float t1(int argc) {
return (argc == 1123) ? 1.234f : 2.38213f;
}
We would generate truly awful code on ARM (those with a weak stomach should look
away):
_t1:
movw r1, #1123
movs r2, #1
movs r3, #0
cmp r0, r1
mov.w r0, #0
it eq
moveq r0, r2
movs r1, #4
cmp r0, #0
it ne
movne r3, r1
adr r0, #LCPI1_0
ldr r0, [r0, r3]
bx lr
The problem was that legalization was creating a cascade of SELECT_CC nodes, for
for the comparison of "argc == 1123" which was fed into a SELECT node for the ?:
statement which was itself converted to a SELECT_CC node. This is because the
ARM back-end doesn't have custom lowering for SELECT nodes, so it used the
default "Expand".
I added a fairly simple "LowerSELECT" to the ARM back-end. It takes care of this
testcase, but can obviously be expanded to include more cases.
Now we generate this, which looks optimal to me:
_t1:
movw r1, #1123
movs r2, #0
cmp r0, r1
adr r0, #LCPI0_0
it eq
moveq r2, #4
ldr r0, [r0, r2]
bx lr
.align 2
LCPI0_0:
.long 1075344593 @ float 2.382130e+00
.long 1067316150 @ float 1.234000e+00
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110799 91177308-0d34-0410-b5e6-96231b3b80d8
memory and synchronization barrier dmb and dsb instructions.
- Change instruction names to something more sensible (matching name of actual
instructions).
- Added tests for memory barrier codegen.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110785 91177308-0d34-0410-b5e6-96231b3b80d8
for some reason they have a very odd MCInst form where the operands overlap, but
I haven't dug in to find out why yet.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110781 91177308-0d34-0410-b5e6-96231b3b80d8
make any assumptions about when the two conditions will agree on when
to permit the loop to exit. This fixes PR7845.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110758 91177308-0d34-0410-b5e6-96231b3b80d8
from inline assembly, except in cases where they had already been seen (in which
case they would get added twice).
- I can't see how this ever worked...
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110757 91177308-0d34-0410-b5e6-96231b3b80d8
(I discovered 2 more copies of the ARM instruction format list, bringing the
total to 4!! Two of them were already out of sync. I haven't yet gotten into
the disassembler enough to know the best way to fix this, but something needs
to be done.) Add support for encoding these instructions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110754 91177308-0d34-0410-b5e6-96231b3b80d8
Apply the same approach of SSE4.1 ptest intrinsics but
create a new x86 node "testp" since AVX introduces
vtest{ps}{pd} instructions which set ZF and CF depending
on sign bit AND and ANDN of packed floating-point sources.
This is slightly different from what the "ptest" does.
Tests comming with the other 256 intrinsics tests.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110744 91177308-0d34-0410-b5e6-96231b3b80d8
patterns generated by clang for transpose of a matrix in generic vectors. This is made
of two parts:
1) Propagating vector extracts of hi/lo half into their users
2) Recognizing an insertion of even elements followed by the odd elements as an unpack.
Testcase to come, but this shrinks the # of shuffle instructions generated on x86 from ~40 to the minimal 8.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110734 91177308-0d34-0410-b5e6-96231b3b80d8
operands. We don't currently have a hook to provide "the largest super class of
A where all registers' getSubReg(subidx) is valid and in B".
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110730 91177308-0d34-0410-b5e6-96231b3b80d8
The live interval may be used for a spill slot as well, and that spill slot
could be shared by split registers. We cannot shrink it, even if we know the
current register won't need the spill slot in that range.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110721 91177308-0d34-0410-b5e6-96231b3b80d8
