a lot throughout many programs. In particular, specfp triggers it a bunch for
constant FP nodes when you have code like cond ? 1.0 : -1.0.
If the PPC ISel exposed the loads implicit in pic references to external globals,
we would be able to eliminate a load in cases like this as well:
%X = external global int
%Y = external global int
int* %test4(bool %C) {
%G = select bool %C, int* %X, int* %Y
ret int* %G
}
Note that this breaks things that use SrcValue's (see the fixme), but since nothing
uses them yet, this is ok.
Also, simplify some code to use hasOneUse() on an SDOperand instead of hasNUsesOfValue directly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23781 91177308-0d34-0410-b5e6-96231b3b80d8
you could be AND'ing with the result of a shift that shifts out all the
bits you care about, in addition to a constant.
Also, move over an add/sub_parts fold from legalize to the dag combiner,
where it works for things other than constants. Woot!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23720 91177308-0d34-0410-b5e6-96231b3b80d8
out, where after the first CombineTo() call, the node the second CombineTo
wishes to replace may no longer exist.
Fix a very real bug with the truncated load optimization on little endian
targets, which do not need a byte offset added to the load.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23704 91177308-0d34-0410-b5e6-96231b3b80d8
like turning:
_foo:
fctiwz f0, f1
stfd f0, -8(r1)
lwz r2, -4(r1)
rlwinm r3, r2, 0, 16, 31
blr
into
_foo:
fctiwz f0,f1
stfd f0,-8(r1)
lhz r3,-2(r1)
blr
Also removed an unncessary constraint from sra -> srl conversion, which
should take care of hte only reason we would ever need to handle sra in
MaskedValueIsZero, AFAIK.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23703 91177308-0d34-0410-b5e6-96231b3b80d8
location, replace them with a new store of the last value. This occurs
in the same neighborhood in 197.parser, speeding it up about 1.5%
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23691 91177308-0d34-0410-b5e6-96231b3b80d8
multiple results.
Use this support to implement trivial store->load forwarding, implementing
CodeGen/PowerPC/store-load-fwd.ll. Though this is the most simple case and
can be extended in the future, it is still useful. For example, it speeds
up 197.parser by 6.2% by avoiding an LSU reject in xalloc:
stw r6, lo16(l5_end_of_array)(r2)
addi r2, r5, -4
stwx r5, r4, r2
- lwzx r5, r4, r2
- rlwinm r5, r5, 0, 0, 30
stwx r5, r4, r2
lwz r2, -4(r4)
ori r2, r2, 1
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23690 91177308-0d34-0410-b5e6-96231b3b80d8
creating a new vreg and inserting a copy: just use the input vreg directly.
This speeds up the compile (e.g. about 5% on mesa with a debug build of llc)
by not adding a bunch of copies and vregs to be coallesced away. On mesa,
for example, this reduces the number of intervals from 168601 to 129040
going into the coallescer.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23671 91177308-0d34-0410-b5e6-96231b3b80d8
previous copy elisions and we discover we need to reload a register, make
sure to use the regclass of the original register for the reload, not the
class of the current register. This avoid using 16-bit loads to reload 32-bit
values.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23645 91177308-0d34-0410-b5e6-96231b3b80d8
store r12 -> [ss#2]
R3 = load [ss#1]
use R3
R3 = load [ss#2]
R4 = load [ss#1]
and turn it into this code:
store R12 -> [ss#2]
R3 = load [ss#1]
use R3
R3 = R12
R4 = R3 <- oops!
The problem was that promoting R3 = load[ss#2] to a copy missed the fact that
the instruction invalidated R3 at that point.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23638 91177308-0d34-0410-b5e6-96231b3b80d8
with the dag combiner. This speeds up espresso by 8%, reaching performance
parity with the dag-combiner-disabled llc.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23636 91177308-0d34-0410-b5e6-96231b3b80d8
