a special case hack for X86, make the hack more general: if an incoming argument
register is not used in any block other than the entry block, don't copy it to
a vreg. This helps us compile code like this:
%struct.foo = type { int, int, [0 x ubyte] }
int %test(%struct.foo* %X) {
%tmp1 = getelementptr %struct.foo* %X, int 0, uint 2, int 100
%tmp = load ubyte* %tmp1 ; <ubyte> [#uses=1]
%tmp2 = cast ubyte %tmp to int ; <int> [#uses=1]
ret int %tmp2
}
to:
_test:
lbz r3, 108(r3)
blr
instead of:
_test:
lbz r2, 108(r3)
or r3, r2, r2
blr
The (dead) copy emitted to copy r3 into a vreg for extra-block uses was
increasing the live range of r3 past the load, preventing the coallescing.
This implements CodeGen/PowerPC/reg-coallesce-simple.ll
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@24115 91177308-0d34-0410-b5e6-96231b3b80d8
generating results in vregs that will need them. In the case of something
like this: CopyToReg((add X, Y), reg1024), we no longer emit code like
this:
reg1025 = add X, Y
reg1024 = reg 1025
Instead, we emit:
reg1024 = add X, Y
Whoa! :)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@24111 91177308-0d34-0410-b5e6-96231b3b80d8
FP_TO_SINT is preferred to a larger FP_TO_UINT. This seems to be begging
for a TLI.isOperationCustom() helper function.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23992 91177308-0d34-0410-b5e6-96231b3b80d8
pointer marking the end of the list, the zero *must* be cast to the pointer
type. An un-cast zero is a 32-bit int, and at least on x86_64, gcc will
not extend the zero to 64 bits, thus allowing the upper 32 bits to be
random junk.
The new END_WITH_NULL macro may be used to annotate a such a function
so that GCC (version 4 or newer) will detect the use of un-casted zero
at compile time.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23888 91177308-0d34-0410-b5e6-96231b3b80d8
the input is that type, this caused a failure on gs on X86 last night.
Move the hard checks into Build[US]Div since that is where decisions like
this should be made.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23881 91177308-0d34-0410-b5e6-96231b3b80d8
For example, we can now join things like [0-30:0)[31-40:1)[52-59:2)
with [40:60:0) if the 52-59 range is defined by a copy from the 40-60 range.
The resultant range ends up being [0-30:0)[31-60:1).
This fires a lot through-out the test suite (e.g. shrinking bc from
19492 -> 18509 machineinstrs) though most gains are smaller (e.g. about
50 copies eliminated from crafty).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23866 91177308-0d34-0410-b5e6-96231b3b80d8
(an unused method).
Fix the merger so that it can merge ranges like this [10:12)[16:40) with
[12:38) into [10:40) instead of bogus ranges. This sort of input will be
possible for the merger coming shortly
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23865 91177308-0d34-0410-b5e6-96231b3b80d8
Add a new flag to TargetLowering indicating if the target has really cheap
signed division by powers of two, make ppc use it. This will probably go
away in the future.
Implement some more ISD::SDIV folds in the dag combiner
Remove now dead code in the x86 backend.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23853 91177308-0d34-0410-b5e6-96231b3b80d8
for types that aren't legal, and fail a divisor is less than zero
comparison, which would cause us to drop a subtract.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23846 91177308-0d34-0410-b5e6-96231b3b80d8
Fix a *bug* in the extendIntervalEndTo method. In particular, if adding
[2:10) to an interval containing [0:2),[10:30), we produced [0:10),[10,30).
Which is not the most smart thing to do. Now produce [0:30).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23841 91177308-0d34-0410-b5e6-96231b3b80d8
that the nodes can be folded with other nodes, and we can not duplicate
code in every backend. Alpha will probably want this too.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23835 91177308-0d34-0410-b5e6-96231b3b80d8
allows us to lower legal return types to something else, to meet ABI
requirements (such as that i64 be returned in two i32 regs on Darwin/ppc).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23802 91177308-0d34-0410-b5e6-96231b3b80d8
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
