According to Intel Application Note 485, this value is used for
"Intel Core i7 and Intel Xeon processor". Just include it with the other
"corei7-avx" entries.
llvm-svn: 134750
The normal tBX instruction is predicable, so there's no reason the
pseudos for using it as a return shouldn't be. Gives us some nice code-gen
improvements as can be seen by the test changes. In particular, several
tests now have to disable if-conversion because it works too well and defeats
the test.
llvm-svn: 134746
RAGreedy::tryAssign will now evict interference from the preferred
register even when another register is free.
To support this, add the EvictionCost struct that counts how many hints
are broken by an eviction. We don't want to break one hint just to
satisfy another.
Rename canEvict to shouldEvict, and add the first bit of eviction policy
that doesn't depend on spill weights: Always make room in the preferred
register as long as the evictees can be split and aren't already
assigned to their preferred register.
Also make the CSR avoidance more accurate. When looking for a cheaper
register it is OK to use a new volatile register. Only CSR aliases that
have never been used before should be avoided.
llvm-svn: 134735
Hook up the TableGen lowering for simple pseudo instructions for ARM and
use it for a subset of the many pseudos the backend has as proof of concept.
More conversions to come.
llvm-svn: 134705
This allows the (many) pseudo-instructions we have that map onto a single
real instruction to have their expansion during MC lowering handled
automatically instead of the current cumbersome manual expansion required.
These sorts of pseudos are common when an instruction is used in situations
that require different MachineInstr flags (isTerminator, isBranch, et. al.)
than the generic instruction description has. For example, using a move
to the PC to implement a branch.
llvm-svn: 134704
We have to do this in DAGBuilder instead of DAGCombiner, because the exact bit is lost after building.
struct foo { char x[24]; };
long bar(struct foo *a, struct foo *b) { return a-b; }
is now compiled into
movl 4(%esp), %eax
subl 8(%esp), %eax
sarl $3, %eax
imull $-1431655765, %eax, %eax
instead of
movl 4(%esp), %eax
subl 8(%esp), %eax
movl $715827883, %ecx
imull %ecx
movl %edx, %eax
shrl $31, %eax
sarl $2, %edx
addl %eax, %edx
movl %edx, %eax
llvm-svn: 134695
- Each target asm parser now creates its own MCSubtatgetInfo (if needed).
- Changed AssemblerPredicate to take subtarget features which tablegen uses
to generate asm matcher subtarget feature queries. e.g.
"ModeThumb,FeatureThumb2" is translated to
"(Bits & ModeThumb) != 0 && (Bits & FeatureThumb2) != 0".
llvm-svn: 134678
It was testing a linear scan feature:
Test if linearscan is unfavoring registers for allocation to allow
more reuse of reloads from stack slots.
The greedy register allocator doesn't access any stack slots in this
function, so the linear scan feature was not being tested.
llvm-svn: 134666
