Low order register of a double word register operand. Operands
are defined by the name of the variable they are marked with in
the inline assembler code. This is a way to specify that the
operand just refers to the low order register for that variable.
It is the opposite of modifier 'D' which specifies the high order
register.
Example:
main()
{
long long ll_input = 0x1111222233334444LL;
long long ll_val = 3;
int i_result = 0;
__asm__ __volatile__(
"or %0, %L1, %2"
: "=r" (i_result)
: "r" (ll_input), "r" (ll_val));
}
Which results in:
lui $2, %hi(_gp_disp)
addiu $2, $2, %lo(_gp_disp)
addiu $sp, $sp, -8
addu $2, $2, $25
sw $2, 0($sp)
lui $2, 13107
ori $3, $2, 17476 <-- Low 32 bits of ll_input
lui $2, 4369
ori $4, $2, 8738 <-- High 32 bits of ll_input
addiu $5, $zero, 3 <-- Low 32 bits of ll_val
addiu $2, $zero, 0 <-- High 32 bits of ll_val
#APP
or $3, $4, $5 <-- or i_result, high 32 ll_input, low 32 of ll_val
#NO_APP
addiu $sp, $sp, 8
jr $ra
If not direction is done for the long long for 32 bit variables results
in using the low 32 bits as ll_val shows.
There is an existing bug if 'L' or 'D' is used for the destination register
for 32 bit long longs in that the target value will be updated incorrectly
for the non-specified part unless explicitly set within the inline asm code.
llvm-svn: 160028
generalizing its implementation sufficiently to support this value
number scenario as well.
This cuts out another significant performance hit in large functions
(over 10k basic blocks, etc), especially those with "natural" CFG
structures.
llvm-svn: 160026
This ordering allows nested if-conversion without using a work list, and
it makes it possible to update the dominator tree on the fly as well.
Any erased basic blocks will always be dominated by the current
post-order position, so the domtree can be pruned without invalidating
the iterator.
llvm-svn: 160025
X86MachineFunctionInfo as this is currently only used by X86. If this ever
becomes an issue on another arch (e.g., ARM) then we can hoist it back out.
llvm-svn: 160009
X86. Basically, this is a reapplication of r158087 with a few fixes.
Specifically, (1) the stack pointer is restored from the base pointer before
popping callee-saved registers and (2) in obscure cases (see comments in patch)
we must cache the value of the original stack adjustment in the prologue and
apply it in the epilogue.
rdar://11496434
llvm-svn: 160002
back of it.
I don't have anything even remotely close to a test case for this. It
only broke two build bots, both of them doing bootstrap builds, one of
them a dragonegg bootstrap. It doesn't break for me when I bootstrap
either. It doesn't reproduce every time or on many machines during the
bootstrap. Many thanks to Duncan Sands who got the exact command (and
stage of the bootstrap) which failed on the dragonegg bootstrap and
managed to get it to trigger under valgrind with debug symbols. The fix
was then found by inspection.
llvm-svn: 159993
multiple scalars and insert them into a vector. Next, we shuffle the elements
into the correct places, as before.
Also fix a small dagcombine bug in SimplifyBinOpWithSameOpcodeHands, when the
migration of bitcasts happened too late in the SelectionDAG process.
llvm-svn: 159991
quadratic behavior when performing pathological merges. Fixes the core
element of PR12652.
There is only one user of addRangeFrom left: join. I'm hoping to
refactor further in a future patch and have join use this merge
operation as well.
llvm-svn: 159982
of the trick merge routines. This adds a layer of testing that was
necessary when implementing more efficient (and complex) merge logic for
this datastructure.
No functionality changed here.
llvm-svn: 159981
Some NEON instructions want to match against normal SDNodes for some
operand types and Intrinsics for others. For example, CTLZ. To enable this,
switch from explicitly requiring Intrinsic on the class templates to using
SDPatternOperator instead.
llvm-svn: 159974
TableGen has support for using an intrinics name directly in a DAG,
but this breaks down when referring to just a node, as that's
handled initializer list stuff entirely via subclassing in the
parser. That is, using an instrinsic like "(int_my_intrinsic ...)"
works fine. Using it standalone for parameterizing the operator
in such a DAG does not.
Fixing this is simple enough, as we simply declare Intrinsic
as deriving from SDPatternOperator, which is the class name
intended for exactly this purpose in TargetSelectionDAG.td.
When the intrinsic is actually used in the DAG pattern, it will
be recognized and expanded to an intrinsic_wo_chain (et. al.)
just like when it's used directly.
Incoming ARM NEON cleanup based on this and a bit of functionality
improvement after that.
llvm-svn: 159973
getCondFromSETOpc, getCondFromCMovOpc, getSETFromCond, getCMovFromCond
No functional change intended.
If we want to update the condition code of CMOV|SET|Jcc, we first analyze the
opcode to get the condition code, then update the condition code, finally
synthesize the new opcode form the new condition code.
llvm-svn: 159955
Access mips register classes via MCRegisterInfo's functions instead of via the
TargetRegisterClasses defined in MipsGenRegisterInfo.inc.
llvm-svn: 159953
This patch removes ~70 lines in InstCombineLoadStoreAlloca.cpp and makes both functions a bit more aggressive than before :)
In theory, we can be more aggressive when removing an alloca than a malloc, because an alloca pointer should never escape, but we are not taking advantage of this anyway
llvm-svn: 159952
subtarget CPU descriptions and support new features of
MachineScheduler.
MachineModel has three categories of data:
1) Basic properties for coarse grained instruction cost model.
2) Scheduler Read/Write resources for simple per-opcode and operand cost model (TBD).
3) Instruction itineraties for detailed per-cycle reservation tables.
These will all live side-by-side. Any subtarget can use any
combination of them. Instruction itineraries will not change in the
near term. In the long run, I expect them to only be relevant for
in-order VLIW machines that have complex contraints and require a
precise scheduling/bundling model. Once itineraries are only actively
used by VLIW-ish targets, they could be replaced by something more
appropriate for those targets.
This tablegen backend rewrite sets things up for introducing
MachineModel type #2: per opcode/operand cost model.
llvm-svn: 159891
It is safe if EFLAGS is killed or re-defined.
When we are done with the basic block, check whether EFLAGS is live-out.
Do not optimize away cmp if EFLAGS is live-out.
llvm-svn: 159888
This means we can do cheap DSE for heap memory.
Nothing is done if the pointer excapes or has a load.
The churn in the tests is mostly due to objectsize, since we want to make sure we
don't delete the malloc call before evaluating the objectsize (otherwise it becomes -1/0)
llvm-svn: 159876
