GOT-relative offsets for PIC (Alpha?)

llvm-svn: 44108

in favour of teaching CCAssignToStack that size 0 and/or align
0 means to use the ABI values.  This seems a neater solution.
It is safe since no legal value type has size 0.

llvm-svn: 44107

BatchReadOwnedPtrs.

llvm-svn: 44105

MachineOperand auxInfo. Previous clunky implementation uses an external map
to track sub-register uses. That works because register allocator uses
a new virtual register for each spilled use. With interval splitting (coming
soon), we may have multiple uses of the same register some of which are
of using different sub-registers from others. It's too fragile to constantly
update the information.

llvm-svn: 44104

from llvm-gcc-4.2 to 4.0.

llvm-svn: 44103

llvm-svn: 44102

from a file containing Function/BasicBlock pairings. This is not safe against
anonymous or abnormally-named Funcs or BBs.

Make bugpoint use this interface to pass the BBs list to the child bugpoint.

llvm-svn: 44101

by inserting unreachable after no-return calls.

llvm-svn: 44099