replacement of multiple values. This is slightly more efficient
than doing multiple ReplaceAllUsesOfValueWith calls, and theoretically
could be optimized even further. However, an important property of this
new function is that it handles the case where the source value set and
destination value set overlap. This makes it feasible for isel to use
SelectNodeTo in many very common cases, which is advantageous because
SelectNodeTo avoids a temporary node and it doesn't require CSEMap
updates for users of values that don't change position.
Revamp MorphNodeTo, which is what does all the work of SelectNodeTo, to
handle operand lists more efficiently, and to correctly handle a number
of corner cases to which its new wider use exposes it.
This commit also includes a change to the encoding of post-isel opcodes
in SDNodes; now instead of being sandwiched between the target-independent
pre-isel opcodes and the target-dependent pre-isel opcodes, post-isel
opcodes are now represented as negative values. This makes it possible
to test if an opcode is pre-isel or post-isel without having to know
the size of the current target's post-isel instruction set.
These changes speed up llc overall by 3% and reduce memory usage by 10%
on the InstructionCombining.cpp testcase with -fast and -regalloc=local.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53728 91177308-0d34-0410-b5e6-96231b3b80d8
use a timer group for the timers in SelectionDAGISel. Also,
Split scheduling out from emitting, to give each their own
timer.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53476 91177308-0d34-0410-b5e6-96231b3b80d8
to DenseMap<SDNode*, SUnit*>, and adjust the way cloned SUnit nodes are
handled so that only the original node needs to be in the map.
This speeds up llc on 447.dealII.llvm.bc by about 2%.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52576 91177308-0d34-0410-b5e6-96231b3b80d8
ScheduleDAG; they don't correspond to any actual instructions so they
don't need to be scheduled.
This fixes a bug where the EntryToken was being scheduled multiple
times in some cases, though it ended up not causing any trouble because
EntryToken doesn't expand into anything. With this fixed the schedulers
reliably schedule the expected number of units, so we can check this
with an assertion.
This requires a tweak to test/CodeGen/X86/loop-hoist.ll because it
ends up getting scheduled differently in a trivial way, though it was
enough to fool the prcontext+grep that the test does.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@49701 91177308-0d34-0410-b5e6-96231b3b80d8
that "machine" classes are used to represent the current state of
the code being compiled. Given this expanded name, we can start
moving other stuff into it. For now, move the UsedPhysRegs and
LiveIn/LoveOuts vectors from MachineFunction into it.
Update all the clients to match.
This also reduces some needless #includes, such as MachineModuleInfo
from MachineFunction.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45467 91177308-0d34-0410-b5e6-96231b3b80d8
This reduces selectiondag time on kc++ from 5.43s to 4.98s (9%). More
significantly, this speeds up the default ppc scheduler from ~1571ms to 1063ms,
a 33% speedup.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@29743 91177308-0d34-0410-b5e6-96231b3b80d8
2. Added argument to instruction scheduler creators so the creators can do
special things.
3. Repaired target hazard code.
4. Misc.
More to follow.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@29450 91177308-0d34-0410-b5e6-96231b3b80d8
separate file. Added an initial implementation of top-down register pressure
reduction list scheduler.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@28226 91177308-0d34-0410-b5e6-96231b3b80d8
the distance between the def and another use is much longer). This is under
option control for now "-sched-lower-defnuse".
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scheduler can go into a "vertical mode" (i.e. traversing up the two-address
chain, etc.) when the register pressure is low.
This does seem to reduce the number of spills in the cases I've looked at. But
with x86, it's no guarantee the performance of the code improves.
It can be turned on with -sched-vertically option.
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the heuristic to further reduce spills for several test cases. (Note, it may
not necessarily translate to runtime win!)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@28076 91177308-0d34-0410-b5e6-96231b3b80d8
up the schedule. This helps code that looks like this:
loads ...
computations (first set) ...
stores (first set) ...
loads
computations (seccond set) ...
stores (seccond set) ...
Without this change, the stores and computations are more likely to
interleave:
loads ...
loads ...
computations (first set) ...
computations (second set) ...
computations (first set) ...
stores (first set) ...
computations (second set) ...
stores (stores set) ...
This can increase the number of spills if we are unlucky.
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to be emitted.
Don't add one to the latency of a completed instruction if the latency of the
op is 0.
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operands have all issued, but whose results are not yet available. This
allows us to compile:
int G;
int test(int A, int B, int* P) {
return (G+A)*(B+1);
}
to:
_test:
lis r2, ha16(L_G$non_lazy_ptr)
addi r4, r4, 1
lwz r2, lo16(L_G$non_lazy_ptr)(r2)
lwz r2, 0(r2)
add r2, r2, r3
mullw r3, r2, r4
blr
instead of this, which has a stall between the lis/lwz:
_test:
lis r2, ha16(L_G$non_lazy_ptr)
lwz r2, lo16(L_G$non_lazy_ptr)(r2)
addi r4, r4, 1
lwz r2, 0(r2)
add r2, r2, r3
mullw r3, r2, r4
blr
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26716 91177308-0d34-0410-b5e6-96231b3b80d8
merge succs/chainsuccs -> succs set
This has no functionality change, simplifies the code, and reduces the size
of sunits.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26711 91177308-0d34-0410-b5e6-96231b3b80d8
